Units Nº1773 - Nº1782 used ex LSWR bogie-block suburban stock as the source of their bodies (these being from the same batches as those used many years earliier for the first LSWR units Nº1201 - Nº1284) and nearly all were mounted onto new SR 62' 0" standard underframes from Lancing. However, five underframes used were lengthened ex LBSC 'AC' electric frames, two odd frames being used under one motorcoach each of units Nº1780 & Nº1781, whilst all three coaches of 1782 were mounted on this type of underframe.

The layout of these units was:-
8 compt. Motor Brake Third (MBT)
10 compt Trailer Composite (TC) with 6 third and four first compartments.
7 compt. Motor Brake Composite (MBC) with three first and 4 third compartments.
The first class compartments of the TC & MBC were marshalled together.

The MBT was converted from a 51' Brake Third with a new cab (9' 1" deep) and van area (8' 5" wide) added at the former brakevan end of the old body. Each compartment was 5' 6" wide and the coach was finished to Diagram 671. It weighed 39 tons, 14cwt and seated 80 Third.

The TC was converted from a 51' Bi-Composite with two additional third compartments added to one end of the old body. The four first class compartments were 6' 6" wide and the adjacent four thirds were 6' 0" wide whilst the two new ones were 5' 5 1/8" wide. This coach was to Diagram 760 and it weighed 26 tons and seated 32 first and 60 third.

The MBC was converted from a 49' Tri-Composite, again with a new cab (9' 1" deep) and van area 10' 0 11/16" wide added to one end, whilst a comptment was removed from the other end of the body during conversion. Each first compartment was 6' 6" wide and three thirds were 5' 10" wide with one at 5' 6" adjacent to the brakevan. This coach was to Diagram 697 and weighed 39 tons 14cwt and seated 24 first and 40 third.

Overall therefore unit Nº1782 weighed 109 tons and seated 56 first and 180 third and was 193' 8" long. The bodywork conversions were carried out at Eastleigh and the part completed unit the taken to Brighton where electrical equipment was installed. Unit Nº1782 went into traffic in August 1930 and was formed MBT 8564 + TC 9658 + MBC 9817.

Coach origins were as follows:-
8564
Body new December 1905 as LSWR 786, renumbered by LSWR as 1883 and SR as 2884. This coach was a 7 compt 51' 0" Brake Third
Frame new December 1923 under LBSC 3280 (A Coulsdon/Wallington Driving Trailer Third)
The body off 3280 was rebuilt as a DC MBT in unit Nº1772 in June 1930

9658
Body new December 1905 as LSWR 250, renumbered by LSWR as 2488 and SR as 4973. This coach was an 8 compt 51' 0" Tri-Composite (11112223)
Frame new December 1919 and intended for use in 'CW' stock but coach put into traffic as 'steam' stock numbered 4109, renumbered by SR as 6267.

9817
Body new December 1905 as LSWR Nº251, renumbered 2489 by Nº LSWR and SR as 4864. This coach was an 8 compt. 49' 0" Tri-Composite (11122233)
Frame new June 1921 under LBSC Nº4113 (a Coulsdon/Wallington Driving Trailer Composite) though used as 'steam' stock and renumbered 6259 December 1924. The body off Nº6259 was rebuilt as a DC MBC in unit Nº1772 in June 1930.

Unit Nº1782 then ran as such until it was augmented to 4 Sub in October 1947. I have no record of any temporary reforms whilst it was a three coach motor unit. As augmented, unit Nº1782 became unit Nº4579, this having a bulleid-style six-aside 'tin trailer' added, numbered 10460. This new coach had 10 compartments of six-aside seating and therefore seated 120 third and weighed 28 tons. They were to Diagram 2013. In four car form therefore unit Nº4579 was 257' 5" long overall and seated 370 third (the first class now being downgraded to third and regarded as seating five-aside). Unit Nº4579 weighed 137 tons.

Unit Nº4579 ran as such until disbanded 14th August 1953 when TS 10460 was removed and converted to electro-pneumatic braking, renumbered 15033 and included in new 4 EPB unit Nº5033 from September 1953. Both MBTs were stored and trailer 9658 went into unit Nº4520 for a while, but was removed again in October 1954 and stored along with the motorcoaches. All three coaches were then converted into Instruction Unit NºS10, the coaches being renumbered as follows:-
8564 to DS40
9658 to DS41
9817 to DS42
Conversion took place during 1956, I believe it was carried out at Stewarts Lane, but may be wrong on this point. Unit NºS10 then remained in departmental use until withdrawn in May 1974.
DS42 retained Guards Van on conversion, DS40 did not.
S10 was repainted blue about 8-69 and renumbered 053 by July 1971.

Here are a few records of its movements:-
At Lovers Walk 10th July 1971, moved to Eastleigh 31st July 1971. Moved Strawberry Hill - Bournemouth 15th January 1972 back to Stewarts Lane 29 January 1972. Chart Leacon - Slade Green 8th April 1972. Stewarts Lane - Lovers Walk 19th August 1972.
Withdrawn 053 stored at Selhurst Depot by 10-74 and moved to Micheldever 28th May 1975 after seven months at Selhurst. Unit finally broken up at Ashford Works May 1976.
I understand that though there was great reluctance to condemn it, the state of the underframes towards the end of its life made scrapping inevitable. These lengthened 'AC' frames had outlived all the others by at least ten years.

Text by John Atkinson.