thumbs...

With USA railroads, a rule of thumb, is if the speed, downhill, under full dynamic braking exceeds one-half mph, it's time for a brake application.
The amount of application, is related to the weight of the train, the steepness of the grade, etc.
The dynamic brake is still used, however one must bail off the air on the locomotive brakes. Bailing off the engine brakes prevents wheel slide.
Trainz Engine Editor, is a tool used to tweak enginespec config.txt files.
A
locomotive force calculator, is from Al Krug, a locomotive engineer with BNSF.
Years of experience, led Al Krug to post
Railroad Facts & Figures, to explain in depth, how engineers handle tonnage, and horsepower, vs tractive effort...
And Ferngren is doing a great job of that too! If you need some of the material explained, please post! I so enjoy learning and sharing, because
Knowing, & Sharing...Is The Only Way!