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More on Southern Drags
YOUR article in the February issue ‘Southern EMU Drags’ shines a welcome spotlight on the operation of such trains, and turns attention to the sometimes overlooked multiple-unit railway south of the River Thames.
The designation ‘TC’, as used for 3, 4, 6 and 7-TC units on BR (SR), stands for Trailer Corridor, with some sources citing Trailer Control but never Trailer Car. 7-TC unit No. 701 (originally No. 900) was never a push-pull unit. Rather it was a seven-car unpowered fixed-formation set; despite being formed with driving cabs at each end it could only be hauled in traffic and not propelled.
The text suggests the prototype for Bournemouth trailer units was a 6-TC unit formed from converted Mk.1 coaching stock. 6-TC unit No. 601, the only six-car trailer unit, was not so formed; it utilised redundant 1930s SR electric stock of Maunsell design. It was also this unit for which No. D6580 was converted as the prototype pushpull Class 33 with high-level jumpers and control pipes. All other push-pull conversions were of existing Eastleighbased locomotives, but on this occasion a Hither Green-based one happened to be in Eastleigh Works for attention and so was selected.
Nos. D6580 and 601 spent most of their time on the Kensington Olympia shuttle service or the Oxted lines rather than testing on the Bournemouth line, but the concept was proved and safety concerns addressed.
Class 74s
No mention is made of the 10 ‘large electro-diesel’ Class 74s, originally designated HB, that were converted from Class 71 (HA) electrics to work heavier boat trains and other duties on the newly-electrified Bournemouth line. They also worked with 3-and 4-TC units, and could haul complete trains in the event of a failure. They too were equipped to operate in push-pull mode, but lacked the ability to provide lighting and heating to TC units so were seldom used for such work. They are recorded, however, as having powered Waterloo to Swanage trains throughout at times.
Through trains ran on summer Saturdays between Lymington Pier and Waterloo but, owing to power supply limitations on the branch, these could not use REP/ TC stock and were instead formed of a pair of 4-CIG units borrowed from the Portsmouth line. REP units have never been to Lymington, but diesel locomotive assistance has been used on rare occasions to drag a defective electric unit off the branch.
Among many duties the versatile 4-TC sets performed over the years, no mention is made of the Portsmouth to Cardiff workings, upon which they were diagrammed from time to time, while these units have also operated to Weston-super-Mare, Taunton and (on charter and railtour duty) very much farther afield though effectively as hauled coaching stock. Class 33 + 4-TC units also performed regularly for some years on Salisbury to Reading and Portsmouth to Reading turns, which were often linked with Salisbury to Waterloo duties.
Other fascinating workings included the evening peak Waterloo to Southampton/Salisbury train, which divided at Basingstoke and made full use of the SR 27-way control system.