What is the purpose of having one locamotive backwards on a train?

Question

http://users.sisna.com/jimbobnay/Abo/Abo_029.jpg

Answer 1

The locomotives in the picture would have been marshalled together at the depot which was probably some distance from the yard where they were to pick up the train, so the set would have been coupled together with cabs at the outer ends to make it easier to drive in either direction. Hence, one engine facing backwards.

Answer 2

It serves no special purpose. An engine can run at the same speed in either direction. They probably didn't have an easy way to turn it around.

Answer 3

Well, you pretty much got the jist of it already from the other folks that have responded. The loco arrangement in the photo is how an Engineer will like to see them lined up when he comes to work. The train in the photo is not a "local", but if it was, one rear facing engine is the one you'll be riding in to go the opposite direction when it's time to come back home. It's an easy enough process to change the lead engine from controlling to the rear engine as controlling. A few pushes with your finger on a computer screen, flip two switches, position one air valve, walk to the rear engine, and try to talk your Conductor in to giving you one of his 23 sandwiches.

Answer 4

Sometimes they do that on locals and work trains that switch direction all the time so the engineer can run from the lead locomotive On mainline freight trains it's just the luck of the draw when they build the locomotive consist.They all operate in the same direction as the controlling locomotive regardless of what way they are pointing.

Answer 5

Based on your picture, I assume you are talking about long freight trains.

That being the case, the locomotives on the back could be "helpers" that are attached to help a train get up a hill or long grade.  They help push until the train gets to the top, and then are cut off to go and help another job later.

It is an efficient use of horsepower.

Another possibility is that they are "distributed power", which are locomotives put there on the back for the whole trip, that are radio controlled from the front.  The engineer in the lead locomotive can control them to help him along as needed at any time throughout his long run.

EDIT:

Okay, if you are asking, "Why is one of the locomotives in the consist pointed the wrong way".  This is simple - locomotives operate effectively in either direction.  When the block of locomotives is done with the run, notice that the last locomotive is pointed to go the other way.  Now it will become the front of the train going in the other direction, and you don't have to turn them around to go back the other way.