3000 class railcar

The 3000 class and 3100 class are a class of diesel railcars that operate on the Adelaide rail network. Built by Comeng and Clyde Engineering between 1987 and 1996, they entered service under the State Transport Authority as a replacement for the Redhen railcars, before later being operated by TransAdelaide and Adelaide Metro. Trains are typically coupled as multiple units, though the 3000 class are also able to run as single units when needed. In total, 70 railcars were built and are expected to be retired between 2030 and 2032.

The fleet underwent 3 major refurbishments. The first, an exterior refurbishment, was carried out between 2000 and 2010. The second, a life extension project was completed between 2018 and 2020, aimed to extend the trains' lifespan. The third and most recent refurbishment, a hybrid conversion was carried out on 50 of the 70 railcars to reduce fuel consumption on the fleet. The program was completed in January 2025.

In March 1985, the State Transport Authority (STA) awarded a tender for 20 diesel railcars (eight 3000 class units with a cab at each end and twelve 3100 class with a cab at one end only) to Comeng's Dandenong rolling stock factory. 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 (7 ft 7 in) longer and with only two doors per side. Because of a contractual requirement to maximise local content, the fit-out was conducted at Comeng's Dry Creek facility. The first commenced testing in May 1987, entering service in November 1987. The eight 3000s were built first with the first 3100 class completed in mid-1988. The last entered service in December 1988.

In the original contract, there was an option to order 76 further examples. However, Comeng came back to the STA with a significantly higher price, so the work was put out to tender, and a contract for 50 was awarded to Clyde Engineering in November 1989. Comeng concluded a deal to sell the 3000 class design and tooling. However by the time construction commenced, Comeng had sold its Dandenong plant to ABB, who backed away from an agreement to hand over the jigs and tooling, so they were built between 1992 and 1996 by Clyde Engineering's Martin & King factory in Somerton, Victoria.

All were delivered with unpainted stainless steel offset by blue and orange stripes. In April 2002, the first was repainted by Bluebird Rail Operations in Adelaide Metro's yellow, blue and red.

Originally they operated on all Adelaide suburban lines, however since the electrification of the Seaford and Flinders lines in 2014 and Gawler line in 2022, they have been confined primarily to the Belair, Grange, and Outer Harbor lines along with the newly opened Port Dock line. They have on occasion ventured beyond the Adelaide metropolitan area, operating special services to Nuriootpa on the Barossa Valley line, Riverton on the Roseworthy-Peterborough line and Balaklava on the Hamley Bridge–Gladstone line. These tours stopped by the mid 2000s.

Only one of bogies is powered per car, originally with 2 Stromberg Electric Motors, which have now been replaced since the 2018 life extension.

The 3000 class bodies were 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.