“The current issue of Modern Railways magazine has an interesting article by Roger Ford on car, train and plane energy efficiency (June 2004, pp30-31). Ford’s analysis, ‘suggests, and I expect that this will generate some howls of protest, that a family of four going by car is about as environmentally friendly as you can get’. He has obviously forgotten the bicycle, but then he is talking about long distance journeys. Given that in theory ‘nothing can equal the steel wheel on steel rail for environmentally friendly transport’, what has gone wrong? A new state-of-the- art Virgin Super Voyager weighs 40% more per seat than an Intercity 125. Second, faster trains use a lot more energy – cutting the London-Edinburgh time by 30 minutes increases energy consumption by one half. Is half an hour worth it? Third, new trains are badly engineered.The new Pendolino intercity trains use 14 times as much energy for lighting as the trains they replace. How can this be?”
Dr Tim Leunig (daily commuter)
Surbiton
There’s no doubt that energy efficiency has been largely ignored by the railways since privatisation. Some of the last British Rail commuter trains were designed to use 20% less power than their (already efficient) predecessors, through lightweight construction, and by using AC motors, which can more easily provide ‘regenerative braking’ – putting electricity back into the supply when slowing down. For various reasons, this system was never made operational, and conventional brakes remain in use today. Meanwhile, the railway power supply is being completely revamped in the southeast to allow even more power-hungry German machines to enter service. Another odd modern practice is the tendency to put a diesel loco at either end of a train, because it’s cheaper than paying Network Rail to operate the points for the locomotive to run round to the front on branch lines! And although I have not seen the figures, I don’t doubt that the new Virgin Voyager is less fuel-efficient than the wonderful Intercity 125 trains (another British Rail achievement, incidentally). As with cars, extra weight through increased crash-worthiness, power-hungry air-conditioning, and greater acceleration are beginning to make inroads into the inherent efficiency of rail vehicles, although as we shall see, the figures stubbornly indicate that both modes are becoming more fuel-efficient.
When comparing road with rail, we must try not to lose sight of the bigger transport picture. Road transport has indeed become slightly more fuel-efficient in recent years: average vehicle consumption improving slightly, from 25.2mpg in 1993 to 28.2mpg in 2002, largely because of the introduction of fuel-efficient small diesels. Incidentally, these figures are drawn from total vehicle mileage and total fuel consumption, so they include buses and HGVs, which might sound unfair. On the other hand, only 5.8% of traffic is HGV, and the figures also include mopeds and motorcycles. Cars and light vans account for an astonishing 92% of total mileage.
In broad terms, the fuel consumption of road vehicles has hardly changed in 80 years because the increase in efficiency has been obscured by increased weight, bigger engines and so on. Only in North America have cars genuinely become more economic (from a very low base, of course).Throughout the developed world, vehicle efficiency is thought to be on the fall again – presumably because of the recent growth in gas-guzzling 4-wheel- drives, and as a side-effect of increasing congestion. And irrespective of the fuel efficiency of individual vehicles, the growth in UK vehicle mileage has caused an increase in overall consumption, from 39.5 million tonnes (petroleum equivalent) in 1993 to 41.5 million tonnes in 2002.
Virgin’s new Pendolino (left). Is it really less fuel-efficient than it’s predecessor (right)? PHOTO : www.the-siding.co.uk
Meanwhile, the amount of fuel consumed by the railway industry (mainly diesel fuel and electricity) has fallen dramatically, from 0.93 million tonnes to 0.72 million tonnes (petroleum equivalent) in the same period, even though rail passenger/miles have increased by almost a quarter.There are many reasons why this might be so – scrapping of older thirstier freight locomotives, reduction of heavy coal traffic, and (hopefully) better vehicle utilisation, being the obvious ones.
If we look more closely at the 2002 figures and remove the fuel used to move freight (about 10% of the total), we find that passenger rail vehicles consumed some 648,000 tonnes of fuel and covered 443 million train/km.This could be expressed as 684 km/tonne or .581 km/litre, or even more conveniently, as 1.7 miles per gallon. As the average passenger loading in 2002 was 89.6, we can deduce a rough figure of 148 mpg/passenger for rail.
Yes, passenger rail vehicles are getting heavier, thirstier and faster, and they’re doing more miles, but because they’re faster, they’re attracting a lot more passengers, which helps to explain why the mpg/passenger figure is holding up so well.
Roger Ford suggests that a family of four can travel long distances more efficiently by road. In theory – provided their vehicle was a little more efficient than average – this would be possible, but as we all know, the problem with road transport is a passenger loading per car that hovers frustratingly around one. In other words, cars are usually carrying one person to work, or worse still, undertaking ‘positioning moves’; running driver-only to pick up passengers howells ac. In ‘cradle to grave’ terms, intensively-used rail vehicles do much better. As always, the answer is to make better use of public transport.
But, as Tim rightly observes, rail could do better and could make more effort to build on its many other environmental advantages.With the right technology, reduced track congestion and even better vehicle loadings, an improvement to 300mpg/passenger or more would be quite achievable.
