How does a freight train engineer control the diesel locomotive engines in the rear?

Question

sometimes i see long freight trains with diesel locomotive engines in the front and rear. how does the engineer in the front locomotive controll the locomotive(s) in the rear?

Answer 1

These are called collectively, "helper engines." There are remotes, which receive commands via radio from the controlling locomotive on the point, or they are manned by a helper crew, usually consisting of an engineer and "lookout."

Answer 2

It's all radio and remote control.

Answer 3

Hoghead referred to them as "helpers".  More commonly in todays railroad, if the engineer on the head end of the train is controlling the rear ones as well......they are called distributed power.  The engines on the rear are hooked up "electronically" to do what the engineer on the head end wants.  You have a DP "distributed power" box or computer screen that has all sorts of different options on the head end of the train.  The engineer can manually control the rear engines to throttle or break regardless of what the head end is doing, or he can "synchronize" the rear units to do exactly what the head unit is doing.  It's up the engineer to run it how he wants.  If it's in sync, every throttle notch the engineer gives on the head end will be duplicated on the rear....same with braking.  The boxes and computer screen referred to above is basically the "control" station for the rear units and most generally they are a touch screen display.  The front to rear linking can be more easily thought of to be like satellite t.v.  You just have to be on the right frequency to get them to link up and work together.