Alco's early diesel switchers, in the 1930s, were characterized by a high engine hood that reached almost to the cab roof. This was necessitated by the height of the McIntosh & Seymour inline 6-cylinder diesels that powered the new engines. Each cylinder in the massive four-stroke motors displaced 1,595 cubic inches, compared with 567 cu.in. per cylinder in Electro-Motive's two-stoke diesels.
But in 1939, Electro-Motive introduced its SW1 switcher, with a lower hood and more cab windows that allowed it to brag about "full front vision." In response, Alco redesigned its engine mounts to allow the motor to drop into a recess in the frame, and in 1940 introduced its S-1 and S-2 switchers, with a greenhouse-like cab that offered ample visibility in all directions. The two models differed mainly in power output. The normally aspirated S-1 with 600 h.p. booted many a small steam switcher from railroad rosters coast to coast. Turbocharging gave the S-2 1000 h.p., allowing it to replace larger steam switchers and branch line engines like 2-6-0s, 2-8-0s and 2-8-2s. The S-series rode on Alco's own Blunt trucks, named for the in-house engineer who designed them to negotiate the tight turns and less-than-perfect track often found on switching assignments.
Introduced just in time for World War II's crush of traffic, the S-2 became a best-seller. Rare was the Class 1 railroad that did not own a fleet of them, and short lines coast-to-coast rostered them as well. By the end of production in 1950, more than 1500 S-2s had been delivered. The engines proved extremely durable, with many earning their keep into the 1970s and '80s, and a number still operating today in tourist railroad and short line service. Like most Alco engines with turbochargers, S-2s are known by railfans as "honorary steam locomotives," for the bursts of smoke they emit when their turbochargers rev up on acceleration.
Our S-2 model rides on prototypical Blunt trucks and features everything you'd want in a hard-working switcher. Walkways have metal handrails and etched safety tread to prevent your 1/48-scale crewmen from slipping on a wet surface. End pilots have separately-added uncoupling levers. You'll find legible Alco builder's plates, and a cooling fan visible beneath the see-through metal grille atop the hood. The numerous grab irons and underframe bell are also separately added metal parts, and the cab features an illuminated interior with two crewmen. Directionally operated headlights and illuminated number boards round out the lighting effects.
Dual pickup rollers on each truck make this model nearly stall-proof on any three-rail O gauge switches. Throttle down as low as three scale miles per hour and maintain that speed as long as you wish, thanks to Proto-Speed Control. Pick up and drop off cars anywhere on your layout, with remotely operated front and rear Proto-Couplers. Listen to the authentic chant of a first-generation Alco motor, rumbling with an off-beat gait that sounds like it could use a tune-up. Simulate light or heavy diesel exhaust with the variable-intensity ProtoSmoke system. While other manufacturers have offered the S-2, no other O gauge model runs more smoothly or dependably, sounds as good, or is more fun to operate.