In 1928 a batch of six 5000 gallon tankers were built by Perry engineering for Vacuum Oil. Initially they were lettered for "PLUME" motor spirit. They were numbered 59-64. Another group of twelve in 1930 became 103 and 121-131. In later years VACUUM oil became MOBIL and the tankers were painted plain black.
In 1971 59-64 were written off but in 1972-3 they were taken over by the W.A.G.R., reclassified JBS and given the numbers 9915-9920 in the same order. They were also converted to a single compartment tank at some point.
In 1986 131 was modified to class JBB.
