NSU-class A1A-A1A Diesel-electric locomotive No.61

Commonwealth Railways

Narrow Gauge


Class operators: Commonwealth Railways/Australian National Railways

Entered service: 20.3.1955

Condition: Good - missing some mechanical parts

Provenance: Commonwealth Railways & Australian National

Ownership: Port Dock Station Railway Trust

Horsepower: 925

Engine type: Sulzer 6LDA28

Traction Motors: 4

Gear Ratio: 65:14

Fuel capacity: 750 gallons

Total Weight: 60 tons

Length (over coupling points)                           46 ft. 4 in

Number in class                                                14

Bore & stroke                                                   11 in. x 14.2 in.

Entered the museum                                        1985

Maximum Axle Load                                         10 tons

Maximum Speed                                               50 mph

Tractive Effort (continuous)                             15,300 lbs @ 15.25 mph

Tractive Effort (starting)                                   22,400 lbs

Bogie centres                                                  7.3

Wheel Arrangement                                        A1A-A1A

Withdrawn                                                       Pre 1980

Built by                                                            Birmingham Railway Carriage and Wagon Company, United Kingdom

Class Builders                                                 Birmingham Railway Carriage and Wagon Company, United Kingdom

Condemned                                                    24.09.81

Cylinders                                                        6 in line

Designer                                                         Birmingham Railway Carriage and Wagon Company, United Kingdom

Height                                                             3.7

Mileage                                                          1,509,948 Km

Model                                                              NSU Class

Number series                                                51 to 64

Width                                                              2.8


The NSU class was purchased by the Commonwealth Railways to replace steam locomotives on the narrow gauge Central Australian Railway, with some of the class serving also on the North Australia Railway narrow gauge system.

The Commonwealth Railways placed a contract for 14 locomotives in early 1951 with the Birmingham Carriage and Wagon Company, England. Each unit would use a Sulzer engine, have a Crompton Parkinson main generator and traction motors, be capable of operating on both narrow and standard gauge and be delivered by the end of 1952.

All 14 NSU’s entered service on the Central Australian Railway, and suffered some minor problems with air and oil filtration equipment, in addition to some voltage regulator repairs done by the component manufactures, but generally they worked well. As work on the standard gauge line progressed to the stage where trains could work over it to Brachina, mainline steam working was almost discontinued, with the majority of services being handled by the NSU’s.

Following the opening of various sections of the Marree standard gauge line, traffic requirements permitted the transfer of two units to the North Australia Railway. These two NSU’s were able to handle all traffic on the North Australia Railway for almost the next 10 years. Traffic levels dropped dramatically after the closure of the Frances Creek iron ore mine in 1974, allowing both units to be returned to the Central Australian Railway.

All 14 locomotives were transferred to Australian National Railways in 1975 and were gradually withdrawn from service, following the closure of the Central Australian Railway in 1980.

Visit the NRM

76 Lipson Street
Port Adelaide
South Australia  5015
Open Daily / 10am – 4:30pm





5-15 yrs & with an adult


2 adults & up to 3 children


  • Prices may vary for special events
  • EFTPOS is preferred payment method
  • Open from 12pm on ANZAC Day
  • Closed Christmas Day

Phone: 8341 1690

The National Railway Museum acknowledges the Kaurna people as the traditional owners and custodians of the Adelaide Plains. We honour and respect their ongoing cultural and spiritual connections to this country. We aim to respect the cultural heritage, customs and beliefs of all Indigenous people.

Go to top