Re: lbf. vs Tractive Effort

Conversation between an Army officer and an Air Force Pilot:

Army: We're computing load weight, when is the aircraft overloaded?

Pilot: When it's too heavy to get off the ground.

There are so MANY variables involved in flight (Density Altitude, fuel quality, COG, fuel weight, and on and on) that it's really not possible to answer that question correctly.

Trainmaster: How much power do you need to top the hill?

Engineer: Enough to get to the other side.

A train in PA climbing Horseshoe is going to need a LOT less "HP" than the same train climbing up to the Moffat Tunnel. As one engineer commented to me, it's not so much the grade but the constant and sharp curves. Most folks never imagine it takes more power to take a train around a curve than it does to pull on straight track! And diesels absolutely hate two things: Altitude and extreme temperatures.

So, with the wonderful magic of Distributed Power, you take four locomotives, and only use what you need. A DPU may never do anything but idle the whole trip, but if it's needed, it's worth it's weight in gold.

Robert



Edited 1 time(s). Last edit at 09/18/2020 02:57PM by rdamurphy.