The last remaining Baldwin RS-12, at the Travel Town Museum in 2012.

(Klaus Nahr, CC BY-SA 2.0 <>, via Wikimedia Commons)



The Baldwin-Lima Hamilton RS-12 railroad locomotive was a 1,200 hp (895 kW) diesel-electric road switcher locomotive configured with an AAR type B-B wheel arrangement. It was the follow-on model to the former Baldwin DRS-4-4-1000, first introduced in 1948. It was more successful than its predecessor selling 50 units to eight railroads, versus 22 units to three railroads. Only one railroad, The Pennsylvania Railroad bought both models.

When Baldwin Locomotive Works merged with Lima-Hamilton Corporation, forming the Baldwin-Lima-Hamilton Corporation and decided to concentrate locomotive production at Baldwin's Eddystone, Pennsylvania plant. There was still one outstanding order for Lima A-3174s but the customer, New York Central Railroad agreed to receive RS-12s instead.

The locomotive could be ordered with either a steam generator for steam heat, or dynamic brakes contained within the short hood. McCloud River Railroad No. 32 and 33 were the only two ordered with dynamic brakes of the fifty units built. One RS-12 is preserved in operational condition in the "Skunk Train" livery of California Western 56 (Locomotive) at Travel Town Museum in Griffith Park; another No. 300 is owned by and occasionally used on the Escanaba and Lake Superior Railroad, with others owned by the same railroad held in non-operational condition.

Escanaba and Lake Superior 207 was leased to the Nicolet Badger Northern Railroad for a short time in the 1990s and was later returned to the Escanaba and Lake Superior where it now remains in storage in Wells, Michigan.

Escanaba and Lake Superior 209 was used for ballast and general freight until the late 1980s when it was put in storage.

Escanaba and Lake Superior 212 started to be rebuilt in the 1980s but the rebuilt was never completed. It remains in storage along with other E&LS Baldwins at Wells, Michigan.


Escanaba and Lake Superior Railroad 207 at Channing, MI on October 5, 1988.

(Roger Puta, courtesy Marty Bernard, railfan 44, Public domain, via Wikimedia Commons)


Original buyers

Railroads Quantity Road numbers Notes
Central Railroad of New Jersey 4 1206–1209
Chicago, Milwaukee, St. Paul and Pacific Railroad (“Milwaukee Road”) 2 970–971 Renumbered 926–927
Kaiser Bauxite Company 4 101–104 104 last RS-12 built
McCloud River Railroad 2 32–33 to California Western 55– 56
New York Central Railroad 17 5820–5836 Equipped with steam generators, Renumbered 6220–6236, to Penn Central No. 8067-8083 in 1968.
Pennsylvania Railroad 8 8105–8110, 8776, 8975 to Penn Central Nos. 8084-8091 in 1968
Seaboard Air Line Railroad 10 1466–1475 to Seaboard Coast Line Railroad 207–216
Total 50


Type and origin
Power type: Diesel-electric
Builder: Baldwin-Lima-Hamilton Corporation
Model: RS-12
Build date: April 1951–May 1956
Total produced: 50
​• AAR B-B
• UIC Bo′Bo′
Gauge: 4 ft 8+1⁄2 in (1,435 mm)
Trucks: AAR Type B
Length: 58’ 6”
Width: 10’
Height: 14’
Locomotive weight: 232,000 lb (105,000 kg)
Fuel capacity: 900 US gal (3,400 L; 750 imp gal)
Lubricant capacity: 160 US gal (610 L; 130 imp gal)
Coolant capacity: 250 US gal (950 L; 210 imp gal)
Sandbox capacity: 30 cu ft (0.85 m3)
Prime mover: 606A
Engine type: Four-stroke diesel
Aspiration: Turbocharger Elliott Company H503 (215 hp)
Displacement: 11,874 cu in (195 L)
Generator: Westinghouse YG42B
Traction motors Westinghouse 362DF (x 4)
Cylinders In-line: 6
Cylinder size: 12+3⁄4 in × 15+1⁄2 in (324 mm × 394 mm)
Transmission: Electric
Locomotive brake: Straight air
Train brakes: Air 6-SL, or 24-RL
Performance figures
Maximum speed: 18:74 gear ratio: 65 mph (105 km/h); 18:65 gear ratio: 75 mph (121 km/h)
Power output: 1,200 hp (895 kW)