Multi-road lash-ups?

[awaken1977]

Is there an explanation, why foreign power units seen mixed with native ones of some railroads?

For example, on Northwestern BNSF routes, NS, UP, CSX or CN units occasionally seen coupled to BNSF power. Especially on intermodal trains.
I know about trackage rights, but it is not about that. Trackage rights give right of track usage for whole train of foreign company, as I understand.

This one is a nice example

[arizonachris]

Good question. From what I have read and understand, if one road, like BNSF, is short on power at a given location, they borrow power from another road as long as it's not needed elsewhere. Saves CSX, again for example, from "running light" all the way back to one of their yards, which costs money for fuel and pay for a crew. When BNSF is done, they fill the tank, hopefully didn't break anything and leave the engine there. There may some lease/ rent stuff involved, I'm sure someone else will chime in here. It also may be that just Class 1 roads do this. Out here where I live, it's all pretty much either UP or BNSF. I never see any other road names, other than short lines like Pacific Harbor Line.

[ErikGorbiHamilton]

In the northwest we get KCS units as well. BC rail and ex Oakways make their appearance. we get CP too

[philmoberg]

Back when I was a kid, and three out of every four boys coveted his Lionel catalogue above all other possessions (including marbles and comic books), it used to bug a lot of us that Lionel packaged their sets with motive power from one railroad and a caboose from another. By the time I was in my teens, railroads were beginning run-through agreements, making the by-then-dormant Lionel lie look pretty realistic. Then came the early days of Amtrak, with trains made up of whatever happened to be on the store shelf that morning. These days, it doesn't seem to have the madness it once [briefly] did, the railroad industry is healthier than it's been in my lifetime, and it all makes for some pretty colorful and interesting railroading. We used to joke about CN run-throughs to New Orleans as being about the most improbable future we could think of ... now, CN calls it home.