2.5" Scale 25 Ton Narrow Gauge Switching Locomotive, Electric Drive. Although a number of companies built locomotives as small as 2 1/2 tons, 20-25 ton units were the most popular size of small industrial switchers. Davenport, G.E., Plymouth, Porter, Vulcan, Whitcomb and others all produced units in this class Perfect Steerable Transfer Cartluding some diminutive cow