# Freight trains question...



## Sheer Luck Holmes (Jul 30, 2006)

Slightly off topic, but as seen from many Amtrak train trips... On some of the longer freight trains that you have over in the USA, I have noticed sometimes a few locomotives at the head, plus some at the rear, and I think once or twice even some also in the middle (but I can't be 100% sure on that last one!)

I can see how an engineer could control several engines at the front, with jumper cables between locos, but can he control others at the rear, or do they have seperate crews? If so, do they communicate by radio? Are all the brakes controlled by the lead engine?

SLH


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## battalion51 (Jul 30, 2006)

Everything is controlled by the lead Engine, DPU's are controlled remotely through radio signals, just as EOT's communicate with the lead engine. Now for Amtrak and Commuter trains when cab cars or an Engine on either end the train is connected together through MU cables that just pass the signal through the coaches.


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## George Harris (Jul 30, 2006)

battalion 51 has it exactly right ofr the mid train units. this sort of system had been used off and on by several companies at least since the 1960's. There are two reasons: reduce coupler forces and to reduce the time of brake pipe air flow.

This may be true for end units at well, but quite a lot of the time they are manned helper sets (bankers in British terminology) running only relatively short distances. There are still several regular helper districts in the US. Cowan on the CSX line between Nashville and Chattanooga, Sand Patch on the CSX ex-B&O west of Cumberland MD, are two that quickly come to mind.


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