The threads about a new K4 and such brought up an old idea of mine. Ignoring for a moment the obvious problems of maintenance and railroad resistance, how technically practical would a new steam engine be? Before you answer, let me present my idea.

Part of the problem with steam is that you have low starting tractive effort compared to a diesel-electric. The power curves for steam and diesel are just about opposites. My theory is, if you place a steam turbine in the tender of a conventional rod engine (say, a 4-8-4) and connect that turbine's generator to traction motors on the pony, trailing, and tender trucks, you'd get the best of both worlds. The turbine would provide the high starting tractive effort that a diesel-electric has, while the reciprocating rod engine would provide high-speed power.

How technically feasible is this idea, given modern technology? Could a boiler be built that could supply enough steam for both the cylinders and the turbine? Could you find enough ROOM in the loco and tender for the boiler, turbine, coal bunker, and water tank (and maybe even a condenser)? How would the heat from the boiler affect traction motors on the pony and trailing trucks? Any other technical problems (besides those of supply in a modern world) that I'm overlooking?

Don't know if the pic link will work, but I'm going to give it a try anyway.

The South Carolina Railroad Museum

mconrad@compuzone.net

> Part of the problem with steam is that you
> have low starting tractive effort compared
> to a diesel-electric. The power curves for
> steam and diesel are just about opposites.

Part of the problem is that you are starting a steamer with one hand tied behind your back. The boiler is sitting all steamed up with no place to apply the stored energy. You can avoid the hi-tech turbine and expense of dragging traction motors around if you figger out how to get more cylinders into action, be it tender boosters or the more complicated three and four cylinder arrangements. My personal vote is for tender boosters (small wheels) that can be disengaged when you are finally firing on "all two" on the big wheels. Might as well get some benefit out of all that otherwise wasted tender weight ... please note that this is old technology, that worked.



lamontdc@adelphia.net

You, unknowingly, are rehashing well-tred old turf.

Ross Rowland and friends, in the late 1970s and early 1980s, pursued a company called American Coal Enterprises, that attempted to present the steam locomotive in a re-engineered package much like your illustration. Despite the involvement of Foster-Wheeler (boiler makers) and at least one major coal railroad (BN and/or Chessie), the project faltered badly. Part of the reason was that the oil "shortages" and price spiles of the 1970s that made coal a possibly-feasible option went away; part of the problem was simply the fact that any fleet of ACE 3000's (as the locomotive was to be called) would still have required a separate-but-equal supply system of water, coal, and servicing (lube, ash disposal, etc.)--more investment.

More on this fascinating topic, can be found in Railfan & Railroad magazines of the early 1980s (I believe the ACE project made the cover of the Jan. 1981 or 1982 R&R). Trains Magazine had an article that basically laid the blueprints of the concept out in June 1974 ("Did We Scrap Steam Too Soon?"). and David Wardale will tell you everything you wanted to know about the subject and then some (including allegations that the American Coal Enterprises project was ill-organized and possibly borderline-fraudulent in nature) in his epic volume "The Red Devil and Other Tales of Steam", which is also a textbook on the pros and cons of modern reapplication of steam technology.

lner4472@bcpl.net

RDG 2124 was built with 70" drivers but was expexcted to pull 12,000 ton coal trains. There's a small reciprocating steam engine mounted on the trailing truck that can add extra TF up to about 10 mph. By that time the big cylinders are effective.

Electric City Trolley Museum Association

Simplicity is the steam locomotive's unassailable strength. In principle, the reciprocating steam locomotive has the most simple transmission ever built for railroad service. Unfortunately, the traditional vertical construction of the machine prostitutes this principle severely.

New engines should not attempt to gain thermodynamic superiority by means of complication. It will not work. My book, THE END OF STEAM points out the reasons the steam locomotive will never be a superior thermodynamic heat engine. Instead, ruthless pursuit of simplicity and ease of maintenance are the keys.

There should be little question that a properly built steam locomotive that is operated correctly (good lubrication and boiler water treatment) will be cheaper to own and operate over the life of the machine than an equivalent diesel electric. Several Swiss rack railways are proving this with new steam power every day!

Bill Petitjean

> The threads about a new K4 and such brought
> up an old idea of mine. Ignoring for a
> moment the obvious problems of maintenance
> and railroad resistance, how technically
> practical would a new steam engine be?
> Before you answer, let me present my idea.

> Part of the problem with steam is that you
> have low starting tractive effort compared
> to a diesel-electric. The power curves for
> steam and diesel are just about opposites.
> My theory is, if you place a steam turbine
> in the tender of a conventional rod engine
> (say, a 4-8-4) and connect that turbine's
> generator to traction motors on the pony,
> trailing, and tender trucks, you'd get the
> best of both worlds. The turbine would
> provide the high starting tractive effort
> that a diesel-electric has, while the
> reciprocating rod engine would provide
> high-speed power.

> How technically feasible is this idea, given
> modern technology? Could a boiler be built
> that could supply enough steam for both the
> cylinders and the turbine? Could you find
> enough ROOM in the loco and tender for the
> boiler, turbine, coal bunker, and water tank
> (and maybe even a condenser)? How would the
> heat from the boiler affect traction motors
> on the pony and trailing trucks? Any other
> technical problems (besides those of supply
> in a modern world) that I'm overlooking?

> Don't know if the pic link will work, but
> I'm going to give it a try anyway.


petitinc@nwlink.com

Hi guys. Thanks for starting the thread; I've always been interested in this topic. I have some questions. Matt, for a given conventional, rod locomotive, the majority of the weight is carried on the drivers, right? Therefore, how effective would traction motors be on the pony and trailing trucks, given they carry a smaller percentage of locomotive weight, and the factor of adhesion would be smaller? Also, tender mounted motors(and boosters too) -- wouldn't they tend to be less effective as the locomotive spent its fuel? Bill, is your book available anywhere? It sounds very interesting, as does the book Sandy mentioned. I had always assumed the heart of steam's lacking in the thermal efficiency department came from the fact that combustion is taking place outside of the cylinder, unlike in a diesel. Then you have to worry about insulation and trying to limit how much heat energy the steam loses on its way to the front of the locomotive. Is this necessarily the case? These are my humble observations, I look forward to any corrections from the more knowledgeable. Thanks. Seth


Wilmington & Western Railroad
sethajackson@hotmail.com

> You, unknowingly, are rehashing well-tred
> old turf.

Not unknowingly and not exactly. I remember the ACE 3000. I was skeptical of the concept myself, since the thing was twice the length of a conventional diesel of the same horsepower. It was also a straight steamer with four cylinders. My idea grew out of the ACE 3000 design, trying to address some of the shortcomings I saw in it.

The South Carolina Railroad Museum

mconrad@compuzone.net