The 3900 class are a class of electric locomotives built by

Walkers Limited Walkers Limited was an Australian engineering company, based in Maryborough, Queensland. It built ships and railway locomotives. The Walkers factory still produces railway locomotives and rolling stock as part of Downer Rail. History In ...

, Maryborough for

Queensland Rail Queensland Rail (QR) is a railway operator in Queensland, Australia. Owned by the Queensland Government, it operates local and long-distance passenger services, as well as owning and maintaining approximately 6,600 kilometres of track and relate ...

between 1988 and 1990.

History

In July 1984, a

joint venture A joint venture (JV) is a business entity created by two or more parties, generally characterized by shared ownership, shared returns and risks, and shared governance. Companies typically pursue joint ventures for one of four reasons: to acces ...

Clyde Engineering Clyde Engineering was an Australian manufacturer of locomotives, rolling stock, and other industrial products. It was founded in September 1898 by a syndicate of Sydney businessmen buying the Granville factory of timber merchants Huds ...

and

was awarded a contract to build 70 3500/3600 class electric locomotives with

ASEA ''Allmänna Svenska Elektriska Aktiebolaget'' (English translation: General Swedish Electrical Limited Company; Swedish abbreviation: ASEA) was a Swedish industrial company. History ASEA was founded in 1883 by Ludvig Fredholm in Västerås as ...

supplying the electrical equipment. These were ordered to operate coal trains on the Blackwater and Goonyella railway lines that were in the process of being electrified. The contract was later extended to 80. The bodies being built and assembled at Walkers's Maryborough factory with Clyde Engineering responsible for some of the electrical equipment and commissioning the locomotives. Following the decision to electrify the North Coast line from

Brisbane Brisbane ( ) is the capital and most populous city of the states and territories of Australia, Australian state of Queensland, and the list of cities in Australia by population, third-most populous city in Australia and Oceania, with a populati ...

Rockhampton Rockhampton is a city in the Rockhampton Region of Central Queensland, Australia. The population of Rockhampton in June 2021 was 79,967, Estimated resident population, 30 June 2018. making it the fourth-largest city in the state outside of the ...

, the last 30 were built to a modified design for passenger and general freight use, and delivered as the 3900 class. They received modified bodies to allow them to pass through Brisbane's tunnels and received higher gearing to allow them to operate at .

3550 class

With an increased need for locomotives on the Central Queensland coal lines, 19 were converted to 3550 class locomotives.3500/3600/3551 Class
Railpage

References

{{QueenslandLocos, state=collapsed Aurizon electric locomotives Bo-Bo-Bo locomotives Queensland Rail locomotives Railway locomotives introduced in 1988 Walkers Limited locomotives 3 ft 6 in gauge locomotives of Australia 25 kV AC locomotives