On long distance trains like the Empire Builder, do both engines pull even when on flat terrain? Or just on inclines? Also, how is the second engine controlled? I could ask the question why second engine is always backwards but I'm guessing it's because the "hook ups" are in the back...no way to hook the back of one engine to the front of another.
I hope these aren't stupid questions
I'll try and take these one at a time-first, usually both engines are "on line" and putting out power when needed, though the engineer can certainly isolate or shut one down en-route for fuel conservation. With both running however, the train will accelerate out of stations faster, among a few other benefits.
The second engine is controlled via the engineer in the lead controlling locomotive. The engines have electrical connections to "MU" (Multiple Unit operation) the locomotives, usually two, sometimes three, occasionally more. The engines all respond to the engineers commands just like the lead locomotive. As in, when he notches up the throttle from 1 to 2, all locomotives respond the same way, turning multiple locomotives into one big locomotive.
The second engine is not always facing the other direction. It can hook up in any manner,either back to back, back to front, front to front, etc-both ends of locomotives have connections to hook up regardless of which way the engine actually faces. It is desirable though, to have them back to back, so there is an engine facing the other way, so the engineer can operate from the other engine if they need to "swap ends" and run the opposite direction. It helps speed the process at the end of the line, that way they won't need to turn the engines around to face the other direction.