The Waterloo to Bournemouth line was electrified west of Pirbright Junction during 1965-67. The Southern Region, who still wanted to operate a through service between London and Weymouth, were faced with the problem that if electric multiple unit stock was used, it would be necessary for it to be loco-operated beyond Bournemouth, but this would be both uneconomic and operationally undesirable. To overcome this difficulty, an elaborate push pull system was developed, using one high power 'tractor' unit, classified as 4REP, which could propel/haul four or eight TC (Trailer Control) cars between Waterloo and Bournemouth, from where the TC sets were hauled by a modified Class 33 locomotive on to Weymouth, discarding the tractor set at Bournemouth. The Class 33s were specially modified for these duties and could be controlled from the remote cab of the TC set by means of 27 wire control jumpers and a westcode system.
The 4REP (four car Restaurant Electro-Pneumatic) sets were constructed at York Works and were formed of a Driving Motor Second (DMS), Trailer Restaurant Buffet (TRB), Trailer Brake First (TBF) and DMS. Each DMS had a standard driving cab at the outer end with a transverse walkway behind; passenger accommodation being provided in two four bay saloons separated by a central vestibule. The power equipment, housed under the coach, consisted of 4 x 400hp English Electric traction motors, one mounted on each axle. The two trailer vehicles were rebuilds from former locomotive-hauled Mk. I coaches, modernisation being undertaken at York Works. The TRB cars were rebuilds from 1961 vintage RB vehicles, with very little alteration to the seating area, but the cooking facilities were completely rebuilt. TBF vehicles were again rebuilt from Mk. I stock, this time CK vehicles, and major alterations included the removal of the second class compartments and the constructing of a guard's office and security compartment. The first class accommodation was also modified to the latest standard. To cover the advertised passenger services, a fleet of eleven REP units was introduced, but no provision for expansion of the service was allowed for and, by 1974, four additional REP units were required, and were again constructed at York Works. DMS vehicles were identical to the previous type, the TRB/TBF cars again being rebuilds. TBF vehicles followed the previous styling but TRB cars were rebuilt from redundant RU vehicles and had a number of detail differences.
The initial fleet was numbered 3001-11 and was painted in standard rail blue, but this subsequently changed to blue/grey from the early 1970s. The 1974 built sets, Nos. 3012-15, emerged in blue/grey from new.
To operate with REP units, a fleet of three and four car TC sets was introduced and these were all rebuilds of Mk. I locomotive-hauled vehicles. The 3TC units, Nos. 301-303, later augmented into four car units, were formed: Driving Trailer Second (DTS), Trailer Brake Second (TBSK), DTS, whilst the four car sets, Nos. 401-428, were formed of a DTS, TBSK, Trailer First Corridor (TFK) and a DTS. The TC units' DTS vehicles were rebuilt from Mk. l TSO coaches, the position of the two former toilets being rebuilt into a driving cab and adjoining vestibule. TBS cars were modified from Mk. I BSK vehicles, the internal layout remaining basically the same with just the decor modernised. TFK coaches were rebuilds of Mk. I FK stock, updated to conform to modern standards. The formation of three 3TC sets primarily came about because if two 4TC and one 3TC were coupled together, and hauled by a locomotive, they would occupy the same platform space as a 12 car electric multiple unit formation. They were also envisaged for possible use on the rear of service trains to convey passengers to Southampton Docks, being 'tripped' into the docks from Southampton Station. When the additional REP units were introduced in 1974/5, six additional 4TC sets were also introduced. The three car formations were augmented to four car by the addition of a TFK and three 'new' sets came into service. All vehicles were again converted from locomotive-hauled stock at York Works and numbered 429-434.
With the late 1980s modernisation of the waterloo-Bournemouth-Weymouth route and the introduction of new WES stock, the REP/TC fleet were phased out of traffic in the late 1980s. The REPs sets did see some unusual reformations during their demise, as traction equipment was removed from sets and refurbished for use in the new stock. In the immediate period before withdrawal the REP sets classified 430 under TOPS were reclassified as 432. The TC sets were also reformed at various times with a concentration of the fleet on additional waterloo-Salisbury services working with Class 33/1s. The TCs original classification of 491 was amended in the 1980s to 438 with sets suitable renumbered in the 80xx series.

Compartment - First
2+2S, 2+1U