3000 class railcar

3000/3100 class railcars
3121/3122 crossing the Port River at Ethelton in April 2005
Interior of a refurbished unit
Manufacturer	Comeng Clyde Engineering
Built at	Dandenong
Replaced	300/400 class Red Hens
Constructed	1987-1996
Entered service	1987
Number built	70
Fleet numbers	3001-3030 3101-3140
Capacity	106 passengers (3000) 113 passengers (3100)
Operator(s)	State Transport Authority TransAdelaide adelaide metro
Depot(s)	Dry Creek Gawler Lonsdale Belair
Specifications
Maximum speed	90 km/h (Network Speed)
Weight	48t (3000) 46t (3100)
Transmission	Diesel-electric
Track gauge	1,600 mm (5 ft 3 in)

The 3000/3100 class are a class of diesel railcars operated by Adelaide Metro (and its predecessors STA and TransAdelaide). They were built by Comeng and Clyde Engineering, all in Dandenong, between 1987 and 1996.

In March 1985, the State Transport Authority awarded a tender for 20 diesel multiple units (eight 3000 class units with a cab at each end and twelve 3100 class with a cab at one end only) to Comeng, Dandenong. The design was based on the stainless steel shell of the Comeng electric train then in production for Melbourne's Public Transport Corporation, but 2.3 metres longer and with only two doors per side. Because of a contractual requirement to maxmise local content, the fitout was conducted at Dry Creek. The first entered service in November 1987. A further 50 were ordered and built between 1992 and 1996 by Clyde Engineering, still at Comeng's former Dandenong factory.

Each railcar features an underfloor mounted Mercedes Benz 475 hp V12 twin turbo direct injection diesel engine, operating at a constant 1500 RPM, which is directly coupled to a Reliance 400kVA alternator. Drive is provided by two Stromberg traction motors, rated at a continuous 130 kW each, mounted on a single bogie. The railcars also feature an auxiliary transformer providing 3 phase 50 Hz at 415 V which supplies air-conditioning and other ancillary power needs.

The 3000 class bogies are built by Comeng and feature airbag secondary suspension. All 3000 class railcars are fitted with electro-magnetic track brakes, which are comparatively rare on trains, though they are commonly found on trams. These are operated separately from the normal mechanical and dynamic braking.