Lateral Motion Devises

Trains Magazine General Discussion
1

How do lateral motion devises on steam locomotives work? Are there more than one kind and where can I get drawings/pictures for them?

Thanks,
John

2

Hi John.Would you explain more about lateral motion devices? The lead wheels (pony truck) helped to inhibit side to side swaying. Cordially,Joe

3

Hi Joe,
The thunderous silence about this topic implies that I hit upon an unkown subject. The pony truck helps guide the engine around curves be lifting the frame front rail. In many cases this lifting is progressive; providing more lift as the curvature increases.
All locomotives with more than four drivers require some lateral motion or they will not stay on the track. Locomotives with long wheel bases need help to be less stiff. Lateral motion devices are located on a chosen driver axle betwee the driver boxes. They allow more movement in a curve while keeping all axles in tram. As the locomotive exits the curve the lateral motion device returns the axle and drivers to their centered position.

Sincerely,
John

4

Re: the thundering silence - suggest you seek a copy of a Locomotive Cyclopedia, which was published by Simmmons-Boardman periodically over the years. Kalmbach reprinted the 1941 edition at one time, which had drawings of every type of device used on steam locomotives.

5

Thanks Gregg,
I have an orignal 1941 issue, however, as a machinist building live steam models, sales burbs on asssorted appiances fall short. I do agree that its great resource but limited.

John

6

Hi John,me again.Have you considered posting your question on one of the forums at www.railroad.net/ their forum is divided into about 50 catagories including garden railroads,live steam,Alco and baldwin.It’s a lot busier then this forum.You are right some sort of lateral play would be needed.I read once the old PRR T-1,and Q-2 were too rigid.

7

Thanks Joe,
I’ll try that. I’m trying to design a new loco and the proto type (2-10-2) had a lateral motion device.

John