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Tuesday 18 June 2019 Florentin Bulot, Soton Uni: Low-cost sensors for
monitoring air-borne particulate matter (PM), using Raspberry Pi .
The 6 St Denys monitors , including live data,
Every year there is about 9 million deaths associated with
air pollution. Thats similar to cigarettes. In the UK its associated
with about 40,000 deaths a year. What is special about air pollution is that
it varies from one street to another and time of day , like at rush hour.
That makes it hard to assess what people are inhaling.
Map of PM around the world, in the UK its not too bad compared to
some other parts of the world.
PM pollution comes from many types of sourcres.
Building and construction pollution is mainly fine PM.
Agriculture pollution is mainly from ammonia.
Fine particles are basically dust that is smaller than 10 micron.
Anything less than 10 micron is PM10. Anything smaller than
2.5 is PM2.5. They come from traffic, shipping , industry , natural
sources like dust/fine sand from the Sahara. So not necessarily
harmful dust, it depends on the source. The smaller it is, the
further into your body it can go and potential health effects.
In the UK the predominent source of the finest pm is the burning of
wood and coal, 38% whereas transport is only 12%.
Woodburning stoves have been promoted recently , but its becoming
the predominent source of fine PM in cities of the UK.
Fine PM when lodged in th elungs cause a range of respiratory
diseases, like asthma. In the blood can cause blockages of blood
vessels leading to cardio-vascular diseases. It is being linked to
diabetes and dimentia.
In the UK we have about 300 monitoring sites called the Automuted Urban
and Rural Network, AURUN. They are reliable monitors and its what is
used to show whether we are complying with legal limits. The gold
standard. It provides 2 kinds of reading , some are roadside
and some are background. Roadside gives us an idea of what people are
inhaling walking along that road. Bckground are located away
from any local sources of pollution , and give a more general
idea of the concentration in a city.
One of these stations cost 100,000 GBP to install and 3,000 GBP per year
to run. Only 6 such stations around Soton, you cant say this street is
worse than that street .
The sensors used measure the mass of the particles directly. The air enters and
is heated , because there is a humidity problem, hence different weight.
Particles collected o na filter , linked to a vibrating plate, the frequency
of vibration is linked to the mass of the particle. And so hourly data
of the mass of PM. Low cost sensors for PM work differently.
For fine particles , inside one is basically a laser and a photo-receptor.
So an optical sensor. Every time a particle pases in front of the
laser the sensor infers the number of particles. Then transforming that
number of particles into a mass. So not direct reading of mass , which
is how the legal limit is defined. Because of that , there are more
limitations. Its sensitive to aerosol composition in the air, its
sensitive to the concentration of PM. So if little particles , it is less
precise. Here we are measuring near the limit of detection so a serious
issue. Also sensitive to humidity and temperature.
The costs of these sensors are lower, the technical requirements
are lower , so can be operated by a larger range of people.
Because of that its possible to create dense networks of sensors
around a city. To start to understand what people are
actually inhaling. The reference stations are good to
have but to understand what people inhale , it only shows what a
person would inhale if he stood all the time near a reference station.
It becomes possible to identify sources of pollution . With a network of
sensors deployed around a city , you can start seeing pollution move
around the city and start to understand where its coming from.
It is important to involve citizens. The st Denys project is creating dat a
that people can relate to. There are mitigation measures we want to impliment
, but knowledge of hotspots/times is helpful in that.
It compliments the existing city network . But the big question is
what is the quality of this data produced, its reliability.
When can we trust the data the sensors produce , just knowing that would
be a great progress, but we don't yet.
Some readings taken at a site in St Denys bewtteen 24 April
at 4am to 2pm. Between 10 and 11 all the sensors follow the same peak
and then another peak later, they all show the same trend but looking at
each value individually recorded , there are big differences.
So these sensors are good for reporting a trend in pollution
but absolute values recorded should be handled wiht more caution.
These sensors cannot be deployed on their own, they need some electronics
for the comms, protected in a box .
So the solution I've developed to put the sensors out around the city.
The Pi takes power and has an internet connection via one lead,
its modular so can just swap out
a sensor. Today we're looking at PM but diferent sensors could go inr
there. If fine particles are no longer a problem in the city ,the
sensors could be replaced with something else and contine their use
for monitoring. There are 6 of these boxes arounfd St Denys to spot.
The public access plots are for readings every 15 minutres.
Difficult to interpret as different peaks occuring at different times.
If you see a truck passing , you can see if anything is happening on the plot
nearby. Shows the morning rush-hour peak, a peak at 4pm so perhaps school-run
then the evening rush hour till 7 or 8 pm.
Comparing my boxes to the reference station , the average of the 6 boxes
locally , they agree quite well in values. The box is waterproof
and removing lid ,shows the 10 sensors iin one box. 10 because of the
variability of output , the spread of data for different sensors.
We take the average of the 10 sensors and 6 boxes .
My earlier deployment was in 2 Soton schools. The reason behingd that study
was to compare different kinds of low cost sensors in a year long
comparison. The outputs are dependent on the composition of the
air being monitored and the time of year having more or less sources
of pollution. The cruise ship season is in the summer mostly
and winter there is wood-burning. We also wanted a wide range of
temp and humidity . One question we don't have the answer to
yet is are the sensors degrading over time, or do they need replacing.
So we compared sensors against each other of the same model and
different makes. We compared them against the reference station.
The 2 schools were St Johns primary school , French St near the
docks and Sholing school . Only one ref station in the city gives
PM2.5 readings which is the one we used.
At each school we deployed 3 boxes and 4 sensors in each box.
One box near the school entrance, one in playground and a third one .
Comparing the sensors against each other , the variation between
different sensors . If 2 sensors have a coefficient of variation of 0
then they perfectly agree. The threshold , from the US EPA is 0.1.
If 0.1 then good for fine particles. We had over 0.1 , close but over.
So 1 of these sensors cannot be used to monitor air pollution.
Thats why we moved to 10 sensors in one box. Was 4 ,now 10 per box,
it is also easier for us to do comparisons with 10. We still don't know
how many sensors are really needed in one monitor ,somewhere between 2 and 10.
We studied 4 types of sensors , the Plantower5 against Plantower7 and the
scatter plot is almpost a perfect line. Both from the same maker, different versions, PMS5003 type used in the St Denys boxes and LoRaWAN quarter-hour data feed for the
public internet .
But looking at other sensors Alphasens compared to Plantower5
there are 3 modes within the scatter plot. That shows if we apply a
correction method to one type of sensor we would need a different
correction applied to another type. These 3 modes are
partly explained by different responses to humidity.
They don't report the same values , in high humidity. Humidity doesn't
explain everything though.
The biggest difference between ref station and the sensors is that the
ref station is giving a reading every hour. While my ones are giving a reading
every minute. The absolute shortest time interval is every second , but that has a
lot of noise , so upped to every minute. All the city sites follow generally
the ref station . For that we've studied the correlation and obtained
? coefficient between 0.61 and 0.88 which is quite good for the sensors.
When we look at the correlation for different levels of background pollution
for the ref station fine particles below 8 . For the lowest levels the correlation
is less and above about 17 the correlation is better. So the sensors are
better at monitoring high levels of pollution .
25 is the legal limit here , so we want to be below that. So it is harder to
use the sensors in the UK , not that we can't use them, just harder to apply here.
So do the sensors degrade over time. So we looked at the correlation between
ref station , in different months of the study.
A pronounced dip on all sensors in August , but after that it returns.
For 2 sensors a straight line showing the performance does not degrade over a
year. For the AlphaSense one you see a lowering in performance. Maybe due to
dust accumulating in the sensor or component degradation .
The dip in Auguist has 2 potential explanations , the wind was mostly
blowing from the coast and we also see a general dip in correlation
for days when the wind was coming from the coast. Maybe more sea-spray
with the particles . The other reason for the dip was barbecues , around 6 or 7
pm and mainly fridays , I'm convinced registered barbies but were not
registered by the ref station.
These sensors can track very short lived pollution events , like barbies.
Also for fires in the city , like the Waterstones bookshop fire in Soton city centre
we could see it in the readings.
A reading at the Sholing school 25 August and the wind was blowing
between sensors , the peak registered on P2 can be seen a few minutres
after the peaks at P1 and P3, so giving a direction of track of pollution, in this case a local barbie.
If we take proper care of the data produced then these sensors can give us
more localised and persom=nalised data on air pollution. To understand
what people are breathing in , while travelling in the city,
because currently we don't know. Another concern, currently unknown is what
peole ar ebreathing while indoors at home.
It will be possible to monitor this high frequency data , wind direction and
data about ship movements and general traffic , then we can get a better
understanding of sources of pollution. We can interact with the populace
to act on air pollution , with the help of these sensors.
The current correction method we use. A paper only published last week.
2 ways. 1/ to know the characteristics of the p[articles , know the
composition, know the density and a few other parameters about them.
Someone else in Soton is working on this .
The second is mor eempirical , based on a regression model , based on
humidity and temp. At the moment no consensus on how exactly to
correct the sensor data.
The next considerations in my PhD , so the schools sensors, the st Denys
network , I'm intending to expand the network to get a better understanding
of pollution in the city. The intention is to produce a map of pollution
in the city. At the moment , the only maps are based on models
and only a few measurement datapoints. We hope for better
precision to the map , with the city-wide network of sensors.
One place of placement of sensors is within the port, I've an agreement with
ABP who are willing. Also sensors at Marchwood so we've an idea
of what is upwind of the port as well as city side of the port.
I'll be characterising the sensors in the lab , controlling the air composition
, temp and humidity . Up to now all my sensors have been
some distance from the ref station and hoping I was measuring the same.
I'll be placing some of these sensors in Vietnam and Morocco. where there is
higher levels of pollution and the sensors would be more reliable there.
In Morocco there is a lot of dust from the Sahara , dirtier cars with a differnt
sort of fuel to here. A totally different environment, and so better to
understand how to correct the sensors.
When you described the sensor box you had data and power along a cable to the
box, but also a wireless antenna. Why 2 data routes?
Every time we are studying a sensor , we need to find a local internet
connection and drilling thru walls, all rather messy. This is a back-up solution to
collect data. With the LoRaWan network you can only send little
data, the maximum rate of output we ar eallowed is every 15 minutes,
sending just the average. Ultimately want to get rid of the hard-wired internet connection.
You don't have an SD card in the Pi?
At the moment 15 locations of these boxes and 150 sensors so I don't want
to go around opening boxes and collect SD cards.
But wouldn't the SD cards store data for each of the 10 internal sensors every minute?
Actually every second . With the wired connection and SD cards we get all the raw data
, but in the end , when we've sorted out sensor correction it will be redundent.
Say you find sensor6 is definitely erroneous you can ignore its data rather than
have it contaminating the average output?
In the end we intend to reduce the number of sensors , currently these are boxes for
testing proposals. Another project just started is how to get this box smaller
. The sensors themselves are low cost between 10 and 100GBP but the whole
box is 1000 GBP. The project just started 2 weeks ago would only have 2 sensors per
Do the sensors have a fan, or natural ventilation?
The sensors have a fan , very small , but otherwise no fans. We could have a
fan , but cost and power consumption goes up. At the moment consumption is
What about contamination of the sensors , they must eventually
Yes, thats why we wanted to study degradation. When you open up thse
sensors after a year you see see dust in there. The sensors are facing
downwards , so dust tends to fall off .
When i first came across this project i thought you must use reference smoke of
some sort. Plumbers and gas-fitters use test-smike for checking flues and
chimneys. They set fire to a little preformed tablet of something that
generates blue or orange smoke. I'm assume the smoke output is fairly
standard in its gradation of particle size. But you don't seem to use a standard reference
smoke at all, for initially setting up these sensors? Perhaps set off one in a metre cube box with a fan and introduce to a sensor?
You are purely comparing to the ref station in the city?
There is no standard smoke in a can . Some studies use incense , some use cigarettes,
polystyrene vaporised and Arizona Dust which is becoming a standard
in the USA, basically dust from Arizona . But no consensus on any
standard dust or smoke. NPL produces gases in cans for standardising and are
just working on cans of standardised smoke. What you said is what I'll
be doing in the lab . Placing a number of boxes in an hermetically sealed environmental
chamber and introduce some PM. I'm not settled on the source of PM
that I'll be using . Also varying the humidity and temp inside the chamber.
Do you have any problem with condensation inside the boxes in UK winters, causing problems with the electronics etc.?
So far no problem. So far I had to change 1 of the 6 . The boxes are warm
from the electronics inside and no condensation issue.
We are running the LoRaWan network, the base-station owned by the uni.
One of those we opened and water flowed out of it, but not these sensor boxes.
Assuming you get the number of sensors reduced and overall cost less,
where do you see the uptake of them? Informing public policy perha[s?
There is a website where you can find the cleanest walking and
cycle routes , is that the sort of application?
Thats one but also public bodies generally , checking that measures
they take actually work.
The council is considering a clean-air surcharge on vehicles entering the
city. So they will only be tackling 12% of city pollution at the best?
There are groups involved with air pollution but so far have
had little data to underpin any actions. If say a group gets 200
residents to go to the council , over some measure to take .
There is "clean Air Southampton" I work with. All the readings are
publically available on the breathingspaces website for this St Denys project.
Large ships in the docks and the container port straddle carriers
ar eworking 24 hours a day. ?
We don't have actual measurements of it yet. NO2 pollution is mor elinked
to road traffic. For shipping its NOx, CO2 and SO3. For NO2 ships are
less significant than cars, just by the models, as we don't have real data on
it. Ships burn much dirtier fuel, so PM output can be much more
toxic . So say the pollution from ships is 5% it might be mor e
harmfull than tghe other 95% around the city.
another uni group is collecting data via a different monitor, like a big
vacuum cleaner, er inside and do a chemical analysis on
the filtered . Thet found there were more harmful particles in the summer
than in the winter, work in progress .
Do you measure the temp thru the sensors as well?
Yes and the humidity.
Why did you go for PM rather than gas sensor?
Gas sensors have been more studied, spo for PhD purposes it made more sense
to go for PM . Gas or PM need completely different techniques , so I
had to concentrate on one only. And fine PM is the more harmful
part of pollution , compared to gases. Now we are cleaning up the pollution process ,
ridding larger PM,
fine PM will come to the fore.
There is no regulation at all at the moment for ultra fine particles, quite concerning in
Have you picked up pollution from other places? I was looking at your local
data and one night about midnight there was a peak at about midnight but nothing on
the other local boxes. Then i was thinking, the same with the one on this hall,
its quite near a gas-burning boiler flue. Do gas burners output PM?
Yes , any combustion process will produce PM. Its also possible for a sensor
to be simply wrong.
Do you know how far such particles do travel, say from a major fire say in Winchester
and the wind coming from that direction?
Some people in London can phe signatiure of ships ick up , all the way from
Soton. It may be just traces , but it can be found.
I was surprised to see that on one random sampling weekday day recently that
161 diesel trains passed thru St Denys.
What about the big petroleum industrial complex at Fawley?
Its upwind of the city so yes. There is a big mix ofg sources of pollution in
Soton. Traffic, the port, airport, Marchwood incinerator, Fawley
refinery. Its not good to live here but its useful to study pollution
here. It makes some sort of sense.
I was doing this sort of thing about 30 years ago , our low
cost sensors were over 5000GBP 30 years ago. It emerged that
November 5th is the time that industry burns anythng it possibly
can . We had 3 sensors around Fawley and nov 05 stood out. ?
A study in Amsterdam found similar peak at New Year.
I'd not thought about people deliberately burning nasties at those times.
With your high frequency data have you found anything that could be precisely
tied down to say planes passing over or mainline train service at a regular time,
My work is to characterie the sensors and less to make sense of the data.
I don't have the time to interpret the data for that sort of purpose,
much that I'd like. I'm sure it would be worth somone trying to
correlate repeated minor peaks with say a regular diesel train service.
It would need a longer tmeperiod of 2 years or so , to rule out
other possible repeating factors,. The high frequency data is available on request.
Are we supposed to discourage friends and families from having barbecuses?
Yes ,and wood-burning stoves. Even the best such stoves , one such is equivalent
to 6 trucks running. All very dirty but its good for the environment
in the sense of being C neutral. Unforseen consequnce again.
Ships burning gas rather than diesel is better for pollution
but not necessarily for the climate. The average distance of a car travelled
in a city is less than 1km. Do we need a car to travel 1km or could we
Tuesday 16 July 2019 Dr Christine Currie, Soton Uni Mathematical Sciences: The Mathematics of Pricing
The work we did on ferries was with Red Funnel in Soton. No commercial price sensitive info here, they liked our vehicle packing info but they have other ways of doing their
pricing. We initially worked with P&O ferries bu tthen we moved to
Red Funnel. Most of this maths work relates to Red Funnel but it will
be generally applicable. S opricing according to ease of packing and increasing the
efficiency of the packing. Awhole research area described as cutting and
packing originally relating to minimising material wastage for cutting out dress
patterns. We will be using the similar techniw=ques for optimal
packing of vehicles on to a cardeck of a ferry.
Big vehicles take up lots of space and awkward to pack so you might think
we should charge them more. Often the big vehicles are freight that come
day in, day out all thru the year. So charging those users a lot of money is
not necessarily a good idea. Wheras tourist traffic is just for Easter break say,.
Red funnel has a ferry terminal in Soton and run to Cowes , Isle of Wight.
31,000 sailings between mainland and IoW and back.
3.4 million passengers transported and about 873,000 vehicles
since 2016 and still increasing , so they have introduced a freight ship as well.
In some ways that has solved some of the problems as that means they can rid
some of the awkward trafic onto the freight only ship.
A related problem is how to arrange the cuing of vehicles on th eland
prior to embarking. There are also WightLink ferries and hoverspeed hovercraft
services to the IoW, so there is competition. There is pros and cons for
choosing relating to road access on the mainland. Soton is easier to get to
but a longer crossing time. So how canwe improve efficiency for Red
RM= Revenue Management. How to maximise revenue by dynamic pricing.
RM appeared in the 1970 for airplane costing after deregulation of the
airline market in the USA. Prior to that prices were highly regulated and
you could not vary them much. Low cost carriers came in and American
Airlines had to compete with these low cost carriers.
So they started to put conditions on their cheap prices. They could sell
tickets for the back of the [lane cheaply, undercutting the competition
because they knew the high payers would then carry over for the whole operation.
Its easier to imagine this in terms of planes than ferries, so the diversion to planes.
Planes have fixed seats and csan only have 1 person sat on 1 seat. They take up the
same seat space whether in economy or business class.
We know we have X seats to sell on this plane. THere is whats called
perishable inventory , meaning after the flight has gone you cant sell it again.
There is fixed capacity, very unusual for a carrier to find another plane
of squeeeze in some more seats. Then the allocation problem we are trying to
solve. If we charge nothing, the demand for those seats will exceede
the supply. So more people than seats, if not, then it becomes a different
problem. So how do we set the prices so we get the right number of people
on the plane. Set the price too high and I wont sell all theseats.
Set the price too low and there would be people who would be prepared to
pay more are paying a lower price. What price do I offer and when.
For dynamic pricing we are changing the pricing going thru time. Its
not one price for the whole season , typically it increases. The close rto
a time of departure, the more a person is prepared to pay. There is
randomness in there, how many people actually turn up for a flight.
More people will be thinking of purchasding nearer to departure time,
giving a peak. That peak will move dependendent on whether a leisure
or business flight. We know that but we cannot quantify how many
will turn up for that one flight. Forecasting comes in there and also
statistics. To get a feel for what this variation is. Also getting an idea
of what people are prepared to pay and how that varies with time.
Then 2 questions almost the flip side of each. What price do I offer
and when , then how many seats do I offer at a price. So we can have 2
different models, one the price varies over time, and the other a set
of price points and a set of seats I will sell at those prices. Closing off one
price point ater selling so many. As a consumer all you see is that the
price keeps changing. We tend to look at dynamic pricing, the price changes.
Customers arrive into the system , so they want to buy a ticket. We assume this a
is a ??? term,
random process with a time varying rate. They arrive randomly but price
changes over time, generally increases closer to departure. Thats while people
think of buying , check prices of competitors , phoning up for offers etc.
Then another term , the probability that they purchase a tickeet. An asumption we
make that this is dependent on the price being offered and the time at which they
look. The closer the time to departure, the more likely they will buy
at a given price. The highr tthe price, the less likely they will buy.
There is a term called Reserve Prices , the price you have in your head
,the most that you are prepared to pay, say 150. Someone else would have a different maximum in their head of 50 and someone else a maximum of 500.
So a distribution across the population , Reserve Price is related to Probability of
Purchase term. We cannot see these prices in their heads, having to rely
on historical data for that, a tricky problem. So you will have some
distribution of prices and rates lambda of t, then we need a method to
optimise the revenue ,for given prices. With the important capacity
constraint , you wont get an infinite number of people buying.
The problem and the assumptions going on uinderneath.
Now look at packing relating to ferries, a bit like playing Tetris,
then how to combine the two.
For a Red Funnel ferry , the drivers drive on and drive off, RoRo ferry.
No turning round of vehicles. There is a mezzanine deck which can be
raised or lowered , dependent on what turns up and can be altered between
sailings, quiote a quick process. It increases capacity for smaller cars.
You effectively get another lane of cars. The space below the mezanine is quite
low , limiting what can be placed there. There are 2 of those mezanine as one on
each side. To choose to use 1 or both of those moveable decks is another
optimisation problem. There is lift acess and some vehicles need to be
close to the lifts for people who cant walk far. There are lane markings on the
decks which makes it easier to solve packing but reduces the efficiency of
packing . A free-attack to the problem of different width vehicles i easier without
lanes. We created 2 solution versions , 1 with lanes and 1 without.
This is the main deck which has mixed traffic, then the top deck
which is cars only. Less interesting as the cars are much the same size. Even so
its possible to squeeze 1 more on by parking it diagonally.
Most of the traffic to the IoW comes on the ferry, so supermarket
delivery lorries, building supplies with width overhanging loads ,
and even large yachts on trailers. There are prison vans with special
requirements as the prisoners are locked in during the passage,
so they have to be placed under the sprinkler system . Sometimes hazardous
loads cross. all sorts of complications. The loads on the main deck are
kind of rectangular . Manoeverability has to be taken into account
, so some spaces cannot be used because of turning circles.
The experienced loaders sort this all out in their head, but have a new loader
and you can see the packing difference, less vehicles loaded on.
So some of our product is for training of loaders. Gives them some practise
before they get started for real. There are 2 ways of looking at this and relates
to the painted lanes. Called the Exact Way and a Simulation Heuristic.
When selling tickets and looking at packing , how do I define the space of a
vehicle. The way of solving , by the most accurate process is to say
I've 3 of type 1 , 2 of type 2 and 1 of type 3 and 4 of type 4.
Each number is effectively a dimension . As you get to 20 different vehiclr types
, which Red Funnel easily have, then you have a 20 dimensional
problem which gets huge to handle as a huge number of vehicle
combinations to fit. So this works , but grinds to a halt over a certain
number . For a 1D problem of fitting to lanes , each lane is a bin
and we're packing htose bins as efficiently as possible.
The other way , allows for all the complications of a massive number of
vehicle types. Instead of this number of each type of vehicles , we look at how
much empty space we have left. Thats how we can define the system.
This speeds things up because we've 3 dimensions . So you have some
area left, what if I pack a big thing next , will I still be able to put
it on. This is why we have simulation heuristics. This packs across the
whole space and not constrained by lanes , makes it more efficient.
The exact method where we are looking at the numbers of each vehicle
type. To maximise useable space we call U, U is space that hasn't been
trapped between 2 lorries. If vehicles were at an angle you would
end up with unusable deadspace between. We are looking for useable space we
can park something in. Plus a symmetry breaker, which increases efficiency
, otherwise if you have lots of lanes all looking much the same , the optimisation
gets confused as to which lane to place into. Its an integre program as we're looking
at integres. We have integre number of variables . All the terms are linear as they
are linear in the variables. Such as a given weight is one variable.
So we are trying to optimise amongst a lot of constraints.
1 constraint , I;ll have to activate an extra lane, a "big M" constraint.
Basically its saying try not to add he extra lane if you don't need to.
2 constraint, limited to lengths, cannot hang over the edge at the end.
3 use the lane with most space available, use it sparingly.
On the other side is the simulator, it doesn't have a set of equations in there,
less mathematical in a sense. Looking at how the ferry is being loaded, looking more heuristically, for optimisig. Its assuming ??? loading on to the ferry, it has the lanes on
the upper deck and then the 2D packing problem on the main deck.
Where our main interest is with the bigger mix of types.
For the simulator, like human loaders , its assumed to take account of the
real world constraints mentioned, lift access , mezzanine deck position,
dropped trailers (lorry beds without traction units which are left on-shore and use the ferry
companies highly manoeverable tractor units) , reverse gaps where something has to slightly
reverse before puilling out. The result is a quick and effective method to optimise
packing efficiency for any particular set of loading types . Also gets used to
prevent over-selling , what we and RF would like is iif they sell a load
then it will all get on the ferry. Having such a simulation package , it
can also function as a training tool for loaders, loaded on my laptop to play with.
Its calculating the remaining space that can be used. It moves the shape along and
calculates the remaining space , the sum of the rectangles left behind.
The heuristic element loks at all the vehicle types that re there on the
dockside . For each of those types it looks at where I could load it, for the
best placing. Then which vehicle type to load next, its not caring where they
lay on the quayside. It assumes it can get to any of them at any
place in the queing on the dockside, that is the next piece of work for us,
where this becomes a constraint on accessibility prior to loading.
It makes its decision by looking at various arttributes and run lots of times
with lots of different scenarios and see what weight we should give each of the
attributes. Tightness is a factor, packing a vehicle in where it just fits
rather than having lots of space around it. Space loss due to stagger parking,
needs minimising. Overlap adjascency ratio ???. The weighting factors we do as
a result of data done in advance. If we are running it for real we'd have the
weightings in there , sum the result and pick the one that works best.
Part o the process is a simulation annealing algorithm.
Q: There is no issue around mass balancing the ferry, say all the lorries on one side?
There ar eissues like that , the most recent version of this has a centre of gravity
that moves around and is output as a visual display , but its not really part of the
optimisation as its not a massive problem as the ships are quite heavy in itself
and they don't know how much these lorries weigh. They ar enot weighed o nthe
dockside, a lot is what the driver says . When we first showed this program to the loaders a
few said we wouldn't do that configuration because all the lorries are down one
side. So we try and balance a bit better. Also if you load something heavy at the
bow , then the stern will rise and can mess up the loading ramp positioning.
The CoG doesn't move around a great deal.
So we've maximised space and now the pricing objective. A decision
variable would be the price offered to each customer and type of vehicle in
each space in each time period. This is how I define space comes in.
Having a nice clear description of the space is important as this will
affect what we know and what we think we know about the system.
Then the capacity constraints , we also need to know whether we can fit these
vehicles on the ferry. Unlike the airline example of 100 seats and so
100 tickets can be sold, there is an area constraint . They can overbook but thats another
talk. With a ferry you can overbook if the estimate is not right. We need a
reliable packing algorithm to allow this.
We split into lots of discrete time periods and go with one booking into each
of those discrete periods, that assumption makes the maths easier.
Q: A minute time period?
The whole selling period is about 1 year. Each discrete period tends to be a
few hours long but it depends on demand. High demand leads to shorter period.
So at least 1 cutomer will buy one ticket in that period. We ignored complications
like group bookings , which tends to be rare for a ferry.
So the model may have a couple of empty time periods where nobody
turns up , then a car with a ticket turns up. Then you have to decide at this
point , an empty state how much time is left, you know what price you
are offering for that vehicle type. Wiht ticket purchase that changes the
the status of that discrete period and that may change the price to the
next offering. You keep going like that and at a later period you
have a probability of a certain type of vehicle ticket purchase.
2 things can then happen buy or not buy. So a tree-like structure ,
does something turn up, if something does turn up it may buy or
may not. You are loking ahead and how you set your price is then
dependendent on how much you coul;d get if you didn't sell to
that person. The technique we use there is Dynamic Programming
, its looking ahead to what could happen . My expected prifit
at atime t and a particular space, I'm trying to find a price that maximises
that. They arrive at a probility lambda(v) for v vehicle type
and this one will purchase with a probability a. If they purchase I
get an immediate revenue P but it won't be giving me any revenue in the
future. The next time period has the same equation
but it will be in a different state as one vehicle space is sold.
This is sort of the opportunity cost, the cost of having sold that ticket
in that time period.
The next situation is arrive but not purchase (1-a ) probability in which
I'll progress to the next period but will be in the same state.
I'll be one step ahead but the state remains the same.
Also a possibility of no one turns up and no purchase. Dynamic
programming can look at this sort of situation very efficiently
almost working your way backwards to get to the answer.
The diagram of the probability structure. If we get to
high price and we're a long way out , very few people will purchase.
If at a low price , even zero , and right at the time of departure
people are more likely to pay.
The exact packing with hte slidefull of compound summation
equations, can be high dimensional for all vehicle types and ccan
be long computer time. We use that set of equations to
define a Pareto? front, where if we put 1 more of any vehicle
on that ferry , then it would be overfull. This is the efficient vehiclre
combination and there's no point in looking outside that front as we
know it will not fit. This limits our safe-space being able to work out what that
is. With the lane structure formulation we use the heuristic structure
when we are a long way departure, we don't need to solve this big
complex program. Only nearer capacity or departure time do we need to
worry about solving the exact equations.
If there are 2 vehicle types there are 2,271 different states . 5 different
vehicle types its close to a million and that is reflected in the time
to crunch the problem. We can solve quickly for 2 but increase to 5
then solving the combined packing and pricing problem the processing
time is getting huge. Go to 20 and its becoming impossible.
The expected revenue , you get better returns if you split the
vehicles into a higher number of classes. For 2 classes , we say anything
less than that size iclass 1 and bigger than is class 2. So you end up
putting 5m vans in a class that goes up to 11m and a lot of wasted space.
Thats why we get different revenue results. For 3/4/5 types we can get a
reasonable revenue from the eact solutuion. For the heuristic one and packing
over the whole space rather than just lanes we can get much higher revenue emerging.
It givesa more efficient atack and a more efficient understanding of what is
Another project was with a big E-grocer 5 or so years ago before
delivery to your door had taken off. We wanted to have cutomer
based pricing optimisation as to time slots of delivery. We wanted to
encourage customers to pick a slot where the a delivery van was already
delivering just down the road. Imagine being i na far off village
then you would be given a cheap slot if you chose similar time to
a delivery to a neighbouring village.
A www page showing the green vans showing the most efficient
slots. A customer would get a whole suite of options for times
and also include green-van slots , with hte prices .
How can w euse the price and maybe the green-van to
encourage people to go for slots that are beneficial ot the
deliverer. Cheeper , more efficient and generally better all
round. So we had to build a model around how a
customer veiws the slots. We would design a tentative route plan
based on the forecast and then inserting the cost of an additional
drop. Used an almpst identical Dynamic Program as the ferries one, just there
was a cost function in there , how much cost to serve that 1 customer.
So modelling customer behaviour, how would they choose between
slots and would they purchase if the delivery cost was too high.
So optimising, then update your forecast routing plan as a result.
So almost the same method as the ferries but on a completely different
problem. These programs improve outcomes, but only based on
simulations, so who knows what happens in the real world.
Sometims a high-value customer would get a negative delivery cost ,
because you could haul them in and keep them shopping with you as the
overall profit is worth it, and also ensure they are in the slot you
want them to be in.
Future work ;- ferries again but multiple drop-off like Channel
Isles ferries, or Scottissh Island ferries where there is a sequence of
drop off at different ports and also other traffic comes on,
all potentially out of sequence. Put something on for a short hop
and you've perhaps lost space for something to doa long journey
as well as the packing problem.
Air-cargo is another one , you're never sure what will turn up
with air cargo, very uncertain so a lot about balancing uncertainties.
Delivery of large awkward shaped packages , so can be plant-hire
vehicles on the back of a lorry , like diggers and ecavators, how do you
do the deliveries. A nice one will be how to deliver packages to
space-ships. For a future with more commercialised activity up there
how do you price the delivery of such material, you've the weight , the
volume , watch this space.
As a non-mathematician , seems a lot of the parameters you're wrestling
with overlap with the container business. I know they have a fied box
, but they do vary in size , and fridge-box containers , multiple
destinations . ?
The regulariy of containers makes a big difference, although there are
differences in size , its not too different. There is stacking as well
though. It comes under a big category called rectangular packing.
Drop trailers problem?
Therre is an issue about how many such trailers you put on a
crossing because RF has had problems with not enough time to board and clear
lorries in the turn around. Drop trailers are kept separate and only a couple can
be moved at a time.
The booking system should be taking in info about your car or vehicle including
dimensions and place straight into the program?
At the moment they give everythinhg a car-equivalent unit and they will look
at keeping that nimber below a certain level , somewhere aroud the 200 mark.
They know that if they had loads that was all cars ,they cannot fit them all
in with that number of car equivalent units. If they have a mixed load they
can fit them in a bit more easily because they are a bit over-generous on some of the
car eqivlaent units. Thats the model they use at the moment but its not
Can they refuse a booking and wait for something better to come along?
We are trying to use price as a lever, so if something big comes along and its looking
quite full , then they will see a high price. So a maed out pricing.
Its rude to say no but set them a high price , thats acceptable.?
Presumably there's a sort of mathematical relationship between supplier
and regular customer on that as well. those customers will have some
insight as to when they will get a better price or some sort of feedback perhaps.
Wheras an onspec car customer would not have.?
Definitely. The regular customers are looked after very well. Other than
freight contract, most of them are island carriers so they will see
slightly different prices going that way. Game theory comes
into this .
Also an element of c-operation as well as competition?
Yes. There are ways of modelling those interactions. We've not done it
here but generally yes. It varies product to product , how important
those interactions are. There is a perhaps mythical story of a
USA professor who would try and book flights that he thought would be
over-booked, so he could get free airline vouchers. The worst that could happen
is he'd have to fly somewhere .
Have you looked at digital ? pricing ?
We've looked at pricing for web pages , clicking-on and also
radio adverts. Radi9o is quite highly regulated and restricted on the
number of assets you can fit in.
Is there rule-of-thumbs with the time-served loaders knowing say a particular
vehicle type turns up , they know a load of motorbikes can go in a specific
space next to it, that sort of knowledge base?
Yes they know a lot of that sort of thing. We keep saying we're
not trying to do them out of a job . They will even assess you as a driver
as you drive up as to how tight a spot they will put you into.
They must have collected data on regular users. Can they look that up
later, yes we know this vehicle , we know this driver?
No . I think its more assesment on the day.
So not a customer database?
There is but not used for loading purposes.
We're trying to develop something so the result works like how the
loaders would fit . They know what they couldn't do , so when it comes to
setting the prices , then yes or no. And also for trainee loaders.
I'm always surprised the short turn-around they have , 55 minute crossing
and most of the time 1.5 hour with turnaround at both ends, no
spare ship to call on. I've never seen breakdowns causing problems or
It can happen . At Cowes in particular they are trying to improve
the situation there . The loading yard used to have a road in the
middle of it, and their vehicles had to cross it.
Also vehicles coming off the ferry went in front of vehicles boarding ,
so no loading and unloading at the same time. so they'd load the car deck
while unloading the main deck for eample. They're currently redesigning the
I've a motorhome ,ring up to go to IoW in July
then something like 300 GBP return but book a weeks camping and
bring my motorhome then about 90GBP, etraordinary gymnastics in
Yes they have arrangements with different companies on the island ,
the loyal customers bit. The campsite becomes the customer and not you.
We did some related work on customer lifetime value . Then the switch point
between RF and WightLink say.
Any eamples of loaders doing favours for their friends?
No , none seen.
For the airline problem it used ot be , start with a high price , then
effectively a Dutch Auction and a standby price a tthe end. Your work
seems to be much the same as all online retailers and travel companies have
these days. That then obviates the need for standby pricing or still
a role for that , if unfilled capacity at the end, sell at a cheap rate. ?
It often depends on the market , its knowing when is the last
minute for airlines . You could have someone who really needs to get to
a meeting and they may be prepared to spend 5000 for that, right at the
last minute, but if you sell it for 200, you've lost , so its often orth keeping it
for that high price , perhaps 1 time in 100 one will appear but
onaverage you're no worse off. Its balancing off the probabilities
and the costs.
For your dynamic programming of pricing, how dynamic is it in
allowing someone to input new variables if something changes like a change of
fleet freight operators .?
I had a PhD student who had a project estimating these models as you go along.
If you have pricing models , say entering a new market or the market is
changing , what prices do you put out inthe market. So you are learning
but making money at the same time, so you have to be strategic as you'd
like to know their reaction to any price. Charge something crazy you'll not
make any money. Then the parameters get updated.
How low a level of staff can change your programming structure?
They would tend to be updated automatically via management systems
constantly feeding dat ain .
You don't have to have a coder come in?
generally not , only if the logic of the process changes.
The pricing algorithm is looking for strange behaviours. Like
every year there is a moped festival on the IoW , can RF all of a sudden
get all those on one ferry.
For the ioW music festival there is a lot more car traffic but because of the
demographics for that , they tend to be smaller cars so can get more on.
Not big family estate cars. Things like that, the model cannot capture
but they will know about certain special ecvents.
Tuesday 06 August 2019 Dennis Doerfel of Reap Systems , Southampton:
Developing hybrid marine-diesel/electric propulsion systems .
first is the concept of hybrids, second is results of the ferry deployment we made
in Falmouth, Cornwall.
In 2015 I met somone at a conference and we discussed what we could do to
improve marine transportation, and he said about the hybrid concept .
We started in Venice , thousands of boats in Venice busily polluting the
water and the air, smoke and noise. We started with the Venetian
taxi boat , that can carry 10 to 12 passengers , usually from airport to
the centre of Venice. This Venetian taxi boat is now in Soton. We converted it
to hybrid , so we could learn about the technology . Its 9m long, not
very tall so it can go under Venice bridges. About 550 such boats in
Venice. The second Falmouth project we had a number of
partners including government funding.
Reap systems is based about 10 minutes walk from here on the river
Itchen. We've been passionate about electric cars for a long time
, buying my first one in 1998 and decided on this area as a career ,
doing a PhD in soton on Li-ion battery tech for cars. We started the
company in 2003. Other projects with another company in Farnham which
makes motors that sit inside the wheel, and we supplied the battery
tech and integration. That car was 300hp and are mainly in China now
because Chinese bought the company. Since 2004 we've supplied
systems to a German company that makes electric boats , many lakes in
Germany are not allowed to use combustion engines on them, they must be electric.
For the hybrid boats we made the whole system , excluding the
manufacture of the engines. We started with electric cars but as a
company we're too small an operation , so we decided to move into the
marine market. We made a small electric RIB and put it on the
boat show in 2013 to gauge the market. Everyone loved the boat
but no one wanted to pay for it, too expensive.
One problem with e-boats is the price of batteries, although coming down now.
Benefits are , no local emissions , even in global emission terms it is lower C
than combustion engine. It is near enough silent , regenerative breaking
is possible , on slowing down some of the energy can be back converted
to the battery, it is very efficient. Another advantage is if you want to rely
entirely on renewable energy , most people would go for electric
not liquid fuel . Take solar or wind power generation or other renewable
structures go for producing electricity first. I*ts moree efficient to
store in a battery than to create a liquid fuel as the energy store.
It is possible to produce methane from CO2 and energy but its not
been widely adopted yet, likely to come soon.
Diagram showing different energy storage devices , for storing in car or
boat for the propulsion. on one axis the energy density how much
energy for the weight versus the power density . Different battey
types on the market , some are high energy batteries for e-cars like
Tesla and a very high energy density but the power density is low.
For a hybrid car you would aim for high power density but you
don't need so much energy. In 5 years ahead this performance might double.
At the cell level 690 W-hours per Lt but at the battery level of combining lots of
cells about 400. Comparing that to diesel fuel , instead of 400 it is 10,000
,so you can store a lot more fuel . That may not be a fair comparison I
thought as a diesel engine is not very efficient compared to electric motor.
Allowing for the lack of efficiency it comes down to effecdtively something
like 4,000 for storage, but its still a factor of 10 better than for battery.
Hence the impetus to consider a hybrid , battery for short distances around
town with much breaking and regenerative recharging but use liquid
fuel for longer journeys.
The speed profile of Thames Clippers in London , on some parts of the Thames there
is a speed limit of 10 knots but other parts up to 30 knots. The boat needs a
lot more power to do 30 kn that 10 knots, not linear , not 3x more like 10x.
For 30kn the battery would have to be enormous but at 10 kn diesel is
very inefficient as its not operating at enough power output. In between there are
stops , a long stop at Greenwich and often the diesels tick over continually there,
to keep the generator and other auxillaries running..
So for a hybrid , run diesel mode when fast running and charge the batteries
and then for slow mode run on electric only, no diesels running and the battery
will supply all the auxillary power needs while in that mode.
But the question is will there be a fuel saving. So could there be a fuel
saving. The efficency plot of a diesel engine , pretty hard to find.
Everyone uses diesel and a lot of talk about efficency but try and get an
efficency plot from a manufaturer, virtually impossible.
Shows the rpm of the diesel, between idle and max rpm.
Shows the torque and the extra curve shows what the diesel is capable of ,
how much torque it can produce at different rpm. Shows up lines of
equal efficiencies, so the highest efficencies at specific fuel consumptions in essence.
So how much fuel does it consume to produce 1KW-hr for example.
The most efficent area is at a relatively low RPM and relatively high torque.
From that area fuel consumption goes up. A factor of more than 2 across
the plot. For a boat , has a propellor, and will run at any rpm
and the boat will accelerate. There will be more torque and more thrust on the
prop. So run the prop at idle speed, you have a torque and it follows
the curve up to full speed of the engine. The aim is to end up at the
maximum power point , because people tend to want maximum speed.
There are parts of the curve where a boat hardly ever operates .
Most of the time a diesel would be on the curve that is far off the
optimum. A simpler diagram just looking at the prop curve
, what is my fuel consumption at different rpm, high fuel consumption at
low rpm , medium rpm is good and then at high rpm it goes up again.
Most boats are operated around 80% maximum, the better
parts are not used routinely.
So for the Venice taxi boat its got to go really fast ,about 30
knots near the airport but in the small canals 2,3 or 4 knots.
So the boat will be operating in the non-efficient areas for very
long times. So the idea is to operate one section on electric
and diesel for the other section. When you operate on diesel ,
you will recharge the battery. So what is the effect on the diesel operation.
Running the generator forces the diesel up into a more efficent operational
zone and that works.
There are different types of hybrids in the marine industry.
Simplest is the diesel boat with engine and gearbox , prop
shaft and prop. Then we are working with mechanical power all the time.
Series-hybrid is the next easier. Electric motor and mechanical
power , gearbox, prop shaft and prop. To run a motor from a
battery you need an inverter because the battery is DC and you need
3-phase to drive the motor. The battery will be empty at some
point . The engine is diesel usually in boats , electric motor working
as a generator , with inverter and charger . Series hybrid because you
have to produce electric power first and then use electric power to
make mechanical power. On big ships there is already big generators
, for them to add a battery would not be too difficult.
The disadvantage of series-hybrid , from fuel you convert that into
mechanocal power, convert to electric power, convert to dc power,
store that as electrochemical power , take it back out and convert to
ac electric power , to mechanical power, convert to lower rpm ,
convert to thrust. A lot of conversions with losses each time ,
so potential fuel savings are probably eaten up in all those
The parallel setup tries to overcome some of these issues and does look
a bit simpler, although more difficult to impliment.
Normal diesel enging, gear box , prop shaft , in between is a
clutch and you can take mech power off and connect an electric
motor to this . Via the clutch the engine can be disengaged and the
boat can be operated from the electic motor or close the clutch
and diesel driving the prop, the motor acting as a generator and
recharge the battery. So less components , so smaller and
cheaper system and most of the components can be smaller.
The electic motor needs to povide full power.
Q: Can you run both motor and engine at the same time?
Yes. you can run as electric only, or diesel only , diesel
with the motor acting as a generator. What we've done, during
acceleration the electric motor is helping the diesel ,
reducing emissions, it sdoesn't really reduce fuel
consumption. The emissions are reduced because the diesel is working
harder. There are also othe reffects. So can do both and add a
generator and you can do more. Most bigger boats already
have a generator, often 2. The generators ar eusually inefficient ,
put on one lamp and the generator has to fully run. Thee it would be
much more efficient to use a battery for that situatin.
So a hybrid generator. You can do mor eon boats than on cars.
The Venice taxi isa planing craft , when goinf fast
a lot of it is coming out of the water, with lower friction.
You can see that in the fuel consumption . Generally a boat is
low efficiency at low speed but this boat , when it starts
planing its quite efficient for a while, till wind resistance and
efficiency drops again. So optimum is probably when just planing
and so reasonable speed but most efficient. Its a bit doubtful
about fuel savngs but there are other benefits of a hybrid.
Reductionof local polution for example , which is pretty
bad in Venice. There is less vibration and low noise from an
electic motor. We tried to create a drop-in hybrid , so can
be retrofitd to old boats. Boats can be quite old, the ferry is from 1934
and the Venice taxi 1982. Just the engine tends to be replaced and on the
next refit , could include a hybrid, thats the idea. Also as the
engine is not running so much , less wear and less maintainence
so longer life a nd a saving there. The engine would be operating at a better
operating point on the curve. Electric propulsion allows you to go
very slowly , so manoeverability goes up. eg going in and out of a lock
they have to continally put in and out of gear , a lot of
clonking going on. Don't need to do that with electric because a motor
can turn very slowly. So much smoother operation .
We had to tart up the boats as they are both old, as part of using them
as test-beds, what are any potential issues and benefits. People underestimate
what is involved. They see all these components are easily available
, so surely it should be easy to put that lot together , but its not easy.
But control systems are not really available off the shelf, a lot of the
money goes into developing software. Imagine you're an operator
of 30 ferries and you want to make them more fuel efficient.
You would want to know how much you will save, what othe rbenefits
and what is the best system . This complete aspect does not exist at the moment.
Systems integration is the name. Before someone commits themselves to buying
an expensive system . The hybrid system is about 3 tmes more expensive than
#a normal diesel only system . Wil la certain system be reliable , which
gives the best results, cost-benefits, what other options are there, can I
use this for PR for instance. Will it consume more fuel . Take a hybrid
car used on a motorway most of the time it will consume more fuel than a diesel
only car. Unfortunately there is a lot of green-wash around this.
Someone suggested to me that I should be selling just the product sticker,
rather sad. Our system we try to make it as simple to install
as possible. Its very short, for the taxi stern drive and no space in the engine
bay, so we have to make our bit small to fit in what space there is.
Clutch and electric motor can do 40KW and the battery is under a
bench. So it takes up no space that would be used by passengers or their
luggage. I think we're the only ones can do this at the moment.
So system consits of the control, high voltage Li-ion battery and its control
unit and clutch+electric motor and lots of cables. Its important that the
interface for the driver has no change, so no confusion introduced.
The only change is a little display , tucked away, that can be used to change
modes. We've used the taxi around Soton for testing and demoing
and we now have to upgrade it to the system on the ferry.
Then take it to Venice, find an investor and supply ?? because the hybrid
system is new tech and we cannot provide world-wide support.
About 2,000 boats in Venice wiith the same drive system and about
20,000 more that are slightly different.
The next presentation relates the results on the ferry, the fuel consumption etc?
Q: What voltage cells are you using?
380V which is more or less what electric cars are using, so we can tap
into the same sort of components.
Q: The taxi , is that the original engine or did you change the engine ?
It would work with almost any othe rengine , but we bought the taxi boat without
an engine and got a new engine for it. The ferry had a very old engine ,
maybe 50 years old. With an old engine we cannot electronically control.
Q: Does stop and start cause a problem.? The taxi starts from the
airport and then its off for 10 minutes , not like the stop/start of a car?
Modern engines can cope better with stop/start, not so much heat mass?
so designed for start/stop. Also allows electronic control of the engine becaus ewe
cannot be utilising mechanical levers. Old engines tend to be dirtier, but we
prefer to go with relatively clean engines.
Q: So the offer would be new engine and battery for a taxi driver, because they
would be in the market because of a worn out engine? The whole thing in one go as part of
normal investment point.?
Yes, In venice these engines tend to last only 3 or 4 years. The cost of retrofitting
a hybrid system to an existing system and running for 2 more years is not
viable, maybe possible in the future.
Q: How long does the new system last com[ared to the existing types?
For the ferry project in Falmouth ,about twice as long, because half the
time it will be on electric. For Venice taxi boats , it would be more as they
are running on diesel a lot, very slowly . The ferry is going rapidly back and forth.
I even had doubts whether hybrid would make any sense , for such ferries, but it does seem to
Q: Scaling up?. Is this just the beginning, can you scale up to quite
I think large vessels are possible. We've been here before. There's not much
market yet but a lot of competition already. Because on a world-wide scale
there are lots of companies and investors who think this has potential.
So we had to look at what is potentially our little niche. There are big
companies doing big ships.
Q: Did you study the Isle of Wight ferries at all. THe 2 big companies
are both saying they are green and hybrid , but don't seem to be in
port long enough to have any payback, I'm confused by this.
Hybrid in the sense that that is what is painted on the side,?
I think it makes not much sense. You can enter the port on both
sides in electric mode , for less emissions , but otherwise
pretty constant operation .
Q: In Corsica this year, tourist boats with 20-30 people on them
, left the harbour with no sound . THe PR value of this was
fantastic . It went into various caves then up comes the
diesel for the main crossing. A delightful experience.?
That is what we were hoping for on the Falmouth ferry.
But the engine is quite loud and an old boat so a lot of
Q: Compaired with a car , the dead weight of a non-planing
boat would not matter, but what about the planing taxi?
Put it at the rear and it would plane all the time. Having a
battery , and its potential variation of placement , helps t balance the
Q: A benefit for leisure craft , if you want to slip in or out
of port at night and not disturb people , that would be delightful,
at the moment we are shouting crew commands over a noisy diesel?
On the Falmouth ferry they do alot of commentaries and previously they
had to slow down at those times because the diesel was so noisy.
Q: There's lots of marine engineers familiar with diesel engines
but what about the electic side of hybrids , a problem of finding engineers
capable in that area for maintainence and repair?
Cumin-Raye? engines are not common at all, we have an issue with that
engine and no one can fix it.
For the fast section Venice taxis are there any hydrofoil hulls?
Not yet, some ideas around hydrofoils and different hull shapes
but at the moment they are pretty conservative. People like the looks of
their existing boats and it will be difficult to change .
Q: It strikes me it can be a minor alteration but a large power advantabe.?
The water buses in Venice are crazy old technology , the marine industry
does not seem ot be fast on the uptake. We have worked in racing , but that is very different.
The Falmouth ferry project.
The official launch was may this year and operational in July.
This ferry has operated between St Maurs and Trellisik in Flmouth.
Its a new route because they did not want to put this piece of innovative new tech
on a very important route . They thought this route, no one is going to use it
anyway. On the first trip we had 35 on board and 160 people transported
on the first day, which was a surprise how well the route was received.
Trellisik is National Trust gardens , a very nice area, and the reason for
making it hybrid. The river is noce and green and people want to
watch the birds and fish , so switching to electic in those areas is much less
noise and no fumes. Its an open boat , during a nice sunny day its
very busy in the open part and no one under the canopy part.
When a diesel boat comes alongside or leave the pontoon ,
they have to reverse, or the wind may blow from the stern and the
passengers are sitting in diesel fumes, not nice. With electric ,
no problem of that.
THe boat itself is called Kingsly 2 ? , its on the historic ship
register and built in 1934. It can carry 50 and up to 60.
We managed to get MCA approval for a hybrid boat , Lloyds register has
endorsed the battery system . Its 50 foot long, longer than the taxi boat.
So what is the fuel saving. The fery leaves St Moors ,goes to Trellisik and
returns, the speed variation is pretty small. It has to come alongside and has to
wait . It may have to slow down in the river going past moorings ,
and other manoevering. But what about any fuel savings.
The engine is directly connected to the gearbox and the prop. In between is
the clutch and a motor that can work as a mtor or as a generator to
charge the battery. ??? . The boat has much mor espace than the taxi ,
the battery is aft of the engine , best for weight distributuon.
There is a dc-dc converter for in the electric mode to charge 12V batteries for the
radios and lights. Otherwise much the same as the taxi boat. The motor is
40KW but only weighs 11Kg. We use the same batteries as Mitsubishi
plug-in car hybrid, of Japanese manufacture Lithium Manganese cell
type which is safer than laptop or mobile types. If it burnt it cannot
release its own oxygen, so you can extinguish it. Compared to cells based
on cobalt which can release oxygen when burning and impossible to extinguish
such fires. Its a little heavier but no matter on a boat.
The voltage is between 290 and 430 volts, 18.3KWh , thats always a lie,
from all manufacturers as it depends on how you use it. You should never
fully use it. You could fully use it but it would probably get too warm
during an 8 hour day of operation of charging/discharging repeatedly.
Q: Would Lithium-ion phosphate be a contender?
Yes but it has other disadvantages , its difficult to determine th state of
charge in a hybrid , because the voltage does not depend reliably on the
state of charge. Most phosphate ones are coming from China and manganese or
cobalt from Japan. So there are commercial disadvantages of dealing
with Chinese and Korean suppliers compared to Japan.
They are also difficult to balance, becasue of the voltage/state of charge problem
as you think they are the same state of charge but they're not.
Q: I bought a leisure one for my motor home , it works very well
but it does seem to loose track of what its doing and needs resetting,
probably what your saying?
Yes, they have some issues. I'm nit sure whether cooling is easy
with them either. Our decision was more based on having known them for years
and hoping to make a business case and working with the Chinese was never going
These are automotive cells , so have received a lot of safety testing, which is
important for insurance and Lloyds Register approval. The Chinese say they cannot
send any certification. Same with Korean batteries, we cannot transport Korean
batteries any more because of dodgey certifications found out by a UK
transportation body. 3 independent test results looked suspiciously the same .
All this sort f activity puts lithium batteries as a whole into a bad reputation.
Its a safe battery , liquid cooled . For leisure boats , used twice a
year but a ferry is used a lot. Put this sort of tech on a leisure boat
it can be made cheaply as it doesn't have to last that long.
Q: I have a Nissan Leaf and its surprising how much the capacity
changes with temperature. Basically the hotter the better ,
then you run up against being a danger above a certain temp. Wht sort
of policy do you have. Also can you charge it up at low temperature
, then the temp goes up , without charging and you get more out of it or
charge it while its hot, I've no idea, a lot of info is just not provided
to the owner of such batteries. ?
Yes, all interesting topics and as usual it all depends. One great advantage of
this type of battery is you can charge it at sub-zero. Whereas all
the others normally theu say don't.
Q: If you charge sub-zero and warm it up , do you get more out of the
battery without charging it any more?
No, its just that chemical reactions work better at higher temps. Yo're getting
mor eenergy but you don't necessarily get more capacity, because the voltage
drop is lower . The over-voltage you need to drive the chemical reaction
can be smaller at higher temps but the aging accelerates, that the problem.
You want to keep it between 20 and 40 degree C , above 40 and aging
accelerates pretty fast. At 60 they will perform really well , in racing they
operate at 85 or 90 which is where you get most power out but they
won't last very long.
Q: Is the cooling internal or external to the battery case? and is that something
your control system takes care of?
Liquid cooling with inlet and outlet, 2 batteries split into 2, so for smaller
boats we can nicely position them. Its not salt-water cooling , there is a
heat exchanger for running the salt-water through there. We are actually
changing that, on the next Venice water taxi we will use sea-water
cooling for the batteries.
Q: For the batteries in theory you could use all sorts of electrolytes , I was wondering about
using salt water and the boat being one of the electrodes, and the other one being
something dangling in the water. Are you having to use Li-ion because
everybody does and therefore the most developed , because your not that
weight sensitive, so there must be other technologies possible. Just thinking
you're floating around in an electrolyte , why not use it? a daft question?
Generally the marine industry is not apt to change . The MCA is familiar
with lead-acid batteries on boats but put a Li-ion battery on board
and they only developed some rules a year ago for that. We had to look
at the system and writ ea long letter saying about safety etc.
I suspect you stating the use of lithium because everyone uses it is probably correct.
For a number of reasons , firstly people know how it works , know whats
available , no patent issues , more than 1 supplier is very important.
Another battery technology had one suplier who sat on it
and its patent but people want 2 or more sources. So there is some competition
and people can't fool around with pricing , you want a replacement, that will
cost you 5 times as much.
Sony? was invented by EA Technology ? near Oxford mainly for space applications
and Sony could see opportunity in this and were the first to put it in mobile phones
Q: It seems extremely narrow that society should just take a Walkman
battery and use it for powering cars , it seems amazing that no one has broadened it out?
We used lead-acid batteries for a very long time , NiCad came in,
that was replaced by NiMH . Lithium is not replacing Lead-acid so
If its a cold rough-sea day and a battery dies , you would be in trouble, wheras a car in that situation can just coast to a stop on the side of the road?
For the automotive industry, they can try 4 or 5 types, spend a fortune on
engineering and validation programmes. The marine industry they don't.
They rely on replication of where its been done before and somewhere else.
Q:Sea-water sloshing over the batteries and extra electronics?
Just the air is pretty corrossive.
Q: But you do have 2 mechansms for powering as long as they work when
one packs up, is better than just having one power source. ?
We've used that redundency a few times , both ways. In Soton we had the diesel
of the taxi pack up just in front o the fast ferry. So I was glad we had an electric
motor that could take us out of the way.
On the ferry we implemented a backup, for the crew. There is a lot
of software , so no longer a hammer and spanner will work . You have to
have 5 laptops and 3 ? at least. So they were all afraid of this complexity.
So its a matter of changing a few relays and its back to their old diesel
only, the whole hybrid structure is disconnected, is a feature that
people like. For the ferry we've over-sized the engine, sounds a bit
counter-intuitive. At one point on the operation curve we need
60hp but we went for 200 hp engine instead and we changed the prop
and gear ratio so the prop thrust curve has changed , overloading
its sometimes called. When you put the gear in , the engine is
ticking over , its not a smooth clutch , so clunk. But as we've overloaded
it , its too much for the engine during an emergency stop and it
stalls. So we've told the electric motor to help it so
it doesn't stop. If it was not a hybrid you could not do this,
another way to make it more efficient.
So you have a fuel powered engine in your boat so
you are already paying for friction in the engine as overheads.
Can you now add the generator and take energy out for battery
charging - how efficient is that because your already paying for the
overheads. So this curve shows this horizontally speed in knots
and vertical axis the engine efficiency. At low speed the engine
is inefficient and becones more efficient as speed goes up.
The top efficency is about 37% for the diesel engine ,
but now add in the generator then we are pushing the engine into a
more efficient region. That means the elctric energy is generated with
an efficency of 35 to 45% from the already running diesel engine ,
which is pretty good.
Q: Do any of your rojects rely on external ?ing?
Its not a plug-in hybrid, its self-contained. Normally thats a
disadvantage because there are just no recharging points on the Falmouth
Q: With that efficency increase are you getting something for nothing?
Not for nothing but you get it pretty cheap , much more cheaply than
running a generator. If your boat needs a generator anyway, diesel
propulsion and a generator it would be better to use the diesel
just for propulsion , than the battery-hybrid system with no generator.
That sort of system exista for sailing boats now. Thats a pretty clever
system especially for larger sailing boats. People have a diesel then
a generator and they don't then need a generator any more.
So the marine market is more diverse and interesting when it
comes to electic propulsion , than automotive as so many different
aspects to consider. The ferry performance, x-axis speed in knots
v the power required to push that boat at that speed.
So if you do 2 knots you need next to nothing like 1KW but goto
4 or 5 knots, the speed limit on the Test and Itchen is 6 knots, you
need 10 kW for a boat carrying 60 people. So a boat is pretty
efficient at low speed. But a diesel cannot operate a boat slower than
this , improves at higher speed where the boat gets worse.
So what overall efficiency. We had a number of laptops logging the
results on a rainy day in Falmouth. The fuel consumption in terms of
equivalent litres per nautical mile.
x-axis vessel speed i nknots , one curve shows the fuel consumption
the boat could have theretically if the propulsion system was 100%
efficient. A propellor good be improved but take it as a boat from
1934. One curve is the fuel consumption if it was purely electric,
pretty close to being optimum. The other curve is diesel only and quite
bad in comparison, because diesel is not very efficient.
The boat is good at one point on the curves but the diesel is bad,
and elsewhere the boat is bad but the diesel is good , so
no obvious sweet spot. But if you have a strong tide , things change
though. The hybrid curve, difference between diesel and the electric
, I cannot go electric all the time and have to recharge and so using fuel.
I'm using more fuel than if I was not charging , so I don't get that
for free , just cheaper . When we go to diesel we will be pretty fast.
The curves show it makes sense up to 7.5 kn it makes sense to go electric
because you're consuming less fuel. One question when demonstrating the
boats is , whats the range. It depends a lot on the speed as the boat is very
efficient at low speed. Go at 3.5kn you can go 12 nm with the ferry
in electric mode. But if you want to go fast 7.5kn then only 3 nm.
How fast does it recharge. Running on diesel at 6kn it takes about
8nm torecharge and go at 10 kn its much the same. Little difference on
what speed you do in diesel mode, dependent on the setting of the boat though.
Its about 30 minutes about 15 min on electric and 15min on diesel.
Going slow is always electric as is manoevering alongside , very slow ,
so disproportionate amount of time , where the diesel is pretty bad for this.
So the fuel saving of combined compared to the same system running
just on diesel.
Go slowly in electric mode about 20% saving , go quite fast and the
saving is only 5%. If you go too fast in electric mode you start to require
more fuel. This does not take into account ,in normal operation ,they
often leave the engine running . It also does not take into account
the ability to overload the engine , there are othe rsavings.
Skippers are now a lot more interested in all this , asking about
fuel saving possibilities as well as how to save the planet, which they
didn't do before. So that is the worst case in terms of fuel saving because that
ferry is not the most amenable to such fuel saving as its just going back and forth.
Venice taxi boats would be saving more than that .
Q:If you could do the whole route under solar panels, would it
make a negligible contribution or some contribution?
I think it would make quite a good contribution because , 2 to 3KW with
panels on the cabin top. Something you'd have to worry about
is spray on the panels. If not marine quality there would be galloping
corrossion and salt deposits , so a bad environment for PV panels.
Q: At either end of the route , is there any shore power?
With appropriate PV panels and daily surface cleaning and assume 3KW
that boat can do about 4.5kn so noticeable. Also its only operating
during the summer.
People don't seem to use the term Lt/nm , they use the term Lt/hr
a lot in marine matters because they use that for calculating
range and fuel requirements. So its pretty hard work to save just that
20%. If people reduced their spped from 9 to 8 knots they would
also save 20% . Much easier to do that . Perhaps they could improve the
hull , use a different prop or just clean the prop and the hull , much
easier perhaps in terms of fuel saving. But a hybrid system does have othe r
Q: less stress on the diesel engine and maybe extent maintainence intervals?
Q: You could be bringing the world of smart meters into the marine world.
Providing something for skippers to aim for.?
Non technical aspects of this should not be under-estimated. With hybrids
and so electrification it enables a lot of other things. It enables solar,
shore-power , cappoccino machine on board and other life benefits.
So the question asked, why should we change propulsion system to hybrid
and just save 20%, does it really matter. Its not just the fuel saving , but all
the other that comes with it, looking for different fuels which could be methanol
or hydrogen for example . Electricity all very nice but hybrid for the range.
Some applications , purely electric would make sense. Other applications
series hybrid or fuel-cell hybrid makes sense. Some applications a hybrid
makes no sense and I'd say don't by hybrid. We had this where someone in Canada was operating 20 boats in a nature reserve and he was keen to buy our dream hybrid
system. But the way he operated the boats he'd use more fuel .
Q: Is the ferry a "Little Ship" one of the fleet of WW2 Dunkirk evacuee ships, they used a lot of boats like that ferry, right age?
This one came from the Scilly Isles and always on Scilly .
Do you see any inerest in having mainly electric but sort of limp-home
diesel that won't give your normal cruising speed but would get you home
eventually, with failed battery capacity? Often big boats with a big engine have a small one for if the big one breaks down?
Peace-of-mind , yes .
I went to a marine talk and someone in Holland had installed hybrid in tugs,
any thoughts on that?
Daemon? has made a few. I know they had asn issue as they gave skippers the
option of using the hybrid or the diesel and given the choice they were familiar
with diesel and switched off the hybrid.
Our ferry skippers are more the other way, keen to go electric, but they
go a bit too fast on electric for my liking .
A featur efor electric cars is supposed to be superb acceleration, is there a
Yes, it really related to manoevering where you have instant response.
You could have bow thrusters electric as well.
A lot of motor-boats have 2 engines anyway, one port and one
starboard. With your system could you have one electric and one diesel ?
Possibly, they'd have to be matched in all performance modes .
Whats the function of variable pitch props ?
I'm not a prop expert , I'm told you can easily save fuel by having
variable pitch props , similar to all this hybrid stuff but you'd not
be able to improve your emissions. On emissions there is argument
as to whether to install a big and expensive scrubber on a boat,
or install a hybrid , but no one seems to have done comparisons.
If you had shore-power then presumably it could be scrubbed further
up the line?
Yes, that comes up a lot. It depends what sort of electricity you buy or
use. Most people who drive electric cars would buy green electricity
from wind+solar or their own solar PV. There is similar issues
with recycling schemes. If no one puts glass into recycling then #
recycling makes no sense. Thinks don't happen nicely synchronised.
We have to clean up our grid and it should all be CO2-free eventually.
At the same time using more electricity. Electricity is the easiest
form of energy we can create from renewable resources.
Liquid fuels have the great advantage of high energy density
but its difficult to produce sustainably, like
methanol from CO2. But if you produce it from CO2,
you're just delaying the release of CO2. At least you
use it twice, so not so bad in that sense.
On speed controls, I recall boats being banged into and out of gear
for minimum speed. But hybrid allows nice precise speed control
on electric. Would skippers accept that? Do you have a sort
of exponential throttle , to take advantage ofthat preciese control at lower speeds?
Yes we have a control that is not linear, so they get more control at
low RPM and also at high RPM.
Q: Do you get unsolicited positive feedback on that?
We went through control system changes in developement with a skipper
settling on what was quite nice and disliking other settings.
On this ferry the gearbox cannot operate at low RPM , so it still
has to be banged into gear. But they are developing hybrid -
ready gearboxes which are supposed to be finessed. Its hydraulic clutch control
and the hydraulic pump is driven off the shaft which has to
rotate at a certain rpm or the hydraulics don't work so then the clutch
You've only got a small sample of uses, 2 boats and a few skippers .
Comparing with electric cars , so many other benefits , no usage stuck in traffic
and other things coming out, a completely different mind-set. You've
not yet been able to cultivate those present unknowns in your audience. ?
We've used questionaires amonst the ferry passengers and thatgiven us some
answers on thinking. The ferry company has a number of skippers , not just 2.
The Venice boat will go to Venice and be shown to as many people as possible.
Irs got to get to the satage where a skipper will buy a hybrid
system because of all the other features he was not aware of previously?
A trouble with the commercial market is the 2 layers, who is your
cutomer , is the passenger or the purchaser . Especially the Venice boat we have
to show to the local council what is possible. Because only then
canthey produce the restrictions for diesel use, at the moment there is no
demand, the demand has to be created. This is a general problem with
sustainability. In general there is no demand , the tech vto fulfil a demand
is there . Killing the planet , new tech developement , but who is
asking for this tech.
I was involved with the developemnet of the first colour IT display
and we deliberated over how many will we sell , as a prestige item
costing 4 times as much as the existing green-screens. So a room of
200 users, but give one to the supervisor as a hierarchical thing.
We thought the market would stand 85,000 , but once they started
getting out there, no one wanted a green-screen. Our customers
buying these , could not recruit staff unless they changed ovver to
colour ones. You only use monochrme these days to signify stuff thats
out of date?
I bought the first battery car in 1998 and loved it, and thought why
is no one else buying these. We were the first in Europe to try
Li-ion batteries in electric cars and hybrids and there was some interest
from the press but no interest from investors then, because they would ask
how big is the market, how many can we sell . Then Elon Musk
believed in it , used his own money, and the rest is history. That is the sad
thing people don't believe in something . The Chinese are believing in this
and they are investing .
For a replacement technology you need a disruptor like Musk?
At the moment people are more reluctant tobuy diesell and hoping electric car
prices will come down ?
A chicken and egg problem with e-cars, they get their ecar ready
Mitsubishi and GM not selling well and the CEO is in trouble.
Something that has worked is Formule-e racing?
In the states with Tesla they go mountain racing at weekends, get to top and then
on the way back regenerative recharging for the braking .
Tuesday 17 September 2019 Malc Pearson Action on Hearing Loss volunteer, talk on hearing loss.
We have support groups in Soton
We have lots of small groups with us, we have training and I'm part of that.
We give training, mainly to corporates , for diversity and deaf-awareness.
We have campaigns, we lobby . We were very active lobbying for subtitling
on TV. We do research , including at Soton uni
on likes of cochlea implants and tinnitus . We also sell eqipment, there is so much stuff
to support you when you are deaf.
Firstly can you hear my voice, because I can't hear my own voice.
Sometimes I shout, sometimes I go quiet, sometimes it goes off pitch,
give me a nudge if I do .
For people who are totally deaf, right thru to the other end of the
spectrum with mild hearing loss , 1 in 6 people.
11 million people in 2018. It goes up in over 35s to 15.6% because its in the
older generation . We're living longer , therefore more people with
hearing loss in the future.
Profoundly deaf, probably sign-language users or lip-readers.
Sign-readers 24,000 but its not taken up by youngsters. Wefind sign language is a
very efficient language. But you need 2 people to tango, if you sign you need someone
on the oteher side to receive signing. So when you interface with an
employer or the general public, there is a problem.
6.7million could benefit from a hearing aid HA , the NHS say they've issued about
2 million, so a lot of people out there who could benefit from a
HA or two.
How to you individually recognise deafness, discuss with your neighbours
for 3 minutes. Deafness is invisible, look at me and how did you know I
I might tell you, I did tonight but normally I would not, if I
met you on the street. If I do then you start to behave very peculiarly.
You start to give me very strange mouth patterns. I need normal
speech to be able to read it, not emphasised. People tend to
react and over-react. So I shuffle along a bit, perhaps flash my
hearing aids at them and slowly go into it.
I have 2 HAs, 2 NHS ones and with short hair they are
very visible, I quite like that as it helps me tell people that I'm deaf.
ts fashionable now to have things stuffed in your ears. It used to be
that people did not want to be seen with things in their ears, not any more.
I don't respond if people talk behind me. I do hear bass notes ,
so something dropped with a loud bass note, I'll hear that.
So people walking along a footpath who want to overtake and say something to
me , i don't get it. My vision is what I hear.
When you're deaf you observe things in a different way. You get glances from
people walking past me , because they've said something, and I've not
picked it up.
The different voice. I've been hearing for most of my life , therefore my
voice is reasonable. Now I don't hear it properly I usually shout .
Usually people who ar edeaf have a different kind of voice.
A colleague of mine who gives talks has never heard her own voice,
has to modulate it by touching her throat to gauge the volume.
Once set for the day , she's usually alright.
Go somewhere and the TV is very loud , they probably have hearing loss.
Similar with loud volume in a car, could be the fshion or compensating
for lack of hearing.
Lip-reading. I only get about half of lip reading content, I have to make the
rest of it up as I go along. SoI get it wrong very often ,misunderstanding
things. If I go wrong like that I can tell from people's eyes that I've
gone wrong, we have to back-up a bit and restart.
As a lipreader, I don't have eye contact, I look a little lower.
I'm actually looking at your teeth and you tongue , so that sort of focus
is slightly off and that does worry people. They get a bit uncomfortable becaus eI'm
not giving them pure eye contact. It can get a bit embarassing at
times, when I'm tired I beging to stare. If I don't know th eperson
and they don't realise what I'm doing , its a bit unnerving for them. But I'm aware of this and have to compensate. So if someone seems to be staring at your lips they're
probably deaf and are lip reading.
As you get older, bits wear out .
I can't go to dinner parties becasue when people are eating and drinking
and also talking , it all goes completely out the window. Equally any
social interaction where you have to interact with people , lots of
people trying to talk to me, it gets very difficult.
I only go out to dinner with people who know me and they can compensate
and help me thru it. If someone is withdrawing from you in a social
situation deafness could be the reason why.
If you want to learn something different , sign-language. It makes you lok
at languages in a very different way. But you need 2 to tango , so you don't usually
see it in action unless 2 people are deaf together or going to a club where
they know deaf people will be present. Some deaf clubs, sign language is the
only langueage that is used inside those clubs. So a place of silence, and if
you tried anything else in there you'd get some very strange looks.
The red and white stick, that means visual impairment and hearing
impairment. Not a barbers pole but red/white/red/white, they won't see
you very well and wont hear you very well. So you have to think about
how you will communicte with them. A light touch on the shoulder and then
move in front of them and then let them drive it, as they know what to
do. They will guide you from then on. If its an emergency , say someone is
stepping into a road, grab them by the arm, if an adult.
Q: I've never seen a red and white stick, I'd immediately associeate
it with a surveyor's staff. Would those poles have one of the
sounding lumps on the end,for echo gauging purposes , looking like a golfing stick?
I've seen the plain white but not red and white around?
They are around Soton.
Q: I've a problem understanding women rather than men, because of
upper frequency sound loss. So if you find male voices easier to understand than
female , that can be a signature of deafness?
It is , when I show you the innards of the ear , you'll see why that happens.
There are 2 big reasons why you can go deaf. I'm not a medic .
Conductive deafness , where you hear everything but at a lower level,
just as turning the volume down of a tv. You hear everything but have to
strain to hear it. The second is perceptive loss, where you've lost a
band of frequencies . Usually that frequency is in the higher band,
but it can be anywhere. My loss was due to an illness and it caused me to
loose several bands going along the route of the cochlea.
This gives you distortion of the heard sound. As you get older you get a mixture
of both. I started off with the second but with age then the first as well.
Ear flaps are designed to catch the moving air. It sticks out and funnels
the moving air down the ear canal to the ear drum. This is a living
membrane that goes across the ear. Inside of that there are 3 small
bones , the smallest bones in the human. The first touches the back of the
ear drum , picks up the vibrations that are now physical
movement and passes thru the next 2 to the end of the cochlea.
Its like that because it needs to move , because your jaw
moves and your whole head moves so it has to be a flexible joint.
As you get older your bones change , these bones change as well
and they're not so conductive , therefore its like turning the volume down.
The transmission of vibrations across that bridge are not as efficient as they
used to be.
The cochlea, thumbnail size and snail shape. Its a hollow tube, 2 tubes
in fact. The centre of the tube is fluid filled . If I straighten out the snail
shape , a tapered tube. Inside the tube are thousands of hairs ,
pointing inwards that pick up the vibrations. At the hair ends are
nerves , which all join together and become the auditory nerve tha t
send electrical impulses toyour brain . Responds best to high frequencies
at the narrow end and bass frequencies at the wide end. All the vibrations
start with most amplitude at one end , takes a lot of work , because all the
vibrations have to pass through those hairs, you loose those, they wear out
and they won't replace. Thats why you start to hear mens voices
better than women's. The illness I had, got into the fluid of the ear
and it destroyed the hairs in some patches, so I've lost those
frequencies. They can't be replaced, nothing you can do about it.
This is all vibrstions that the hairs pick up , converted by the
nerves into electricity and the brain does all the work of converting into the
sensation of hearing, same with eyes.
Why is one tube larger than the other?
Just a schematic , the main tube is what I,m describing here. There is a
second tube that picks up secondary waves , and the brain compares the two, so
more complex than what I was saying. For the purpose of understanding ,
just considering one.
What s the normal hearing frequency range of ordinary people?
About 20 hertz to 20 Kilohertz, only for very young people, it drops off
quite quickly as you get older.
So the communication needs of different people. If you're a hearing aid
user , you need signs and subtitles as we are using our eyes as well as
the small bit of hearing we have got.
If we're lip-readers , we need note-takers and speech-to-text to
help us. Note-takers are professional peole who will come with me to
a uni lecture , because I can't look at a lecture and write notes at the
same time. Speech-to-text where someone with a special keyboard
would type in what is said and it would come up[ as large font print
on a screen. You see this in courts where there are people with
hearing loss involved. There are signer-readers and interpreters,
people who will sit between and a hearing and a deaf person who
is using sign langauge. You can engage such people by booking thru
the charity Action on Hearing loss. With an interpreter its very eady to
end up talking to the interpreter and not the real interviewer.
Aubtitling , I use it all the time. It started with BBC doing some programs
and now its across most of the companies. Usually subtitling is pre-recorded
bu tsomething live like the 10 o'clock news , they don't know what they will say until
being on air. You can tell the difference, because it comes up in blocks
and often a wrong word in there or mixed up . The software they use protects from
strange words coming up .
Q: I noticed on BBC reletext this week that they're stopping the red button business.
I've always liked that facility , compact concise precissed text and if anything
piques my interest I look on the internet for it, armed now with a few keywords. Snippets of news in that
structured /teletext/ceefax way I'd have thought was very useful for a deaf person?
Its wonderful for us as an information source and as a communication source.
Q: Is that text-biased news/weather etc very useful to the deaf in the same manner as
It is important to us. I've not heard any comments , no lobbying that I've
seen about the red button , its only just come up in the news, early days.
We've had a long campaign to support subtitling ampng the various
companies . When we have a problem reported to us we go and try to
sort it out. A problem with subtitling is its often imported films
, which is inadrqute, they need to put it on for an English voice.
Everybody lipreads to some degree. Have a conversation with a
friend and put a hand in front of your mouth and I guarrentee that your
friend a few minurtes later will ask you to move your hand.
Its also reassuring to see the lips as people get the emotions
along with the speech. If the conversation
is going well , it flows well, a nice smile on your face, a warm look
that people acknowledge. Lip-reading isn't just about the lips,
its the whole image of the face.
Lip-reading needs a lot of concentration, I can only lip-read
for about 30 minutes , after that I've lost it, I have to go outside.
All a bit strange as I do most of the talking , so lip-reading
can be a challenge to do at the same time.
I get to a point where things become jumbled and I go out and have a coffee,
unfortunately the peole come with me. I just want to go away and have
some time on my own for a few minutes. About 50% accurate.
Its a bit like predictive text, people say things and you respond to things
in set patterns . When your close to someone you can almost tell what they will
say before they say it. A lot is inteliigent guess work, but that also
creates mistakes and you've got to acknowledge that.
I come wiht a kitbag and when you go to lip-reading clases , they tell
you to carry a kit bag with you. I'm happy to share some of my tricks with
you but not all of them. The first one is I start conversations, you
don't stand a chance of starting a conversation with me, because I will
start. When I meet you ,I'm in there . Then I know what we're
talking about. If i let you start , I'd have not idea what the
topic is, it could be M£ traffic, a sunny day or whatever. If I start , it
lets me relax and it lets me know what we're talking about.
Some people think I'm pushy because of that, but hey, thats the way it works.
We have thinking words and one of them is really!. If you say really to someone
it answers most things. So if I'm stuck, I say really and we can move on,
without shocking?. As soon as I shock?, then the funny mouths and all
the rest of it. I like people to speak a little slower than normal.
I can slow you down, by making my speech slower , you'll slow down.
Try this with someone in conversation. You need good lighting
, I can just about manage with the low level lights here for the projector.
Often the new downlighter LED lights in houses now are terrible because
your nose shades your lips. Often people are standing under one of those
strong lights and I can't see a thing. I move to the
side and the other person moves with me. I don't have ot say , lets move,
they come with me without explanation. We do come out of lipreading
training with a load of tricks.
As a demo of confusing groups say amongst yourselves as pairs while looking at
Say ma (as in murder), be ( as in Bert) , pe (as in pearl).
You should see they all look the same shape, known as confusion groups.
Most of you were smiling then, as soon as you smile , it distorts the lips so
you have to do this with a flat face.
Some more Che (as in church), Sha (Sherbert) and ga (as in gerbil)
you can feel your tongue going into different positions from the previous group.
The and Fe (as in fir) is tonge position.
Finally Ta (as in turban) and De (as in dirt) your tongue is behind
your top teeth and again your jaw shape is diffferent.
Its not just your lips , its your whole face shape, that changes.
If you say, tea on Saturday and dinner on sunday, look at how those
appear as lipreading, very close lips similarity, so easy confusion.
When you're communicating with someone with hearing loss, the image
your portraying becomes part of the language.
So drink a cup of tea with me look at my face appearance . Or driving
along a road in the country without a care in the world compared to
facial appearance when driving a bus in the rush hour.
How can you help with hearing loss. Find a quiet place, this room is
wonderful, lots of rooms have fans and other noises going on and
traffic noise coming into the room. So how would you get my
attention there. If I'm focused over my laptop say, bring your hand
into my vision from the side. A light touch on the shoulder , a heavy
touch if there isa fire. Face the person, a lot of people try to face the
person but end up half way, come all the weay round.
If you're going to talk for any length of time , try to include the
subject in your first sentence. Slightly slower than normal but try
to keep the normal rythm going. Going slower tends to exagerate the
features on your face around the lips. Take turns in talking,
if you talk over , it will all fall apart. If you shout at me
and I understand it , I'll shout back, other than that your face looks
angry. So if someone shouts I immediately see anger and therefore
I assume there is a danger.
Its quite panicking when you see someone you don't know shouting at you.
Don't waffle. When you study sign-langauge its amazing how many
words are unnecessary. Keep to plain language. Re-phrase something
if its not going well . If it gets to the time where I can't take any more,
pack it in and restart in half an hour. But please don't give up and walk
away. Worse comes to worse write down on a bit of paper.
If you walk away , I think he doesn't care and this errodes friendships.
I have a sheet here with communication points from both points of
view, hearing and hearing-loss.
You can check your own hearing by our health check ,
phone the number 0845 600 5555
and press the keypad for different tones for about 10 minutes
and use a landline phone not a mobile . It will say your ok
or need to have it checked . Also repeat again for the other ear.
NHS service are via your GP or you can go the private route.
Learn to lip-read, quite a few free tutorialsd on the internet.
There are some on our websirte as well but if you ant to do it
seriously , you join a group, often attached to libraries,
so you go to a community, you just practise. There is a structure
to it but most of the time its quite social .
There's never been a better time to be deaf with all the tech
around. You could spend a fortune on it if you want.
Communicating text , there is Whatsapp, all these apps gives a deaf
person access to communication that was not possible
before. THe leaflets I brought along , do get out of
date very quickly , so go to the website where the pdf files
are updated . There are hundreds on there. Any sort of issue,
you'll find something about hearing loss there. We have an
email newsletter as well , once a month.
Q: A language spoken with a lot of sibilance is very difficult to
When you talk vto people who are not deaf , they do pick up
a lot from what we do not say. Particularly youngsters, I'll
be talking at the Solent uni on friday , they ar eso interested
on hearing loss because its such a common thying.
Q: I went to have my ears tested and he said a lot of people have
accelerated hearing loss because they have these things in their ears.
I'm told that when you're on a train you can hear the hedphones of
someone two people forward, buzzing around. That is so
dangerous - also the noise in a car.
Earlier when you all were discussing how you would recognise
deafness in someone, you registered 80 dB, via an app on my
phone. 95dB is the starting threshold for hearing damage.
That sort of damage is recoverable if you go somewhere quiet
afterwards, but do it continuously or for a long time, damage
will be done.
Could you saya bit about signlanguage. My daughter is teaching
my granddaughter a simplified sign langauge, macaton?
Often used in schools especialy children with spacial needs as well.
Is it a stripped-down Brittish one?
The language structur eis different. If you are asking what is my
name, it is structured name/me/malcolm. Word order is changed from
English and trivial words are just lopped off.
The important stuff comes first, incredibly basic like that.
Why is there no international Esperanto sign-language?
No one could agree. Not enough people because to develop
you must have someone to sign to. Lip-reading is very
common now. If you can look at signed TV program
you see the word order is completely different to what is being spoken.
For TV signing they use exagerated facial expression?
Yes, a lot of the separation is the face, different expressions have different
I've heard they use male speakers for older viewers and then there was complaints
about gender equality .
Very true . There is AD audio description , like teletext but
describing the scene. Where this is done by a woman they choose someone
with a lower pitch of voice . But they also needed a voice that did not
clash with what was being spoken . Have a go with the AD button
on your TV controller, not available on every program.
The aspect of everyone can lipread to some extent. I used to know
someone with cerebral palsey and because of the distortion of his
speech , I found I dropped into a mode of looking away
from him and then I could understand him. If I looked at him, somehow
the distorted mouth-form distracted or confused my underestanding of his speech.?
It just shows that we all must have some background ability at
lip-reading , by this converse.
Its easy to have a hearing test, these days its almost automated.
It comes up with a graph that shows your hearing loss. Then they can
set up any HA to your needs.
to be continued
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