Driving Wheels turned Opposite Directions

[dangie]

Apologies if this is in the wrong section, but it is about traction.

On another forum I belong to, someone mentioned that many years ago a steam locomotive was designed and built that when tested the driving wheels on opposite sides of the loco turned in opposite directions. One side drove forward, the other in reverse. I'd also seen this in an old book.

Does anyone know any information about this? I've Googled it but can't find anything.

 

[edwin_m]

Unlikely to be opposite sides since opposite wheels are almost always joined by an axle. However driving wheels at opposite ends going in the opposite directions does ring a bell. I think it was one of Webb's compounds for the LNWR where the high pressure cylinders drove one axle and the low pressure cylinders drove another. But I may be wrong...

 

[Peter Mugridge]

I'd agree it's a Webb and I remember reading about this years ago in "The book of heroic failures" by Stephen Pile. No idea if it's still available though. I recall it stating that the LNWR frequently had to use two engines, one of Webb's and one of another design, just to get the train started.

That latter bit sounds like an exaggeration, but it certainly gives the impression that the writer intended!

 

[dangie]

Found this. I think Post 3 covers all. You are right, it was Webb.

http://www.railforums.co.uk/showthread.php?t=79819

 

[krus_aragon]

Found this. I think Post 3 covers all. You are right, it was Webb.

http://www.railforums.co.uk/showthread.php?t=79819

Hm. I was about to contribute to this thread, but it seems that I've (unknowingly) done so already!

 

[RAGNARØKR]

The Webb compounds has what was known as a slip-eccentric valve gear for the centre cylinder, probably due to lack of space. The outside cylinders had Joy's valve gear. When the locomotive backed onto its train, the slip eccentric became set for backwards running and stayed that way when the train started.

There was no room for coupling rods so the driving wheels were uncoupled. I think it was Tuplin who pointed out that the locomotives would have been quite successful if they had been fitted with Walschaerts valve gear, which would have allowed the driving wheels to be coupled.

The Web compounds were probably the "wrong way round", with two small outside high pressure cylinders and one large middle cylinder. The Midland compounds had the high pressure cylinder in the middle and two low pressure cylinders on the outside.