What would be a typical range for the tractive effort of a prototype Shay the size of that represented by the Atlas model? I managed to find figures for three truck Shays, nineteenth century two truck Shays, for Heislers and Climaxes, but none for a Shay like the Atlas model. I did manage to learn that the tractive effort tended to vary quite a bit among prototypes that appeared to be the same, but I could not find a figure or range for this type of Shay.