After World War II, the Victorian Railways was severely run down from years of Depression-era under-investment and wartime over-utilisation.

The United States was more divided, with General Motors' Electro-Motive Division at La Grange, Illinois turning out modern E and F-units 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.

By 1949, the then-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.

[4] 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.

The project was abandoned in mid 1985 after rising costs due to structural fatigue, with the eleventh and final rebuild delivered in August 1985.

[12][13] 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 B61 and B65 later being resold to Southern Shorthaul Railroad.