Cafe Scientific, Southampton, UK, past talks , start of 2016

Latest update of this file 13 July , 2016

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Some summaries etc of past talks held at the venue, The Southwestern Arms (upstairs room) , 36 Adelaide Rd, St Denys, SO17 2HW
Some hosts are not alowing remote linking now , so to view a "forbidden" picture you have to right click on the mouse and select "view". Not verbatim, and there will be homonyms, transcription, transliteration, typing and spelling errors and misattributions in the following write-ups. Q&A , grouped under one "Q" or ? terminator tend to be dialogue with / multiple questions from one enquirer. ? for unheard / masked words , ??? for phrases.

Monday, 18 Jan 2016 , (NB third monday of the month) Robert Stansbridge, Experimental officer for the faculty of Engieering and the Environment, Soton uni , return visit Sound and Vibration: "Why study Acoustics?" Though sometimes perceived as a narrow topic for the recording studio, acoustics is widely used throughout science, medicine and engineering. These are some applications which have proved Really Useful. 29 people, 1.5 hours Acoustics is a huge area of research. What is there beyond just the study of sound and vibration, my attempt to give some answers to that. Acoustics is the study of waves in gases , liquids or solids. Years ago Iwas told that everything is a wave. Your left leg is a wave, he said. A biro is a wave. If I tap this biro, I hit the molecules at that end, those molecules push the ones next to them , etc until it reaches the other end, and the whole thing moves. So every physical thing is a wave just by being, by existing. I'll be talking about ultrasound and infrasound. A diagram , showing the areas where acoustics is relevant from the Journal of acoustics. Including mechanical, architecture, visual arts, music, speech so mobile phones and MP3 , psychology, medicine, earth and atmosphere physics such as seismography, oceanography . ISVR students have had a 100% take-up rate, meaning all our graduates got jobs in acoustics but in very different fields. A source of sound an actuator, a bunch of molecules in a tube, which are being squashed up together. Push and relax, a wave moving along the tube. One designated molecule is hardly moving at all. The molecules themselves don't move much but the wave does move. A super long slinky spring. It used to be thought by the Greeks that when I talk to you, that wind comes from my throat and goes towards you. The Arabs figured out that it was like waves on water, after a stone is thrown in. With lightning, you see the flash and then later you hear the nthunder. That sound travels at about 340m per sec, 750mph. Dependent on temperatur eand pressure. So about 3 sec per km or 5 seconds per mile. Start counting after the lightning flash and that gives how many miles away it is. If the molecules are close together then it goes faster, so in water the molecules are closer together than in air , so they bash each other more quickly and so travels faster in water. The speed in steel is 5,960 m per sec or 17 times faster than in air. If I go to the Grand Canyon and shout out hello , then a few seconds later "hello" comes back. Use a stopwatch, divide by 2 , then knowing the speed of sound you know how far it is across the canyon, to the nearest point opposite. The sound of "hello" as sent , let alone received is messy, it would be much better if you fired a gun. A gunshot gives a reasonably narrow peak , so an accurate strart and a first echo returned gives a much more accurate measurement. This is done on stage in concert halls, when measuring the acoustics of a building, they fire a starting pistol. In the Grand Canyon you would not just hear one hello echo, as it bounces around. In the concert hall situation, all the seats give a return . the returned sound from the gunshot is then a sort of map of the concert hall. You have to have some idea of what sort of hall it is , to unravel, but fundamentally it is a sound map of the hall. Another hall with a big back wall , and much more recogniseable echo. Wallace Clement ? invented architectural acoustics. A museum with a lecture hall added to it and the acoustics were terrible, no one could hear what the lecturer was saying. He was a physicist so they hired him to try and sort it out. He measured how long it took for the sound to die away. He came up with the term absorbtion coefficients and reverberation time . He tried to fill the hall with cushions to try and deaden the sound, the first person to do this sort of thing. With that hall it bounces right across the hall. He failed to improve this hall, and they demolished the hall, leaving just the front of it. The plans for that building still exist. So it was possible to create a computer generated model of it. They can tell what it would have sounded like , playing the resulant simulation of the mangled speech of the original. The model of the room looks like a classical world ampitheatre which is fine acoustically. The difference is the sound hits the seating and bounces upward in ampitheatres, proper. In this hall , he failed to control these echoes. You can use those ideas fr other applications - eg ultrasound. Used for detecting icebergs underwater, to alleviate pain, motion of the heart and pregnancy. With a normal loud speaker and low frequency stuff, they emit high pressure waves and spead out all around it. For middle frequencies they don't spread out so much, the sound from one place starts interfering with sound from another place, and doesn't come out to the sides so well, its more directional. That is why with your 5.1 stereo you place the speakers carefully but the woofer you can hide under the sofa , because for the low frequencies , the whole room , gets high pressure, then low pressure. Wheras for the tweeters its much more directional. The higher the frequency you go, thr narrower the beam you can get. I could make a sound map of this room , by making a clap, and recording. But you cannot tell which sound is coming from what reflection, as from all directions. Much better if I could direct the source of sound and change its position each time, which is what you can do with ultrasound. Ultrasonic crack detection , jelly used the same as antenatal sonograms. If the sound hits the air in between then you loose the transmission . So conducts the sound from the piezo vibrating source , to the metal. Transmitter and receiver in the probe, transmits and measures the transit time of the pulse off the back surface and any crack within. So knowing the speed of sound in steel , we then know how thick the steel is, when returned from the rear face. If there is a crack in there then the reflection off the crack will be larger than the reflection off the back , so can determine the distance and extent of any crack. They do this to all sorts of structures, aircract propellers or pipe welding etc. For antenatal use, you don't want a gunshot type of noise close to baby. To get around excessively high power , they use chirp. A rising siren type of sound, a sine wave that starts at low frequency and rises in frequency. A mathematical technique called correlation that interprets the sent and received signals. You don't need a big surge of energy, a big bang. Spread it out over a longer time as in the chirp as you can get the same energy in total but spread over more time. At the same time there is lots of other things going on. Consider under water, its very noisy, boats, waves, rocks, similarly in mum's tummy, lots of gurgling going on. The task is to pick out what is important from the mush. At each point on the plot of the sound a computer stores them as a number as a number. They multiply numbers and look for a match . If there is a good match, then you get a high number, if a rubbish match then a low number, a correlation. When it sees itself, it can identify that it is its own sound. The chirp noise is easy to identify and will give a spike where found. Processes along and finds another, but smaller match, smaller because it is an echo. You end up with some good separated peaks that you can do good measurements off, the same as if you had done a gunfire source sound. Another technique is required. Consider 2 loudspeakers right next to one another, put a sound through, waves move out . When you are more than 2 foot away, then it sounds like one loudspeaker. But if you slow one speaker output down, start one off then the other one , then the combined beam front is moved off to one side. So it is possible to steer the resultant, possible to make the beam swing round, or go the other way by delaying the other transducer of the pair. So now we have everything to be able to do an ultra-scan , a narrow beam, can swing it round and we can pick out what our signal is from the gurgling. Where there is a high correlation you make the pixel bright and where rubbish you make it dark, and the shape of the object is revealed. Sweeping across and mapping out what is going on inside. The Doppler effect. If you have just a loudspeaker , the sound goes in all directions . But if the source is moving then the waves are compressed on one side and stretched at the other and the pitch changes for a static listener . Using that , you can tell whether stuff is moving and which direction it is moving. An ultrasound pic of a kidney and the blood vessels within it , orange in one direction and blue in anothe rdirection. An umbilical cord, some the blood is going towards the baby and some is coming away from baby. A heart beating , showing the relative motions. Geographers use the same technique to motitor the seabed. Send down a chirp , the first reflection is from the nearest one, giving the depth and profile of the bottom. Infrasound, if human hearing goes from 20Hz to 20KHz , ultrasound is > 20KHz, the higher it is the narrower the beam. Go lower than 20Hz is infrasound, sometimes your stomach can detect them, eg amplified bass guitar. Infrasound weapons did not take off, for an unavoidable reason. If you have an infrasound weapon , then the sound emerges all round, and you get affected before they do. Also it needs to be about 30m across to decently do that sort of thing. Geologists can use infrasound to distinguish different layers of rocks, sedimentary from igneous etc. A network of geophones surrounding a loud source of infrasound, and interpret the reflections from soft or hard. When there is a difference in hardness then some is transmitted and some reflected. How they find oil. You don't need to make a bang youself as the Earth can do it for you. When they refer to an epicentre of an earthquke as geographical position and its depth, the crack sources infrasound and that spreads out. The speed it travels depends on material of the rocks. Primary waves are longitudinal waves using slinkey spring, the pulse type ones move faster, Love Waves. Otherwise transverse waves called Rayleigh Waves at a slower speed. In the middle of the Earth is the core , a great lump of iron . The transit paths curve as the rocks ar edenser, the further down you go. The greater pressure produces greater densitry and things move faster . The change in density produces the curve on the way down and the way up again. The primary waves can get through the core. So with different types of vibration and different monitoring sites , they can tell whwere the core is and what its made of, and the different layers. One of the courses they teach at the ISVR is earthquake proofing of buildings. They put buildings on giant ball-bearings, so when the earth moves the building can stay in its original place. Or layers of rubber, the building is designed to take the weight straight downwards, very strong in the vertical plane. So the rubber bends and the building stays straight up. Now for some modern stuff, going on at the uni at the moment. Acoustic particle manipulation, bio-chemical engineering sort of area. Using sound to steer things. A set of tiny worms, that you can make cluster by turning on ultrasound. The worms move to where there is less vibration, in the standing wave pattern. So you can position them , where you want them to go. Particles in a fluid, in the fluid vibration pattern , marking out where there is high vibration and low vibration. Video of ultrasonic tweezers, new human cartillage cells for knee joints moved into place sonically. The ultrasound is able to manipulate each cell and then construct a structure , tailored to fit each individual patient. Ultrasonic tweezers could find cancer cells amongst the millions of other cells in blood. To study how leukeimia cells grow in combination with other cells. Because cancer cells are a different size to ordinary cells they can steer the cancer cells towards a detector. They can do strange engineering just by altering the waves and positioning in a precise place . Q: I've never understood how ultrasound can brteak up particles? Particles have their own natural frequency. Everything vibrates at its own frequency when stimulated. If you can stimulate at its own natural frequency resonance you can get a large amount of shaking going on. If you can get enough energy there, it tears it apart. So for a kidney stone, it has a particular mass and size in a particular location. If you give it a bit of a ping with ultrasound , then you can detect what the actual resonant frequency is of that particular kidney stone. Hit a wine glass and you get a ting. If you can sing that frequency , then it amplifies the motion and it gets so strong thst the molecules no longer bond together and so it shatters. Do the same with kidney stones. They do time reversal which is jolly clever, to reverse time. Give a kidney stone a ping, record the characteristic response of that stone. Detectors all around and easuring that ping. The different detectors will get their reception of the ping at different times as at different distances. Record that and then when they want to zap it, they play that back , amplified , starting from the one farthest away , putting energy back in the opposite way it came out. All those signals then meet at one spot , at one time, inside the kidney stone and shatters it. The only place that energy is concentrated is in the stone, as it is distributed around all those source transducers, so no localised harm to the body at the transducer sites. Q&A What happens to these waves in space? No one can hear you scream in space. The atmosphere doesn't just stop, it gets thinner and thinner for a hundred miles or so, signals get weaker and weaker, the molecules become too far apart to hit each other. I have heard a sound recording of the Sun , doing much the same as you were saying about seismology, apparently, somehow, how did they get that? They've done the same for Jupiter. You hinted at the reason why high frequencies don't sread out so much. Is it just difraction or something else going on.? Each vibrating molecule is its own little sound source, so every point across that wavefront is acting as a new sound source. With higher frequenncies, the wavelengths are shorter, the distance between high and low pressure points is getting smaller . The pressure wave from one molecule source is met by a pressure wave from another one and start to cancel each other out as they get closer together. It depends on how big the transducer is and how big the wavelength is. Towards the edges they tend to cancel and in the middle of the beam they can transmit as they don't get cancelled out. It took me a long time to figure that out for myself, for years I did not know why that was. Is it the proximity of the molecules that determines the speed of sound or is it the rigidity? The proximety largely and also the mobility, mostly by temperature. When its hotter , they're vibrtating faster , they bash intoi each other more vigorously so its the density , pressure and temperature. It doesn't matter what the sound source is , loud sound or soft sound, high frequency or low, makes little difference, its the interaction between the materials for that material at that temp, that determine the speed. In normal life , where would we come across infrasound.? Its actually all around us. When people measure traffic noise they use sound level meters. Our researchers or students want to do top quality work , so I give them a sound level meter. Whats all the A or C weighting. A weighting means its adjusted so it only detects what your ear would detect, a filter that filters out everything below human hearing and everything above and matches the profile of typical human hearing. They say, "we don't want that, we want pure data, not filtered data, throwing away all that valuable data". They want pure flat response . Then they find the meter won't work because the needle or display numbers is going all over the place, but that is telling the truth. Just the wind, you can't hear a draught but it causes low frequency movements. You can feel the movement as its cold but your ear is not designed to detect the corresponding noise. So ina big open building , the amount of infrasound swamps the "normal" sound. Its lucky our ears can't hear it , otherwise we would not understand each other conversing. Lorries rumbling by, vibrations from trains, even quite an amount of background seismic activity . You wouldn't class 50Hz vibration or sound from refridgerator pumps as infrasound? No. People tend to feel unwell if there is a large amount of sound just outside of human hearing, even a bit depressed. Its been stated that even ghosts are associated with infrasound. Its also associated with balance, as that sense is in the ear also. There was a documentary on a blind boy who clicked his way around. Does it bounce off wherever he is? A click is a very good sound to produce , because inside a click is a wide range of frequencies, although very quick. Different materials absorb different frequencies , absorb some and reflect some. So you can tell the difference between a hard and a soft surface. Also from the time it takes to come back you know where you are. Could anyone do that? I don't think so much they calcultae it, they just feel it. We have an anarchoic chamber , that gives no sound reflection , in theory. Fibre-glass wedges in sacking. When people go in there and the door is closed and its pitch black , they feel really unwell . If you go into a darkened normal room you can hear your own footsteps , and your breathing. If you mafde clicking noises you can tell when you are close to a wall. If you are blind you get trained to that because you get to know what things sound like. But go into an anarchoic chamber they feel totally lost , disorientated very quickly, they cannot say where they came in. Subconciously , to a limited extent, people are doing this sort of local environment awareness check all the time aurally. At one time I used to regularly walk down a road with over 100 yards of corrugated iron fencing, sheets mounted vertically . Every footstep you made , this pinging noise would ring back at you, a very distinctive noise, because of the regular spacing of the corrugations, reflecting. It had to be corrugated iron, it couldn't be anything else giving that response. ? Am I right in that even the acoustics of this room , where there is no plaster over the brick of the wall, you can get echoes coming back related to the 9 inch pitch of the bricks, is that the case? Pyramids have particular response, where they are stepped , the Mexical pyramids especially, have very strange audio properties of the sound pattern that comes back. People speculate whether it was designed for this . What is the frequency of infrasound? Anything less than 20Hz all the way down to zero, steady pressure. Is there a peak of infrasound to be found at some frequency? Depends where you are . If you're away from earthquakes then its buildings, trains and trucks, related to the speed of the wheels and separation. I had a query from civil engineering, doing things with power cable lines . They were trying to determine, if in an earthquke area, the lines would topple. They were taking measurements of the strength of the supports embedded in concrete, how much concrete needed. They were using accelerometers and the results were moving all over the place. These were new technology accelerometers , the older technology could not detect the very low frequencies. The pylons were moving all the time,hundreds of miles long , coupling the pylons . With temperature change on sound, in high summer, do things appear closer than in winter? And at night you hear the motorway more. Thats because of the temperature difference between close to the ground and higher up in the air. Its like a mirage. During the day the sound just spreads out, but at night the sound folds over, because one part of the sound is going faster than the other part and it bends round. You sometimes think that you hear it because the wind carries trhe sound towards you. The wind is moving perhaps 1 m per sec, but sound is going at 340mps, the wind will make practically no difference. Wind is caused by pressure variations, more pressure in one place than another, usually caused by temperature. Its due to the temperature and pressure variations in the air , not the actual wind. So when its something like -42 degree in Saskatchuan, and you can hear your neighbours 3 miles away putting out their milk bottles, ios that why? Its not so much the actuial temperatuire but the temp variation. And stillness as well, the snow damps down the other sounds. If the ground is very cold and the air above is a bit warmer then you get the sound folding over, and perhaps direct it towards you. Can sound cancel sound out? Yes, most definitely. The main use, we have a demo rig in a room at the uni. In the USA there is a lot of prop aircraft. They make a lot of noise for those in the cabin. Mounted in what look like ceiling tiles thaere are loudspeakers , they detect the sound from the prop and microphones around the cabin. If you have one seated passenger and one source of nooise , then all you do is put equal and opposite sound going the other way and it will make it silent for that person. THe problem is the person next to them , will get twice as loud, because they have the prop noise plus the sound of the speakers. So microphones right through the cabin , loudspeakers also all around the cabin and a computer program works out what you have to put through each loudspeaker to give the least sound for the greatest number of people. More than that, what they've found , a lot of the noise is caused by , each blade going round , sends a pulse of air against the side of the fusealage. That is made of aluminium and also struts and it slike a drum and that is where the sound is coming from, the walls of the plane. So they put a transducer , like the coil of a speakaer which pushes against . The pressure coming is detected then this coil pushes back to stop it. We have spinout companies that do this stuff in the USA, video graphic of that process. Finite analysis model of the fuelage, with system on and off. Noise cancelling headphones work on the same principle? In headphones, in a noisy place especially for the military, detect the noise that is arriving and add some equal and opposite noise to cancel it out, the vouce comes separate over the top,.

Monday 08 Feb 2016, Dr Julian Whitewright , Southampton Uni: Intro to ship archaeology: I would like to cover the following things as the fit well with the work being undertaken by the Maritime Archaeological Trust, locally in Southampton - Copper/metal analysis, dendrochronology, photogrammetry. The last would replace conservation with PEG, but is very state of the art and the MAT is doing some cutting edge work in that field as we speak. To that end I will bring a couple of my colleagues from the Trust along and we will divide things between us, probably 20 minutes on each topic. This would mean that things would be covered in a much more expert way, than if I do everything. 40 people, 1.5 hours Myslef, Sara Rich and Brandon Mason are all from the Maritime Trust , talking about different aspects of using scientific analysis and techniques to understand shipwreck material, located along the south coast of England and a bit farther afield. I will look at the metallurgy of copper and its alloys as found in wrecks, Sarah will talk on dendrochronology and Brandon on photogrammetry. The Maritime archaeology Trust was established in 1991 , origionally as the Hampshire and ioW Trust for Maritime Archaeology and has the clear primary aim to manage,preserve and research the maritime archaeological record of the region, much as originally set up, of Hants and IoW. It was the first such place in the country to have this facility and its still the only commercial type outfit in the UK, that is dedicated to maritime archaeology. It was also tasked with public awareness , so talks like this, involving volunteers and fieldwork and research. And also initiatives on a broader scale. 2013 the HWTMA became the Maritime Archaeology Trust to reflect that we were increasingly doing work outside of Hants and IoW, over the rest of Britain and increasingly over the world. The annual report, handed out here, outlines sonme of the different places we're working along the English Channel coasts , down into the Bay of Biscay, across the Med and some in Northern Europe. England's shipwreck heritage is vast. Within the National Monuments Record for England ther eis 37,000 records of shipwreck losses. Not all of them are mounds of material on the seabed, in fact most of them , we don't know where they are. Only about 5000 have a confirmed location and around 2,800 are dated before 1918. Going further back in time , the smaller the number is. So go back before 1860, then just over 100 , we know where it is and what the date is. Of those only about 50 that are protected, another 10 in Scotland and a few in Wales and one in NI. So not many wrecks given legal protection, in comparison to something like 450,000 listed buildings in Britain. The preponderence of known sites off the south coast, really only reflects the advent of sports diving and scubu from the 1960s onwards, rather than any geographic reason. More people went diving off Scilly than in the River Humber, is the moral there. In the Solent we have quite a big proportion of wrecks generally but also a proportion of the protected sites. The Swash Channel wreck , in the news recently, with the enormous carved rudder head being raised. The next along is HMS Permone off the Needles. The Mary Rose , then the early A1 submarine in the east Solent. A big range of vessel types in these protected sites, from Tudor Galleons and Carricks to much more modern iron vessels. There are big peaks of sites off Hampshire in the 1780s and 1790s reflecting the Portsmouth anchorage and then all else is skewed by the first world war, in the 12 mile limit of the territorial waters. So for 1911 to 1920 a massive peak of losses in 1917 when the U-boat campaigns are at their height. Unprecedented amounts of shipping being lost quite close in to shore. A huge variety , from warships , submariens to big steel merchant ships and also wooden ships being lost. One of the major current projects of the Trust is to document and understsand and publicise a lot of these WW1 shipwrecks. Because a lot of the focus on WW1 is on the western front , the trenches and the Somme, and the naval element is overlooked. There should be more , later this year, surrounding the Battle of Jutland for example. Involve people with those wrecks and being able to do research on them as well. Because its relatively recent, its not just acchaeological remains but also a huge resource of historical documentation and a lot of that has not been really looked at since the end of WW1. Brandon will say how we are using new technology to record and understand some of these. The bottom of Cutty Sark, now litterally a different ship, since its been renovated and lifted up. Hull clad in amazingly coloured sheathing of copper. Copper and brass have a twuin role in how we understand ships and shipbuilding, particularly 1780 onwards. Trying to stop wooden ships being eaten by marine organisms, by ship-worm etc. For millenia people have coated the outside of ships to stop them getting eaten. The Romans used lead sheathing, lots of copper nails. In 1750s and 1760s the Royal Navy started to experiment with copper sheathing . By this time the frames of the wooden ships were bolted together with iron bolts, which had the effect that put the copper and the iron together, in the saltwater of the bilges, an electrolytic reaction , the iron corroded. The copper worked brilliantly keeping worms and molluscs off the outside of the ship, but all the iron bolts that were holding the ship together, had disappeared. A few of the sheathing plates were removed, the bolts had disappeared . A few well documented cases of shis simply disappearing due to bottoms dropping out of them with great loss of life with storms in the 1780s. There was a stop put to the sheathing of the fleet until a soulution could be found. The obvious solution was to use copper bolts but such in the 1780s could not be manufactured strongly enough. Some fiddling around by copper magnates , particularly around Birmingham they came up with a process. Take the bolt and pull it through a narrow hole which halved the diameter of the bolt and made them incredibly strong. So the sheathing with copper started up again and constructing the ships with copper bolts. The whole navy was rapidly transformed by this. And became strategic for the Napoleonic naval wars as it reduced the time the ships had to come into port to be serviced, the bottoms scrubbed etc, by about a third. So in effect it gave them 30% more ships. The policy at that time was having the whole navy at sea, blockading French ports. The ships could also go faster, now not covered in seaweed and barnacles. HMS Impregnable was about the first to be copper bolted and sheathed which sank in 1798 off Hayling Island. It ran aground, while bringing a convoy back from Portugal, and the master was blamed. He was court martialled, the captain was exonerated. The ship broke up where it lay in quite shallow water. It was big, 3 deck, 98 gun ship and its loss meant HMS Victory being brought out of mothballs and fighting at Trafalgar. From the archaeology of this site, this wreck is important. We know from historical documents, it was near enough the first ship to be bolted in this way. We have some of the bolts from the site, they have the maker's stamp. Forbes in Scotland , a lot of the material has the broad arrow , which the navy stamped on everything, so pulley blocks, bits of sheathing, anything owned by the navy. The trust has been working for about 15 years with Peter Northover of Oxford uni, who is an industrial metallurgist. He has a passionate interest in the developement of copper in the industrial period and in particalar the compositional analysis. He's developed how this changes over time. He fires neutrons at the copper bolt surface and from that the molecular structure of the surface and whether the bolt was made in Forbes or Collins the competitor bolt manufacturer. He can give a whole level of info above what we had , for the ones that don't have any obvious stamps. We see from the composition of them, they are about 98.2/98.3% copper and then the impurities , which is the crucial thing to understand them as we go through time. The next site of relevence in the loss of HMS Permone off the Needles. The trust grew out of work on it in the early 1990s. The master was found negligent again, he did confuse the the needles light with the Hurst Spit one. It broke up and a big lump floated into Alum Bay. 2 lead lined box the anchor lines ran through , surrounded by lots of copper bolts, a few were loose so raied to do analysis on and some pieces of broken hull sheathing from just below the hawse holds. The material matched closely the material from HMS Impregnable, in terms of the Cu composition and impurities. The sample handed round , its hard to make out the broad arrow mark but was naval copper, up till then not confirmed as part of HMS Permone as drifted site. From this work we can now confirm. The parts atr the Needles are very broken up , bits of sheathing , a few bolts , including something with a datestamp on it, sheathed Dec 1804 at Chatham Dockyard, corroborated with historical sources. This gives PN a firm fixed date for some of his analysis of metal composition. The copper in the sheathing is much more pure than that in the bolts, very small numbers 99.2 rather than 98.5%. This comes about because there was a lot of recycling going on i nthe naval copper rolling mills. Every time the copper was recycled, the impurities were being removed from it. A ship up in the Arctic, HMS Investigator, the crew were probably the first to pass through the NW passage. It was sent to look for Franklyn and his lost ships of the 1850s. It eventually got stuck in the ice also. Parks Canada found the vessel a couple of years ago. Side-scan sonar image of it sat on the seabed in not much water and incredibly well preserved. Just like the Cutty Sark, the sheathing has the numbers for the draft when loading it. Again a naval vessel and the Cu analysis is very similar to what we see 50 years before on Permone. Back in the solent, The Flower of Uguy built in Sunderland 1838. Entirely of wood , at the end of wooden ship building. In the Lloyds survey report , it was very well built , given the top rating of A1 (where that phrase comes from), for 12 years. Except the surveyor did not like the fact that some of the wood was French oak so he down-graded it to only being a 10 year rating. We get one of the earliest remains with copper bolts in it , a differnet signature to the earlier use , the Cu is purer than earlier like the Permone, Impregnable etc. Also they are starting to use brass bolts. Cu is always expensive, so by mixing Cu and zinc, get an alloy called yellow metal that is bright yellow. Just need a file to tell the difference between cu and brass. 67Cu/33Zn in this case. That balance changes a bit over time , 60/40 is what they eventually settle down on. The trust has fed PN with this data over the last decade and created an understanding of the internal composition of wooden ships of this time. A Goodwin Sands site off Kent , the Stirling Castle , a lost ship in the archives but an incredibly well preserved ship. Its like the Mary Rose in terms of the range of material that has come of it, the personal possessions of captain and crew. Amongst it all is some copper bolts. The ship sank in 1703 and we know people weren't putting copper bolts like them , until 1780s. So this has got into the physical archives at some point in the 1970s and early 1980s when the material was being gathered together . Knowing where the divers were on the seabed was not so good then. Material was brought uip and dumped together. PN did some work on this for us. Because we have a lot of comparative material from about 30 vessels, worldwise, not only does this stuff definitely not come from the Stirling Castle becuae the impurities in the Cu are completely wrong for 1700 but fit for 1800 or so. So this collection in a dozen boxes is from 2 different ships. There is material that matches the earlier Impregnable and Pamone and later material that fits much closer with the likes of the Flower of Ugi. By that time the bolt manufacturing people were starting to recycle that as well. With that rough dating we can go back to the historical sources and try marrying up with recorded losses. So quite a common article class to study, particularly from 19C. This stuff doesn't get studied that much in detail and the records where someone states copper bolts found , half the time they are brass bolts because you cannot say without filing the surface. We have built up the picture, firstly of the use of the ciopper fro m1780 onwards, the refinement of its content from about 1807 and then developements of brass from 1830s. Where it is verty useful for us is vessels like the Flower of Ugi, can't carbon-14 date them as they are too recent . Dendrochronology did not work on it because the wood was from France , N America, Africa using wood like ebony which we have no dendro sequences for. The normal dating processes for a lot of these vessels don't work. Being able to take the most commonly found items , in large numbers and being able to place in some sort of date , not as precise as dendro, but at least placeable in a 10 year bracket. I'll hand over to Sarah. I'm here on a two year post-doctorate. I'll be talking about a very dull material - wood. Its brown its dirty , under water its mushy. So with all the nice materials available to study in archaeology why study wood. Wood goes along with human civilisation. The earliest tools, how we built shelters, how we transport carriages or ships, objects of worship and use, all involve the conversion of trees into somehting more functional. However wood is not ever present in the archaeological record. We have a saying ,absence of evidence is not evidence of absence necessarily. The reason we have little in the record is because its already been destroyed . Julien was talking of ship workms and torredo worms, that is just 2 of a huge number of zylophagic organisms, organisms that eat wood. There ar e2 conditions, in particular, where wood does tend to survive. Aerobic and anaerobic. Aerobic means there is air and likely to be these organisms. Anaerobic means no air , and less likely to have these organisms in the depositional record. So anaerobic situations are under water especially when its protected by a layer of peat or very dry conditions like in Egypt, wood preserved for thousands of years. Dendrochronology is an absolute dating method. Comparing with carbon-14 , is kind of an absolute dating, but technically it is relative as it is relative to dendrochronology. C-14 dating is calibrated by using the annual growth rates of trees. A piece of wood from Germany , 1600 first year of growth, continues outward until the last year of 1748 when it was felled. The growth rings are like barcodes and you can match the codes further and further into time and use these as a reference for unklnowns that come in from the archaeological record. So a living forest and we take samples from various trees and each line represents one year of growth. If you're lucky you could go back 1000 years, most times a couple of hundred years. You can go further back by looking at hisdtorical buildings. Roof beams from barns or anywhere there is anice long sequence. Then match that up with your living forest sample chronology. So an overlap . You can perhaps go further back by finding wood in a glacial source or a peat bog if in the UK. You can keep going back , finding partial overlapping sequences . This gives you an absolute chronology that is anchored in the present. The great thing about dendro is when you fisrst come across an artefact, there are 2 questions. How old is it and where did it come from and with dendro you have the potential to answer both. You can get to a specific felling date. For C-14 you get a range of dates. In some cases you can even get the season it was felled. Unlike most archaeological methods, very specific. You can sometimes get the provenance as well. If you have one of these nice solid master chronologies for a region. From an unknown sample you can get the date it was felled and where it came from. Where you have multiple chronolgies that all line up, but matches with one better than another then that sample probsbly came from that particular area. Because trees react to their environment and even the altitude , you can see this in the tree ring data. What happens if you remove one of these over-lapping references in the long term sequence. Then you no longer have a master chroniology anchored in the present. These floating chronolgies are problematic . How do we get samples from living trees. You don't have to clear fell and take cross sections. A relatively harmless method is taking core samples. It is quite fun boring holes in trees, climbing mountains, climbing trees. They do recover . Increment form? corer, folds up nicely, looks like a cork screw. You crank it into the tree and when you get passed the central pith of the tree then you extract the tool , setting the tongue in place , and you get a core sample. A small cross section of the tree. When you get a set of cores from your chosen forest , you sand them down , to see the growth rings clearly. Then you measure them, this part is a bit boring unless you like sitting veiwing through a microscope for hours on end. So you have a set of tree samples but the trees were all different ages, these ones cedars and cypresses. You look for areas of growth that are very determinant. For instance a sequence normal, growth spurt , then a really big growth spurt , then lesser one, and then a lesser one and then back to a normal ring. Looking closely at other cores you can see that exact smae growth pattern. Matching those patterns together then creates the tree ring series . Cedar is coniferous so early spring growth then slows down during the growth season and at the end of the year you have a blind?. For measuring you go from the first cells of the year to the last. For oak you have ring porous appearance, an example to pass around with magnifier. Huge vessels grow that are visible to the naked eye. This growth occurs in spring and late winter, based on the food the tree has stockpiled the winter before. The things that look like bubbles are the early spring growth, as the growing season goes on it gets slower and slower. Oak is a north European godsend, because it grows very regularly , its not finicky like coniferous trees and there are chronologies that go back thousands and thousands of years. Conifers in the east Mediterranean, one sample showing a growth anamoly and other samples lined up with that one at the same growth anomaly. There is a 600 year long chronology of cedars on Cyprus, then you can go back to historical buildings , sarcophogi and keep building on this chronology back intio time. More generally, with different species there are gaps in the chronolgies, the floating chronologies. Even if you were to collapse all those bars into one, you would still have a few gaps, so still considered floating chronology. With regional and species specific chronologies, you can't get an absolite date. With no absolute date , you can't get a provenance either, you have to look to other methods. In the uK you can use dendro to date practically anything of oak but in the near east you have to use supplementary methods. A 4th century shipwreck , a diver,me, sawing it up . The only way these gaps will ever be filled is if you get more and more samp[les measured. With pine a gap is right around 4th century, so with mor eand more of these finds, hopefully we can close the gap. We also work on more recent shipwrecks like La Magdalena , in the historical archives as from Spain. A frigate that tragically went down with several hundred peiople in a stoirm, very close to shore and everyone perished. My group tried getting samples from this ship and others of this period to try and find out where the wood was coming from, in order to highlight trade networks etc. Many succeses in dendro. The Newport ship , found during construction , in the river Usk , perfectly preserved in the mud, anaerobic deposition. Dendro could date it to 1465 or 1466 AD, not just the date but a probable geographic match to wood from the Basque area, also artefacts from Portugal and Spain. So this ship which was only modest in ize was engaged in very international trade at the time. Dendro not only used in shipwrecks, but also for dating submerged landscapes. Boulner Cliff i nthe Solent, off the IoW. A submerged forest, but also a lot of worked wood, underneath peat , so perfectly preserved, in anaerobic conditions. The trees wer esmall , the one shown here , I'm cutting through is an oak, in the surrounding area you can see preserved leaves of those oaks, unbelievably all 8,000 years old. This site was dated using a combination of C-14 and dendro and wiggle matching. Tree rings are used to calibrate C-dating which always has a probability curve. Wiggle matching takes floating dendro chronologies and uses incrementally radio carbon dated segments of tree rings, to then match them into the C-14 calibration curve. Getting tree-rings back into their ??. That process had a 95% confidence interval dated to a little over 8,000 years ago. Dendro has other implications beyond provenance and dating, because of the close relationship between trees and climate. You can use it to find things like volcanic eruptions. Ash gets blown up into the sky , a reflection of solar radiation back into space , meaning the Earth cools off but the stratosphere gets hotter. That means trees slow down their growth almost completely all over the world. Find these kinds of anamolies and we can re-write history. Its being done right now with Minoan culture near Crete and Thera. Over to Brandon My talk is dependent on an internet connection. I'm an archaeologist with the MAT in Soton. Generally I work on wind-farm sites and environmental impact sites for renewable energy sites and then photogrametry 3D modelling of archaeological sites, computer software, geeky stuff. Some of the tecniques we've been using over recent years. Its starting to change the way we approach recording and some of the objectives we hope to achieve. A foreshore site in Gosport, Forton Lake, volunteers scrambling around in mud doing a "nuts and bolts" archaeological survey, using much the same technioques as used for 100s of years. Using tilateration , triangulisation but pencils, boards , paper and tape measures , surveying the outline and extent of that hull. After several days of work a plan emerges, with a scale, north arrow, but still rather basic record for a lot of effort. With advances in 3D visualisation , and processing photos into 3D models, here is a survey conducted over 30 minutes. Using a single photographer , with not much experience , and no need of know-how to approach that sort of recording. We get a full 3D record of a site, that you can move arounds and explore from various angles. This isa steam pinnace on the foreshore, a stern , details of the boiler . Its not justr static imagery , you can explore it. We not only have a record of the salient features , but when we zoom in, we can see individual rivets , sizes of plates etc. Its not just the 3D we can see but we can pull out of it the lines and then compare them with the plans of the original vessel and understrand the extent of preservation and what has happened on the site in the intervening years and what that means for ongoing management . Much more easily than from a simple lines plan. The underwater situation is much the same. Very limited time under water, perhaps 20 minutes at this example depth of 42m. Again they are using tape measures and drawing boards. Having to deal with problems like nitrogen narcosis , low light levels often. What you can achieve is quite limited. Unless you throw a lot of time and money to a site like that. Sometimes we can encourage large corporations , with lots of money, that they should go and spend quite a bit on surveying their sites. In 2014 we got to take out a piece of kit , an AUV a Gabia? modular AUV, with side-scan modules and multi-beam for images of the sea-bed. In the middle of the North Sea we surveyed a site and got a sde-scan mosaic of overlapping lines, about 30m in length , a wooden vessel. A drop down camera shots showed us the construction was wood clinker, not commonly used on a vessel this size , these days. We could look below the surface at geophysical data. It sits ina huge scour feature, a paleoscour? . This suggests it stood up on the seabed for a long time , the currents carved out a massive pit , so the vessel then subsided . Largely preserved, a bit like the Mary Rose. A 3D perspective from a multibeam survey also from the AUV. A point-cloud showing the outline of the hull on this the Sfenyar? a ww1 casualty. An excellent result but costing many thousands of pounds, lots of people and effort. The humble camera , with software advances , has allowed us to achieve something at a much lower cost, much less investment. Sometimes just 1 person, could be just a bloke up a ladder or a drone with hi-res cameras, which can get to advantage points that people with sticks and ladders can't. Photogrammetry is basically using triangulation , establishing a [point from 2 other known points , doing it millions of times . The hardware in the office runs about 1 billion calculations a second. The clever thing is that we don't even know the starting 2 points. Its doiung something called bundle-adjustment, where its comparing the persp[ectives between 2 different images and hten automatically calibrating the position and field of view of the cameras and their orientation. You need about 60% overlap of shots . So you see every point atleast 2 or 3 times and lots of overlap. We get a sense of where those camera posistions were , create a point-cloud and a surface and a model of what was viewed. Whether an enormous landscape , all stitched together. You don't need to plan the survey, no tripod, no pre-planned determination of camera positions . You can just walk around a subject , snap away, the only requirement is to have in mind that 60% overlap. So its great for diving, you arrive at a site, never been there before, no idea what is there. You just start recording and return to process the result. Generally this has been used by crowd-sourcing images. Tourist photos used to reconstruct the Colossium, in this case , each of the black dots representing the vantage point of each of the images from the internet. Projects like Palmyra in Syria, reconstructing some of the lost sites in warfare, again from crowd-sourced imagery. Returning to underwater sites, we've been using photogrammetry since 2012. Summer 2015, we went to the wreck of John Mitchell to survey it. A WW1 vessel 42m long. We wanted to see if we could record it with a team of roughy-toughy divers descending onto the site. Each of the blue squares is an imag e shot by a diver. Descended to the middle of the wreck, proceeded to the bow, just snapping away, 674 images. Came back, a few tours of the salient upstanding features, and ended up on the stern after 20 minutes and back to the surface. Take away the images and there is an array of points that represents every single overlap and correlation between each of the images. That gives a sparse-point cloud, and cansee the outline of a wreck , but not too promising at this stage. The next stage of processing, each of those images is interpolated and then a detailed model, a dense point cloud. A few gaps under the hull and things like that. The next step is to create a surface, a triangulated mesh , each of the points is connected up to create a solid surface over which you can drape the original photos , to create photo-realistic model. Quite an engaging visualisation of the site. This demo is running live fro mthe website where the models are hosted. Can turn on different views or layers, highlight various features by textual effects. A bit of the history, an animation , and a view of a wreck that very few people have seen since 100 years ago. John Mitchel was lost in 1917, an admiralty steam drifter , a vernacular ship . Very little known about it or remembered or recorded but did a stirling job in WW1. They were requisitioned to undertake minesweeping operations . It came from Yarmouth, it collided with the Buerka? on a foggy november night. All hands were saved , went to the bottom and discoved by a local historian and dive-boat skipper Dave Wenless? , located within the now defunct Navitas Bay windfarm area, off Bournemouth. We had some side-scan and multi-beam data before planning the dives . The level of detail is phenominal , you can zoom in , such as the stem-band? the wooden hull has gone , the metal band is still in-situ and it lines up nicely with the orientation of the boiler with steam valve on the top of the boiler . We can start to understand some of the formation processes of the site. A 3 pounder gun at the bow , where it would have been originally. A windlass, large anchors, bower anchors in place. Just behind is ammunition for that 3 pounder. Some of the wooden timbers in-situ, the steering pedastal and even views inside the boiler and fire tubes. We don't just stop at the model , we can get a rectified image, from which we can take measurements and compare to the original line plans. The next day we had excellent visibility and we headed off to SS Galia ? also lost in 1917. This is a bigger site, a wreck over 100m long, in total we capured a site 150 x 80m, 2,000 images again by a single diver . We have the track the diver took . We just cannot see at any time this much of the wreck in one shot , in even the best visibility. The hull has collapsed onto the port side , the bow detached from the main part. The starboard gunnel has collapsed to the seabed. The belly of the ship has split open, revealing engine , triple expansion, upside down . The underside of the pots? showing, and the legs it was stood on. The camshaft in place, attached to the prop shaft. The stern is very broken , it was topedoed by UB40. Also the vessel descended stern first , impacting the seabed there. Again the scour features, we can understand the processses of the intervening 100 years. The dominant tide accelerates over the body of the vessel, when it was much more upright and creating vortices, that excavated large pits in the seabed. As the ship has broken down, reaching more equilibrium those pits have filled in with finer sediments and you see large bands streaking across with the tidal flow. It tells us the best way to manage the wreck in future years. We can export digital elevatiuon models , georeferenced , input it to othe rtypes of software to analyse what is happening on this site and compare to other surveys , conducted annually , to see where changes are happening, which parts are at most threat. More often than not we don't have good visibilirty. SS Warnight? sunk in collision with OB Jenny ? an American steam turbine engined cargo vessel, carrying oil from the USA. It caught fire with huge loss of life and sank SW of the IoW in Freshwater Bay, in 12m of water. More than 100m long wreck and with 2 to 3m visibility. We could focus on smaller areas and get more detail. About 600 images but covering a smaller area , much more overlap and stitched together. The definition was not up to ovelaying the photos to the model but we could extract the geometry and play with the light source to highlight featres on the seabed. We see the steam turbines , the propshaft, the oldest steam turbine in UK waters. So a treat for engineering specialists. We have lots more sites that I encourage you to visit. A Tudor merchentman, The Grecan ship? from around 1574, laying in Stoney? Cove which we have a tour of. A Spanish Galleon , River Dare wreck in Northern Spain and Boulner Cliff that Sara was talking about, peat shelves stuffed with artefacts. Also UAV imagery of megaliths of Brittany also on our site. Q&A On your protected sites, you had one up the Hamble? The Grace Dieu, Henry V great carrack, 1470 or so. Just north of the motorway bridge. You can see at at very low tides but if you go walking over it, then you are breaking the law. That was a huge ship, it had only sailed around the IoW. I recently had a go at dendrochronolgy. I took pity on this oak tree that was felled in Marchwood the end of 2015. By the time I came back with a camera , someone had marked off the bands. It was such a clean felling that all the bands showed easily on cammera shots, no need to sand it down. I started analysing my photos and realised he was 1 year out, because the 1976 band was obviously wrong. There was a website, not quite climatological scale , but exteme weather on a yearly basis in the UK. There was a sequence of 3 years I forget dry or cold or something, so another reference check. How far back can you use such weather data as a cross-check, I imagine the Chinese have a long record of such , but that is China, not Europe. Is there long term meteorologiclal records in Europe.? There are but its hit and miss. I don't know how far back such met records go back for the UK, but it makes a huge difference. I know in Cyprus it goes back to 1908 or 1912, associated with British colonialisation. That is daily records, but is there more cumalitive, yearly records , such as the summer without any sun or little-ice age period, not quite climatological but not meeorological either? Yes, weather anomalies, there are records of that. Especially the Babylonians, were adept astrologers/astronomers. They redcorded astronomical and meteorological phenomena . Santorina event and how much you can trust hisorical records, debate concerning these and tree-ring data and what radio-C is saying. I thought ship builders didn't want to use brass as it de-zincs in saltwater, leading to friable weak copper .? For the sheathing the zinc did migrate out, the copper sheathing had to be replaced every few years. Part of that dezincing process, shedding its outer surface , antifouling basically. Even modern antifouling paints loose their thickness over time. It does confuse the percentages of the compositions, the zinc 2% of the original gets lost. The percentages in the yellow metals , there is a bit of estimation there , for the zinc. The loss of surface is part of the feature. I imagine for photogrammetry one of the main problems is poor visibility. But one camera and one diver is one way around that and then stitched together. But with a Lidar type setup with one station, capturing in one go, do they use the very short duration pulse system that seems to magically be able to peer through all the plankton and stuff? I don't know what wavelength, but in essence like the use of infra-red by astronomers to peer through interstellar dust. ? The most recent advances are in blue and green lasers , because you loose the red spectrum within 6m of seawater. They still suffer from problems of turbidity. But an optical camera sees more than a human eye does, the eye gets very confused by underwater turbidity but a camera will capture more detail. When diving we perceived 30m visibility on Gallia but the camera was picking up features from 40m away. With lasers you have the problem you have to put it down on a station, and you are then not seeing many surfaces , obfuscated by other parts of the vessel. I've seen an experimental one, mounted on an ROV. But again you loose colour, so tremendously accurate points , much better than photogrammetry but loosing colour, some of the appeal omn a human level. We have a 6cm accuracy over 100m on Gallia, calibration of the lens, distortion through water etc, of the ordrer of the width of a pencil line on a dand-drawn plot. Issues with turbidity have not been resolved yet, no sure about pulse technique. That is more of a military technique , nano-second pulses or less , it may take hours to build up an image so useless for your purposes.? 20 min diving but a lot of post-dive processing , stitching, processing for best view and contrast, playing wiht white balance etc. Cleaning up the point clouds, as you would with a laser scan also. Optimising the mesh, all these stages, for the Gallia about 4 months to process. You said about ??? how the ship came to lay in that position, underwater. How easily is it reconstructed to determine the positioning of the ship during the time from sinking to touching the bottom. Can the models help in reconstructing that ? Not very well, hard to interpolate. We can give likely determinations of how the hull impacted on the seabed , and we could suppose that if the model suggests it landed on its keel , landed in soft sediment, and perhaps stayed there for a while and then gradually moved over to the port side, if that agrees with the dominant tidal flow perhaps. There is a lot of what-ifs and buts. Its only a point in time, its not going to show us every point. But we could repeat these surveys and track differences over 10 to 50 years and see what happens to the site. Then reverse engineer and then be able to say with more confidence, what was the original orientation of the hull as it hit the seabed. Copper recycling. Through that process , the percentage of copper actually increases, so wer ethey mixing it with pure copper ? There are impurities in there , and i'm not sure if they are adding more copper or just the process of melting down repeatedly, refines the metal by losing the skimmed off dross each time. Its quite impressive to be able to tell which foundry it came from? The technique is ?microscopy and the new one is the neutron activation analysis at Oxford Uni. It is clever what can be told , from the rearrangement of the molecular surface as bolts get drawn through the dies. With shipwrecks you get good dating calibration, compared to the likes of steam-engines that are tinkered with over time by repairers and restorers, and lost provenance there. Military ships are very well dated , record books etc. The Impregnable there are the order books for the admirality at the foundry and shipbuildrs yards. For merchant ships , the yards son't have the records. How do you archive your huge datasets? which presumably can only exist in huge hardrives? I would say the photos are the best archive, in a TIFF format , there are standards for archiving images and metadata containing how the photos were produced and later procesed. For this sort of record as the software improves , you can go back and reprocess the photos and probably produce models with more detail as the technology develops. The photographic record is the most important part of the 3D models that we've produced. You can archive the 3D models themselves, then you get into issues of long-term compatibility. There is the York Archaeology Data Service a trusted digital repositary, that can curate digital material. That has built in proceedures for data migration, to make sure formats don't become obsolete. And backup procedures to make sure nothing gets accidently deleted. Doesn't matter whether your file is 100M or 2K, its about security and access, using about 3 servers. For photos you'd ideally acrchive them in a RAW format , that is not compressed, so you can go back to the binary code and recreate the image from that. TIFF is ok but RAW is recomended , but there is a problem with proprietary RAW formats, eg Nikon have their own RAW format, that you can convert into a different RAW format. The piece of copper you passed around is green, from being in the air now? Its green in the sea , verdigris, the oxidation process starts in the sea. In the archives , like of the Stirling Castle, someone has polished the whole thing back to its original colour. A lot of the seabed examples come up with big lumps of wood on them because whatever has eaten the rest of the ship wreck, gets to the vicinity of the copper and tastes disgusting so leaves the wood alone. Copper bolts will act the same here as any sheating. A lot will depend on whether buried in the sediment, in an anaerobic environment. We have a large variety of copper in our archive , from different ships, complete range of greenness and redness and yellowness. Its very difficult to taske a yellow metal bolt and a copper bolt , that come off the same wreck, the Flower of Uguy, put them on the table and tell the difference without filing a bit to expose the original colour. With dendro , do you ever get thrown where you have one reference piece of timber which happens to be from the south side say of a tree and your piece is from the north side, a patterning mismatch possible? The pattern itself should not mismatch because the rate of change between growth years that creates the pattern , so even if the tree is on a slope , leaning some way, the rings on the slope facing side will be narrower than on the upward side , the rate of change from year to year will be the same. How do you manipulate the tree ring data? To make your life a bit easier , when sampling a tree ,you try to get it in the middle, so representaive of the growth of the entire tree. But no statistical manipulation. That coring instrument, I'm assuming there is 2 parts , the rotating bit with a cutting edge to the cylinder and then a sliding bit that holds the core, so the core is not twisting when you're cutting through? They can get twisted , not good. Its like a corkscrew with a casing around the outside, and the core up the insice. If it gets twisted its normally when retracting, the tongue is inserted , and they get twisted. I've seen film of Nigel Nailing sawing through baulks of archaeological timber, why not use this relatively non-destructive coring instrument ? You can't do it underwater. You have no leverage under water. On land its quite an abdominal workout , underwater and especially with tides there is no chance. Its hard enough even with a saw and even then you have to hold on to something. There is a pneumatic chain saw , but you need hard-hat diving qualification to use it. In a standing building it just would not do sawing a major beam in half. There are powered corers for use in historical buildings, that also make our life easier, heavily geared down power drill . When you dive a wreck , do you know something is there or just go to a location in roughly the right area? Most tof the wrecks we dive are already charted positions. We might find new wrecks by prospection , sidescan surveys . The search for the Malaysian Airlines MH370 aircraft has revealed a couple of new wrecks, some large 19C cargo ships that were not previously known, chance discoveries. They can be found as a result of surveys prior to offshore construction, windfarms for instance. We look at alot of that kind of data and might find wrecks, not previously known. But generally the seabed and bathymetry off the UK coast is well understood , so finding a new wreck =thwre is fairly unusual. A windfarm off East anglia wher they've just found a WW1 U-boat, an important discovery. When we're diving we put together research design, specific questions that we want to ask of a wreck other than just going there ad hoc. This sets us apart from the treasure-hunters, an objective to find out more about the people , the culture or the technology, that you need to set out and understand before we dive. If you have a suspected wreck, how do you go about finding out what that might be a wreck of? If it was a totally unknown sitr, you'd start with understanding the dimensions, survey geophysical or remote sensing or diver based, materials, the artefacts, recording as much info as possible and bring it all together. First is trying to understand identity , and if not enough for that then understand it enough in terms of significance, what type of construction , what period in history, how much do we know about other wrecks from that period. If you go back befor e1800 you've automatically have something of high importance, because there are so few surviving examples. Thats the sort of frameworks we start working within.

Monday, 14 Mar 2016, Prof Jacek Brodzki , Soton Uni, Measuring the World: from Pythagoras to Big Data. Geometry is the study of study of shape, size, and properties of space. Since its creation in antiquity, it has been a central part of mathematics and it is indispensable to our understanding of the world in which we live. This talk will trace the development of the main ideas that have shaped this exciting subject and which today form the basis of modern mathematical data analysis.This will be supported by examples from recent research. 37 people, 1.5 hours I've never given a talk about maths in a pub. We will talk about a Greek invention, geometry. Your teachers wanted you to believe that the subject was important, its a conflation of 2 words geo that relates to Earth and the rest comes from measurement. So measuring the world is what we'll talk about. A really beautiful path from the dark mists of pre-history all the way to now, which we can retrace by replaying the important problems that people faced. Then we realise that many of those problems are very similar to what we are faced with. En route we will be impressed by the ingenuity of the ancients. So the problems are just the usual ones, trying to make sense of the world around them. It started with some very difficult quextions about astronomy . One thing for us moderns to appreciate is how amazing the sky at night is, of what you can see against a dark sky night. Its no wonder that people wanted to figur eout what it is, how to use it. Then there were numerous practical problems through surveying, if your field got flooded periodically and the flood plain is where stuff likes to grow. Navigation is as ancient as humanity, where they were and where to go. Time measurement. Here is a sundial image, the variety and ingenuity of sundials is phenominal. Back when these were designed there wa sno standard unit of time beyond the day was divided into 12 hours and the night divided into 12 hours, so you have 365 different days and different nights. They repeat with the seasons , the day-hours are different to the night hours and today's hours will be differnt to tomorrow's. Within reason people knew how to deal with that. We begin with Pythagoras, a special person. Someone who made schooldays very difficult to many people over the centuries. I could relate to that. When you read geometry as it was talked to us in the traditional Euclid style its full of statements like : in a right angled triangle the square on the line opposite the right angle equals the sum of the squares containing the right angle. So the reaction to the like of that from a teenager is you want to waste my precious youth to fathom what this means. One thing that may be different to how you may have seen it at school is there are no letters , no formulae here, and thats how the Greeks viewed numbers in computation. In those ancient times , a number was the length of something. It did not represent a length but was actually that thing. There was no concept of multi[plication. If you construced a rectangle was, what we would call the product of 2 numbers. The two were synonimous. The square is how you would multiply a side by itself. When we say something is the square of something, that concept still persists, again for the cube of a number. You visualise a length and make a cube out of it, calculate its volume and that is your number. In all langueges, I've come across, this idea persists , so it must have been handed down to us from antiquity. This intercepts with reality beautifully because you can create patterns. If you want to convince that Pythagoras Theorem is true, you can arrange patterns. A right triangle with equal sides, you can build the squares and count the constituent triangles and hopefully convince yourself it is true. proof by construction. There are now more than 350 proofs of Pythagoras' theorems. Reason number 2 that today is special. It is Einstein's birthday. He was born March 14, 1879 , when Maxwell died, a circle of life. We draw a perpendicular line from the vertex to the hypoteneuse. This creates 3 triangles , the original one and 2 smaller ones. All these triangles are similar, which simply means you can get from one to the other, to the other by simply scaling. Disregarding scale, they are identical. This is Einstein's idea, we have 3 triangles. We construct squares on the hypoteneuses of those 3 triangles. If each of the triangles had been cut out from its corresponding square then the area of the triangle to the area of the square from which it came , is the same for all 3, it is constant, just scaling. If you call the constant f then in modern notation . What you have on the left is the area of this triangle plus the area of the other triangle, but we cut them out from the first triangle, so it just adds up to the third one. The constant is non-zero, so you can divide by it, its dangerous to divide by zero , so don't do it. I managed to sneak in a bit of algebra. Without the invention oof algebra we would not have been able to use what the ancients came up wiht in the way of geometry. It makes computation possible, and without it , you're reduced to drawing circles in the sand. If you read the proofs handed down from Euclid and Archimedes etc its amazing how we've developed. Formalism has also developed by introducing good notation, it simplifies things. Pythagoras Theorem was ancient in the time of Pythagoras. There are clay tablets with cuneiform symbols on them that record on them , for reasons mysterious to us , Pythagorian triples. If you square one , square the other, add them and then you get the square of the third. The Babylonians don't discover something like thus by accident. You need to know how to build these things. Calculations like these are difficult, try working them out by hand, beyond mental arithmetic of most of us. When you discover a result like this you write it down. Do you happen to know the square of 8,161 , it happens to be the sum of 4961 squared and 6480 squared, this is how you get to be the high priest. Archimedes was one of the most brilliant people who have ever lived. He created large chunks of maths by himself, building on Euclid and other predecessors. A few things slightly different to how you saw them at school. For measuring the circle , he says the area of any circle is equal to a right angle triangle in which one of the sides about the right anfgle is equal to the radius , the other is equal to the circumference. At school we are told a formula and we memorise it. But the formula is not the understanding, but how would you want to figure out, relates to other things that you know. The formula is great when you want to compute but understanding relationships like these is where we build our knowledge. If we convert to modern notation. The area of a triangle is 1/2 its height, the radius r, times the base the other is the circumference which we know as 2*Pi*r , multiplying gives Pi*r^2, the formula at school. But he did not have this notation, he did not use the letter Pi. He was the first to discover that the following makes sense. Take any circle , the circumference divided by the diameter is constant. Take a small circle, measure the circumferenc and divide by the diameter you get something, do it for a large circle and the same answer. This is just a coincidence as it is done in the flat geometry. We do not live on a plane, we live on a gigantic ball. Picture the equator, thats a circle, how would you measure the diameter of such a circle, only by walking along the surface. Any diameter would have to start on the equator, go to a pole , and down the other side. But that is half the length of the circle described as the equator, divide the two and you get 2. Archimeded worked out that the ratio of any circle's circumference to its diameter is less that 3 + 1/7 and greater than 3 + 10/71, a very definite statement, in our school-learnt notation between 3.1428... and 3.1408... To achieve that , noone had done it before and it took humanity a long time till about 19C, that we finally nailed the proof that he left behind. So what is the circumferenc eof a circle?. When you give a name to something it feels like you've understood what its about, but no. How am I ging to arrive at the number that I think it might be. He inscribes a polygon in a circle and circumscribes with a polygon. These are straight segments, so numbers , so he has no trouble in working out what the circumference of a polygon should be. So the circle should be included within these 2 polygon peripheries. Slice up like a pizza with 3 cuts, you get 6 equilateral triangles, where each peripheral line is equal to the radius, so the circumference is 6*r. The outside is trickier, but we have Pythagoras theorem. The circumference of the large hexagon is 4* SQRT (3*r). I'm sneaking in Square root. I know its the number that if I square it, I get 3, but what is the number. A large part of Archimeded derivation is estimation of roots of numbers, because there were no tables for him to look them up. The ingenious machines that the Greeks had, did not calculate square roots. So pi is between 3 and 3.5. He then went to a polygon with 96 sides, scribing with finger in the sand. Reason 3 for March 14 to celebrate today, it is Pie Day in north America, the convention in the states is to say month,day, so 314, which is a great reason to eat pie. In the UK the pie day is 22 July, 22/7. Archimedes was most proud of the ratio of the volume of a sphere to the ratio of the cylinder . He worked out the volumes of all these figures, he understood the relationship between them. A ball just sits inside a cylinder, the height of the cylinder is the diameter of the ball. He said the ratio of volume of the sphere to the cylinder is 2/3. He wanted this fact placed on his tombstone, so proud of it , was he. He died in Cyraceuse , killed i na war. His grave was discovered by Cicero , when he was consul in Sicily and he wrote about it in his books. I want to compare this precision to other material that was available in his time. A map of Europe from ancient times and so therefore the world. It has some vaguely recognisable features, bodies of water, 2 blobs where the UK is . For all the precision achieved by Archimedes, drawing an accurate representation of the world is altogether another problem. First there was no agreed units of distance, typically then distances overland were measured in terms of the time required to travel between 2 points. So typically in caravan-days, but if your camels walk quicker than my camels then your distance units are differnt to my ones. Also when you sail, thats a different unit, which could explain why seas on this map are smaller than we would expect relative to the land areas. 11 or 12C maps still looked cartoonish. By the enlightenment , they knw of the americas, so S America has an east coast but no west. This was the sort of map Magellan had when he proposed his trip to go from Spain to the spice islands, over an unknown distance. No one knew how far it was. More recently , co-ordinate geometry. Decartes discovery of a coordinate system and coordinate geometry. All those gradients, intercepts . This discovery allows you to combine beautifuil geometric ideas with the computational power of algebra. As for distances, fron the time of Archimedes it was fairly obvious , if you could travel in a straight line. We declare the distance between 2 points can be worked out by Pythagoras Theorem, and this works in any dimensions. Dimensions means the number of co-ordinates you need to fix the posistion of a point uniquely. So the equation of a circle of radius 4 in Cartesian co-ordinates. This allowed peole to po push Archimeded ideas on approxiamation much further, to global distances. How do you make a map of a country?. Triangulation is one way. If you have a shape, say a circle, and you don't understand what it is, you fill it in with shapes you do understand, like triangles. People laboriously divided up their countries into large triangles, measured the sides and angles. Surveyors had to travel everywhere. To make one such triangle can be huge distances, you like them to be huge distances. Carl Fredrik Gauss was involved in this. He supervised the surveying of North Germany, living at Goettingen. In his diaries , for Hamberg and Villsedei? , he wrote the distance as 42,454 metres. So to the 20C . For the sphere distances are measured along great circles, not straight lines, this is how we navigate by plane or boat. Take one great circle, intercepted by 2 others. This fixes 4 points on the equator and 2 poles. Is there something easier than the sphere that we can understand. We can build a pair of pyramids , joined at the base, which resembles the equator and 2 poles. Imagine this happens in a number of dimensions that you cannot visualise and you say , is it similar to a sphere or something else together. If you can find a simple shape that has the same properties . The properties of a sphere are that it has a hole inside , hollow and it is of one piece. So if you find something else that is of one piece with a hole inside, maybe thats enough. On the left a truncated icosohedron , known to the ancient Greeks. On the right is a football. To get the football , first you have the left shape and then inflate it. The inflation identifes the 2 as one as far as topology. Geometry distinguishes between the 2 objects . One is easier to kick than the other, topolog doesn't care. This is a powerful iddea, how topology understands shape. Imagine a shape with a hole in it, sample it , take some points and give them little umbrellas. Open the brollies and they intersect at some places, they don't in others. Mark where the umbrellas overlap , something begins to emerge. Imagine this room is pitch black, we are where we are and we try to figure out where the stairs are. We need to gathe rlocal information, each of us can feel a small area around us . Then the difficulty is combining each persons discovery. Topology gives us a computational device , where if we anlarge the brollies perhaps we will get finer information about where we are. So we connected all the points that we sampled , and there seems to be a large loop that goes around the hole, so maybe that is the hole we discovered. But there could be another loop which does not surround a hole. So we can discover something useful but also stuff that doesn't exist. We enlarge the umbrellas and repeat , and we have one piece with one hole , great. But we increase the brollies again but now the hole disappears, it is nonsense. This corresponds well rwith the idea of resolution. It controls the resolution of which you view your space. If the resolution is wrong, you may not see the details you want to understand. We have a computational device , in the last 10 years or so. Collecting all these measurements together . We draw one bar for each piece (too graphical to transcribe). Counts the number of loops we have. This has an application, done last year and will be published this year. Arterial Trees. If you've wondered how your brain gets nutrients, where the blood comes in. Its delivered by arteries, which forms a structure like a bush, a tree that starts at the base and branches out to fill your brain. Paul Bendisch? tells me this. When you show a scan to a brain surgeon , he'll look at it and tell among othe r things , how old the brain is. When you ask how do they know, they'll give an answer that you don't understand. Essentially its easy , after staring at tens of thousands of these, then its obvious. But others might want to know the same. These arterial trees change as we age. A scan of a 24 yearold and a scan of a 68 yearold brain. The computational machine will discriminate and do othe rthings as well. Fencer? Networks. Mobile phones rely an there being a network of masts with which they comunicate. Each phone knows where it is relative to a cell. Some othe rnetworks are not fixed so well. To measure the temperature of the oceans for example , it is possible to build a contsainer load of thermometers , in floats that float at a particular depth , chuck them overboard and let them swim , wherever. But each of them has to be able to communicate with its neighbours. How do you know if you have enough of them or would the network have any holes in its coverage. If you had fixed masts, you could figure it out, Archimedes could do it, but we can do it very efficiently. We have a way of organising our thinking ,these days. It is to do with hte 7 bridges of Koernitzberg, which is now Kaliningrad, a piece of Russia that is detached fro mthe rest of Russia on the Baltic. Not all 7 exist now, can you invent a walk that traverses every bridge, but only once. Traversing the bridges end to end, not allowed to stop half way and return. If you want to say there is no way to do it, how will you do this?. Will you list all possible paths and say nothing works. Even in this simple case that method would not be simple. Euler said, given the question is about the bridges . Bridges connect landmasses but what you do inside each of them , does not matter. 4 land masses, he gave a dot to each, the map shrunk to 4 points. Then how are these connected to the rest. The land at the top has 2 bridges leading to the land in the middle and 1 bridge to the landmass to the right. Continue like that. The land at the bottom is connected by 2 bridges to the land in hte middle. A beautiful distillation of what you're trying to do. If you want to pass through a point , you need a leg that comes in and a leg that goes out. No matter how many paths go through this point you need them in pairs. If you have an odd number of bridges you can either start or end at that point. Every path can have at most one starting point and at most one end point, that's it. Only 2 of those places are allowed to have an odd number of legs , all the others have to have an even number of bridges connected to them. So you just count them, 4 vertices have an odd number of legs , so impossible. Archimedes told us to pay atention to neat solutuions to difficult problems. Now a map with contour lines and elevations, not just the position but how high above sea level or below sea level. So we have some land and we measure the height of every point above some plane. Then we pay attention to ranges of those heights. So you split this shape into shapes that represent heights that you're interested in. Then you do as Euler, retain the main info about it. So in this case 2 pieces at the required height but not conected to one another. So convert them into 2 blobs. and the other blobs, like Euler, they get a connection if they overlap. You look at this plot and you realise that data that people want can be squeezed into this sort of pattern. The first plot deals with diabetes. 1977 at Stamford there was a studty the precise nature of the relationship between diabetes type 1 and type 2 , the early onset and the adult form. 145 patients ,blood tests and 6 variables for each, small data but it is in 6 dimensions. We can't see in 6D , we can't even see in 3D , each eye sees a 2D projection of the world and our brain computes to 3D. The abstract describes the visualising of this data. The emerging picture was a "boomerang with 2 wings and a fat middle" the phrase used i na technical report from Stamford. Needed a human to look at 2D projections and put them in a plausible 3D shape. So what is this fat middle, it turns out that they are the controls, the people without diabetes. If you remove them the 2 wings fall apart , there is now no connection between them, one wing is type 1 and the other is type2. This construction , though simple, is strong enough to tell you these things. A modern version of that study. We fed the data from that study into a machine that understands how to this blobbiness thing and a stick-person that represents the same data. One arm is type1 and the other is type2 . A similar representation of more recent data concerning type2 , splits into 3 main types. If you are treating people , you need to know this sort of variability. We looked at many data sets using these methods , one is pre-eclampsia anothe rmysterious condition . The difficulty there is there is no easy way to say who is going to get it. You know you have preeclampsia when you have it. This blobby machine was applied to a dataset that we got from our ? at the hospital, shows some very clear structure in that data, just using simple minded idea. Mathematics is regarded as this mysterious thing that seems to live outside of human endeavour . Mathematics is not an issue, it simply is a systematic way of thinking about complex problems. Like music, that is a systematic way of making sound. Non systematic ways of doing this are not so interesting. If you do it systematically, this is where the beauty occurs. It just cares about 2 things, truth and beauty and this dichotomy is tremendously appealing to me. Truth is where logic lives and if you overdose on logic things become difficult. I guess this is why a lot of people get turned off by mathematics. Frequently it seems there isn't a detail so small that it couldn't becme the centre of a major quasi-religous cult. Beauty is where we declare it to be and that is up to us. Mathematics never forgets, another strength. Whenever you have a good answer to a difficult question we remember it. THen this millenium or the next we find good use for it. Q&A One of the slides you showed was the ratio of the sphere to the cylinder and 2:3 ratio but the formula for a sphere is 4/3? Sphere is (4*Pi*r^3)/3 and cylinder is Pi*r^2*h where h=2r, so the ratio is (4/3)/2 = 2/3 Could he prove that it was an exact ratio of integres? He didn't know. The way he did this was another ingenious construction. What is a sphere, it is a circle rotated in 3D. So imagine you take a circle with a circumscribed polygon and rotate that. You get a many faced surface on the outside, stare at it long enough , because these are shapes of revolution, that whatever is inside of a sphere, you've cut out from a cone. You've previiusly worked out the volume of a cone. I beleive it is 1:2:3 cone:sphere:cylinder that he worked out. His method is a long way along the path to calculating the length of something that is not a straight line. The procedure to approximate something to polygons, better and better, it feels like it converges to something. It took us really to the 18C to nail this concept, to show it is not dependent on the choices you made, not some whacky coincidence, that works for one class of polygons and not an other. I can't help but thank the Archimeded would not be impressed that we managed to prove what he knew, just more precisely. Are you aware of the Antikythyra Mechanism?, as far as I know it was just for then astrological, we'd call astronomy now , was there any mathematical calculation involved, as far as I know it was ratios of very oddly number teethed cogs.? Calculations were clearly involved in the design of that mechanism. It was a mysterious artefact that was probably discovered last century, in a shipwreck in the Aegian Sea but only small fragments of it survived. It seemed to have been a sophisticated calculator for the phases of the moon, solar eclipses, the dates of the year and when the Olympics would be. I said there was no fixed unit of time, I'm not entirely sure the year was fixed, but this mechanism could cope with those variations/variabilities. So it was like a programmed computer , it would do one thing. The calculations had gone into the design and then the design was fixed in place, by the ratios of varoius cogs and wheels inside. We've seen various computer animations of how it worked. A moon moving round, showing what phase it is etc. Jus tthe mechanics must have been clever because Babbage's Difference Engine came to grief because there was too much friction in the movements.? But babbages machine did work, but not in his time. The Science Museum built one and it did work, just as he thought out. Its big but it did work. When did we learn that the Earth was not spherical? I think we knew that for a long time, but either people didn't believe it or forgot it. There is the well in Egypt . Aristothenes who lived in 2 cities I believe one was Alexandra and the other was Cera? and he noticed that for a well in his city that on a particular day of the year, the Sun would shine straight the way down the well to the bottom. So the question is why it would happen on only one day of the year. If the Earth was flat then it would happen just like that. I asked why the Earth was not spherical, isn't it slightly oblate.? Again its intertwined with units of length. At some point they decided to calculate the circumference of the Earth. The kilometre was so defined. Its difficult to come up with some unit of lenght that would be workable and everyone could use. You would not be surprised to know ther e is the Greenwich Meridian and the Paris Meridian, differing by about 1 degree. Someone proposed that the length of 1/4 of a great circle along the Paris Meridian was 10,000km, by definition. Then people went out to measure this, using triangulation , dividing up that vast length into something measurable. People like Sir Isaac Newton I would expect was certain the Earth was not perfectly spherical. An opinion rather than by observation? Yes. He knew about the tides , the tides are related to the phenomenon you are talking about. If you imagine the Earth is spherical and the tides are attached to it. The tides occur because the water is pulled on either side, away from the shape of the Earth. If you freeze it, then that is the shape of the Earth. If for whatever reason , the oceans froze over , then the last tide is the shape of the Earth. When it was exactly measured , I don't know. Could you explain the geometry of my Romansco cauliflower there?, the self repeating spiral structure.? This is a tremendously intricate pattern, I'll pass it around. Its just a vegetable, a cauliflower. It has flowers of differnt sizes, the ones at the bottom are bigger than the ones in the middle and all kinds of repeating patterns . So one flower looks like one head , looking closely, with spiral patterns inside. This is the difference between knowing how something looks and understanding where it came from. I can describe to you my best understanding of the shapes, but I would not be able to propose how it came about. The fact we have a theory for something , doesn't mean we undrstand what that thing is. Newton understood this very well. He understood that his theory of gravitation explains how gravity works but not what it is. He said "I don't frame hypothesese" that swhat he meant. It would be no more than a hypothesis on my part. It is a cool vegetable, and it tastes nice too. Would it relate to Fibonacci number series as in Sunflowers? It might, but I don't really know what to make of these coincidences. Unless there was some deeper understanding , like Pi. It was relevant to figure out what it is because we knew it corresponds to some very definite geometric feature, divide the circumference by the diameter and you get a constant. Could you explain to me , what topology is the study of and how that came about from geometry? Geometry is very precise. At the bottom of geometry is the measurement of distances. Once you decide on how you measure distances, that fixes shapes. What is a unit circle, in the plane, is all the points whose distance to the centre is exactly 1. I said distance, there are many ways of measuring distance. According to which one you pick , your circles can look different. We tend to think we measure distances along straight lines, but we don't. Straight lines , but only over small distances. Nobody got to this rooom by following a straight line. Topology is quite more flexible. It tries to classify shapes according to some key features. Take the sphere , consists of 1 piece, a hole in the middle, we detect it through topology. Therre is another important feature. If you draw a loop on the surface of that sphere and shrink it to a point, it will slide off, it won't get hooked up on anything. Imagine you have a taurus , a doughnut. It is of one piece, a hole in the middle , but also has this other feature. There will be a loop that you can create, thatcannot fall off. The question is, what properties survive continuous transformations. Survive being stretched or shrunk, without breaking or gluing. Topology describes shapes, according to what survives continuous transformation. When you have that complex polyhedron and you blow it up and get a football, in topology these are teh same objects. THe polyhedron contains the same amount of information as the football. In geometry they are different. Its a more flexible way of understanding shape, the lack of precision is outweighed by the fact it is easy to calculate the main characteristics of shape, if you give yourself this amount of freedom. The more precise you know something, the more complex it becomes. Give yourself a bit of flexibility , perhaps it does not matter precisely , but it keeps certain key features, like the 7 bridges, but ignored everything else. I've shrunk everything else I didn't want , to a point and that was sufficient to solve the problem. Geometry is indispensible in some situations and topology in others.

Monday, 11 Apr 2016, Dean of Engineering and the Environment ,Soton Uni, Prof William Powrie : Developments in railway track engineering. 26 people, 1.5hr In the 60s&70s we saw extensive closures in the rail network, including quite a lot around here. In the mid 1990s,when the operation of railways was privatised, I'm sutre they thought they waere handing over an industry that was in genteel decline. Run it down further and close it down for good. In the last 10 or 15 years an astonishing thing has happened, not just the UK but around the world, a surge in passengers and freight. It seems to be uncoupled with economic growth. You might expect a growth in gerneral transport with the growth of an economy, but that does not seem to be the case. As an example of the retrenchement of the 60s and 70s. A plan of the network in Devon in the 1930s, then along came the Beeching report, titled ironically Network Developement. THe proposal was was the lines in Dorset would be reduced to that shown and looking at the system today , that is pretty much what happened. I like railways and one of the things, through the good offices of SUSTRANS, quite a lot of the closed lines were transformed t5o leisure routes for walking and cycling. To maintain these walkways and cycleways we have to maintain and look after some quite significant infrastructure, such as viaducts and bridges. It is interesting that we were not determined to continue their original intended use as a railway. Over the last 8 years , we see that UK GDP has near enough flatlined but rail has continued rising. Another thing that has happened around that period, the percentage of people around the world living in urban centres has increased. An increasing population living in cities. Projected to have , mid 21C, 70% living in cities and with that sort of density that clearly encourages the developement of transport systems, including rail. I see a role for rail in high speed city-centre to city centre, 500km or so of genuine intercity or so. Where the train is quicker and much more environmentally efficient . We've seen a huge growth in metro around the world, linkages within cities. Considering london and where you can get to within 1 hour of london centre, a reasonable commute, the travelling people, goods and services that needs to travel into London, the railway has a key role in doing that. There are still places that the railway supplies a real lifeline , places like mid-Wales , Devon and Cornwall, where despite the improvements in roads, railways still are the most efficient and quick way of getting around. The role for inter-city is partly brought about by speed. Graphs of world record train speeds from 1930s compared to graph of maximum service speed, the one tracks the other, with a lag of about 1 decade. As the speeds go higher , the distance they serve also grows. That is one reason behind intercity growth. The growth of Metro systems around the world, Singapore, Dubai , Delhi, etc. Where can you get to 1 hour from London. So you get as far as Winchester in our direction but as far as Tamworth or Bradford when you go north. The isocrome of eaqual commuting time is not necessarily linked to straight geographic distance. Even in terms of the rural life-lines we see for instance in Cornwall a 75% increase use over a decade. Where otherwise the rural road network remains poor. We are seeing evenv the reopening of some rural railways. I think in all those areas, rail will have some role to play. Rail is currently the only transport system that offers 0 CO2 emmissions at the point of use. We can generate the electricity off-site, deal with the CO2 there, and pick up the energy by overhead or third rail. Its inherently efficient in energy terms. I went to the railway museum in Sweden where they had a ton on rails, and you could ush it along quite easily on the level. The only resistance is rolling friction of steel wheel on steel rail. You couldn't do that with a car. Some will say rail is challenged by road and full occupancy of the roads, rail is very effective at combatting congestion. People building HS2 will tell you that in the terms of throughput of passengers, HS2 is at least twice as efficient as any motorway. If you factor in real costs of environmental damage, you'd always come up with railways over roads. It can be a good experience, despite you may disagree with some of the recently introduced trains. You can do work on a train, you can read etc, compared to driving which is just tiring. The network today is about 30,000 Km of mainline , 200km of sidings . Interestingly over half of that involves earthworks, either in cuttings or on embankments. We have 500Km of vulnerable coastal routes, remember Dawlish, but not just Dawlish. In 2014 there was 62 billion passenger Km travelled on our network, which is twise that of 1960 on a network that is half the size. A 4-fold increase in efficiency. The challenges we face are also pretty amazing. So there is that intensity of use, our trains are becoming faster and more frequent. They are heavier becausue they have to be more crash-worthy, have air conditioning etc. So the trains are making more demands on the track. Its very different running a 60mph railway than a 120mph railway. The punishment to the track almost increases exponentially over time. The working day is getting longer, when I first moved to soton 20 years ago , the last fast train out of Waterloo was 20:30, it is now 22:30. They are talking about 24 hour tube. so the time available for maintainence, over night , is going to get smaller and smaller. To offset that all sorts of the routine mainainence is becoming increasingly mechanised. We have an aging workforce. I worked for British Rail at one time and the hardest physical work I've ever done is spot shovel packing of ballast, backbreaking stuff. People don't like doing that sort of stuff and it is increasingly mechanised. Anothe rreason for this move to mechanisation , is its a lot safer, not having people on the tracks. Those are some of the network challenges. There are financial challenges. 2014/15 Network Rail spent about 5 billion on renewals and enhancements, and that was short of their target. So about half the operational budget on renewals and enhancements. There is a feeling that the cost of railways is getting ever higher. There is a set target of 22% efficiency gain over the current financial reporting period, but projecting to get 16%, pretty good but its not 22%. Over the last year we've seen what a headache the repair of vulnerable coastal sections has been. There are 3 government reports about to come out, The Hendy Report and at least 2 others. All of them have the government breathing down operators necks saying, why is it costing so much, why aren't you delivering. Nationally the transport split is roughly 90% by road and 10% by rail, so a 10% reduction in road traffic by shifting to rail would double rail traffic on the current network. I just don't think that is doable with existing infrastructure. On some routes I believe we have supressed demand by excessive pricing. The debate about HS2 would be over and we'd be building more infrastructure. I spoke to someone at the DofT and asked why you aren't talking about new infrastructure , the answer was that it is long term, we can get more out of the existing. But there must come a point where we seriously talk about building new lines. A personal anecdote. 3 of us needed to go to Nottingham so we look at the journey details Soton to Nottingham , starting at 7am for 1100 meeting at Nottingham for a total with return of 744GBP. But seriously would anyone expect us to turn up spending 744 to get 3 of us to Nottingham. We hire a car, left at 7:20 got there at 10:15 and return journey was nice and easy as well. 25GBP to hire the car, 3 for insurance, 34GBP for diesel, so 62 quid as compared to 744 quid. The problem is that that journey is towards the London direction and we would be travelling on peak time trains. Cross-country services are now so popular tha tits quite difficult to use an off-peak ticket, with no advance purchase tickets available at that time. Go via London and again its peak travelling time and they don't want us to do that. We are bwing priced off rail and onto road. If we could provide that sort of capacity on a rail system then we'd be in a different place. Not just Dawlish, thr Cumbrian coast between Carlisle and Barrow, a landslip at Unstowe? on the Midland mainline, close rto home a recent major slip at the Botley embankment i n2014, Stonegate in 2014 and 2015 between Banbury and Leamington Spa at Harb? 40 or 50m depth of cutting. They shifted millions of tons of earth there to stabilise it. What happens with our embankments with our weather patterns and vegetation. We see , rainfall through the year is fairly constant , a bit drier in the summer . The problem is the vapo-transpiration , the amount of moisture that can potentially be taken out of the soil by a combination of evaporation by the sun and transpiration by vegetation, trees and leaves. So in summer when we get more sunshine and the plants are active, ther eis the potential to take out 100/120mm of rain out of the soil. That makes it go into suction which is good from the point of view for stability. In the winter perhaps only 10mm being taken out, but there is rainfall replenishing by about 80mm , so in the winter the soil wwets up. If we are talking of a clay soil , which many of our embankments are, they get wet in the winter and dry in the summer and its like building a sandcastle on a beech. If the sand is damp , you can make a sandcastle with steep sides, but add water to the sandcastle , so wet rathe rthan damp , then it colapses. So in summer our embankments have damp soil and we can have steep slopes but winter and the soil slumps. We recently had 2 very wet winters , intense periods of rainfall, and wet sandcastles all over the country. It turns out its not just that winter bu t the combination with the summer and winter before, looking at the total of 1.5 to 2 years. With climate change, that kind of event is more likely to occur, than perhaps 20 years ago. Projecting into the future we forsee more of a problem there. Management of earthworks is one of the biggest challenges we face. These strategies are captured in the 4 Cs , Carbon = rail being 0 CO2 but road is catching up, Capacity = running out of room on the network , Cost = many feel costs are out of control , and Customers = need to have a good experience. They don't want to be standing and don't want to pay 750 quid, when you can drive somewhere for 70. All those things are linked i nthe challenges we face. Track is its major asset, so if we can maintain and operate the track more efficiently the chances are we can make substantial savings. Ballasted track. Rails rest on concrete sleepers with tie-plates that hold the rails in place. That all rests on a bed of stones known as ballast. The idea of ballast is they are quite difficult to move aroiund. Its a material of known strength and stiffness , the idea is to make it thick enough so the load is transmitted from the trains to the sub-base , spread out so as not to cause a localised settlement or failure. There are often pads between rail mounts and sleepers. We heap the ballast up as shoulders to give a bit more resistance against the track from moving from side to side . So what is wrong with ballast. Running a 60mph train is different from running 120mph. Both use much the same components of rail and track. We've gone from timber sleepers to concrete, we've changed the shape of the steel but fundamentally it is the same as 150 years ago. As we traffic the ballast we get a gradual settlement and that occurs differentially at different points along the track. We start with level track and then after a few million tons of trains over it, it develops deformation, resulting in discomfortable rides and bigger loads that worsen the deformations. As we've increased the speed over ballasted tracks we've seen 2 other things happen, ballast migration and balast flight, with very fast trains people believe the ballast can become airborne and either strike the train on the underside or worse is when a small stone comes to rest on the rail and crushed by the wheel and damages the rail. With all railways there is gradual settlement with traffic, so people have to go in and [ut it back. That is one of the reasons that network rail spends so much on maintainence. Can we do something with the ballast, relatively simply, that would improve its performance, so it does,'t settle so quickly under traffic. If we could extend the maintainence schedule cycle by a factor of 2 we'd substantially redice costs. In the lab we have a single sleeper that sits in a ballast bed, polythene on the dsides to make sure we don't have side friction , we hydraulically subject it to 3 million cycles , representing 3 million 20 ton axle loadings , over about 10 days. Equivalent to 2 or 3 years of a heavily traficed mainline railway . So we can look at things that may make the sleeper settle more slowly. It loads at 3Hz, lots of data. This plots permanent settlement , to the number of cycles on a log scale. Initially we get a lot of settlement, then approx linear increase plotted on log scale. At the end of 3 million cycles, nearly 6mm of ballast settlement. If that was evenly distributed, that would not matter. So they reposition in an operation known as tamping, wher ethe track is lifted then tines push down into the ballast and vibrated sideways, squeezing the ballast sideways to bring it up to the right level. 2 problems with that. We have a ballast structure that is nicely bedded in , carrying vertical loads and wecome along and squash it sidewat=ys, so the first train over and there is lots of settlement. So they try to over-tamp , so the first train over , brings it back to where they want it to be. There is dynamic track stabilisation wher ethey simulate the passage of the first few trains. But tamping disturbs the structure of the ballast. There is a school of thought that with tamping we break the bllast particles , making them less robust. So the first time we lay the track , run it, tamp it, it then settles more quickly , then after the next tamping it settles even more quickly. So we are damaging the structure of the ballast by the mainainance. So our aim would be to do something that slows the rate of settlement of the track, so tamp less often and so less ballast damage. What we used to do was drop coal dust in , clay would come up from under, toilets that would dump excrement on the track. This contamination by fine particles was also considered to be one of the reasons for this gradual deterioration. If you look at an old railway sleeper, they are beaten up on the bottom face, because the ballast particles embed in there. When we moved to concrete sleepers, we had a hard interface. So now the sleeper bashes up the ballast at contact points. We investigated this with pressure sensitive paper and over 2.5 million load cycles , the number of contact points and the area of real contact between concrete and ballast is pretty small. So a difficult interface, high stresses . Ballast migration only really started to occur in the UK , when we started running Pendolino tilting trains. When those trains go round a curve ther eis a very asymetric load , twice the load on the outer rail than the inner rail. The track is canted also. Where the outer rail is higher than the inner rail, over many train passages, the ballast walks itself downhill, leaving the high ends of the sleepers exposed and ballast in a heap against the low end rail. It only occurs over about 5 sleeper bays, a puzzle, seems to be a different cause each time, a weld that has not been ground quite flat which sets up a motion in the bogies and thumps the track is one cause. If you are running at higher speed, you need a tighter maintainence tolerence. Ballast flight is also a puzzle, probably a combination of air turbulence with the train and ground-bourne vibration. A small bit of stone, landing on a rail, causes a dip in the rail and you have to cut it out. The French are good at high speed railways. A record breaking run , on you-tube, of the TGV and there seems to be a cloud of dust behind the train, not sure, but some of that may be flying ballast. Thev French will not officially disclose. But again a concern. There are ways around it, that we're investigating, but it is only at higher speeds. So why don't we lay the track on concrete and get rid of ballast problems. Rails bolted down to reinforced concrete slab, but its not really a solution. We still need to prepare the sub-base and you probably need better foundations. Drive over the concrete bits of the M27 or the roads in Townhill Park locally, all concrete . High initial cost and high embedded carbon but proponents of slab-track would say you spend more intiially , but less in maintainence and on balance, whole-life, you benefit. There are also concerns with cracking with slab-track. We don;t have much experience with it so don't really know its pros and cons. People have had a go at determining the costys, but a fairly close run thing. Such analyses crucially depend on what assumptions you make, how often you need to maintain the track, as to cumulative costs. The DfT has compared German, Japanese slab systems and ballast track over 90 year life, and came to conclusion that over 90 year slab track comes out more expensive. Our challenge is to reduce the renewals and maintainence part of the equation. Ballast is pretty good at absorbing noise, generally quieter than concrete slab. One stufdent project was thre amount of embedded energy. Again showed slab-track starting higher , bu tthe total energy costs criss-cross and really depends on whether you have to have a major renewal. She found that ballasted track on clay, required tamping more often than on soil or sand. So underlying ground conditions are important. It turns out to be a pretty close run thing over a 90 year period. If we can improve the performance of ballested track , there are potentially some big wins. We've looked at under-sleeper pads, rubber pads that soften up the interface on the underside of the sleper. We've looked at changing the ballast grading. We tend to use single size stones , but actually for other applications they would use smaller stones in there as well, giving better mechanical interlocking and more stable structure. We looked at randonm fibre reinforcement , plastic strips in the ballast, which as the ballast deforms , holds the ballast in tension. We've also looked at reducing the shoulder slope. We did some tests on desert railway , where we the ballast was sand, and that was surprisingly beneficial. For under-sleep pad we get more area of contact , spread over a biggewr area , reducing the streeses , so less likely to break bits off the ballast. We doubled the number of contacts and increased the area. Plot of settlemnt v the number of cycles , with 2 undersleeper pads we've roughly halved the rate of settlement. The importance is not so much the difference on the vertical axis , but on the horizontal. So if we say a settlement of 4mm indicates when we need to go in and tamp , then we've moved that point from 100,000 cycles out to about 3 million cysles, so a huge benefit, if that translated to reality of the track. For 2 different ballast gradings , moving the proportion of finer materials , again an increase in the time of settlement. Plastic , cut from damp-proof strip , as the ballast starts to move, it goes into tension, holding the ballast together, better ductility, and as we shear the material it has less tendency to expand, a good thing. Again plots of settlement v number of cycles, ther eids a small improvement . In later iterations, we improved the mix of fibres and mor eimprovent. What surprised us was trhe effect of balast slope. A view near Hexham of an embankment , the track is sitting on a very steep shoulder of ballast, almost as steep as we could make it, then a load on the top and it tends to move quite a bit. We run tests where instead of the shoulder slope of 1 in 1 , lets make it 1 in 2. Again plot of settlement v cycles , again reduced the rate of settlement using reduced slope shoulders. The reason turns out m, that we are confining the ballast and with the steep slope, as we load it vertically , the ballast rolls down the slope . Making it a bit less steep , that effect stops. That is perhaps the simplest intervention they could do, where ther e is space to do it, a caveat. People say that when the ballast gets fouled, we have to replace it. We did some tests with a desert railway , as they were concerned about what happens when sand blows into their ballast. We filled up the spaces with fine desert sand , specially flown in from Saudia Arabia. As we gradually added mor eand more sand , nothing hapened, until the sand got up to the underside of the sleeper, then after that all further settlement stopped. So it could be beneficial to have the ballast all filled up with sand, although it still needs to be able to drain . It also went very stiff so would require resiliant pads between rail and sleeper . So plenty of scope, from the lab results, to extend the maintainence schedule by at least a factor of 2. The next with Railtrack and London Underground, is to do some field trials of some of these techniques, so see if the lab results transfer to the more onerous conditions , in the field. Embankments and cuttings. Often never really designed as such, and often don't know how they were built . They are getting older, and being subjected to increased loads and also the effects of climate change. An old embankment, constructed about 150 years ago. Spoil dug out of a cutting farther up the line , and end-tipped , forming the embankment. No comp[action . If there was trees i nthe way or a road in the way , it was just covered over with hte earth. If you dig clay, it comes out as clods , so wnen returned to the ground, it is a matrix of clods and softer channels of material inbetween. Often we can't see that by naked eye but do a CT scan it would look like a solid block of intact clay , but we can then see the original clods and the soft material infil. That is fairly typical of railway embankment. Vegetation takes moisture out of the soil in summer and then putting moisture back in the winter. If it is a clay then it shrinks and swells, moisture out it shrinks , moisture in it swells. This is why network rail don't like trees, although they give some stability to the earthwork , they change the level of the track, non-uniformly and unpredicatably, swelling and shrinking. We had a trial of cutting down some of the trees on an embankement in Southend. They cleared all the trees, leaving some scrub. Originally a uniform cross-section , but setttled , and then made up to the correct profile with ash and the rails on top. We measured the moisture content of the soil , at different depths and also measured the vertical displacement, before and after the tree removal. 4 years of data , looking at 1m down , close to what the track is seeing. By 1 June we start to get settlement, 40mm of settlement , through to the autumn, then in the winter the soil wets up and after a year , back to wheere we were. Then cutting down of the trees , the whole embankment started to swell , with no trees abstracting moisture and embankment rewetting. So 40 to 60mm of swelling but no cycling. The downside is its back to the wet sandcastle principle, losing the benefit of the trees, so a mixed blessing. After 2 years the whole profile of moisture content has changed but in a worse situation in terms of stability and a potential that it could fail. To investigate further, we've developed ways of modelling trees in numerical analysis. Traditionally you would introduce water at the surface representing rainfall, and out from underneath representing trees. Then what is the effect of moving trees from the embankment. With trees on an embankment and over multi season weather sequence , areas where the soil is in suction ,holding soil particles together, good in terms of stability. Remove all the trees , leaving grass and shrubs, after a few years there is no suction zones, so that in the winter , no suction and pore pressure in the embankment can be high enough to cause failure. So we looked at leaving trees over some of the embankment, the bottom third , you can get rid of the damaging shrink/swell effects at teh top of the embankment but still a zone of suction remains even at the end ofa wet 18 months. So hopefully leaving trees on the bottom of an earthwork will gain the best of both worlds, reducing the seasonal shrinking and swelling but maintaining suction. But there are no absolutes to this. As we project climate forward, in 40 or 50 years its quite possible that even that will not be enough, potentially a big future headache to rail infrastructure. If we remove all trees then it allows rewetting and loss of suction zone protection of stability. If we can remove the high water demand trees , close to the crest , and retaining trees at the toe it can give us the best of both worlds. Sometimes that is not enough and we can stabilise by introducing individual concrete piles . So work we did was how far apart can they be . Too far apart and the soil will spill between them , too close and its uneconomical , where i nthe slope do they need to be and how deep. We monitored a number of sites in Kent and london, some embankments and some cuttings . On one site it was only necessary to stabilise one side of the embankment , because of the direction of groundwater flow, flowing into the cutting . Where the vegetation was removed, it was replaced with stabilising piles , to ensure an overal stable system. From our work on this, they were able to reduce the cost of such stabilisations and the time required by about 50%. So a saving over 5 years of between 65 and 100 million gbp. Monitoring bridge scour . Bridges with piers that go down into the river bed , then if you have abnormal current conditions , scouring can leave the bridge foundations exposed. At the moment they send divers down to inspect , in turbid water the consistency of Brown Windsor soup, so difficult to tell the difference between a scour hole filled with loose mud and something that is intact. We've been working on using a sonar device which can check changes in density. The rail bridge over the River Hamble. Some scour holes that had been reported as being ok. So we're developing this for a more effective and cost effective way of picking up vulnerability to pier scouring. The West Coast mainline recently was shut at the Mannington? Viaduct due to scouring . We need to get smarter at detecting things like that. Q&A You were very scathing of the high rail fares, surely they are indicating what the market will stand, increase the network capacity and you'll be able to recoup that quite quickly? Faced with increases , they will travel another way. Most of the people travelling up to London, on a season ticket , is quite a good deal. If you have to travel at peak timnes then you have to pay it. Many will look at those prices and go by car . I think ,on cross-country lines, the killer is the inability to use off-peak tickets. When I first came here there was no restriction of using off peak ticketing cross-country. They changed an 8 coach train every 2 hours to a 4 coach train every hour , demand went sky high , but then not the capacity as the die was cast. If you go from here to Birmingham, setting out before 9:30 its something like £150 but if you split your ticket at Reading and Banbury then its about £66. A lot of people use cross-country trains for short hops. An off-peak to Birmingham is about £80 , reasonable. So are you saying it needs computer analysis of what the customer is prepared to pay? I'm sure the airline industry can do it . There was an article by Ian Warmsley? , went thru an analysis. Looking at the cost of running a train-coach and if you could fill it with season-ticket holders and only ran it into London in htr morning and out in the evening, you would be making a profit. So why don't they do it. Were do those extra passengers comnme from , they come from the next coach where they are currently standing up , they are currently paying but standing up. Then we've made it quite difficult to add extra coaches. Sometimes just not possible. If you're running a 12 coach train , then thats it. But the voyager 4 or 5 coaches the soultion ought to be run longer trains and have more sensible prices for some of those journeys. Surely the pricing structure is used to prevent people from travelling. ? Yes that was my point. Rather thanc meet the demand , we supress the demand by the pricing but is that a sensible thing to do, given the damage to the environment with cars. From a train company point of view they are behaving just as they should. But from a national transport policy POV, its inappropriate. Do high speed train networks have the same problems or are they're constructions better? We know ballast migration occurs on European railways , ballast flight occurs often because of lumps of ice that fall off trains. I don't think they can do things better than we do. The challenge that we have, separately, is that we try to run a whole variety of trains on our old network. If you build a network from new and only has one type of train , same speeds, same cornerings that is a lot easier to design for . Some of this the operators are quite coy about. On the ballast issue, has anyone though of using glue? If we glue it, we can't tamp it . They do at certain locations , they use certain techniques that in effect glue ballast together , its expensive , so only used on very specific locations. Some places they opt for gluing and it turns out not to be the right solution. Isn't glued ballast just a concrete slab ? Not really. Even just a layer of PVA or something , a surface layer , is probably quite effective at stopping initial disturbance. The intention is to have something not as hard as a concrete slab , retaining some of the flexibility of ballast . Various systems use polyurathane , but then how stable is it with UV sunlight. Locally there is a problem with the track here , with an underground stream , with yellow T plates for local speed restrictions. Every now and then someone comes along and I thought they were apraying cement paste in that suspect area, would that be a gluing process? Certainly the Korean rail system has a project to convert ballasted track into slab track by injecting cement paste, how effective it is , as not really designed and engineered. Is there any benefits in having some sections as concrete slab and the rest as ballast? Every time you change from one system to another you give yourself headaches . There is a bit I did not cover in the tal;k concerning transitions from bridges to embankment , because of the massive change in stiffness causes problems. Its one of the things with HS2 that is on slab track all the way through tunnels , it may well end up on slab all the way to Birmingham , not because ballasted track won't work, but what you don't want is repeated transitions. Slow speed tunnels like Southampton is all slab , tens of mph, but try and operate at 200mph then an issue. With high speed tracks, small interventions and changes , get magnified . You talked of large ballast mixed with sand , how does that compare with using large,medium and small stone ? I don't think you'd want to go to ballast and sand. If you look at road building its well known that what you want is a mixture. You want something with a mixture of sizes to be mechanically stable and not so many fine particles which would be susceptible to ballast flight . It is achievable, but the railway administrations are quite conservative , a matter of persuading them that yes you can do this. So you would advise a wider range of sizes? Yes. In the old days, dropping coal dust in and toilets, with the big particle sizes they would not clog up. We have covered coal wagons these days and container toilets so no longer an issue there. Do you have data to support that? Some data but I think we could push it further with smaller particles. But the next step is trials in the field. Is the angularity of the agregate important? It is certainly if rounded. A theory is that as the ballast gets abraided , so less angular , so looses its inherent strength . One of our current projects is , could you just design it for a degraded state. Once the ballast has been trafficed to this degree , its angularity changed by this much , then that is all the properties we need and no need to renew it. I'm thinking of just traditional footpaths , they always used a mix called hogging which is graded angular down to coarse sand. As sand is used for added traction purposes on rail heads , the sand component would seem to be ok.? Sandboxes are not a problem if the sand is fine enough. Hogging is basically the angularity of the mix of particle sizes, but it doesn't drain very well. That is the trick , something that gives the benefit of the mechanical interlocking but still gives good drainage. With a given packing volume of various sizes, have you looked at the void volume as a means of quantifying the effectiveness of the settlement, so a useful tracker for the differenet mixes to trial? With any granular material , you have a maximimum and minimum possible void volume. Like when you buy cornflakes it always says sold by weight and not volume. The packet is filled and then it settles. Those are standard tests we do on any granular material then try and get is somewhere near its densect packing , when its in place in the field. We've looked at how the density changes with trafficking. Thats one of the problems with tamping, you loosen it all up again and the process restarts. The ratio of void volume to total volume is quite an important indicator of the state of packing, yes.

Monday, 09 May 2016, Jonathan Ridley and Jean-Baptiste Souppez of Solent University: Yacht Design 27 people, 2 hours A bit of background to the courses at Solent University, where we both are. We have quite reknowned courses in yacht design. The courses started in 1969 as a 3 year Diploma in Yacht Design and Manufacturing. In 2005 the then Southampton Institute became Solent University, and the course became Bachelors , now 2 courses, Beng in yacht craft and design and the Yacht Design and Production. Facilities include at Warsash a ship-bridge simulator, at Timsbury near Romsey we have 15m manned models for captains to practise ship-handling. If you crash a 15m long one , no great issue, if you crash a 300m one , more of an issue. We are very lucky to have a 60m towing tank allowing us to test different types of craft, to work out boaat resistance and with a wave maker at one end we can genarate various waves and see the behaviour in waves, hydro-dynamics. There is a smaller stability tank to explore some of the concepts of naval architecture, hydrostatics, to determine heel angles, stability etc. We have a composite workshop for building panels, model yachts up to 3.5m dinghies. When we've buit test panels we wreck them by structural testing to see the material properties and feed that back into the yacht design cycle. Computational design is a large part of yacht design these days. Software suites include 2D drawing, 3D modelling , 3D analysis etc. The first week on the course, with very basic materials , build a tiny catamaran . By the end of the first year you have to design and build and race a 70cm model yacht, a formal assessment. The race results actually count towards exam grades. Its the funnest exam you will ever do. The third year you do a disertstion where you design a boat, could be a superyacht , catamaran, cruiser. We won't be talking about the aesthetics of yacht design, we leave that to stylists. It is a big constraint to us, a nice shiney surface could be structurally hopeless. So we will put aside super-yachts where the naval architect has to bent to the whim of owner and stylist. There is a very good book, The Principles of Yacht Design by Lars Larsen. A quote from it “The most advanced tunnel for sail testing is that at the Yacht Research Unit of the University of Auckland” After graduating from Solent, I went to New Zealand for 1.5 years to play with their twisted-flow wind tunnel. A brilliant facility to look at sails , maesure forces. Start with a big fan , honecomb in mesh, then a series of bars and then twisting vanes. 2x 3.5m diameter fans, which as they are rotating , is not even flow. We need to straighten that flow , hence the 2 fine meshes, then honeycomb structure, that straightens it. We want to replicate what a real yacht would see on the water, trying to model as close as possible to reality. As air is moving towards a real boat there is friction at the surfsce , tending to slow the flow, so a velocity profile is developed. As you go up, friction decreases , and so more wind. For kite surfers, on the beach, there might not be much wind but by the time your kite is 40m in the air, then can be windy up there. This is the boundary layer. You need a long length of tunnel to develop the full velocity profile, perhaps 500m , so not practical. So we trap the flow by using some horizontal bars at tlow level, to produce the velocity profile. Getting quite close to what we'd find over water. We start with Vt , the true wind speed at any hight z. The reference height is usually taken meteorologically as 10m. For your average 40 foot boat, 10m is pretty high up the mast. Then there is z0 which is the roughness of the water, for water we have a nice expression to calculate thiis. Put in a spreadsheet and you get a nice velocity profile. This is what we replicate with those bars. For those twisted vanes, we need to look at the apparent windspeed. When sailing there is 3 different winds True windspeed, what you would feel standing on the beech. Then the boat speed Vb, with no wind but move yourself at 30mph you will have a 30mph wind on your face. With a boat we combine both "winds" to give the apparent windspeed. This is what the sails see. The angle between Vt and Vb is the wind angle compared to the true wind, Betaw. 2 vectors giving the resultant of apparent windspeed Va and apparant angle of betaa. As the true windspeed change, the apparent windspeed will change . As I go up the mast I get a different apparent wind, the wind is twisted. Now in the wind tunnel, the boat is basically stationary so we need to artificially create a twist in the flow to replicate reality over the water. We trick the flow into what it would be on the water. We mount the boat model on a turntable, so we can change its angle relative to the flow. A camera on the top, 3 cameras to the sides, to track the sail shape as the winches mounted in the turnatable are trimmed by remote control. Pull the sail in , open it more, add more kicker and so "sail" the boat as if on water, all the same controls. Under the boat is the force balance, measuring all the forces, all the degrees of freedom. Any body has 6 degrees of freedom and for yachts these have 6 names of 3 forces surge, sway and heave and 3 moments called roll , pitch and yaw. Surge is the longitudinal movement forward, essentially your boat speed . Sway ,how much movement sideways and heave the vertical movement. For a cruiser-racer not much vdertical movement, but a catamaran can have large vertical movement. Roll is what on sailing yachts we call the heel, apply wind on one side and the boat will heel over. Pitch is the bow going up and down, rotation about the transverse axis and yaw , rotation about the vertical axis. So we measure all those forces, mainly to predict how fast the boat will go. You sit in the control room , adjusting by the remote control ,essentially sailing indoors. We are trying to establish the sailing equilibrium which is the balance of all the forces. Yor boat speed will be a function of how much drive you provide to go forward agsinst how much resistance there is to that forward movement. So we get the actual boat track, the veer the angle the sails are seeing, lift that is generated perpendicular and if lift there must also be grag and that is parallel to the flow. End up with sail lift and sail drag , typically on a racing boat a ratio of 3 to 1, 3 times more lift than drag. If I combine the 2 forces I'd get a aerodynamic? force. I can put that back into the coordinates of the boat, looking down the centreline, this is then the drive, the amount of the aerodynamic force that is tryng to make me go forward. With that drive force, I also get what is called the sail side-force, the boat is heeling . For this to be in equilibrium , we need equal and opposite forces. for the drive we will have the drag, for sail side force we must have a keel sideforce, which is the keel providing lift to counteract the lift generated by the sails. So opposite to the aerodynamic force is the hydrodynamic force which can again be broken down into 2 components, keel side-force. So basically my boat will accelerate until the drive is equal to the drag, the equilibrium that will give my boat speed. We call this the VPP, velocity prediction programme. This is the endgame for us , is that boat going to be fast enough. If you're going to build a 5 million pound racing yacht you want some level of confidence that you stand a chance of winning your race, otherwise you will not build it. The output is a wonderful pole plot, a quadrant with the angle to the wind , the boat speed . For a given line at that angle the boat will be that speed. If you are sailing that coarse in that windspeed that is how fast you can expect. I've a chance of winning the race with that set of results or no, please make it faster. So the VPP is essentially trying to solve for equilibrium all those degrees of freedom. My boat will heel until the heeling moment is equal to the righting moment . The way it works typically is we do some towing tank tests. We figure out what is the drag of the boat, how much resistance in this particular position , more heel how does that affect resistance. We then develop another matrix in the wind tunnel, trying all the sails at different angles and different windpeeds , different heel angles . Put is all into a VPP . That is the theory but its not always the best way. From the wind tunnel you can figure out the lift of your sail, my boat had that much lift . That lift is generated in an environment of density of the air, sail area amount . This is fixed and you can calculate the lift coefficient, from that, later on, you can use it again to figure out what the lift of the boat is. Its not very efficient as you're measuring a lift, bringing back to a coefficient , to convert back into a lift, a bit of a painful process. As you are developing this matrix, you will normally rtest your yacht at about 18 degree of heel and again at 25 degree of heel. If you're in the middle you have to interpolate which may result i na loss of accuracy, so not always the best way. The othe rproblem is, the wind tunnel testing is typically done by the sail trimmer of the sailing team but towing tank testing is done, say for the America's Cup team they would give you the hull to test. The sail trimmer is the one taking the remote control as he is the expert in his field, much more so than myself or any other testers, as we would be on that competitive yacht otherwise. He comes in and has to do all those weird tests at heel angles that he would never be in, so not ideal for him . At the end of the day he has no idea if the boat is fast enough. He has to wait until you have done the maths and return to him 2 weeks later. So we developed the Realtime Velocity Prediction Programme. We take the towing tank data, put in our computers, work out the drag of the boat and adjusting everything realtime. Its windy, the nboat heels, more windy and it heels a bit more, at the same time your trimmer is there saying in that condition I'd put in more main , but that produces too much heel , uncomfortable for crew, so let some power out. He gets a direct indication of what the boat speed is and what the heel angle is. He knows straight away whether that boat is the one he's looking for. He can adjust the trim to the particular heel angle. Never would you test a boat at 19.7 degrees of heel, but as realtime the simulation can adjust to that particular angle. It makes it easier for us, less calculations and very good for the sailor as he is getting a direct feel of what the boat will do on the water. There is computational fluid dynamics , trying to predict everything numerically is quite important. But you need to validate that , being able to say that prediction was good or bad. For sails, the problem is, they're soft. Its very difficult to achieve the same shape over and over again. So we've made a rigid sail , model that sail on a computer. Then CNC cut foam mould, then a rigid sail built, that you cannot change. you do all the wind-tunnel testing giving a proper benchmark to validate your computer model. We also investigate yacht interaction, models of siimilar size , in a racing situation whare do you want to be placed. Where is the best spot if you are behind, to steal the wind from the boat in front or if the guy in front , where is the best airflow and keep going faster. Change the racing conditions, place boats as close as we like, something very difficult to do on the water for real. Computer fluid dynamis works well, the output moves up and down because we are trying to solve Napier-Stokes equation and we can't. If you can the USA is offering a million dollars. To try and do it on a computer is time consuming as an iterative process. Trying a solution , refining it and refining it, hence the jerky output. Finally converges on a solution the comp[uter is happy with. Full size tow-testing. For catamarans its easier to built the craft because the computer modelling is difficult and at the small sacale in the towing tank it does not work too well. So Emirates Team New Zealand, making a large scale model and trying out on the water. A tow-line to the mast, pulling the craft and getting a feel for the dynamics. A Stuart 34 cruiser racer, load-cell and tow-line to a racer dinghy. We've improved the setup since ETNZ, they towed at centre at height , we now take a towing point from where the resultant forces on the sail would be. That allows us to put more power in or let some power out, some control over the power in the sail. With all the forces acting, there is relatively little force that is driving the boat. We don't have that much drive force available so we have to make sure the drag force is as small as possible. So my job is to design a hull with the absolute minimum drag as possible for a given set of scenarios, easier said than done. The drag on a boat through water is a resistance to motion. A bit simplified, we assume the drag on the hull is made of 2 separate mechanisms. The viscous resistance or viscous drag and 2/ the wave-making resistance, the resistance caused by the waves the vessel creates. Water is heavy, viscous ,sticky. If you are creating waves, that requires energy that is effectively only coming from the sails. Reduce the wavemaking, making it slippier and move through the water easier and if we can reduce the frictional resistance on the hull as well, that will make the boatr even faster. Hence the idea of hydrofoils where you lift the whole thing out of the water and get away from the sticky stuff as far as possible. If you imagine a flat plate held stationary in a river , water flowing past it, we'd find the individual water molecules , right on the surface of the plate are effectively attached to the plate, stuck in the roughness of the plate. The next layer of molecules slide or shear slightly over those, not the same speed as the rest of the river. The next layer over , shears a little faster etc. Even on a huge contsiner ship going flat out at 20 knots, this layer may only be 10 cm thick. We get this boundary layer, basically trapped water on the surface of the plate or a vessel. Water is quite dense stuff, the change of momentum creates a lot of drag. Typically for a yacht at fairly slow speed , up to normal sailing speed, this viscous drag could be 60 to 90% of the overall drag ,simply caused by pulling a lot of water molecules on a large scale. For the maths, we work out for the boundary layer, the velocity going into it , velocity of flow out , it is incompressible so we can work out the momentum and from change of momentum determine drag. Unfortunately for boundary layers its not as simple as saying its a flat plate. For an oval shape with water flowing in left to right, red is high pressure, blue is low. Water flows in , hits the leading edge of a hull , rudder or even a mast, it slows down. As it slows Bernoille Equation says the pressure must increase, so the stagnation point , at the leading edge of our hull where there is an increase in pressure. Then the water flows around the sides, it accelerates to get round the object and the pressure drops. When it gets to the back of the shape it has a fight between the velocity and pressures changing and the water trying to flow away from the back of the vessel. It almost sucks the boundary layer out , to be a bit wider and a bit bigger. The viscous drag is primarily determined by the surface area of the hull . Mor esurface, more trapped molecules , more weight it is dragging along with hte hull, but because of the curvature of the hull we trap more water than we would otherwise think, and that is very difficult to predict. We have the equations the Navier-Stokes equations , non-linear partial differential equations . Just to give an idea of the complexity and loads of money available if you solve them. If we wanted to work out for a simple cylinder, if we needed 100% accuracy to the flow around it, if we ganged together alll the world's supercomputers and solve by trial and error we'd die of old age before the solution. So other than a research environment they cannot be applied on an industry basis. We also create waves. The hull made waves again are difficult because very dependent on the shape of hull and the speed. There tends to be 2 separate yacht generated wave patterns. Kelvin wave pattern, a series of waves that diverge away from the vessel, the classic V. And transverse waves which move along with the vessel, 90 degrees to the vessel path. The length of the waves is dependent on the boat speed. From equation, the wavelength is proportional to the yacht speed squared. As we go faster the wavelengths get longer and longer. This is where wave drag becomes difficult. Around the stern of the vessel, the 2 wave patterns will interact with each other. As with physics, electricity etc, if you have 2 waves interacting you can get cancellation and superposistion. Diagramatically , keeping the wave amplitude the same, increase the speed one Kelvin wave system off the bow another Kelvin wave system off the stern, the wavelengths increase . We get various points where peaks and troughs meet and the wave system cancels out . Other points the peaks coincide and superposistion . At different speeds the wave resistance goes up and down and up repeatedly. Part of our job is to find the sweet spot of a particular speed where the wave resistance is cancelling maximally, without creating too much area of hull. Despite all our computers, the best route is to build a scale model and test it in a tank. Still cheaper to make models than to use large computer power. And much more fun than sitting at Excell for hours. Example of a student project of testing a novel bow design. We tow his model along the tank, under a carriage which is measuring the drag , side-force, pitch,heave,trim all measured and recorded. We get a very good idea of how well the model behaves. We can put cameras underwater and see the flow on the underside of the hull. By attaching bits of wool in various places , low tech but very effective. This particular test showed something interesting. As we were accelerating the model down the tank, started gently , bow lifting as expected . Then we got to s speed where the whole thing was vibrating, in fact so much we were concerned the test rig might fail. We were not sure why, why tank testing is so useful. It was difficult to see on the camera images , the bow wave coming off the model, there is a little light line in the image. The novel shape of this hull was creating a very small vortex . You can never line the model up absolutely perfectly , always .1 degree out of alignment or so. A tiny bit of cross-flow at the bow. And in reality at sea there would be a bit of leeway angle. Although the bow shape was reducing the resistance quite well that slight bit of cross-flow was rolling off a vortex under it and the vortex was attacking the hull. Banging against it with enough force to make the whole model resonate and oscillate. So little things like that, you find out from tank testing, which are invaluable. One thing with tank testing is getting the scaling right. We reckon that going from model scale to full scale we can predict the resistance to +/-1.5% . The reason we can't do it completely accurately is because the 2 components of resistance , annoyingly, scale differently to each other going from model scale to full. The wave-making resistance scales by the Froude Number proportional to the square root of the length of the model and the viscous resistamnce scales with the Reynolds Number which is directly proportional to the lenght. So we can scale up the wavemaking resistance or the viscous resistance, we can't scale them both properly, a real headache. In the true traditions of all science, we have to apply a scientific bodge. We say the viscous resistance is not very sensitive to scaling, if me make a 10% error in the scaling then not too much error in the viscous resistance. What we find is that if we make the water in the tank a little bit more turbulent, then that helps to solve our scaling problem. At full scale the turbulance of the sea is a bit greater . We cheat by making the wate rin the tank a bit more turbulent. That is difficult for the entire tank , 180 tons of water in it. Requires a lot of energy to make all of that turbulent, so we cheat on the model. Zooming in on the bow of a model ther eare tiny dots in the pic. We put tiny studs about 2mm diameter , 1mm deep on the hull surface to deliberately make the hull a bit rougher. Sometimes we would use a thin strip of sandpaper, here is B&Q wet and dry fixed with double sided tape , we call a turbulent flow stimulator. That little bit of extra roughness , thickening up the boundary layer a bit makes it a bit mor elike it would be at full scale. Choosing where to put that on the model and looking at the results afterward and deciding whether or not you believe it, is where the art and science mix. So have minimum surface area of the hull to reduce viscous drag and reducing wavemaking by having as hydrodynamic and aerodynamic a shape as possible. Wavemaking is directly proportional to the vessel weight. Double the mass and double the wavemaking drag. For a performance vessel the wavemaking drag is probably about 85% of the drag. When you look at the Americas Cup guys, they are spending millions just to save 30 or 40 Kg. For the Vendee Globe, round the world race, they reckon for each Kg saved they cut 6 minutes from the world trip. The difference between the first 2 competitors in the last race was about 2.5 hours in it, so translates to not much weight, if the second one could save 20Kg they could have been first. So the structure is key to weight saving. A structural engineer has to first identify the loads. If you put in more force and more load than you expect , you get structural failure. We class them on yachts as 2 types of loads, local loads and global loads. A local load would be the weight of the engine, supported on engine beds, we have to support the weight of the rudder and the keel and the forces coming through from those. Global loads are things like hydrostatic pressure, the force of water pushing against the vessel. When we drop a yacht in the sea, the sea tries fighting back, creating bouyancy that makes it float. We can't get rid of hydrostatic pressure so we need ribs and frames in the vessel to prevent that. We get quite large torsional loads , the vessel tries to twist as it goes through waves. We have rigging loads, tension the rigging to reshape the mast to make it more effective will put loads on the vessel. Its quite possible to take a cruising yacht and tension it so it goes banana shaped and something will go bang. When the stantion lines around the deck go loose you get to know sonmething is not right. We have to design for waves, this is where naval and yacht design becomes interesting. Because the question is how big is a wave. How big a wave do you design a vessel to survive. Again a lot of subjectivity in the design. Designing a high performance sailing dinghy to get around the Solent as quick as possible you may think the worst wave it will meet was 1.5m . Designing a round the world sailing yacht , the 2 biggest waves ever recorded in History was the Hurricsne Ivan wave in 2004 recorded at 27m in height , recorded via pressure sensors on the seabed. They cannot be absoloutely sure of the accuracy of those sensors and a friend of mine who works in that area tells me it could have been as high as 40m. You cannot design a vessel to survive a 40m wave. The largest wave that was definitely recorded was the Draupner Wave recorded on thr Draupner oil Rig, Norway. Third way down from Bergen to Edinburgh in 1995, measured at 25.6m. A frightner that came out of the blue, the wave trace of sea under the rig and a single spike is that wave. Important in the area of naval structural engineering because sailors over history would come back saying the waves were this high and the architects would say , no much less, like the fisherman and the one that got away. After the Draupner we had absolute evidence. A year after that I was on a ferry in exactly that area, in a storm, the ferry just under 200m long , the wave size was such that the ceiling panels were falling down , my bunk became detached from the bulkhead when we hit one wave. A video of a smallish 40 foot ketch meeting a 100 foot wave, scalled down in a Dutch wave-making test tank, with the world's largest wave maker. Could we realistically design a structure to survive that, the answer is probably not. And now a video of an America's Cup yacht sailing in not particularly large waves, below their design limit. The back-stay is starting to go loose,very gently, very slowly the hull is folding itself in two. That was the end of several million pounds of boat. It shows them the time between them first noticing the back stay going loose and no more boat, about 90 seconds. Luckily there were support boats nearby and not far off shore. That is why we double-check our structure calculations. The effect of mass is also important. Even in a small dinghy on the Solent , you are tsaking a risk with the sea, dangerous stuff. We can't take risks on the strength of a vessel. The heavier our boat the slower she will go, a real challenge. There is a strong similarity between Formula1 racing cars and yacht design , that one of our naval archotect graduates is on the Red Bull F1 team. Its the same challenge , to build a structure light as possible , as strong as is possible, to go as fast as possible. McClaren also used to have a naval architect, who left, coincidently? see what happened to their performance. F1 and eerospace and yachts are now all embedded in exotic materials. We used to use steel for yachts , but its horrendously heavy, relative density of 7.8 and steel does not like seawater. As naval architects, we have a rule of thumb that if your looking after the steel , protecting it with paint etc you have a corrossion rate of about .1mm a year. Typical yacht hull is probably 12mm thick so after 10 years lost about 10% of your strength. An alternative metal is Aluminium , bu tthere is a problem with Al and composites to be fair. It burns , a sailors worst nightmare is not flooding or sinking but fire at sea. Al above a certain temperature will effectively ignite, its not counted as a safe structure, so it ghas to have lots of fireproofing like rockwool which adds to its weight. You can get weight saving from Al but its very expensive and weaight saving not as much as you initially thougth. so we switch to more interesting materials The basics of fibre reinforced platics, fibreglass was the original. Take a bulk material and stretch it as long as possible into thin fibres it changes effectively the material properties . We take E-glass, electrical insulation glass , stretch it to very long fibres, a good strength to weight ratio. By itself its weak so we encapsulate it in plastic, polyvinyl, polyester or epoxy resin, generally 2-part these days , that supports and protects these fibres. The fibres take up load from tension and the plastic takes compression loads. I'll pass around these samples, resin sample, CSM mat chopped strand mat, chopped and randomly mixed orientations to form a mat, the sort of stuff in a Halfords car body repair kit. High performance yacht design has more in common with dress-design than you may think. That CSM is pretty nasty to work with, so we take the fibres and weeve very fine cloth, like a silk cloth made entirely out of glass, similar to the inside of oven gloves. Put it in a mould , e-glass or s-glass both cheap and good at their job. But if we want to go a bit lighter and stronger we move to kevlar, the bullet-proof vest material. Again kevlar in a fabric form , yellow fabric, again encase in plastic until it sets. Kevlar is excellent at impact , but also light and strong in yacht construction. A colleague tells me that if you fold that cloth 8-times over , it will stop an 8mm bullet from 8 yards, but interestingly alternatively you could pick up a biro and push a biro through it. Its a strain dependent material , requiring the impact energy for the fibres to hold. It works because the fibres are very fine. You can't cut it with scissors, you need special shears. There are a few more types of fibres around these days but the next step up normally is carbon-fibre. It starts with a precursor a type of plastic called a polyacronotryl? placed in a carbon rich environment at very high temp, takes in the carbon and becomes carbon fibres. t stretches and moves just like a piece of cloth, but incredibly strong material. If we want to make it really stiff we put a sandwich material between it. So like how an I-beam works by separating the material to resist stress. The sandwich is made by pushing 2 pieces of carbon apart. A sample of a layer of carbon about .25mm at the centre, if you bend it you can hear the resin start to break. To make it less flexible we take 2 of these layers and place between , some core material to force them apart and hold apart. The core could be honeycomb , paper dipped in a particular resin and incredibly light and strong material. Its a bit flexible but try and crush between your fingers, placing it in sheer, it is very strong. So a combination of the 2 flexible carbon layers with honecomb between , that is not flexible by hand, amazingly stiff and very little weight. Another core material is foam of different formulations. But its only foam , so you think it can't be very strong. All it has to do is resist sheer forces, difficult to crush by finger pressure resisting sheer. Steel wire is about 2.7 GPa tensille strength varying on different alloys. e-glass 1.95, but its density 2.57, is much lighter. s-glass similar but stronger. kevlar is about 3.6 for a density of 1.5 compared to 7.8 of steel there are as many types of carbon fibre as types of wood , but for off-the-shelf T800 product density of 1.8 and strength of 5.6 so about double that of steel for much less weight. For normal off the roll cloth as it arricves, 1m wide, per m for a single layer is about 26GBP. Not as expensive as it was but not cheap. As carbon is pretty brittle we try to combine it with kevlar, in vthis sample the gold lines are kevlar , black lines is carbon. Mkes a very stiff structure with excellent impact resistance. A part of the steering wheel of an Americas Cup yacht , incredibly light cannot bend or twist it by hand, unbelievably stiff. Carbon fibres about 6micron in diameter , kevlar about 12 micron, very fine. They don't wet-out equally though. When building out of any composite material we have to get ratio of resin to fibres to be absolutely correct. Too little resin the fibres will be dry no wetting out, so the structure would be random blobs of glue and loose fibres. Too much resin , it gives no additional strength but add weight. The traditional way to build is wet lay-up. Take the mould , cut out the glass mat , place over the mould, get the bucket of resin , poor over and use a brush to stipple in, until you've used the correct volume of resin. That was 25 years ago, it gives us a structure, it works , loose more layers and you get a stronger structure but its a bit hit and miss in terms of qualiity of fibre/resin ratio and bad environmentslly as the chemicals in resins are horrendous, you don't want them on your skin. Some of the molecules are so small they can effectively pass through your skin into your blood and you end up with a plastic liver or kidneys. We want to build these structures, with as little contact with the resin as possible. Now we take the mould, place inside all the materials completely dry , tacked in place with a little adhesive. Then a release material to allow removal of the bag covering , an enormous vacuum bag , pull the air out of the bag , which pushes together all the layers of laminate . Then a tube goes into a bucket of resin and at the other end of the bag, the vacuum pump draws the resin through. So we can measure exactly the amount of resin that has gone in , watch it flowing through, we can introduce resin and vacuum at different points to control the rate of flow . The process is called resin infusion , producing a light and strong structure with very good material properties. It is a bit hit nd miss , if a tiny leak with the bag , a bit embarassing to have a hull with obvious bubbles in it. We have to make sure the boat floats upright. A video of a sailboat coming into harbour , overtaken by a huge wave. The boat rolls over but it returns upright with mast in place. So we need to design in stability, so she will self-right if some sort of disturbing force. ith high performance craft , not just side to side or transverse stability but also longitudinal stability , to balance fore and aft. A video of kite hoisted, bows lifting, a largish wave, too much power forewards, tips over and capsizes as well but comes back upright again , with just a few bruised egos . This is down to the physics of stability. 2 forces acting on our vessel, for stability, bouyancy pushing up supporting the vessel, gravitational force trying to sink the vessel. For equillibrium the 2 must be equal to float at a particular waterline. Centre of bouyancy acts at 1 single point in the middle of the underwater volume, so a function of hull shape. As the vessel heels over the middle of the underwater shape changes , the centre of bouytancy moves out, pushing up from a new position. The gravitational force, assumed to act down through a single point , the centre of gravity, a function of the distribution of mass , the loading and structure of the yacht. The CofG stays where it is relative to the yacht , rolls as the vessel inclines, the CofG stys on the centre line. Put in the centre of bouyancy and CoG , the bouyancy centre should be far enough out to give a couple effect and should roll the boat upright again, a righting moment. We have to design the vessel to make sure we create a righting moment. If she starts to heel over she will come up again. So the wight of the boat must be appropriate and the distribution of that weight is appropriate. If the CofG is too high in the vessel , gravity and bouyancy will take over and she'll just continue to heel over. The stability of all boats, not just yachts is quite precarious. Last year you will have seen coverage of the Hoegh Osaka that had an incident on the Bramble. Basically she fell over because she did not have enough stability. Stability is a double-edge sword. If we make our vessel too stable she will pop upright fairly quickly. If she is unstable, she'll roll over. But if she is too stable she will roll too quickly , to the point where it is too difficult to stand upright. I knew a designer on a Sail Training Assoc sqaure rigger . It was difficult to design a vessel that would carry enough sail , but when it rolled it would not roll so quickly that it would not throw Johny out of the rigging at mast top height. With ships like the Hoegh Osaka , if they are loaded to their legal minimum stability there could be the situation whare a change as little as 15cm between those two centres, of bouyancy and CofG could result in capsize, that marginal. To look at boat stability we look at what is called the metacentre. This is an imaginary point where the line of bouyancy crosses the centre-line . As long as the CoG is below that metacentre, we're alright. We have to work out where the metacentre is above the keel, work out where the CoG is above the keel and make sure the CoG is at a suitable distance below the metacentre, but not too far so the vessel rolls too quickly, and hence bad sea-keeping. We can look aty stability at different angles as well. So yacht design is not just a science but an art, a balance between lots of different requirements, often diametrically opposed. To get something that works to specifications, built on time and on budget, that is the challenge. The design is a mixture of stabilities, structures, and powering. Change the structure, we change the mass, the CofG that upsets the stability and make the vessel slower. If we play with the stability to make her more stable or better seakeeping, we will upset the structure and the powering. To make the vessel go faster we will need more sail area, that will upset stsability , create more loading , so need more structure, all horrendously inbred. Everything we do in yacht design has an impact somewhere else down the road. So the challenge is to get all these things to balance, getting them to work and then getting the craft to go fast enough. Q&A How much does the hull surface finish affect drag? As a rule of thumb, roughness below 1 micron, no effect really. For large scale ships, quite an accurate rule of thumb , from fouling, build up of barnacles , for every day out of the dry-dock viscous drag increases by about 1%. How often do really big container ships get into dry dock? Not as often as they should. The industry used to use a really strong anti-foul paint called tri-butyl tin, TBT. Very effective at killing marine growth but killed everything else around it. It got outlawed and replaced by less effective coatings ,but nicer to the general environment. A large ship is probably dry docked every 3 to 4 years, particularly if poor performance and excseesive fuel use. Its not unusual for divers to go down and in particular clean and polish propellor blades. There are companies developing underwater drones to clean while sitting alongside quay discharging the cargo. There is some research on shark-skin , there is anecdotal evidence that sharks have very rough skin bu tthey swim very quick, so something going on there. The latest thinking on that, yes the skin is quite rough and does create additional drag but that drag around the tail is moving more water and so creating more thrust and the thrust increase overcomes the drag increase. We still can't manufacture materials to the same consitency to test that for certain. We won't see it on yachts as there is nothing moving to affect propulsion. There are people looking into it for rowing, if Oxford or Cambridge win the boatrace very quickly one year we'll know what they've done. Does the finned keel structure does it mean in extreme wave environment , keeping the hull in the water, ends up on the tops of the waves? For the worst case scenario, for smaller yachts, is not necessarily a yacht meeting a very large wave . If sailing a 20 foot yacht into those sorts of seas you haver to ask why is it htere in the first place. The worst case load on a vessel is being lifted out of the water. When its craned out of the water with a strop near tthe bow and one near the stern and most of the weight amidships if it survives that then it will probably survive waves. We tend to design it for that and a good factor for safety. For a small craft with no large R&D budget that is a fall-back criterion. Adding fins to the keel does not make a massive difference, the winglets tend to add resistance in heave but not a huge effect . It doesn't hold the hull down into the water. If you are going upwind and the keel is creating a lot of lift it stops some of the cross-flow and makes the keel more efficient. They get more structure low down in the keel , effectively a bigger weight on the end of a cantilever , so a bit nmore internal structure for that lower CofG. I was imagining the fins holding the keel in the water and the rest of the hull separating from it and keels dropping off? Most keels dropping off are people finding the seabed earlier than they expected, hard grounding and no inspection afterwards. Then secondarily build and materials failure for keel dropping off. If you sail at only 10 knots into rock there will only be one winner. What is the current thinking on 1 or 2 keels? Bilge keels or tandam keels. Bilge keels will always be around for smaller yachts, just a practical option. With tandam keels with one keel in front of the other, perhaps both going to a bulb, its been tried. Americas cup tried it, GBR tried it in 2002 and others before that. It is more efficient, gives better lift , breaking down into smaller surfaces , more of a biplane effect. Downside is it makes the vessel harder to control. Most yacht racing rules stipulate that you can only have 2 foil surfaces to control un=derwater the vessel, so 1 is the keel and 1 the rudder. Combing one of those into your rudder , you have less steering , trying to balance the boat. Thats what GBR Challenge found out with White Lightning. When the wind hooked up, the sails hooked up , the keel was set perfectly she was a rocket but that only happened once of 10 times out sailing so a low hit rate. Since then , there has not been much R&D into that. So side by side is just for taking the ground , its not efficient? Yes, not that efficient, quite a large wetted area , so more viscous drag, more weight in the middle so more structure to support it. Probably more weight at each keel than you need . The only real advantge is trhat you can profile the keels so they are effectively asymetric so when you are on one tack your more vertivcal keel can produce more lift, bu tthat does not outweigh the drag penalty. If you want to dry out at a mooring there is not much other options for a good nights sleep. On the americas Cup rules thing, are there rules that limit what you can do , as in the F1 situation they clamped down on anything changing shape? Its a huge rule book. Some are very strict , its a one design so you can't change anything. Some are more flexible, you can vary this by that much . There are often restrictions on materials. You can get carbon in almost any grade you want and sometimes they stipulate the maximum properties of the allowed carbon. To stop people spending more and more money for higher spec materials. They usually put limits on the sail area. As a designer you want to find a little loophole in a rule. In the boats of the 70s they had tumblehome, wider on the water and narrower on the deck, so the hull comes back on itself. The rule then for measuring the width at the deck , but in use the wider width at the water meant it was more stable, more power out of it and more speed. The Emoka 60s? on the Vendee Globe race , 60 footer , similar to Ellen MacArthur's. They have a fixed number of appendages. You're allowed 5 appendages, 1 is the keel, 2 rudders and then you can add 2 dagger boards for generating the sideforce. For recent ones they've turned the dagger boards into foils for the boats to leap out of the water. If you're going into the wind they do badly . For the last Fastnet race, the wind was light and they could not move, drifting away because if the boat is not going fast they are just useless. But as soon as the wind comes over the stern and starting to surf they just lift out of the water. As a designer you have a set rule and trying to optimise it for whatever will work best. For the Vendee about 2/3 is about down wind sailing, so better off having the foils and suffer a bit on the last leg. Going around Antartica is the easy bit because you are down wind , its the last leg of Cape Horn back to France going upwind, slamming into the waves and after 2months at sea that is just too much and a lot of failures in the last 2 weeks, stopping in the Azores because the boat won't take any more . Whats the function of those noisy kevlar panels on sails that sound like steel plates? Either aramis?, kevlar or carbon fibres within it , its just a reinforcement for the sailcloth. Its nothing to do with rigid aerofoil section? There are sail makers who will mould the shape of your sail and those panels will retain the shape better, but its principally just strengthening it. Looking at the sail its usually darker around the corners, because a higher density of fibre, because thats where hte maximum loading is. Its acting like those composite panels , adding the carbon fibre , to reinforce. Will we see larger ships with sails in the future or will that not happen? There is a lot of research into having kites to provide extra power. A lot of research on rotors. If you rotate a cylinder you can generate lift, to the extent you can slow down the engine but continue moving at the same speed. Unfortunately the main driver for this research is not preserving the environment but saving money on fuel. With drop in oil price a lot of those projects are now on hold. There is legislation coming up that says marine industry must reduce greenhouse gas emissions by about 35% by about 2025/2030. There is one company that is close to putting large scasle sails on bulk carriers . They've identified the carriers, they have the systems, know how it will work, the next stage is building fullsize prototypes, currently at the fundraising stage. A serious and well-respected company. It will be in 5 to 10 years, and will be on a route between Australia and India where it will first appear, right winds and running coal supply. One of the challenges they found was finding anyone who had actually sailed any vessel that large. The plan is to have its normal crew on board and somewhere remotely , perhaps in London or somewhere around the world, there will be an office and someone remotely setting the sails , for them. We're hoping that will come off as that will be for us as yacht designers, in retirement. It would be all automated, no sail trimmer on board these vessels. It would be a tri-plane, 3 vertical solid sails with trailing edge flaps they can control and rotate the whole rig. So not kites , which are interesting. There are real positive benefits for kite sails. Very good downwind and off the wind. The limitation is how big a kite you can go and how much power. When they get a 30 knot cross-wind , not difficult in the Southern Ocean area , the sails will produce more drive than the main engiine, for the solid triplane arrangement, kite sails won't do that for the scale needed and be able to control it in those winds. Off Holland there has been some near misses between ships with kites and aircraft. If you are near oil-rigs with a lot of ferrying helicopters and a kite-sail at 3 or 400 metres an issue. And good lightning conductors as well, and a whole new set of collission regulations for ship versus airplane. For a normal sail you have the twist in the sail I don't remember seeing that on kite? sails. ? The back part is broken down , so you can get some of the ? back . Because they are going so fast , they can go 3 times the wind speed. It doesn't matter where the wind is coming from , the apparent wind angle is near enough close ???. Because you are so close to the wind , the twist is fairly small. There is a possibility of soft sail going downwind and a lot of twist , can get away with near enough flat with just a slight change. They are constantly sailing upwind , thats why no spinnaker as there is no downwind for them. Do you know what height commercial ship hauling kites would be deployed? It is of the order of hundreds of metres , because the higher you go , the higher the windspeed and the more thrust available. If the wind goes too high or they see a chopper they can wind it all back in again by the deployment winch. And its supposed to self-fold in theory. Will there be regulations to outlaw kite deployment in low cloud? I really hope so. I don't think anyone has got to the real operational stage of using these. A lot of aerodynamic and engineering research , feasibility studies in terms of can we do this, I'm not sure anyone has asked should we do this. These kites as they stand have no radar signature. but often the regulation comes after the accident. There's been accidents already, just the kites have not been attached to ships. Yesterday there was an incident in Bristol, police helicopter landed and shouted at someone flying a kite at 300m, a bit scarey. We used to get it in Afghanistan all the time, because they have this game there where they fly their kite to saw through the line of the competitor's kite. Flying a helicopter near that its not so much fun.? With current kites, if the kite comes down at full speed, the line could easily slice someone's head off. I think the size of vessel where kites are more practical there is lots of other efficiency gains to be had , from better fuel , smart systems, hydro-technology etc, a more known quantity than kites. Wind propulsin, envisages, will be on particular trade routes where you know the wind is blowing at a certain angle at a certain strength for a certain percentage of the year. South America up to India is one. As with most novel technologies , develop it for the easy stuff first. Most of the high performance end is going towards multi-hull these days, are mono-hulls done for now? Not done. Americas Cup is always a trend-setter, now its foiling catamarans and everyone is enjoying that. There will always be an interest in monohulls, if not for out and out speed, but for the tactics, the number of crew. At club level there is not the money and its a known technology. I think match racing can be as much fun as going as fast as you can and perhaps killing yourself, which multi-hulling seems to be evolving into. Not much investement going into developement of monohulls. Investment into lighter structures for more performance, and hull shapes. But not the rapid jump in technology of hydrofoils. There are ways of using hydrofoils to provide righting moment instead of lead keels, but it is very conditions specific, right wind speed and direction, right combination of foil sections. Monohulls won't disappear. For the Americas Cup and moving to multihulls, what I like, for the sport of sailing, its brought it so much closer to the shore and the public. Look at the keel boats with draft of 5 or 6m you have to be far out at sea. The public that could view those races was limited. With the catamarans with virtually no draught the finishing line can be 10 or 20m from the piers and quays. With the cup coming to Portsmouth in July and you will see them racing just 50m from you. For popularising and accessibility of the sport, multihulls are great. Conventional Americas cups with monohulls , with all the pre-start jostling was pretty impressive. With multihulls initially they are much more stable than monohulls , the problem is when you're gone , you're gone. A knockdown there and they don't come back. Don't they have flotation bouys on the mast top like car crash air bags? Yes, the idea is , if the mast goes close to horizontal it will stay at horizontal instead of complete inversion. 2 years ago one of the Artemis72 capsized and a sailor was trapped underneathand drowned, so they made the regulation about the inflatable mast-top bouys. Unfortunately its the accident that drives the regulation. Inflatable bag and an air cylinder and a tilt switch. I've seen these big catamarans , failing to take a corner and digging in of the bow. The structural stress must be immense? You see how fast the crew fly forward, massive deceleration. What is thought happens there, is if you get the foil too close to the surface, the pressure round the foil is low enough that the water changes state to vapour , basically cavitates , sits in its own bubble which does not do much for its drag coefficient , so all of a sudden you can loose lift on a set of foils. If you trim a bit too bow up , the foils get too close to the surface, they will ventillate, loose lift and drop and you go nose down. If a wave catches then , all the momentum is trying to roll you over, a huge deselaration. When we were designing Solent Whisper , our hydrofoil we designed in-house a couple of years ago. One of the tests for that was to see what if we stalled a set of foils. we found a convenient Red Funnel ferry and jumping off its wake. What happens loosing the foil action, the bow drops down. The shape of the bows on these are shaped such that as soon as a bow goes under, you pick up bouyancy quickly, the reason for the reverse-bows, to give bow up-moment as fast as possible. Ron who did those tests did not have a fun day doing those tests. If you look at the full-size testing of the cat in NZ, that is what they are doing , as developing in a tank or computer model is very difficult, to predict the behaviour on the water is difficult. Its faster and cheaper to build a batch of different foils and test on the water. Then get the sailor to say I never want to see that foil again. Will it work in real life , you try it in real life straight off. What would you think the next trend in shape of cruising yacht will be, we've hide the wide stern, the straight bow? The plumb bows in terms of resistance , not much difference until it comes to anchoring and easier to loose your gelcoat. Wide sterns , was following the off-shore racing yachts, make the sterns wider and they'll look faster and more internal volume so another berth in there. With cruising yachts I think , not so much massive changes in hull shape but smarter and better use of technology, in terms of materials. Vast majority of such boats are glass-fibre. We vcould use kevlar or carbon, more costly , but we use less material. There will be a break-even price point sometime in the near future, particularly with carbon and its heavy use in aerospace, the bulk price has dropped a lot over the last 10 years. 10 years ago going to a yacht builders they were using CSM and placing in wet, now Discovery Yachts at Hythe or similar, they are using the insusion technique, to build stronger lighter hulls. Get the weight down, we improve performance without having to change anything else. I don't think we'll see foils on cruising yachts, but you never know. Have the solved the hygroscopic absorbtion problem with glass-fibe hulls, and gelcoat failures? The industry started with polyester resins. One particualr boatyard decided that making glass-fibre whiter , by putting chlk dust in the gelcoat. Chalk and water is not a fantastic combination. Polyseter is still used by some boatyards but generally given way to polyvinyl which has better resistance to water. Now ,especially high performance, has switched to epoxy resin, basically araldite. That has rid the water absorbtion and hull-weight increase problem? Yes, epoxy is much better with regards to absorbtion. If you take a 1960s yacht , been in the water for a very long time and you test its material properties, they have degraded , but if you let the fibre-glass dry out it pretty much returns to normal, to its original condition. Is that an easy process? A big oven , lots of heat lamps and lots of patience, lots of pennies for the electricity meter. Just heat, no vacuum used. Cost-wise its probably more sensible to buy a new yacht. What was the block of plastic that you handed round? That is straight epoxy resin , a test pot that has cured so the plastic without the fibre. Its not as heavy as I would have expected? Its relatively light . You cannot tell from that block but its fairly flexible, about 20 times more flexible than with fibres within it. Very good in compression but not in tension, if you dropped it , it would shatter like glass. What is the end-of-life situation, lots and lots of GRP boats around , some must be getting to end of life.? We don't know. Engineering is good at saying can we do this , rather than should we do this. Glass fibre is an issue . Most GRP yachts at the moment are chain-sawed up and go to landfill. The way environmental legislation is going particularly with carbon fibres and exotic materials , landfill is out. The current industry trend is looking at recycling fibres. Taking a panel of carbon fibre say and using certain acids to etch away the resin, leaving the fibres, but those fibres are silghtly damaged so you can't use them for anything structural , but for cosmetic fairings etc. The industry is quickly getting a grip on sustainability, again even at the Americas Cup team level are starting to look at. One of the advances on the horizon is basalt fibre. You take basalt rock, superheat it to molten , pass through a fine sieve , you can draw into very fine fibres with similar mechanical properties to carbon fibre. The romans were building roads out of basalt fibre 2000 years ago, they knew it was a tough material. With basalt fibre that is basically rock , acid etch off the resin and some resins now are more environmentally friendly , can be broken down by deliberate chamical reactions. At the end of basalt fibre use you can chuck it back in your volcano and become basalt again. I think the industry will be taking a bigger stance on green issues. Yachting insustry tends to follow car and plane industry , so recyclability of components , true-life costs , dispossibility will be taken into account. We still see 50 year old GRP yachts sailing quite happily, when their time comes I'm not too sure. Bringing the life-cycle issues into the design stage will be enacted. Did they make hulls out of concrete? There was seacrete a special formulation for conrete, it wasn't too bad. Go to the British Pathe archive , type in concrete boat and there isa video . It was alright for river cruisers and similar, but not for yachts, it was quite heavy. The advantages were you did not need much internal structure. You can still see some on the Broads and places like that. With dinghy sailing and you're going upwind and flap,flap,flap, that will not happen on a yacht. When you design the hull does it have an optimum shape for heel angle? Very early in the design you would identify what your typical sailing angle would be. If it will spend most of its time at 15 deg of heel, you will design it for 15 deg of heel. Is that symmetric shapes? Once you heel , you get an asymetry in the water plane that will generate some lift upwind. You can try and optimise that for this asymetry assist side-force once heeling. For cruisers and other bigger yachts there would be a wider range whare they would sail more efficiently? Your average sailor would not like 30 degree of heel, so depending on the sail area you have something called the Delandbow ? Angle, a sort of back of envelope calculation giving a good estimate of where your boat will spend most of its life in terms of heel angle. You start from this point and develop your hull shape. We usually take it that getting to 30 degrees we would usually start unloading the rig and sails. We tend to design the rig , worst case, for 30 deg and a good factor of safety to go past it if you need to. For cruising yachts, after 30 deg we usually assume its time to reef a bit. For an outsider's perspective, Boaty MacBoatface? As a Frenchman I would say , yes, very British. Boat names can be quite funny, walk down the marina ther eis the "Slippery when Wet" "Unsinkable 2" and similar. They've named that boat something more serious and given that name to its ROV I think, all very British. There wa sa company called Titan Shipping, named all their ships after the different planets , imagine Titan followed by the name of one planet, that crew had to sail around the world on that.

Monday 13 June 2016, Dr Matthew Mowlem, NOC, Laboratory on a Chip 12 people, 1.5 hours (Euro football clash ) At the NOC we have science teams and engineering teams, developing new kit for marine science for use in the deep sea. I'm head of the group that develops kit for scientists to use. We also have the logistics divisions providing 2 research ships and all the kit that goes on them , autonomous subs, ROVs . Lab on chip has been aroubnd for several decades, it came out of the micro-electronics industry, where some of the fab-houses were wondering whether there was anything else they could do with silicon. They strated making little channels in the silicon and passing water down it . The first devices were using electrophoresis , applying electrical currents across the fluid and seeing what chemicals were separated out by the elctrostatic intetraction with hte ions. There is a journal , Lab on Chip, by the Royal Society of Chemistry. Since then I think 5 billion has been spent on lab on chip research. There has been a lot of publications, a lot of novel stuff has come out of it, not much has made it out into the popular world or industry. Q: Have you heard of the vampire watch? I know several people hav ebeen putting micro-fluidcs into phones and watches. Q: This pricks your skin and checks your blood and send something electronically to the cloud and have it analysed. I imagine the vampir ewatch is doing some flow analysis with LoC and the data will go up. It is quite big in the medical industry , but not that many products are actually on sale. It might be doing something like a full blood count. I'll later show a device ew have that does a similar thing. The bit in between is probably doing some sort of flow analysis, lab on a chip,LOC, then the data will go up to the cloud. That would be a micro-fluidic device. Its quite big in the medical industry, not that many products are actually on sale. It might be doing something like a full blood count, I'll show you later a device that does something similar , counting different types of cells. These samples I'll pass around are glass with layers of platinum and [plastic . In the middle of it is a little channel, where water or blood can pass . The silver lines are electrodes passing over the channel. With that device, the hydrodynamics, the nature of the flow , the cells tend to line up in a line, pass over the middle of the chip and you can measure the electrical and optical characteristics of single cells. So you can count thenm and tell roughly what they are. Billions have been spent but not that many products, a few projects used in biology labs for analysis , a few hospitals, but npt really mass market. Thats the space we got in and wondered if there was some use for this technology in oceanography. Q:You described decades of research but little in the way of products, are you aware of any specific blocker that was preventing exploitation, no market or some insurmaountable technical challenge? We did a whole seminar series with the Royal Society on that question. A number of things. The microfluidics community is very university centred, doing the latest and most novel thing and if its been done once by somebody else, then don't repeat it. Very limiting, not maturing, not engineering-out the encountered problems. You have to do black magic over some of the prototypes to get it to work a second time, and a lot was just luck it worked the first time. Its beginning to mature now, and some products coming through. Some was so outlandish and difficult to find which areas were safe bets. Then there was a couple of horror stories at the beginning where companies invested an awful lot of money and still no product at the end. The investors became shy , Philips, Samsung, Sharp all put in big money and no big sales return at the end. In a way that was good for us as all those companies and people solved a lot of the problems and had investigated what you could do with hte technology and allowed us to see if it could be applied to our problems. In our group, we're developing a load of things to help marine science . A lot of that is sensors work, how to measure water , to tell whats in it . motly chemisdtry and biology, physics is quite easy to measure. How conductive something is can give saltiness, measure the temperature , combine those 2 and you get the density of the water, basically all that physical oceanographers want to know. For the chemists and biologists we can take a sample , bring back to the lab and get the results , but how to do that on a small robot submarine or an ocean surface float, why we started looking at this area. Some of the stuf is not lab on chip, its quite big. A device we designed to sit on the sea-bed for 10 years and data release pods and preprogrammed time intervals, released to the surface . Autonomious surfboards, powered by the waves, and squirt data to satellites. We produced the kit for a UK team trying to get in to a sub-glacial lake in Antartica 2012/2013, Ellsworth (Bostok was the Russian attempt). Unfortunately BAS never made the hole , so it never went in. a 6m long vehicle that could measure factors in the lake, and having only 6 living cells on it before it went in there , after sterilisation. Different. interesting work, bit not at all LOC. There is an awful lot in the ocean that people don't know enough data on. The chemical and biological constituents of the water to try and work out how much CO2 the oceans could abdorb in the future. How much food for fish stocks etc. That is all encapsulated in computer models and broadly, there is not enough data to error check those models, to validate them. Earth should be called ocean , look a tthe Pacific and its near enough all sea. A few tens of research ships that might make a few transits over a given year, bu tthe very variability of biology basically means you've no idea what is going on. That is what we were trying to hit against. We started with an Argo float, stand <>2m high , cost about 20,000 dollars , sink down to 2000m , change their bouyancy and float back to the surface . On the transit from 2km down , to the surface , they are making physical measurements. January 2015 there was nearly 4000 of these floats in the world oceans. If on the same transits you could capture chemistry and biology, we're away. Argo floats only measure conductivity and temperature, relatively easy to do. So some space on board, to invent a small unit to do some chemistry and biology in. We try to do most things, from radio-nucleides ,via nuclear industry leaks , to trace water masses, through to measuring cells , measuring genes, measuring CO2 in water, to measuring nutrients. We thought we'd make a long list , have a crack and see which ones we could achive. We to a thing called Technology Readiness Assessment, NASA do this, the military do this. level 1 is , I've had an idea in the bath and level 9 is its commercial and we are selling it to do a job. So we are about 7 on the scale, actually doing it, devices in the ocean taking measurements, not commercial yet . Fro mthe original list of dreams, we've done pretty well. We've assembled a team who can do all the bits, integrated systems, so electronics , optics, microfabrication . Typically with a LOC, passing around some examples, the smallest channels on ther are 150 micron wide, .15mm wide. Made in the lab at the docks in Soton. We do the design, actually the chemistry changes at that sort of scale as surface area to volume ratios change. So needing a lot of chemistry optimisation . Microfluidics , you cannot scale down from macro-scale mixing environment, as the Reynalds numbers are all wrong, it doesn't spin, so no mixing. So you have to do some special things in our devices to overcome this. Q: I can't imagine how you stop these channels getting clogged or silted up, contaminated etc? This is why the USA thought that it wouldn't do LOC for oceanography, they just assumed everything would silt up, a barnacle would sit on your inlet and you'd be done. We thought the same but gave it a try. Our first experiments were just using basic channels, not trying to measure anything, open channels into the dock in Southampton witha pump on it and see how long to clog them up. And we never clogged them up, a real shock to us as everyone assumed they would. It transpired that the grade of silicon we were making them from at that time , the biology did not like them much. We kept them dark , so plants would not grow on them much. The flow is so low through these tiny channels , but consistent, and it seems bacteria don't like growing there either. So by luck its not so big an issue. Where its very silty , we have to place a little filter on the front end, but as its microfloidics and not pumping much volume. So for off-the-shelf medical filters for use with a syringe, with 0.4 micron pore, that filter would last us 6 months. So all surprising, you'd think that would be the limit. Because the US thought that would be the limit has probably given us 4 years on them. Q:Going the other way on that, aren;'t you continually fighting capilliary action, with intended slow flow rates, and it would zip through? We are completely submerged. If you had an air transition then you would. And also to get around capilliary action , you can shange the surface energy of the walls, a chemical treatment, making it either hydrophylic where the water zips in or hydrophobic and the water struggle to get in, you can manipulate it. But we are totally submerged, no air interface, and no problem. Some of the big shiney things this can go on. A sea glider like an Argo float with wings , on a downward journey you can imagine it gliding and glides on its way back up also. Placed on ships and a raft of other platforms they can go on. On our research vessel , Discovery there is the biggest and oldest autonomous submarine a ROV, 2 robots that go along the surface and a fleet of the gliders. Pass round a real deal LOC device. The clear chip with all the fluidics in , in real life we make it out of dark plastic , to stop outside light interfering with measurement and also we're doing coulorimetry? where you don't want light bouncing around in the chip. Make the windows thin over the light sensors , out of dark plastic , that is ok. On top is a syringe pump , some barrels, a plate that moves. The metal cylinders are solenioid operated valves and the rest is electronics. The chip is designed with a groove to take an O ring , we place 2 coaxially back to back in a tube. These sensors wil lgo to the very bottom of the sea, we've pressure tested to 7,000m equivalent, 70MPa of pressure. Each one of those is about 1500 USD, might sound like a lot, but that is cheap for a lot of oceanographic sensing eqipment. The reason its cheap is we are not trying to resist the pressure. Most traditional ocean sensor kit has a very strong pressure case , typically 10,000 USD, for the case before you put anything inside it. We wanted to make them cheap so able to put lots of them on lots of robotic vehicles. Instead, we fill the whole thing with oil with a rubber diaphragm that allows outside pressure to communicate to the inside. The problem there is everything in the way of electronics has to withstand full ocean pressure. So we've qualified every resistor, every capacitor , every microprocessor must withstand those conditions, thats what we do. We've now a list of otherwise standard components we can use in the deep sea. The Lemo connectors will be gone in the next version to bring the price down. The really expensive Lemo is an IE55 deep sea pressure rated connector, I think the 2 there are nearly 500 GBP, the rest is all quite cheap. Q: Qualifying means soldering , joints and that sort of thuing? Yes, we put 25 of them in the pressure pot and cycle them and see what breaks. Broadly what these devices are doing is they are sucking in water , into the internals of the chip and suck in some reagents , mix some water with some chemistry, get a colour or a flourescence or luminescence change and measure that optical signal. Once you can do those things, you can subtly redesign the chip , use different chemisties and a load of things you can measure. Everything from nutrients to dissolved organic components . Some of the advantages of this approach compared with competitor technologies. Like knitting tubes together , plumbing etc its small, its low power, relatively easy to build , consume very little reagent . Our optical measurement port is 150 micron channel , about 2.5 mm long, that is all you need to fill to make measurements. So we can collect the waste from say 10,000 measurements and collect in a relatively small bag inside the instrument . A lot of the competitor technologies , at the monment anyway, I'm not sure for how much longer, they are chucking the spent reagents into the sea or the river. In most of the devices the measurement is by colourimetry, an LED producing a light , through the sample , absorbing some of the light, so the light changes and we measure that change. Typically we pump through some of the sea or river water with no chemistry, first, get the background signal , then progress. Some examples of where it has worked , we've mixed academic research that would otherwise stay on the lab bench, with engineering , that s probably the big thing. To make the 150 micron channels is done with a tiny mill , that makes the rough pattern. We then expose it to a solvent vapour that polishes out the defects from the machine. Q: So why not laser etched channels? Laser etching is good for doing rough cutting but at this sort of scale is challenging. Lasers work by shots , so it is individual bites at the material and you can't get one bit right next to another bite without a sufficient margin and tend to create quite circular patterns. Carry that through and you get a scallopping effect as you rattle across and it also tends to make curves rather than straight edges. So when it comes to bonding 2 surfaces its difficult to align all the laser spot cuts, its not so precise. Q: so lasers will not even give a straight line? You can get straight lines but it will have curved edges , looking more like having chain-drilled . Q: So standing back it looks straight, but the closer you look the worse it gets? Yes, for features of about 200nm scale . Q: So an engineering mill can go down to that sort of precision? Yes. Our surface roughness , for the polishing rprocess is 200nm and post polishing we can't measure it, its down to the natural roughness of the material. Inside are valves and syringe pumps , 3 syringe barrels in this one and a network of channels . The technology is scaleable, we can adapt to different platforms. It would be easy to scale up production and currently we are doing commercialisation and hopefully within hte year we'll be making these with a company and selling them. Probably oceanography will not be our biggest market, it looks like in the USA they are instrumenting all their water and waste water treatment plants and that is where we'll be selling them to. So generating income that can they go towards marine science. So an example of a deployment in somewhere really rugged in quite a big housing. We stuck that in river banks and all over the place. We were using medical blood bags to carry the reagents, this one stuck in the docks. Wiggley lines showing the saltiness, and the chemistry. No one had ever seen such wiggliness in the chemistry before, not measuring at high enough frrequency before, at best daily samples. Or hourly if someone cranked up the lab costs. The physics changeds as much as the chemistry in these environments. That led to a number of discoveries. We tried it in some ghorrible environments , tried to break it. We put some of these devices in a glacial melt-stream. They look black , enormous amount of clay in it, boulders the size of cars, chunks of ice, really bad. We thought we would not get any data at all. We saw a nice diurnal change signal in nitrogen levels as the glacier melted on a weeklong period. One thing a post-doc did was add anti-freeze to all the reagents of the standards and that would winterize it at -15 deg C. Lugging it in a backpack , at -15, it survived, placed i nthe water and still got the data out. So to the question , does it clog up, no. Recently we put it in Christchurch harbour along the coast. A swet winter with lot of flooding , the whole site got flooded and again lovely data measuring nutrient , a daily cycle that changes with hte amount of rainfall. It washes out that diurnal signal in the flood . Nearly 2 years of data from 3 locations in that estuary. The big hurragh, on a big shiney yellow vehicle , in the ocean, off the SW approaches, due south of Ireland. To get it in a glider , the bags are tucked around whatever space is available inside. We sat the senser just behind the bouyancy bag of th eglider. So 12 years work got us to this point. April just as everything is warming , the seas starting to react biologically , for the plankton a growth spurt and then in mid April loads of growth , measuring nitrate. The surface zone starts to suck away the nitrate as time goes on . High nitrate at the beginning and after the bloom the levels fall, but at depth the niutrate levels increase as the plants die and sink down . Previously in such a region you might get one bottle sample every couple of years and suddenly now loads of data. Thats all simple chemistry but there has been a revolution in biochemistry and so we tried that too. We now have a device , not deep-sea , operating on the bench at the momnent, that can measure genes and whether genes are active in sea-water. Copying what the immune system does for recognising chemistry , to look at organic contaminents in sea-water. We had a project funded by the oil industry , for this technology. Q: Has Australia expressed an interest because of the coral reefs? Yes, we've had a couple of people go out to Oz . They have an active glider programme and they want to instrument some of these observational platforms on the east coast, CSIRO. We have good links with them and a programme with them this year or next. We're at the cusp, starting to scale up and do it in anger. On the bleaching of coral, there is only theories at the moment as #to why its happening. Is it the acidity , is the nutrient levels, is it the temperature . Al ot of corals are symbiotic , relationship between algae and coral. With the gene sensing and carbonate sensing of LOC we can determine what is going on. Q: Or simply UV? Unlikely because of the depth of the coral , below the tidal zone . Q: and the Crown of Thorns invasion? We have a project where you can look , via EDNA environmental DNA, take the water, what DNA is present , from sloughed off skin or faeces. You can tell what organisms are present and roughly what concentration there is . That is a good system for looking for things like urchins and symbiotic algae. The cytometer I passed round earlier is for measuring single cells in water, could be blood or river water . This isn't classic LOC as no water flowing thriough the chip , but probably the one that will hit the market first. Made in same way as the cytometer , measuring physics and dissolved oxygen. The company is picking up the simple thing before they move onto my latest shiney new invention. The simple things often win out , measuring temp, conductivity in the world's oceans fo ra cheap price. Big thanks to the team, about 40 engineers about 25 of them working on the sensor element and 15 on LOC. Q&A Team based here at NOC? Its split between here and Liverpool. All the LOC stuff is down here. Some of it is with the university , with which we have strong collaborative links. Oceanography must be an interesting science, about 6 new species a month they find? Its the old adage, we know more about Mars than we do the deep sea. As far as I know , the swage works down the road still sample for heavy metal contamination and that sor tof thing by sample bottle once a day or so. You could adapt LOC to near enough real-time sampling? How do you select the power sources for long term operation? We have a project at the moment looking at Lithium-Sulphur batteries , used in the latest generation of electric cars. For Li-S cells , they float , so you don't need a load of extra floatation and net power per Kg , a useful measure for us, is useful for us . Otherwise we use Lithium primary batteries because they have so much power, but then there is the issue of shipping them around the world. We've used Lithium-polymer and those and Li-S will operate at high pressure, because they are kind of squashy anyway, put them in oil and they will operate right down to deep sea. On our first vehicle ,Autosub3, 2as with standard torch batteries D cells, loads of them , taking 4 hours just to change them all. At the time, 20 years ago, they were the highest energy density you could get. We have done a project with fuel cells, but by the time you've put them in a pressure-proof can and how to get hydrogen in and out , its not worht it , for us. The Japanese have gone mad on fuel cells , seems technology for technology sake. Have you looked at solid electrolyte systems? We have. In battery technology we're not innovators , rapid adopters maybe for anything that looks promising. Soon as developement curves go the right way , we try developement projects with them. We're evaluating super-capacitors , 2 years ago we would use them as adjunct for high current in spike situations , but they've not taken over batteries like we thought they would. The fast recharge factor of them does not matter in our applications. Even with rechargeable batteries , we tend to swap out the whole pack on the vessel rathe rthan charge up on the deck. If its a small vehicle like an argo-float , there may be a number of them , and charging them up and deploying in sequence but the big vehicles its 50,000 GBP a day to be on a ship so if charging for any length of time, you would rather buy some more batteries. You can control quality control issues by swapping over . Charging is not doing science. What sort of temperature ranges do the batteries have to endure? We do go close to the super-heated deep-sea central ridges but we try not to get things too hot. We typically design for 35 deg C as the top end typically , but for the sampling tip at a hydrothermal vent will take 400 deg C. The coolest we go is in polar ice regions so -4 deg C there though we also design in any carrying to that environment at -15. So use at -5 to +35 and survive -15 to 400 for short periods. Is the surrounding oil something special super pure say? Its a very generic mineral oil , like a baby oil, very simple. It has to be low viscosity and non-agressive. Its messy , you want the sensors to be reliable , you don't want to fiddle with them at a later date. Are you saying that nowhere have you had a microchannel clog up with tar or oil or plastic ? I would not say never. We had a period with problems on the pump itself. The syringes running in the barrels and that would wear the seals that are rubbery and the bits of rubber would come off, go in the microchannels and block from that. The only other than that , was of course a high-profile one. They X-prize , Burt Rutane? , Wendy and George Schmidt of the Google Foundation set up an ocean X-prize for measuring pH in the oceans. We went in for that, went out to the states , did really well, looked like we may win and we got a blockage . Actually we made a mistake in the making up of the chemistry , it precipitated out , it crystalised in one of the channels, that did for us, only 2 million quid. Do your vessels always have to come to the surface to conmmunicate back? To do the sat-com yes. There is a couple of ways around that . The data release capsules and you can capture data over 2 to perhaps 4km with an acoustic modem, WW2 submarine technology. Lately there has been line of sigh optical modems, optical flashes, maybe over 300m on a good day, typically its more like 5m but you can transfer huge amounts of data, internet type datarate transfer is possible, without any mechanical coupling. Suck perhaps a year off one of the landers, go to the surface and retrieve the data. We get involved with that sort of stuff bu tnot inventing any of it. There ar ea lot of commercial providers for that sort of kit and we bolt it on, get the most out of it, and make it work for the science. With drift over time , is there a way of recalibrating the sensors on there? 2 things we do. On board there are ports for a standard and a blank , so we carry a chemical standard anda blank which we keep referring the instrument to, measure before deployment and measure after (hopefully) recovery . In terms of climatilology you try to get it come close to something else that is making good measurement of the same thing, or another vehicle deployed i nthe same patch. When you're profiling the really deep layers it is very consistent over time and you can use that as a sort of virtual calibration point. If you see changes in that check , you know there is something going wrong. You have to do QC the whole time. The science community using sampling bottles and full lab facilities are not going to believe our results unless there is full QC. You then have to worry about your standards degrading. So we actually put some poisons in our standards , to make sure biology does not get active and we characterise any degradation in our standards. Things like nitrate is consistent and will last for years, but ammonia, as a gas , tends to diffiuse out of the bags, its a nightmare . I seem to remember the black smokers were originally discovered by sample bottles and detecting somme chemical indicators in the water and eventually zeroed in to the source. With your near enough realtime sampling analysis , I inmagine you could have a sort of shark-sensing , the rubby-dubby effect, miles away and go off beam it decreases, and go on beam to the stream it increases, for oil industry leaks or a downed plane for sniffing kerosene , can you see that coming? Currently,honestly, these units are not that fast, one down side of the current design, so we're working on it. Near real time a measurement about every 15 minutes, so not perfect for a shark-effect and homing in, it depends how big your plume is. We're currently working with the energy industry on carbon capture abnd storage. Grabbing the CO2 out of cement factory stacks or from energy generation , putting it down a pipe usually in a liquid state, injecting back into depleted oil formations. But do these old oil fields leak, so we have a project for chemical sensing above it, to check these CO2 depositions are not leaking. The sensing measurement is these days very precise, very accurate , but a bit slow, coupling them with faster but inaccurate electro-chemical sensor which gives very quick measurement , cross-calibrate the outputs , you can then get quick and accurate enough to go plume-hunting. So the project is coupling wiht our fast version of pH sensor . You have to do a number of measurement types as when CO2 leaks into the deep sea it changes the pH, gets dissolved in organic carbon which can happen if the biology is there and is respiring, so you have to separate out the 2 sources, so we look at the phosphate and nitrate to tell if the biology is active. Also look at the oxygen as that is easy to measure. Combine all that data and you can spot where any leaks are. Off the planet now, but when a lander landed on Titan and there was seas of methane would a similar system to yours work , analysing anything in methane as well as water? Yes we can do organics . One of the sensors on the table is actually a methane sensor , would be no good on Titan thougha s detection limit is 200picomolar, as there is very little methane in seawater . The nice thing about this game is that almost anything is technically feasible , its about how much will and how much money you have behind it. I have been out to JPL, Passedina a couple of times, talking about things they would like to do, so a certain amount of cross-over , but I say. Doing stuff in space is quite hard perhaps one bar of differential pressure bu twe deal with 6 or 700 bar of pressure . Presumably things like temperature come into it as places like Titan are something like -180 deg.? Thats a bit more challenging , indeed Is anyone working on using mass-spectrometry under water ? Yes, a few. Mass-specs have come down in size phenominally a quadrapole mass-spec down to our size limits, not the performance of the big beasts but approaching 1 atomic mass units, so pretty good. The problem is , getting the sample in. Even in the surface ocean you have perhaps 10 bar of pressure , an awful lot of water . Most mass-spec don't like a lot of water in them. Looking for something typiclly of a very low concentration and a very high water background. What has been successful is something called Membrane Inlet System, a hydrophobic membrane then only gases that can pass through there will get analysed . Doesn't do all the proteins etc but light gases work quite well, so yes kind of works. not the full works of a mass-spec , everything in very good detail. Can you reprogram these systems remotely to change sampling regimes? There is a mixed solution to that problem. There is increasing levels of autonomy on the instruments. Some of the bigger autonomous vehicles wil lrespond to changes in the environment and change their measurement parameters . There is enough processing power on the one in front of me, that we can do a bit of that . But most of it is on the vehicle, they are commanding when they think a measuremnt should be made. You have a surfacing event and you pass info both ways via Iridium sat , re-prioritize , do mission planning and change responses to it. So yes, can be reprogrammed, bu t have to surface typically. There are projects involving trying to do it by flying over, or sailing over with a surface vehicle and acoustic telemetry, but i don't think anyone has successfully done that yet. All the argo floats with wings, the gliders , come up and retrieve their plans for next deployment via sat-link. Is the iridium system a set of satellites so one is always available for cummunication? Not 100% global , a constellaion of them , I think bust about 4 times , but its still running. It was going to be culled. Several overlapping footprints . It is expensive to use, it has to be , to keep the whole thing going. The new Gallileo system , for positioning , does it include communication? The new comms one is Argos3, a number of sats, new high bandwidth comms. Gallileo is purely for European GPS. For people attaching electronics as tags on animals to track their movements , backs of seals and penguins and such, they use the Argos sat. It is old technology , it used to shout every now and then and the tag would reply with its message. Sometimes the Argos sat would hear it sometimes not . It would give a posistion fix by triangulation . It is now being replaced by the higher bandwidth Argos3. We have worked with St Andrews, putting tags on the heads of elephant seals. Pretty brave doing that as they are huge, smelly and randy. Having to get a sack over their head is the start of the procedure, then epoxy glue the tag to their head. We've tried putting our oxygen sensors on that device. You mentioned being 4 years ahead of the USA and commercialisation , this is naievety on my part , but what is the significance to NOC of being 4 years ahead of the Americans. I assume NOC has access to the leading technologies , is there academic pride ? I suppose its not that important tobe the first at anything but to open up new avenues of science , as soon as possible, is what we are trying to do. Being first probably means getting to market first and in the current economic climate where govt funding is coming down every year, if we can replace that drop with commercial income . There is a formal responsibility to aim at commercialism, manufacturing as well as consultancy? Yes, exactly. 5 years ago 70% of the income of my group came directly from govt sources, its now 30%. Flat? cash will ramp down at 3% a year for however long . Maybe in 10 years time we might be down to 10 to 15% level, and the missing must come from somewhere. You'll have access to the best profducts , because they are the most mature, because you developed them first? Yes and some financial return , by selling them and fund the next thing and hopefully that a virtuaous circle . For water analysis and terrorist threat, I'd have thought you'd be well up ther? The cloak-and-dagger mob can't tell each other what they are working on . They cant even tell you what they want to measure, so they ask you things like could you measure water parameters in water, well yes, but what do you actually want to measure. It is difficult and they've not much money these days. There was a flood of money post-911 , Homeland Security, a lot of eople in LOC made a lot of money but no successful product came out of it. Is there interest from fish-farming ? There is , one o fthe grants for us is the BBSRC ?, for sustainable aquaculture looking at our tech to look for genes in water to look at e-coli and faecal contamination of shellfisheries. Hopefully we will be getting another project to look at harmful algal blooms , toxic phytoplankton getting into shellfish , the aquaculture people love this stuff. Again a low margin industry but when there is a mass poisoning event potential, there is funding. You have communications with USA ,do have contact with India or China say.? Thats very topical as I said we were flat-cash funded from th egovt. We're only there because they've done clever accounting called tucking-under. So for instance they say we'll spend 5% of GDP on science and we'll send 5% of GDP on international Developement. Both of those things can be true but you've not said that 3% of those things overlap, and the total spend is only 7% of GDP, not 10%. Even national government budgets employ this wheeze. So we do something like 1% military and 3% international developement research and thats why the inflation-protection bit of our cash assessment is 3 ?, it means , if we want to maintain our cash funding we have to work with countries that are in the list for international developement, which currently includes China and India but they may not stay i nthe list , but includes Afghanistan , the othe rstans , Madagascar etc. In China and India we have lots of students that have worked with us in the past, so good links and collaborationes there. How do you get on with languages or is it all English? One time we worked in French, by default , because of the way French science was working at the time and our contingent was about 80% French and so a French period. We're currently coming to the end of our Greek period, it is very international. Our working language is English. With your units that spend alot of time on the bottom or the gliders , at some point they're commanded to come up, if that fails is there an absolute fail-safe device that after 6 months say, will guarantee it will come to the surface? There should be , its not always a functional guarantee. One of our subs is in long-term storage under the Fimble? Iceshelf. That will be stuck for another decade. Recently we had athing called a sediment trap , an Argo float with some buckets attached to it, that collects marine "snow" , the rain of particles. It didn't reappear , we waited around on the ship at 50,000 a day and it still didn't reappear, so we went home , leaving it. Then yesterday we got a message saying "I'm here" with a GPS location, so we know it came to the surface. Its exactly that problem. It had a drop weight , a loop of stainless steel wire , holding the drop weight . Apply a current to the wire , it fuses , the weight drops . If the whole craft ends up upside down? Then you're scuppered , yes. We use the drop weights and extra bouyancy and up you pop. So if you sell these things , do you get into complications guaranteeing they will reemerge from the deep? This is why I'll probably never sell directly , eithe rset up a company or license a company who would then have that responsibility. Yes legal quagmire could be rapidly entered. As we're pseudo-governmental, we're not allowed to sell dirtectly anyway, state-aided, we would be competing with industry , so not allowed to do so. I think a lot of the accompanying sales blurb ,assumes you are going to loose it once in the water, the default position. As soon as you put anything in the ocean that is what we expect, if it comes back, its a bonus. That is why there is so much effort on getting the data back, even if you loose the craft in the pursuit. Is there anything going in the direction of like cube-sats , very much reduced size technology and almost throw-awsy when it gets down to 150mm cube sort of size? The argo floats are never recovered , they're 20,000 plus our sensors , so alot of money and never recovered. 4000 in the world's oceans and they deploy them at about 1000 a year. You may think our weather forecasts are still pretty rubbish but there is ameasurable increase i nthe realiability of our forecasts and some of that comes from , we have Argo floats measuring ocean physics. That world distribution plot you showed of them , looked remarkably random, I expected loads of these floats in Gulf-Stream type areas , it looked well distributed around the whole globe, unespectedly so to me? Its been affected by where they are deployed. You can predict the currents fairly well . You will notice some areas with gaps , Antartica as really difficult to get anything working there, too shallow in the North sea etc. Not enough money to put many at our latitude, mostly USA . Japanese have put some in, a concentration around Japan.

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