 The AT carriages became 1-12T and 14-18T respectively, joined by 13T and 19-26T which had not been converted in time for the AT classification.BT cars became 27T to 111T, plus 126T.109T, 110T, 111T, and 126T had been the pre-conversion odd vehicles 20AB, 49B, 51B, and 108B.