Comprising ex-diagram 2005 SO No. S1351S and ex-diagram 2403 BCK No. S6687S, Set 601 operated between November 1959 and December 1963. From September 1960, the set was noted as operating in the London Central District, on the Horsham to Guildford Branch, as well as on Horsham-Shoreham-Brighton cross country services. From June 1963, until scrapping, the set moved to the Central Section of the Southern Region of British Railways.
Typically coupled with a Wainwright ‘H’ Class locomotive before the introduction of diesel/electric multiple unit traction.
By 1959, there were still forty six Pull/Push sets in service with British Railways (Southern Region), but none of them were under thirty years old and their wooden bodies were causing safety
concerns over impact damage and the possible resulting fire damage. With the British Transport Commision issuing an instruction to replace any carriage over thirty years old, BR (SR) faced losing their entire stock of Pull/Push carriages and a quick solution needed to be found.
The answer was for BR (SR) to convert twenty Pull/Push sets from two Maunsell vehicle types, under orders L4634 and L4746 in June 1959 and February 1960. The conversions took place on
ex-diagram 2403 BCKs and ex-diagram 2005 SOs, the brake end of the BCK being modified by inserting two windows to form a driving compartment, with the corridor connection removed and droplights replacing the familiar former guard’s lookout duckets.
The outer end of the SO also had its corridor connection removed, but the corridor connection between the two vehicles was retained. Large electric stock pattern buffers were installed and all the
lavatories were sealed, their windows sheeted over, although the frosted windows on the opposite sides were retained.