 The reason for this was the potential use of these locomotives on the railroad networks of Europe and the USSR where broader gauges precluded the use of unmodified US locomotives in the event of a major war.While built to the same specifications, there were external differences between the EMD and Alco MRS-1s as can be seen in the rooflines.For a small railroad, the FEMRR rostered a surprising extensive collection of passenger, freight, maintenance-of-way and other cars, totaling 168 pieces.