Real life companies and locomotives

[Nitsujy12345]

(Yes, sorry this isn't related to railworks, I have no other place to post this to) I don't think of it much, but looking at how often this happens, how does other railroad companies end up on a different companies train? At the moment, there is a UP heritage unit on an NS train 10N. (As of 10/20/14), which is just lucky, but how does, say, a CN locomotive be power on a Norfolk Southern train? How do they not keep companies on their own line? It isn't good for the rail line owner because they are responsible for the loco if it is on the rail line's train, like on an NS train. There was a BNSF SD70ACe that's nose got smashed in while used as power on an NS train and NS sent it to Juniata Shops to fix it.
Sorry this post is so long and unrelated, but now I'm thinking about it and can't find the answer online. If anyone knows, please let me know. Thanks.
Here is an example: BNSF on NS train at Gallitzin PA.

IMG_1849.JPG

[simer4]

For things like this, you can post them in "The Jungle" forum.

[DrewG]

When a railway needs more power, they will borrow other railways locomotives that were sitting in the yard. Generally railways will try to keep there power on their trains but if need be they will use others. THey will then own the other railway Horsepower Hours. A simple explanation of Horse power Hours- complements of Wikipedia "railroad A borrows a 2,500 horsepower locomotive from Railroad B and operates it for twelve hours, Railroad A owes a debt of (2,500 * 12) 30,000 horsepower-hours. Railroad A may repay the debt by loaning Railroad B a 3,000 horsepower locomotive for ten hours."

[GSkid]

It's basically a barter system that railroads use when they need more power. If a railroad has a sudden boost in business and they don't have enough power of their own, they either get locos from leasing companies under contract or they get locos from other railroads that have them to spare (excess capacity).....OR owe them horsepower-hours.

http://en.wikipedia.org/wiki/Horsepower-hour

It's cheaper to just barter locos than to lease them because no actual money is being spent. You just loan the power to another railroad and they maintain it while in their service. Then when it comes time that you need power, they let you use their locos. The currency is not money, it's a back and forth running tally of horsepower-hours as currency.

I'd imagine railroads sometimes borrow locos even when they technically don't need them just so the trade balance doesn't get too lopsided. It would let them collect on a chunk of horsepower-hours owed while allowing them to temporarily store their own locomotives and thus saving wear and tear on them.

[Rich_S]

Some units are leased, NS currently is power short and that is why they are leasing and buying anything they can get their hands on. But there is another reason you'll find foreign motive power on a railroad, it's what's called run through power. Let's take an example, say you have a train that originates on the Union Pacific and is delivered to a customer someplace on Norfolk Southern. Instead of swapping Union Pacific locomotives with Norfolk Southern locomotives at the interchange point, NS will just add one of their locomotives to the head end of the consists and allow the train to continue to the next major yard or crew change point. Doing it this way saves time. When that power reaches the next major yard, it's usually send back West toward the UP. On the UP end, the same thing will happen. On some trains like intermodal trains, the power can stay with the train from port to port.