TTQuebec wrote:Wondering if someone could tell me the wheelbase, axlespacing and driver diameter of the BR81? What other x-8-x's are there around in TT? Looking for something for a base to build a USRA 0-8-0...
I take it that you want the dimensions of the model, not the prototype. The prototype had 1100mm drivers (43.307 inches). The wheelbase of one of my Class 81 models is 15 feet (1.5 inches).
There have been quite a few eight coupled TT scale engines.
HP Products made 0-8-0's, 2-8-0's, 2-8-2's, 4-8-2's, and 4-8-4's.
Examples of German eight coupled include the Class 92 (0-8-0), Class 06 (4-8-4), Class 56 (2-8-0), Class 86 (2-8-2). I do not know if any models of the Class 06 have been made, I have examples of the Class 92, Cass 56, and Class 86.
The USRA 0-8-0 had 51" drivers (1,295mm), and a wheelbase of 15 feet, 0 inches, a match for the BR81.
It looks like if you are not too picky about the wheel diameter, a BR81 chassis should work fine.
Besides, during the course of an engine's life, changing the size of drivers is not unheard of. Areas where there are a lot of steep hills often saw locomotives with smaller drivers than locomotives used on level terrain.
I hope that I have been of some help.