locomotive horsepower

[Anonymous]

i remember when i was a young boy. i would go with my father to the fec hialeah yard. and see a GP-9. pull about 25 loaded rock cars. now i know that fla is flat. but i've also seen a SCL U23B. pull 32loaded woodchip cars. uphill in tallahassee . i love to see engines pull without comuters or tech reps having to run out there to save the day....

[BRAKIE]

I recall one night while working on the PRR,we had 1 GP9 pulling 41 cars of crush stone.That old gal worked her heart out and got the job done! That 567b really sounded good!Another time while working on the Chessie we had 2 GP9s on a mine run.That night we had 75 or 80 loads of coal coming out of a hollow with a 1.3% grade.Those old Geeps lifted that train over the grade and through the curve on that grade.Yes,EMD made a very fine engine in the GP7/9.You gotta love 'em!

[Anonymous]

Locomotive horse power???? Here is a question for you guys. What unit can pull more cars. An SD-38-2 with 2000 HP or an SD-40-2 with 3000 HP. Now both units weigh the same and they both have six traction motors. The answer is both units would pull exactly the same amount of cars. When it comes to starting a train horse power has very little to do with it, because no matter how much horse power you have if you do not have tractive effort to grip the rail you will not move that train. Horse power equals speed that is why the ATSF use to buy GP-60's and B-40-8's because they always put lots of units on their trains and they were not really concerned about tractive effort they were more concerned about speed. With the 4 axle units the ATSF had all that HP is feeding 4 traction motors. Wow those units would really fly!

[BRAKIE]

Here is a question for you.What is black has both units sanders open and pulling 250 loaded hopper cars? Hint. I bet Ed King Knows!

[Anonymous]

Larry: Great stories! Just a small correction: The GP9 would have had a 567C engine; not a 567B engine.

[Anonymous]

Larry: Great stories! Just a small correction: The GP9 would have had a 567C engine; not a 567B engine.

[BRAKIE]

***, You are correct.The GP7 had the 567b,the 9 had the 567c.Slip of the old gray matter on my part.Thanks for catching it.I always kind of thought(no proof)that the 567c had a little more whine to it then the 567b when reving up.I also always thought(again no proof)that the 567d in the GP18 loaded a little faster then the 7&9.Any comments on this?

[Anonymous]

Sorry for question, but I know nothing of how traction motors work. Could someone please explain how the deisel hp is turned into speed and/or power for the traction motor? Thank you.

[Anonymous]

Dear Ted

Simplified answer is that diesel engine drives a generator or alternator to make electricity. The electric power goes to the traction motor where it turns a shaft with a toothed gear on one end. That gear engages a toothed ring gear just inside of the wheel on one side. The ring gear is rigidly mounted to the axle so the axle turns. The wheels are rigidly mounted to the axle, so the wheels turn.

Mac

[Anonymous]

Thank you for the answer Mac. I appreciate it. I was wondering how it worked.

[Anonymous]

Just a note to your topic. Yes, horsepower is speed and tractive effort is the grunt(torque if you will). That is one reason the SD45 was so unsucessfull in the east and still around in the west. At slow speeds all that power went to waste but out west where they could streach their legs they were best.