Edit post

Edit your reply below.

Post Body
Enter your post below.
Quoth GP40-2: "The DM&IR M3/M4 produced its maximum HP at approx. 45MPH." I wonder how much of the operating time of these engines was spent at or above this maximum horsepower speed, if indeed it was that high. I suspect not, because horsepower curves peaking at 40-50MPH were found on locomotives with higher drivers - 67-72". The Big Boy, Allegheny and N&W A all produced maximum horsepower in the low 40s. I suspect that the 63"-drivered M3/M4 2-8-8-4s developed their maximum horsepower at a lower speed - in the neighborhood of 35 MPH. Considering that most of the DM&IR loaded movement was actually downhill, which placed most of the strain on the engine's two air pumps, with the engine not producing much, if any, horsepower, and that the uphill movement was with empties, one is given to wonder about the GTM/TH/$ achievements of these engines. Anybody got any figures? Old Timer
Tags (Optional)
Tags are keywords that get attached to your post. They are used to categorize your submission and make it easier to search for. To add tags to your post type a tag into the box below and click the "Add Tag" button.
Add Tag