Sounds like my last date...:D

(de-lurking because this question didn't really get answered)

Railroads often place additional locomotives on the end of a train, and sometimes in the middle. It's called Distributed Power.

Basically, if all the power is at the head end of the train, this can put enormous stress on the couplers. Adding locomotives at the end or in the middle helps move the train more efficiently. This is especially important in hilly/mountainous areas.

It helps to remember that those big diesel locomotives are actually diesel-electric locomotives. The diesel engines under the hoods generic electric power which is then distributed to the wheels. Nowadays, there is all kinds of fancy computer-controlled circuitry to monitor load levels and properly distribute the power to whatever axles are available, be they all at the head, in the middle, or at the end.

That said, railroads will sometimes take two trains that happen to be leaving the same yard, around the same time and going the same way, and just stick 'em together. That would also lead to seeing one or more engines in the middle of a train. Once everything is hooked up and the locomotives are all talking to each other, it is now logistically just one train to keep track of instead of two. At some yards hundreds of miles away, they'll break them back up again.

Thanks Orbert!

Nice de-lurk, btw, :welcome: back!

Thanks. It was bugging me that no one had answered your question, and I knew the answer. It doesn't happen a lot, but I try to contribute when I can.

Delurking much appreciated!

I add my voice to the thanks and welcome back you've seen.

Y'know, we could use the input... We don't charge by the post, it's clear you're pacing yourself, and doing a*heroic* job of it.

Please, consider posting more.
��

Also...

I have many pics of trains, mostly locomotives gathered during our WASP Odyssey. But I catch more than I post.

Over on Gravdigr's Photo Safari I mentioned the White Tail(ed) Deer that I encountered at the Railroad Interpretive Centre, in Douglas, WY.
This was the mighty loco that I was looking at at the time.
It's a scanned print so less than perfect.

Attachment 66768

The info board (photo to hand) says that it's a 4-8-4 steam loco #5633 of the Chicago, Burlington and Quincy Railroad, but then y'all knew that, didn't ya?
Prior to seeking out the print I mentioned the story to Dad and said that I thought that the loco would weigh in at about 200 tons.
Got that wrong, didn't I? It was 317 tons and twenty eight were built.
I wonder how often they renewed the track. :eek:

Gandy Dancer's employment assurance. ;)

I happened on push-pull at Wiki today.

Saw a train yesterday with a loco at the rear, none in the middle this time.

I guess this is something they've started doing in this neck o' the woods.

Worth noting is that the entire train was double-stacked cargo containers (four to a car), they've only started that on a regular basis (around here) a year or so ago.

Stand back or get a snow job...

High speed rail in China

http://cellar.org/img/chinese-hispeedrail.jpg

bigger version at imgur

That ought to be it's own snow plow at speed. :haha:

This is an excellent description on how our Railroads and trucking work together, and why US railroads are the cheapest and most efficient in the world at moving stuff.