This is the trailing end of the train; there was a lot more than this.
The two flat-ish cars on the right are for railroad ties, and are specially built so that the equipment on top can move along the top of the cars and handle ties, either setting them out along the tracks or picking up used ties to be taken for disposal.
Bringing up the rear of the train (the orange-and-green BNSF locomotive poking into the frame at right is parked on one of the Fernley "house tracks") is a specially-rebuilt maintenance-of-way locomotive, one of several the UP had made for them for use only on MOW trains. I read about these in Trains magazine a few months ago, but I cannot right now remember what special features these locomotives had added to them when they were built from "trade in" units.
Yesterday, there was a locomotive that I wanted to photograph, but I couldn't get my phone out and the camera app activated in time. Digital photography is great, but when you have to wait several seconds for your camera to boot, you often miss spontaneous shots.