The first 10 F class have the distinction of being VR's first diesel locomotives. They were mainly used in shunting service around Melbourne but were also used at Geelong, Seymour, Wodonga and Bendigo and perhaps other locations. Over the years quite a few changes were made: they were delivered in a black paint scheme then went to red with a yellow stripe and finally VR's familiar blue and gold, near the end of their careers at least one was painted V/Line orange/grey. Their road numbers were changed in 1958 as SECV 3 would have become F 320 but T 320 was already in service.

The last 6 were purchased second hand from the State Electricity Commision of Victoria on the dates shown below. No evidence exists that SECV 3 - 6 ever actually worked in SEC service, it appears that VR leased them upon delivery until they purchased them

All of the F's were built by the Dick Kerr Works in the United Kingdom

• blk: As delivered all black scheme
• ry: Mainly red with yellow stripe (1955 to 1971)
• vrb: VR blue and gold (First F painted blue, 1964)
• secg: Hawthorn green, as delivered
• secb: Very similar to VR blue and gold but with a thinner yellow stripe
• vlo: V/Line orange/grey