 The conversion had also reduced the water capacity of R 707's tender such that there was insufficient margin for delays or bad weather running on many routes, confining the locomotive to the shorter Melbourne to Geelong and Seymour lines.The experiments were discontinued and R 707 was converted back to black coal operation in 1957.R 719 and 748 were converted to oil-firing during the mid-1950s using oil tanks and burner equipment salvaged from the four scrapped S class steam locomotives.