The 81 class is a class of mainline diesel locomotive in the state of New South Wales. Introduced between 1982 and 1984, the 81 Class is currently the largest class of locomotive in New South Wales, and for many years has been the backbone of the fleet. They are used anywhere on the rail network, when it comes to freight and coal to passenger services. Eighty of these 3,300 hp (2,500 kW) locomotives were originally introduced in 1982 by the State Rail Authority of NSW, with a further 4 were introduced in 1991 partly made up of spare parts. They were constructed by Clyde Engineering, Bathurst. The class were ordered under the administration of Alan Reiher, and are considered one of the most successful locomotive designs used on an Australian railway. In early years, the class were used on general freight and also on passenger trains such as the Sydney/Melbourne Express, but today are used on general freight, as high power shunters, and in coal/grain haulage. Built with "Super Series" technology, trialled by a member of the 422 class (42220), these locomotives have proved themselves to be extremely reliable - so reliable that the spare parts for the 81 class were used to build another four 81 class units in 1991. With an EMD 16-645E3B turbocharged engine developing 2,460 kW (3,300 hp), they have a mass of 126 t, have Co-Co axles, and has a maximum speed of 115 km/h. Altogether, 84 locomotives were built. 13 of the class were transferred to National Rail, but were reunited with the rest of the class along with the formation of Pacific National. A few of these locomotives have been painted in the National Rail Livery, another lot in Pacific National's new livery. The remaining retain the Freightcorp livery, with Pacific National decals. The 81 class wore the SRA Candy Livery when first introduced, and two (8120 & 8172) were painted in the Bicentennial Livery. One of these locomotives has been written off, locomotive 8147 was burnt out beyond economical repair in a fire following a derailment subsequent to a fatal crash at Garema, near Forbes, New South Wales on 11 March 2007.