I have a Visual Basic train computer program that I wrote several years ago.  Someone wanted a copy, so I updated it and made it a little more user friendly. It calculates things such as 

1. What speed will a train of X tons, y cars, and z HP go up a given grade?
2. What is the drawbar pull on a certain train/grade?
3. How much HP is needed for a certain train to go up a certain grade at a specified speed?
4. What is the max tonnage a specified HP can pull up a specified grade at this speed?

It is based on the Davis formula.  I guarentee NOTHING. If you use it and stall or break in two don't come whining to me.   The file is only about 55KB and is VB which means Windows and VBRUN300.DLL on your computer will run the file.

AAK