While it is a fact that several class 56s were allocated to ‘Trainload Petroleum’ sector pools during the late 1980s and early 1990s, there was only one loco (56036) which actually carried the official sector symbols of this particular sector. The attached photograph shows 56036 at Old Oak Common depot, courtesy of Jack Resay.
For the record, the other 56s allocated to Petroleum pools during the sector years were:
56035, 56036 & 56048 – FPLW – Petroleum Sector, West Wales
56084, 56094, 56106 & 56126 – FPGI – Petroleum Sector/Contract Services pool, Immingham TMD
56104 & 56127 – FPCA – Petroleum Sector unspecified code
56003, 56008, 56012 & 56014 FPYX- Petroleum Sector- Stored (these locos were destined for fitter training at Immingham).