A short-lived route compared to many, the 240^A was born in November 1947, a renumbering and extension of certain Monday to Saturday short workings on the 240, initially operated by LT Scooters.  The 240, meanwhile, continued to be partly single-deck and partly double-deck operated, the latter out of Cricklewood and running north-east from Mill Hill Broadway to Golders Green.  The low bridge at Mill Hill Station provided the obstruction to through double-deck services.

At the time, it was planned that the Northern Line would be extended along the old railway line from Mill Hill East to Edgware, but the extension never came and the rails were lifted in 1964.  Meanwhile therefore, the Mill Hill area needed links to the tube, and the 240^A provided a service over new roads to the east of Mill Hill Broadway, initially to Page Street Bunns Lane. 

In May and June 1949, Edgware's Scooters on the two routes were replaced by nine new TDs, a year after Cricklewood's STLs on the 240 had been replaced by new RTs.  The following year, the LMR station at Mill Hill was renamed Mill Hill Broadway, but still only offered the north-south service that is now Thameslink (officially 'First Capital Connect').

July 1951 saw the service introduced on Sundays and extended daily to Mill Hill East Station over further new roads.  At the same time, the 240 was cut back from Edgware to Mill Hill Broadway by the withdrawal of the single-deck workings and the frequency of the 240^A increased substantially to compensate.  As they had run along the same route, the practical difference of this latter change was minimal.

The new TDs were highly prized and thinly spread, so when the service was increased on the 240^A in November 1951, a pair of former Green Line 10T10s were required until a couple more TDs could be found after the winter.  Apart from this period, the TDs settled into a routine throughout the 1950s.  Meanwhile, the introduction of the RFs and in particular the service reductions after the 1958 strike saw the TD fleet diminish so that by late 1959 they were working only at EW and at Kingston, where the 215^A was deemed too tight for RFs.  These latter finally gave way in February 1962, leaving the 240^A to run London's last half-cab single-deckers on 9 October 1962.

Throughout this period, the route had run a more frequent service between Edgware and Mill Hill Broadway than further east, with the short-workings described in the timetable as Mill Hill Watford Way and on the blinds as Mill Hill Broadway.  The RFs continued this arrangement, running for just over three years until more changes came to the 240 and 240^A in 1966.

The road under the railway was lowered, permitting through operation by double-deckers.  This was introduced by the extension daily of the 240 over its 'natural' routing through to Edgware, using a mixture of RMs from Hendon, RTs from Edgware and RTLs from Cricklewood.  In addition, trolleybus-replacement route 221 was extended on Mondays to Saturdays from North Finchley to Edgware over the full route of the 240^A, replacing it on those days.  The 240^A remained as a Sunday-only route, now RT-operated.  The RFs last ran on 22 Jan 66.

RF407 on the short-working to Mill Hill Broadway.

Photo © Michael Rooum, Peter Gomm collection