locopilot750 posted:One big advantage DP trains have, is that each consist has a feed valve, and can reduce brake pipe pressure to set the brakes on the train, at the same instant brakes are set with the lead engine. The brakes on a long train respond much faster than with a single feed valve on the lead consist. And, when brakes are released, they all begin to feed to the train line at the same time, quickly restoring brake pipe pressure, and the brakes release just as quick as they would on a short train. Especially helpful in very cold temperatures on a long train.
There can be a problem with this. I discovered it when I ran radio trains back in the late 80's early 90's. If the combined feedvalves let too much air escape at one time, it can cause an undesired emergency brake application to occur. Hopefully, they have this problem taken care of by now
