People prefer trams
From Energy-Experts
Subject: RE: Too much emphasis on rolling resistance
Dear All
I am sorry but Fred is not correct for two main reasons (there are many others):
1 It is an acknowledged scientific fact that the rolling resistance of steel wheels on steel rails is very much less than that of rubber tyres on tarmac. If the bus lobby wishes to counter this argument then it is up to them to prove whether the difference is “negligible” or not. Until that is done we should assume that the preference should be for the most energy efficient system, namely trams rather than buses.
2 The first rule of successful marketing is to find out what the public want and then to provide it. There is ample evidence from all over the world (eg Prof Carmen Hass Klau’s research) to show that the public greatly prefer trams to buses. The result is that trams achieve a much greater modal shift from private cars to public transport than is achieved by buses. This effect is very far from being trivial as it means a dramatic reduction in the use of cars. It is a waste of resources to spend more and more money trying to make the public do something they do not want to do ie ride on buses, when it is perfectly possible and more economical to provide what they do want ie trams.
I entirely agree that we should try to be objective about this and look for facts rather than opinions. I am sure that Prof Lewis Lesley will write an excellent chapter on trams as he is an acknowledged authority on the subject.
Best wishes
J
James Skinner, Sustraco Ltd
Subject: RE: Too much emphasis on rolling resistance
Dear All,
Dr Starr very much regrets he got caught up once again on the subject of trams.
His main point, which has never been answered, is that if every conceivable tram route was built in the UK, the amount of energy savings they would make, compared to what is curently used in the transport sector will be negligable.
He looks foreward, however, to receiving a chapter from Lewis Lesley on the impact of trams on UK energy needs and how they would compare with other public transport options.
Best regards
Fred
Dear All
I attach an extract from Wikipedia on the subject of rolling resistance. I am not sure that I am too swayed by the evidence offered by Fred - that he found it easier to push a truck than he expected. Does this pass for objectivity in the Claverton book?
I can never quite understand the importance that seems to be given to quantifying the exact amount of energy saved by rail vehicles, given that no-one can seriously dispute that they are so much more efficient on the flat than buses. It seems to me that the onus is on the buses to prove that they can compete with trams as far as energy efficiency is concerned. It is a physical fact that rolling resistance is greater for tyres on tarmac than for steel wheels on steel rails. So surely it is up to buses to prove whether or not they can compete. Why do trams have to try to prove their energy efficiency rather than buses? If we are to be truly objective why don’t we just assume that trams are more efficient until proved otherwise - which might be quite hard to do. I have in fact asked the Transport Research Laboratory to do some work on this but they seem to be too busy to bother about trivial matters like energy efficiency in public transport. Perhaps someone else could ask them to compare buses and trams in operation - I have no doubts personally as to which would be the most energy efficient. I am, of course, referring to Ultra Light Rail as opposed to heavy conventional light rail, which is obviously heavier and may therefore be less energy efficient than hybrid ULR, although still probably a lot better than buses.
In my view probably the point of most practical
importance is that trams
have been shown to be much more popular with the
public all over the world
and that is why they achieve much higher levels of modal shift. Trying to
encourage people to use buses can be a very
expensive exercise (cf London
where a subsidy of £750 million a year and rising
has not yet achieved the
patronage levels of 20 years ago). Bus patronage in
the rest of the country
continues to stagnate or decline except in a few
highly subsidised pockets.
Total expenditure on bus subsidies is currently
running at £2.5 billion a
year, including around £1 million per day subsidy
specifically for diesel
fuel for buses - none of this seems to be very
objective.
Even the smallest energy-saving factor in cars, fridges etc is taken to be worth while (quite rightly) whereas the enormous difference in energy efficiency between trams and buses on the flat is constantly queried. although most routes in towns are mainly on a pretty level gradient. Horses may have found it a bit of a grind going uphill all the way from Wandsworth to Croydon but a modern autonomously powered tram will take that in its stride, making use of the power boost from the on-board energy storage so that the engine need not be too big. It will recover a large part of the energy used to go uphill, through regenerative braking on the return journey, again taking advantage of its hybrid drive train.
For some reason Fred seems to be deeply prejudiced
against trams but he will
have a tough job arguing for buses against ULR.
Best wishes J
James Skinner, Sustraco Ltd
Websites: http://www.ultralightrail.com
http://www.passenger-transit-systems.co.uk
Subject: Re: Too much emphasis on rolling resistance
Dear Clive
The main reason why the horse drawn Surrey Iron Railroad collapsed, was that in contrast to other
railways in the North East, the most important loads were from the River Thames at Wandsworth to Croydon.
This is a gradual ascent all the way. The advantages of rail over road quickly disappeared for this reason.
But my main point was, over a years operation on a practical type of track, anywhere in the UK, what is the energy expenditure of trams compared to trolley buses and buses.
I also got the impression from having to push start a 20 tonne truck (with others) that the rolling resistance of trucks is quite low.
Best regards
Fred
PS......as some of you know,part of the Surrey Iron
Railroad is the trackbed for the Croydon Tramlink.
Unprofitable in 1805 and unprofitable now!
Low rolling resistance tires Maglev in some cases has lower power loss than wheels
