Buses and trams
From Energy-Experts
Dear Lewis
Thanks very much indeed for the info. I think your comparisons are not quite balanced because they do not compare like with like. · Underground is underground so a) not such a safety problem and b) it’s much faster (3-5 x?) and predictable than bus. If bus lanes were exclusive like tram tracks then differences would be reduced (5-10 mins to go down to train and back up?). I’d rather use the bus (or tram) than the underground any day, if it were not so much slower. · Underground carries more passengers because it is faster and on high volume routes. · Buses often do a different duty in towns, their stops are closer together and they have more routes making access much easier,Dear Lewis
Thanks very much indeed for the info. I think your comparisons are not quite balanced because they do not compare like with like. · Underground is underground so a) not such a safety problem and b) it’s much faster (3-5 x?) and predictable than bus. If bus lanes were exclusive like tram tracks then differences would be reduced (5-10 mins to go down to train and back up?). I’d rather use the bus (or tram) than the underground any day, if it were not so much slower. · Underground carries more passengers because it is faster and on high volume routes. · Buses often do a different duty in towns, their stops are closer together and they have more routes making access much easier, especially for those who can’t walk far. · Electric buses pretty quiet and smooth - I’ve been on some. And some metro trains have rubber wheels! (see http://en.wikipedia.org/wiki/Rubber-tyred_metro for advantages)
I guess the optimum will be some mix of train/underground/tram/bus/ electric taxi that will vary according to circumstances, perhaps most importantly p.km over different routes and stop intervals; I have no commitment to any particular mode. What we need is an optimising model to find least cost/energy mix to find the right horses for courses, so to speak.
This is a very useful overview of transport and energy: http://www.ptua.org.au/myths/energy.shtml
And this is interesting too: http://www.dft.gov.uk/162259/187604/206711/206721/214566/REF
Best wishes
Mark
Dr Mark Barrett, Principal RCUK Academic Research Fellow Bartlett School of Graduate Studies
From: Lewis Lesley [1] Sent: 16 June 2008 14:18 To: Mark Barrett
Subject: Re: cars/trams/buses etc
Mark, Many are running on either dedicated bus lanes or busways. The nearest example is Runcorn New Town, built around a busway, opened in 1967 to give faster bus journeys than driving a car. The Master Plan target was 50% modal split in the peak, the actual figure was 15% no better than other UK towns of the same size without busways. Today sections of the busway have been abandoned.
Further away Adelaide has a large guided busway system, and Ottawa a busway network (like Runcorn). Both have decided to convert to light rail because of a failure to attract car commuters. The only successful busway is Coritiba in Brazil but here car ownership is low. Experience everywhere is that as prosperity increases people buy cars to escape from bus dependence ( a slight simplification).
Steel wheels on steel rails have one major benefit over buses running on tarmac or concrete, very smooth riding. The guided busway in Edinburgh (WEBS) had to be relaid 3 times because the ride quality was so poor buses had to run at 20mph for the safety of passengers, even though buses on a parallel road ran at 30mph. Trams being electrically powered have smooth jerk free starting and stopping. Even with automatic gears buses are jerky. Trams can also accelerate at a faster rate than buses, especially when full so giving a faster average speed even if the maximum road speed of buses and trams is the same.
Can I suggest you do a little thought experiment and ask why in London the underground (excluding the main line commuter rail services) carry the same number of passengers as the bus network which is 100 times more comprehensive ? It is not just about speed. Lewis
On 16 Jun 2008, at 13:07, Mark Barrett wrote the write my essay:
Dear Lewis
Agree havent looked at this. But a question I have is: are these buses running in proper bus lanes to give about same speed as trams? Many/most/all bus lanes and their operation (priority etc.) especially in UK, are very poor so average bus speed no better than car.
Or are you saying that there is some great preference for steel wheels on rails as opposed to rubber tyres on roads?; because buses/trams are otherwise more or less the same. This would really surprise me; convenience, time, cost are surely the great concerns to users.
Best wishes
Mark
Dr Mark Barrett, Principal RCUK Academic Research Fellow
Bartlett School of Graduate Studies
From: Lewis Lesley [2]
Sent: 16 June 2008 12:55
To: Mark Barrett
Subject: Re: cars/trams/buses etc
Dear Mark,
One big disadvantage you have not included is that worldwide bus based public transport attracts only a small number of car commuters, typically less than 5%, whereas trams and light rail consistently attract 30-40% ex car users.
You might like to look at www.gluas.com a new tramway being promoted in Galway City (pop 65,000). A two line tram network will raise public transport use from a present 5% (bus only) to about 20%. There is little point discussing the supply side of public transport without a consideration of the demand side. Cheap but empty buses are not economically viable, especially as about 60% of bus costs are for staff.
Sincerely,
Lewis Lesley Technical Director TRAM Power Ltd. www.trampower.co.uk
On 16 Jun 2008, at 12:38, Mark Barrett wrote:
The advantages of the (electric/hybrid?) bus:
Can introduce incrementally (and more cheaply?); dont need rail system, but __do need bus lanes__ which can safely be used by bikes etc unlike tram rails. Can update technology more easily
Routeing much more flexible and can change routes/bus size according to time of day etc. to sustain occupancy factor.
Disadvantages:
Range! 150-200 km. 10 round trips of 15 km what does a city bus typically do each day? Can batteries be replaced?
Engine/battery efficiency probably ~65% of efficiency of rail system
Many links http://www.cleanairnet.org/infopool/1411/propertyvalue-17734.html http://www.busonline.ca/regions/kel/news/hybrid_electric.cfm http://transit-safety.volpe.dot.gov/Publications/cleanair/DesignGuidelines/HTML/DesignGuidelines.htm http://www.electric-fuel.com/evpro/Phase3.pdf Solar elec bus!: http://www.adelaidecitycouncil.com/adccwr/publications/guides_factsheets/tindo_fact_sheet.pdf At the risk of repetition, see particularly point 1. and effect of occupancy. Slide numbers refer to attached. 1.Energy per passenger.km depends on vehicle size, type, speed and occupancy factor. (e.g. slide 13). A car with 4 people is better than a bus with 8 downsizing could reduce car CO2 by over 60% (slide 15). So sometimes bus/train better, sometimes car better. Walk/cycle always better. 2.Carbon per passenger.km depends on 1 __and__ fuel used. Train/trolleybus/tram can use zero carbon elec, cars more difficult but the way to go, aircraft very hard indeed. 3.For internal combustion engines with standing heat losses there is a minimum energy per km speed which is not zero. (slide 17) Main energy loss is not rolling resistance but drag/transmission/engine 4. Many other benefits going away from cars: congestion, safety (slides 19-21) but you pay a steep price. I was driving on the north circular yesterday. Pedestrian crossing every km or so. So to cross the 20 m road you need to walk about 1000 m 50x distance penalty not uncommon on many urban roads. This penalty + safety penalty + . Explains fat gits like me and kids in cars. Best wishes Mark Dr Mark Barrett, Principal RCUK Academic Research Fellow Bartlett School of Graduate Studies
From: Dave EU Andrews [3]
Sent: 16 June 2008 11:10
To: [[4]]
Subject: PROGRESS..Fuel consumptions. Cars v buses v trams. Cars appear to use 6 times as much per passenger km and it has to be liquid fossil, trams can use wind power.
Excellent Roger. So what you are saying, I think, and I agree, is that we need the total number of annual tram km, divided presumably by the number of actual passenger kM. Can the tram experts serve us that up please? Agree of course about the fossil fuel power stations, but it also works with Sustraco bio gas powered vehicle..... London has a large amount of digestion within the city.... and a huge refuse problem - what better way to get rid of it, than digest it, and use the methane in Sustraco vehicles? I note the old Blackpool trams do pretty well? Why does HMG force new trams to be much heavier and less efficient? Do I detect incompetence, a conspiracy theory, or seats on the board of energy companies when thepeople whowho make these decisionsretire?
Dave A
From: claverton@yahoogroups.co.uk]] [5] On Behalf Of Roger Button
Sent: 16 June 2008 10:52
To: [[6]]
Subject: RE: [claverton] Fuel consumptions. Cars v buses v trams. Cars appear to use 6 times as much per passenger km and it has to be liquid fossil, trams can use wind power.
Hi Dave, Here is my table, using real data from my VW diesel Golf: || Tram: || kWh/km || Passengers || kWh/person-km || || Blackpool || 1.5 || 20 || 0.08 || || Manchester || 4 || 20 || 0.20 || || Sheffield || 4.5 || 30 || 0.15 || || City Class || 1 || 20 || 0.05 || || Car: || || || || || VW Golf || 1.1 || 1.3 || 0.85 ||
There are various caveats. Obviously the electricity for the trams is assumed to come from a non-thermal power station, or the power would need to be multiplied by 3, say. The tram loadings need to be averaged over the whole length of the run, with and against the peak flow, and over the whole day and evening, and this is where I probably part company from the tram enthusiasts. I suspect that although an 80 seater tram may be fully loaded during the peak couple of hours in one direction, for the rest of the journey, and day, it will not. I think an average loading of 25% would be very high, and I would welcome some real data on this. If the Sheffield tram were, in fact, powered by electricity bought from the National grid, and therefore thermally generated, the consumption would be around 0.45 kWh/person-km. If the loading of 20 passengers were only achieved half the time the consumption would rise to 0.9 kWhr/person-km, and be the same as the VW Golf. Thus, for serious energy savings something much lighter, and with a much lower spec, than a Sheffield tram is required. If the City Class really does use only 25% of the energy on comparable routes (Sheffield hills) then significant savings over private cars are indeed possible. Kind regards, Roger Button
From: [[7]] [8] On Behalf Of Dave EU Andrews
Sent: 16 June 2008 07:26
To: [[9]]; 'David Olivier'; 'Clive HINCHCLIFFE';[[10]];[[11]]; 'Mark Barrett';[[12]];[[13]]
Subject: [claverton] Fuel consumptions. Cars v buses v trams. Cars appear to use 6 times as much per passenger km and it has to be liquid fossil, trams can use wind power.
To take this discussion forward, can someone please provide a table giving kWh per passenger km, either wise we are talking round in (the )circles (line). And there is no need to include power station losses, since the assumption is we will be using wind power direct to the bus. I've made a start but really this is for the transport gurus not the moderator.
Quote from Lewis Lesley http://energydiscussiongroup.wikispaces.com/space/showimage/Modern_Railways_May_2008_%287.JPG// // or Tinyfied: http://tinyurl.com/6mhc4n // "The 18 tonne Centenary trams in Blackpool consume 1.5 kWh per km run, the 46 tonne Manchester Metro link cars 4 kWh / km and the 54 tonne Sheffield Supertrams 4.5 kWh/km. The 22 tonne City Class (Prof Lesley's group) was measured at 1 kWh/km." // Endquote Assuming say 20 passengers average then I get this to be 0.05 kWh/passenger km. You can see details of Sustracos technology at :http://energydiscussiongroup.wikispaces.com/space/showimage/Sustraco+%282%29.pdf or tinyfied: http://tinyurl.com/5xt2hv
Taking a golf, (beloved of David Oliver, yes and a very fine car, I had one once,) lets say 60 mpg in town, and 1.3 passengers average. That's 1/60th g per mile, or 1/60th x 0.625 g/km. At 40 kWh per gallon that is 1/60th x 0.625 x 40 = 0.415 kWh.km. Or say 0.32 kWh/km/passenger. That is 6 times more than the tram, and the tram can be all wind power. Can someone please refine my figures... I am sure the Sheffield Super tram takes more than 30 passengers. Clive could you perhaps produce a table including your ULR device? I am guessing that half of all car mileages are in town and could realistically be replaced by trams - Mark Barrett - any views - you seem to have acutally donw the work on this, ulike us theoreticians (stricly armchair) Kind Regards Dave A especially for those who can’t walk far. Electric buses pretty quiet and smooth - I’ve been on some. And some metro trains have rubber wheels! (see http://en.wikipedia.org/wiki/Rubber-tyred_metro for advantages)
I guess the optimum will be some mix of train/underground/tram/bus/ electric taxi that will vary according to circumstances, perhaps most importantly p.km over different routes and stop intervals; I have no commitment to any particular mode. What we need is an optimising model to find least cost/energy mix to find the right horses for courses, so to speak.
This is a very useful overview of transport and energy: http://www.ptua.org.au/myths/energy.shtml
And this is interesting too: http://www.dft.gov.uk/162259/187604/206711/206721/214566/REF
Best wishes
Mark
Dr Mark Barrett, Principal RCUK Academic Research Fellow Bartlett School of Graduate Studies
From: Lewis Lesley [14]
Sent: 16 June 2008 14:18
To: Mark Barrett
Subject: Re: cars/trams/buses etc
Mark, Many are running on either dedicated bus lanes or busways. The nearest example is Runcorn New Town, built around a busway, opened in 1967 to give faster bus journeys than driving a car. The Master Plan target was 50% modal split in the peak, the actual figure was 15% no better than other UK towns of the same size without busways. Today sections of the busway have been abandoned.
Further away Adelaide has a large guided busway system, and Ottawa a busway network (like Runcorn). Both have decided to convert to light rail because of a failure to attract car commuters. The only successful busway is Coritiba in Brazil but here car ownership is low. Experience everywhere is that as prosperity increases people buy cars to escape from bus dependence ( a slight simplification).
Steel wheels on steel rails have one major benefit over buses running on tarmac or concrete, very smooth riding. The guided busway in Edinburgh (WEBS) had to be relaid 3 times because the ride quality was so poor buses had to run at 20mph for the safety of passengers, even though buses on a parallel road ran at 30mph. Trams being electrically powered have smooth jerk free starting and stopping. Even with automatic gears buses are jerky. Trams can also accelerate at a faster rate than buses, especially when full so giving a faster average speed even if the maximum road speed of buses and trams is the same.
Can I suggest you do a little thought experiment and ask why in London the underground (excluding the main line commuter rail services) carry the same number of passengers as the bus network which is 100 times more comprehensive ? It is not just about speed. Lewis
On 16 Jun 2008, at 13:07, Mark Barrett wrote:
Dear Lewis
Agree havent looked at this. But a question I have is: are these buses running in proper bus lanes to give about same speed as trams? Many/most/all bus lanes and their operation (priority etc.) especially in UK, are very poor so average bus speed no better than car.
Or are you saying that there is some great preference for steel wheels on rails as opposed to rubber tyres on roads?; because buses/trams are otherwise more or less the same. This would really surprise me; convenience, time, cost are surely the great concerns to users.
Best wishes
Mark
Dr Mark Barrett, Principal RCUK Academic Research Fellow
Bartlett School of Graduate Studies
From: Lewis Lesley [15]
Sent: 16 June 2008 12:55
To: Mark Barrett
Subject: Re: cars/trams/buses etc
Dear Mark,
One big disadvantage you have not included is that worldwide bus based public transport attracts only a small number of car commuters, typically less than 5%, whereas trams and light rail consistently attract 30-40% ex car users.
You might like to look at www.gluas.com a new tramway being promoted in Galway City (pop 65,000). A two line tram network will raise public transport use from a present 5% (bus only) to about 20%. There is little point discussing the supply side of public transport without a consideration of the demand side. Cheap but empty buses are not economically viable, especially as about 60% of bus costs are for staff.
Sincerely,
Lewis Lesley Technical Director TRAM Power Ltd. www.trampower.co.uk
On 16 Jun 2008, at 12:38, Mark Barrett wrote:
The advantages of the (electric/hybrid?) bus:
Can introduce incrementally (and more cheaply?); dont need rail system, but __do need bus lanes__ which can safely be used by bikes etc unlike tram rails. Can update technology more easily
Routeing much more flexible and can change routes/bus size according to time of day etc. to sustain occupancy factor.
Disadvantages:
Range! 150-200 km. 10 round trips of 15 km what does a city bus typically do each day? Can batteries be replaced?
Engine/battery efficiency probably ~65% of efficiency of rail system
Many links http://www.cleanairnet.org/infopool/1411/propertyvalue-17734.html http://www.busonline.ca/regions/kel/news/hybrid_electric.cfm http://transit-safety.volpe.dot.gov/Publications/cleanair/DesignGuidelines/HTML/DesignGuidelines.htm http://www.electric-fuel.com/evpro/Phase3.pdf Solar elec bus!: http://www.adelaidecitycouncil.com/adccwr/publications/guides_factsheets/tindo_fact_sheet.pdf At the risk of repetition, see particularly point 1. and effect of occupancy. Slide numbers refer to attached. 1.Energy per passenger.km depends on vehicle size, type, speed and occupancy factor. (e.g. slide 13). A car with 4 people is better than a bus with 8 downsizing could reduce car CO2 by over 60% (slide 15). So sometimes bus/train better, sometimes car better. Walk/cycle always better. 2.Carbon per passenger.km depends on 1 __and__ fuel used. Train/trolleybus/tram can use zero carbon elec, cars more difficult but the way to go, aircraft very hard indeed. 3.For internal combustion engines with standing heat losses there is a minimum energy per km speed which is not zero. (slide 17) Main energy loss is not rolling resistance but drag/transmission/engine 4. Many other benefits going away from cars: congestion, safety (slides 19-21) but you pay a steep price. I was driving on the north circular yesterday. Pedestrian crossing every km or so. So to cross the 20 m road you need to walk about 1000 m 50x distance penalty not uncommon on many urban roads. This penalty + safety penalty + . Explains fat gits like me and kids in cars. Best wishes Mark Dr Mark Barrett, Principal RCUK Academic Research Fellow Bartlett School of Graduate Studies
From: Dave EU Andrews [16]
Sent: 16 June 2008 11:10
To: [[17]]
Subject: PROGRESS..Fuel consumptions. Cars v buses v trams. Cars appear to use 6 times as much per passenger km and it has to be liquid fossil, trams can use wind power. Excellent Roger. So what you are saying, I think, and I agree, is that we need the total number of annual tram km, divided presumably by the number of actual passenger kM. Can the tram experts serve us that up please? Agree of course about the fossil fuel power stations, but it also works with Sustraco bio gas powered vehicle..... London has a large amount of digestion within the city.... and a huge refuse problem - what better way to get rid of it, than digest it, and use the methane in Sustraco vehicles? I note the old Blackpool trams do pretty well? Why does HMG force new trams to be much heavier and less efficient? Do I detect incompetence, a conspiracy theory, or seats on the board of energy companies when the people whowho make these decisionsretire?
Dave A
From: claverton@yahoogroups.co.uk]] [18] On Behalf Of Roger Button
Sent: 16 June 2008 10:52
To: [[19]]
Subject: RE: [claverton] Fuel consumptions. Cars v buses v trams. Cars appear to use 6 times as much per passenger km and it has to be liquid fossil, trams can use wind power.
Hi Dave,
Here is my table, using real data from my VW diesel Golf: || Tram: || kWh/km || Passengers || kWh/person-km || || Blackpool || 1.5 || 20 || 0.08 || || Manchester || 4 || 20 || 0.20 || || Sheffield || 4.5 || 30 || 0.15 || || City Class || 1 || 20 || 0.05 || || Car: || || || || || VW Golf || 1.1 || 1.3 || 0.85 ||
There are various caveats. Obviously the electricity for the trams is assumed to come from a non-thermal power station, or the power would need to be multiplied by 3, say. The tram loadings need to be averaged over the whole length of the run, with and against the peak flow, and over the whole day and evening, and this is where I probably part company from the tram enthusiasts. I suspect that although an 80 seater tram may be fully loaded during the peak couple of hours in one direction, for the rest of the journey, and day, it will not. I think an average loading of 25% would be very high, and I would welcome some real data on this. If the Sheffield tram were, in fact, powered by electricity bought from the National grid, and therefore thermally generated, the consumption would be around 0.45 kWh/person-km. If the loading of 20 passengers were only achieved half the time the consumption would rise to 0.9 kWhr/person-km, and be the same as the VW Golf. Thus, for serious energy savings something much lighter, and with a much lower spec, than a Sheffield tram is required. If the City Class really does use only 25% of the energy on comparable routes (Sheffield hills) then significant savings over private cars are indeed possible. Kind regards, Roger Button
From: [[20]] [21] On Behalf Of Dave EU Andrews
Sent: 16 June 2008 07:26
To: [[22]]; 'David Olivier'; 'Clive HINCHCLIFFE';[[23]];[[24]]; 'Mark Barrett';[[25]];[[26]]
Subject: [claverton] Fuel consumptions. Cars v buses v trams. Cars appear to use 6 times as much per passenger km and it has to be liquid fossil, trams can use wind power.
To take this discussion forward, can someone please provide a table giving kWh per passenger km, either wise we are talking round in (the )circles (line). And there is no need to include power station losses, since the assumption is we will be using wind power direct to the bus. I've made a start but really this is for the transport gurus not the moderator.
Quote from Lewis Lesley http://energydiscussiongroup.wikispaces.com/space/showimage/Modern_Railways_May_2008_%287.JPG// // or Tinyfied: http://tinyurl.com/6mhc4n // "The 18 tonne Centenary trams in Blackpool consume 1.5 kWh per km run, the 46 tonne Manchester Metro link cars 4 kWh / km and the 54 tonne Sheffield Supertrams 4.5 kWh/km. The 22 tonne City Class (Prof Lesley's group) was measured at 1 kWh/km." // Endquote
Assuming say 20 passengers average then I get this to be 0.05 kWh/passenger km. You can see details of Sustracos technology at :http://energydiscussiongroup.wikispaces.com/space/showimage/Sustraco+%282%29.pdf or tinyfied: http://tinyurl.com/5xt2hv Taking a golf, (beloved of David Oliver, yes and a very fine car, I had one once,) lets say 60 mpg in town, and 1.3 passengers average. That's 1/60th g per mile, or 1/60th x 0.625 g/km. At 40 kWh per gallon that is 1/60th x 0.625 x 40 = 0.415 kWh.km. Or say 0.32 kWh/km/passenger. That is 6 times more than the tram, and the tram can be all wind power. Can someone please refine my figures... I am sure the Sheffield Super tram takes more than 30 passengers. Clive could you perhaps produce a table including your ULR device? I am guessing that half of all car mileages are in town and could realistically be replaced by trams - Mark Barrett - any views - you seem to have acutally donw the work on this, ulike us theoreticians (stricly armchair)
Kind Regards
Dave A
