Re: Model Railroading ala Russo Loco

Russ, I have been told that since the thing had all 3 cylinders the same size that high pressure steam went to the front two sets and the third set was fed low pressure steam from the middle set. That, of course made the third set somewhat less powerful than the front two. Whether or not there was a distributing valve to allow high pressure steam to the rear set I do not know, but if so, it would have caused a severe back pressure problem for the middle set, since it exhausted to the rear set.

I think that the thing might have worked better if you could have supplied high pressure steam to the middle and rear sets and had a large set of front low pressure cylinders like a standard Mallet compound, but I really don't know.

The results with the Erie and Virginian triplexes seemed to be that the demands of the three cylinders for steam at the moment when peak tractive effort was needed outstripped the boilers ability to make steam and so the engine basically fell down.

When better steels for higher pressure boilers were developed, train speeds had increased also and the emphasis was on horsepower not tractive effort, and no one attempted to revisit the concept.

Think of what an N&W Y-6b boiler which could provide the requisite amount of steam, along with its driving system with the huge low pressure compound cylinders could have done with an extra high pressure engine under the tender.......