The B class are a class of diesel locomotives built by Clyde Engineering, Granville for the Victorian Railways in 1952/53. Ordered and operated by the Victorian Railways, they initiated the dieselisation of the system and saw use on both passenger and freight services, with many remaining in service today, both in preserved and revenue service. Some were rebuilt as the V/Line A class, while others have been scrapped.
The B class were the first mainline diesel locomotives built for the Victorian Railways. The design was based on the successful Electro-Motive Diesel F-unit locomotives with the distinctive bulldog nose. They were unusual in having a streamlined drivers cab at each end.
After World War II the Victorian Railways was run down from years of Depression-era underinvestment and wartime overutilisation. Chief Mechanical Engineer Ahlston traveled the world studying railway rehabilitation. Britain leaned towards steam locomotives, while France was moving towards main line electrification. The United States was more divided, with General Motors' Electro-Motive Division at La Grange, Illinois turning out modern E and F-units diesels. However the EMD units axle load was too heavy for the Victorian tracks, and the Commonwealth Government would not allow the use of foreign currency to purchase United States diesels. As a result the £80 million Operation Phoenix featured steam locomotives and electrification of the Gippsland line, either locally built or imported from the United Kingdom.
To achieve a lighter axle load a six axles / six motor Co-Co wheel arrangement was required. By 1949, the head of Electro-Motive Diesel Dick Dilworth was convinced that lighter axle load locomotives would be popular in Australia and other foreign countries. Frank Shea of Clyde Engineering had also negotiated with EMD to build the new locomotive locally, in order to overcome the foreign exchange restrictions. The order was placed in 1951 and the first locomotive was delivered on 14 July 1952.
The 26 members of the class operated on broad gauge lines throughout Victoria, working the majority of the important passenger trains, as well as fast freights. Many timetables were accelerated, and steam locomotives began to be scrapped in large numbers. The visit of Queen Elizabeth in 1954 saw her ride behind B60 on a special train.
While costing £80 per horsepower compared to £60 for steam, the new locomotives ran 130,000 miles per year, compared to 35,000 and 60,000 miles per year for main line steam locomotives. The Chief Engineers Office found that one B class did the work of three steam locomotives. Their success led to further dieselisation, with the delivery of the T class branch line units from 1955, and the single ended S class mainline units from 1957.
As part of the 1980s New Deal plan to reinvigorate country passenger services, it was decided to rebuild the B class with new traction equipment as the A class. The rebuild contract was let in January 1983 to Clyde Engineering, Rosewater, with the first unit entering service in May 1984. The project was abandoned in mid 1985 after rising costs due to structural fatigue, with the eleventh and final rebuild delivered in August 1985.
At the same time newer high power locomotives had been delivered, including the N class passenger units and the more numerous G class freight locomotives. The B class gradually retired by V/Line from 1982 with some scrapped. Six were purchased by West Coast Railway in the early 1990s for use on their Melbourne to Warrnambool passenger service.
In May 2004 the Victorian Department of Infrastructure issued an alert on stress cracks on the underframes of the B class locomotives, including the units owned by West Coast Railway. Following West Coast Railway's demise in August 2004 these were sold to Chicago Freight Car Leasing Australia and refurbished with some being resold to Southern Shorthaul Railroad. This saw some converted to standard gauge and their sphere of operation increased to include New South Wales. Seymour Railway Heritage Centre have B74 preserved in operating condition and is the only preserved locomotive in operation.