"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: 16 Aug 2007 - this issue has now been looked at in detail - see detailed report on the subject 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/) However I wonder if methane (produced from organic waste) might be an even more environmentally friendly option - something I had never thought about until I accidentally came across on a recent visit to Somerset a company called Organic Power Ltd (see http://www.organic-power) that has developed not only the technology for producing the stuff but has a prototype car fitted out to demonstrate its suitability as a fuel for internal combustion engines.

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. Certainly Christopher Maltin at Organic Power scoffs at government assistance because it would impose too many constraints on his plans and actions, and he prefers to finance his project through private equity.  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."

Dr. David Smith (see Who's Who page), who works for boiler manufacturers Mitsui-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: Whilst not offering significant environmental gains, pulverized coal combustion would offer major advantages over lump coal combustion. It would eliminate the "grate limit" phenomenum and problems associated with clinker formation, spark emissions and ash disposal. Stoking could also be automated much more easily making one-man operation a real possibility. Effectively it would have all the advantages that oil-firing confers. The technology was in fact used successfully in Australia, Germany and the UK in the 1920s, 30s and 50s, as described in Chapter VI of a book titled "Brown Coal" by H. Herman (one-time State. Director of Geological Survey) published by the State Electricity Commission of Victoria, Australia in 1952. The chapter titled "Brown Coal Dust Firing for Locomotives" is reproduced here.