I've always been interested in these trucks, they look cool. I infer from the text with this picture that non-steerable trucks provide less tractive effort than steerable types; I also guess that the steerables require maintenance.
Are the more simple looking trucks on EMD SD locomotives, for example, also steerable using a different method? If not, does anyone know how much this reduces total tractive effort? Does this only make a difference when starting load on a curve?
http://www.railpictures.net/viewphoto.php?id=126306
Example of SD trucks (note that maintenance crew is on a different track :))
http://www.railpictures.net/viewphoto.php?id=555890
Also, the class(?) lights are cool, kinda like Conrail marker lights.