KansasMike posted:In my neighborhood the KCS uses a lot of DP, especially on coal and grain trains. The odd part is that one coal train may run with 2 on the head and 3 on the rear and the next one may be 2 on the head, 2 about 2/3 back and 1 on the rear. I haven't had a chance to talk with anyone that would know (actual railroad employee) and ask why one coal train runs 3 x 2 or 2 x 3 and the next one is 2 x 2 x 1.
The placement of DPU power throughout a unit coal train is mostly dictated by the coal mine and/or the unloading site at the power plant. Very few, if any, coal mines throughout the Powder River Coal Basin, allow mid-train DPU power since such placement up-sets the flood-loading of the 100+ car unit coal trains. I've see what happens to a nice new SD70MAC when the coal delivery operator screwed up and "loaded" 130 tons of coal on top of a mid-train DPU!
