Mid-Train DPU's

[CSXfoamer1997]

There's one problem about Mid-Train DPU's. It would take more time to remove them from a train than it would the rear DPU's. For the rear DPU's, you would just have to detach them from the train when no longer needed and the train could move on. Whereas, for the Mid-Train DPU's, when they are no longer needed, you would have to detach one half of the train and then put the DPU's on another track and then recouple the other half of the train and go on.

I know the main reason for Rear DPU's, which is pushing. But what's the reason for Mid-Train DPU's if they're harder to remove from a train when no longer needed?

 

[CCC1007]

Up north, winter brake pressure is the primary reason, as cold weather causes more leaks and causes a long train to need more pumps spread out to release the brakes.