New South Wales Government Railways 4002.

(Commissioner Geoff, Public domain, via Wikimedia Commons)



The ALCO RSC-3 was a diesel-electric locomotive of the road switcher type rated at 1,600 horsepower (1,200 kW), that rode on three-axle trucks, having an A1A-A1A wheel arrangement.

Used in much the same manner as its four-axle counterpart, the ALCO RS-3, though the axle load was spread out for operation on light rail such as are found on branch lines. This locomotive had much better success as an export unit than in the domestic market.


Original owners

Locomotives built by Alco

Railroad Quantity Road numbers Notes
Algerian Railways 5 DG1–DG5
Ferrocarril Central del Uruguay 3 1601–1603 1,435 mm (4 ft 8+1⁄2 in) gauge (last one, 1602, withdrawn in 1993)
North Western Railway of Pakistan 26 3301–3326 to Pakistan Railways 1,676 mm (5 ft 6 in) gauge
Panama Railroad 3 901–903 5 ft (1,524 mm) gauge
São Paulo Railway, Brazil 12 550–561 1,600 mm (5 ft 3 in) gauge
Caminhos de Ferro Portugueses 5 1521–1525 1,668 mm (5 ft 5+21⁄32 in) gaug
Consolidated Railways of Cuba 6 1606-1611
Seaboard Air Line Railroad 7 1537–1543 to Seaboard Coast Line 1111–1117
Soo Line Railroad 4 372–374, 2380 2380 owned by Wisconsin Central Railway
Total 71

Locomotives built by Montreal Locomotive Works

Railroad Quantity Road numbers Notes
New South Wales Government Railways 20 4001–4020 NSW 40 class
Pacific Great Eastern Railway 8 561–568 to British Columbia Railway
Total 28

Locomotive ALCO RSC-3 7653, originally manufactured for CPEF, having operated in FEPASA,

Ciminas and SPA Engenharia.  Currently belongs to IRON and operates in rented Supervia.

(João Bosco Setti, CC BY-SA 2.5 <>, via Wikimedia Commons)

Preserved Units

Some preserved units include:


  • 4001 Preserved at the NSWRTM Thirlmere
  • 4002 Preserved at the PRHS Western Australia
  • 4006 On static display Wickham WA


  • 7653 operating in Supervia


  • PGE 561 operating in Squamish at the West Coast Railway Heritage Park


  • 1525 operating in SOMAFEL


Alco RSC-3 Overview

Type and origin
Power type: Diesel-electric
Builder: ALCO; MLW
Model: RSC-3
Build date: November 1950 – June 1955
Total produced: 99
Configuration: AAR A1A-A1A
Gauge: 4 ft 8+1⁄2 in (1,435 mm) standard gauge and others
Length: 53 ft 1 in (16.18 m)
Width: 10 ft (3.05 m)
Height: 14 ft 5 in (4.39 m)
Locomotive weight: 254,840 lbs. (115,590 kg)
Fuel capacity: 800 US gallons (666 imp gal; 3,028 L)
Prime mover: Alco 244
Engine type: V12 Four-stroke diesel
Aspiration: Turbocharged
Displacement: 8,016 cu in (131.36 L)
Generator: DC generator
Traction motors: DC traction motors
Cylinders: 12
Cylinder size: 9 in × 10+1⁄2 in (229 mm × 267 mm)
Transmission: Electric
Locomotive brake: Straight air
Train brakes: Air
Performance figures
Maximum speed: 65 mph (105 km/h)
Power output: 1,600 hp (1,190 kW)
Tractive effort: 42,470 lbf (188.92 kN)
Locale: North America, Central America, South America, Portugal, Australia, Pakistan