In 1964 Esso introduced a fleet of 282 vacuum braked Class A tank wagons, 200 of which were built by Pickering 6000 - 6199. The final 96 were in sets of 6 with close coupling between them (diag 6/215). The vacuum braking was unfortunate, for within a year or so BR began to require airbraking. In the 1980s many of the wagons were fitted with new Bruninghaus suspension, and usually at the same time air braking. In 2012 many continue in use, possibly the oldest large fleet of wagons on BR