V/Line A class Co-Co (1984)

The A class are a class of diesel locomotives rebuilt from B class locomotives by Clyde Engineering, Rosewater for V/Line in 1984-1985.

History
The class were rebuilt from B class locomotives originally constructed in the 1950s, as part of the New Deal reforms of passenger rail operations in Victoria. The rebuild contract was let in January 1983 to Clyde Engineering, Rosewater with the first locomotive entering service in May 1984, but the project was abandoned in mid 1985 after rising costs due to structural fatigue, with the 11th rebuild delivered in August 1985. It was decided to instead built more of the N class locomotives, mechanically similar to the A class. The major difference was the addition of head end power generators, as it was believed this was a more efficient way of supplying power for air-conditioning and lighting than power vans or individual generator sets under carriages.

Four locomotives were named after Australian rules football players in September 1984, while A60 was named after former railway commissioner Harold Clapp. In July 1986, A85 was regeared for 160 km/h operation, and tested between Glenorchy and Lubeck, to test an H type carriage set fitted with high speed bogies, but was returned to the standard 133 km/h gearing soon after. In preparation for the privatisation of V/Line, four were allocated to passenger services and seven to freight services.

When the engines were initially converted from B class units they were intended for light, high speed passenger traffic, but in Freight Australia service this had limited value. The engine frames could not be easily reinforced, but by 2002 the D57 traction motors were swapped for D77, which raised the current axle from 825A to 1050A. To better make use of the increased power the gear ratios in each unit were changed from 59:18 to 61:16, improving adhesion and overall providing an increase in tractive effort of 35%. The lower-power traction motors were cascaded to the Y Class fleet.

The V/Line units were not upgraded in this way, and continued to operate in regular service supplementing the N Class locomotives on mainline services. Another fixed roster was to Stony Point, as the MTH carriages allocated to that service were fitted with on-board head-end-power generators. V/Line withdrew their fleet with A60 operating the final service, the 16:15 Southern Cross to Bacchus Marsh on 24 April 2013. V/Line subsequently returned A66 and A70 to service, with the both since withdrawn. Pacific National withdrew its last examples in May 2014.

Between 7 and 18 January 2019, Pacific National units A73, A77, A81 and A85 were dismantled and disposed of at South Dynon broad gauge turntable.

Livery
The class were delivered in the V/Line orange and tangerine scheme. In February 1988 A66 which was painted in a green and gold livery to celebrate the Australian Bicentenary, later appearing in a second special livery to advertise the Melbourne bid for the 1996 Olympic Games. Today the class appears in either the 1995 red and blue or 2008 red and yellow V/Line Passenger liveries, or the green and yellow Freight Australia livery with Pacific National logos.