within 10 years. The high powered () EMU tractor units were classified 4-REP (Restaurant Electro-Pneumatic brake), the trailer units 3-TC and 4-TC (Trailer Control) and the push-pull equipped diesel locomotives were converted from 19 of the Southern's native BRCW type 3 fleet (eventually to become designated class 33/1). Initially, eleven 4-REP units were built to propel the TC units to Bournemouth and pull them back to Waterloo. The 4-REPs were of the contemporary 1963 BR(S) EMU design and were formed of two driving motor second/standard saloons (DMSO) sandwiching a trailer brake first corridor (TBFK) and a trailer buffet (TRB). The DMSOs were new-builds but otherwise the TBFK was converted from a loco-hauled Mark 1 corridor composite and the TRB from Mark 1 loco-hauled Restaurant Buffets (RB) in (1966–67) or Restaurant Unclassifieds (RU) in (1974). Each of these restaurant/buffet cars were given names, the decorative panel behind the buffet counter carried the name of that particular car. The 4-REPs were as a result the most powerful 3rd rail type EMUs in the world, with a total of available, in order to be able to provide the traction for up to eight trailer cars – just less than the famous "Deltic" Class 55 diesel locomotives. Each REP unit had eight traction motors, and because of this to avoid an overload, a REP could only work with another powered EMU or Electro-Diesel Locomotive (EDL) if sufficient traction motors in the overall formation were first isolated. Each power bogie had a shoe beam with two pick-up shoes since there were two power circuits. In 1974, an additional four units were introduced to increase the frequency of the service and to provide cover for extended maintenance of the fleet. Even at this late stage, the by-then obsolescent Mk1 design was adhered to and a lack of Mk1 stock fit for conversion meant these last units were built from scratch – thus they were among the last Mk1 cars built. The 1974 build units were fitted with double-glazed windows (except for the sliding toplights) as fitted to contemporary CIG/BIG stock. When first introduced, the REPs appeared in overall rail blue livery with small yellow warning panels and small aluminium BR arrows below their side cab windows. The yellow warning panels were subsequently enlarged to cover the whole cab front. They were repainted during the early 1970s into blue and grey, losing their aluminium arrows in the