Chris Newman responded as follows:
This is a very valid question that I have been asked by several people recently, and one that I have responded to with the following response. (Note: my opinions on the matter have not been endorsed by Dave Wardale, so I offer them tentatively):
"The question is very pertinent in this day and age, but it has not as yet been looked at seriously for the 5AT project. [Note: this issue has since been studied in detail - see "Review of Carbon Neutral Fuels with Potential for Use in Modern Steam Locomotives" by Brian McCammon.]
Certainly L.D. Porta saw a great future for steam technology through the burning of biomass - in fact the only letter that I ever received from him shortly before he died included the words: "May I venture to say that after the first 5AT loco runs, there will be an avalanche of steam loco buildings. But let me say that the cardinal point is to make them run on biomass, a matter of which I started to have experience as apprentice fireman in 1940 when I was 18: invaluable experience!"
The reason why biomass hasn't been given serious consideration so far is because of the perception that to be commercially successful the 5AT will (a) need to run in a diesel traction environment where refuelling with diesel fuel will require no special infrastructure, and (b) it will have to be highly reliable. The latter requires that all (or practically all) the technology that is used on the locomotive is tried-and-proven, which biomass fuelling (and the technology for feeding vast quantities of the stuff into the loco's firebox) would not be. In the project's early days, consideration was given to fuelling the loco with LPG to make it more environmentally friendly, but this idea was abandoned because of perceived dangers (and perceived difficulties with safety authorities) associated with transporting a large volume of flammable gas in a high pressure container at high speed immediately behind the locomotive.
John Johnston in the USA has put forward the idea of fuelling a locomotive directly with corn (avoiding the cost of converting the starch into ethanol) and is planning his own project to design and build an environmentally friendly locomotive in miniature (see http://www.greenloco.com/)
As to seeking government grants, the only comment that I can make (and I make on the basis of hearsay only) is that the hurdles imposed by the government on any organization applying for grants are so great as to often render the effort unwarranted. Still, I'm sure grant money could be sought if we had a sufficiently robust commercial proposal, but at present our focus is aimed at the simpler (but still very difficult) task of putting together a strong enough plan based on "known" technology, to attract private finance.
If the recent rises in oil prices continue, then "alternative" fuel options are going to become more and more attractive. As I say though, methane suddenly has great appeal to me but it is an idea that I've not pressed on the others in the 5AT planning organization because this is not the time for radical new ideas. Planning an oil-burning 5AT is radical enough as it is! The same applies to biomass and other fuels. Certainly though, once the 5AT has demonstrated the possibilities for steam technology in the modern world, then there will probably be a rapid demand for experimentation with alternative fuels."
Note: In 1987 L.D. Porta presented a paper titled "The Contribution of a New Steam Motive Power to an Oil-less World" at an International Seminar on Railway Technology in Mexico, July 1987. The English translation not published but a 4MB PDF version transcribed from the original typescript is downloadable from this website.
Dr. David Smith, who works for boiler manufacturers Doosan-Babcock, offers the following additional observation:
"Oil firing is enough of a technological step in the first instance. As an aside there is a lot of work being done on co-firing biomass with coal in UK power stations at the moment. I remain skeptical about biomass in a locomotive boiler though (or rather I think it would take a considerable amount of development work) where there is enough difficulty keeping relatively large lumps of coal on the grate, never mind small (therefore light) granular biomass materials (GPCS or no GPCS!!). A possibility is to go for pulverized fuel combustion - but how would you pulverize the fuel? - what fineness is required to get complete combustion in a locomotive firebox and so on?.....Plus - there can be a lot of moisture in some of these fuels (I saw 50% quoted for bagasse) which means a big latent heat loss." (Note - see FAQ page on coal fuel for further comments on pulverized coal firing.)
As mentioned in the Fuels page under the Environment section of this website, one obvious advantage that steam traction offers is its ability to burn almost any combustable fuel, including renewable fuels like wood. These possibilities are further discussed in several papers downloadable from this website, including:
- McCammon B., "Review of Carbon Neutral Fuels with Potential for Use in Modern Steam Locomotives", an unpublished paper prepared specifically for the 5AT Project.
- Porta, L.D., "The Contribution of a New Steam Motive Power to an Oil-less World" presented at an International Seminar on Railway Technology in Mexico, July 1987. English translation not published. 4MB download).
- Keyte, J., "A Vision for the Future" published in New Zealand Solar Action Bulletin No 88 Oct 2009.
- Newman, C.J.E.,"Could there be a place for Steam Traction for Rail Transport in a 'Sustainable Energy' World?", published in New Zealand Solar Action Bulletin No 88 Oct 2009.
- Newman, C.J.E., "Considerations relating to costs of 'Sustainable' Railway Traction Options", published in New Zealand Solar Action Bulletin No 88 Oct 2009.