On modern trains, why is it that when they have two engines at the front, one of them is backward?

Question

On modern trains, why is it that when they have two engines at the front, one of them is backward?

Answer 1

The one engine in the front is for pulling the other is for pushing what I mean by that is trains that have the engines facing away from each other usually have to go up a steep incline in which one engine pulling by itself would not have enough power so the other engine assists it by pushing it up the incline.

Answer 2

Because they can run at full steam in forward or reverse. My guess is the direction with the 2 engines have a tougher load to go.

Answer 3

Because you don't want one engine sniffing the other engine's butt.

These are train engines, not dogs!

Answer 4

redundancy

Answer 5

so that control booths are close to each other

Answer 6

Because it's really hard to turn a locomotive around!   You can't just do it anywhere, you need a special wye or turning loop.

All modern locomotives work equally well in either direction.   But the cabs are set up so they're easier to drive in one direction.

If you set em up like this <== ==> then you get the best cab setup in either direction, no fuss!

Answer 7

Hog would be correct.. He's the man.

Answer 8

Modern American diesel-electric train engines have the ability to run full speed in either direction.   This is actually true of most modern diesel-electric and electric only locomotives around the world.

One reason for a pair of engines may be back to back while pulling a load is so that when they're later uncoupled they can immediately be used on another train without having to worry about turning the combo around.  It's not that it's hard to turn an engine around, just that it wastes time and isn't always convenient.  And since all engines can be controlled from the lead unit, it doesn't matter which way they're facing except for the lead unit (and it only matters on the lead unit for visibility).

So, if you have a pair of engines (with Engine2 leading) hauling a load from West to East, it might look like this

Train-Engine1-Engine2

Now when the train reaches its destination, the engines can be quickly uncoupled from the train, switched to a new track, and coupled to a new train headed West (with Engine1 now leading) which would look like this

Engine1-Engine2-Train

Notice that by having coupled Engine1 and Engine2 facing in opposite directions, they can be used for opposite direction trains without having to find a place to turn them around.

So it all comes down to saving time and making things easier on the crews assembling a train since it doesn't matter which way the engine is facing when it comes to power.

Answer 9

The answers are close, though, All American.........

The locomotives run equally well in either direction.  When in a "back to back" configuration, it is simply for the convenience of having a cab at each end of the consist.  The number or direction of intermediate units in the consist is usually the luck of the draw.  

When most consists are coupled for service in Multiple Unit (MU) operation, the number of individual units is determined for how much horsepower is needed to move a given amount of tonnage over a district(s).  When MUed, all the engines run in the same direction, regardless of which way the unit is facing, as direction of movement is determined by electronic means.  The units operate as one engine.

The benefit of having the units on either end face in opposite directions is more a time saving measure as anything else.  When the train arrives at its terminating destination, the units can be put on another train to run in the opposite direction, without having to turn the consist so that the controlling locomotive is facing in the right direction.

Control of the consist can be set up on any of the units in the consist.  So, if a northbound train arrives at a terminal, the power can go right on top of a southbound train.  All that is needed is to transfer control of the consist from one end to the other, by cutting out and cutting in the brake valves, and positioning of other switches necessary for operation, such as the headlight control set up switches, engine run, control and fuel pump and generator field switches.

Zippty bang and they're on their way again.  The carriers don't like to have them sitting or delayed any longer than possible.  When they're not moving, they're not making any money.

Answer 10

so when they stop they turn one on and put the other one to brake

Answer 11

the engine in the rear part of the train supply the electric power to the cars (for lightning, air conditioning, etc)

also when the train reaches it's final station it's easy for the operator (driver) of the train to reverse.

if the train has only one engine it must go to a triangular siding in order to reverse

Answer 12

I'm not a pro but I also do not believe ANY of the above answers   /