Conversion of FD class louvred vans to FDP class poison vans started in 1973. This was another of those cases where classification in a different group would have been a little more logical. Class FDP would perhaps have been better somewhere in the D group as they were not really louvred vans in the sense of the rest of the wagons in this group. However, the last group (converted in 1980) did not have the fully boarded sides of the earlier wagons and were barely distinguishable from some contemporary FD's. Unusually, they were never painted in the Westrail yellow livery. This was to make them stand out (the DE class explosives vans were also never painted yellow) because of their dangerous cargo. A late document from 1984 shows that it was intended to repaint these wagons in BS381C 537 Signal Red but I don't think that any of them got this change before they were written off.

All of the FDs were lettered POISONS        ONLY RETURN EMPTY TO KEWDALE on the sliding door.

Conversion of the class to FDP and disposals are as follows:
1973	13433, 13698, 13935, 14031, 14037, 14126 from FD
1974	13401, 13475, 13495, 13564, 13574, 13582, 13587, 13598, 13622, 13629, 13661, 13676, 13711, 13802, 13807, 13826, 13836, 13840, 13883, 13968, 14003, 14018, 14046, 14052, 14058, 14123, 14136, 14197, 14284, 14355, 14370, 14372 from FD
1975	13840 written off
1980	13752, 14070, 14088, 14160, 14254, 14309 from FD
1983	13587, 13629, 13826, 14031, 14037, 14052, 14370 written off
1985	13495, 13574, 13802, 13807, 13883, 14126, 14160, 14284, 14372 written off
1986	13433, 13475, 13564, 13582, 13598, 13622, 13629, 13661, 13676, 13698, 13711, 13752, 13836, 13935, 13968, 14003, 14018, 14046, 14058, 14070, 14088, 14123, 14136, 14197, 14254, 14309, 14355 written off
1987	13401 written off

The WAGR outline diagram is shown below. Apologies for the poor quality diagram.