It's not about how many engines are needed on a particular train, it's about the fact they don't have engines to cover the assignments when summer track work picks up. In reality, many work trains they run only need one engine, but they like doubling them up in case one takes a dump or they need one on either end for a quick move to reverse direction without shoving. The welded rail train empty or loaded could be pulled with one or two (usually ends up having 2 on each end). Long ballast trains coming from Pond to the Island should use two. One is always in Jamaica as a protect, they keep one in Holban and one in LIC for switching duties. The RF1 crew usually has two of them as well as the late weeknight work trains out of LIC supporting the East Side Access project. The two 1001s with ASC are out of service and the others usually sit idle except for the Richmond Hill drill job. The 1001s have been very underutilized after the departure of LIRR-run freight operations. Remember, just because the LIRR has about 15 or so 1500s left doesn't mean they're all available for service constantly. I'd estimate they have 9-10 ready for service at any given time with the others being worked on, fueled, inspected or undergoing heavy repair in the Sheridan Shop in Richmond Hill.