ALCO DL420

Infobox Locomotive
name=ALCO DL420 (S-5 prototype)
powertype=Diesel-electric
builder=ALCO
buildmodel=S-5
poweroutput=800 hp
aarwheels=B-B
gauge=RailGauge|ussg
The ALCO DL420 was the prototype ALCO S-5 switcher diesel-electric locomotive.

It was built in August, 1951 using an early six cylinder 251 engine rated at 800 horsepower and RS-3 subassemblies in its construction. It rode on two-axle trucks, having a B-B wheel arrangement, and was the first ALCO switcher with a front radiator opening. This one-of-a-kind unit spent its time at the Niskayuna, test facility and then at Schenectady as a shop switcher (#6). The unit was scrapped in the late 1950s.

References

* [http://users.inna.net/~jaydeet/s6.htm Data from The American Locomotive Company A Centennial Remembrance by Richard Steinbrenner pp. 311-312 photo, 340 photo, 394 photos]
* [http://alcoworld.railfan.net/as.htm Rolf Stumpf's ALCO World website switcher specification page]