Big six-wheelerThe RF Story

Part 1 - Development

 

One of the predecessors of the RF.  This is an example of the LT-class six-wheel single-deckers, known as 'Scooters', dating from around 1931.  Many, including this one, were rebuilt after the war to extend their lives until the new RFs were available.  LT1136 catches winter shadows as it works towards Hounslow in February 1950.  The 237 was one of the first batch of Central Area routes to be converted to RF operation.
Photo © Alan Cross, Peter Gomm collection

 

After the second world war, London Transport’s fleet needed major renewal.  First in line were the double-deckers, always by far the largest part of the fleet.   From 1947 to 1954, LT rapidly built up the largest fleet of standardised double-deckers in the world, the RT family.  It also purchased 231 new single-deckers (the TDs and post-war Ts), mostly of essentially pre-war design.  Meanwhile, it continued to run a large number of elderly single-deckers, including Ts, Qs and LTs.
 
The AEC Q-type was a 1932 design that included a side-mounted engine.  Five years later, the Leyland TF appeared with an underfloor-mounted engine laid on its side, providing the direct forerunner to the RF.  In both cases, moving the engine from its traditional front position increased seating capacity within the permitted bus dimensions of the time.
 
Photo from Mike Morant CollectionThe AEC demonstrator UMP227 on loan to London Transport and working the 355 from St Albans to Borehamwood.  The bus is now at the London Bus Museum ('Cobham') undergoing complete refurbishment.
Photo © Geoff Morant, Mike Morant collection
 
These design ideas were applied to the 1949 prototype AEC Regal IV, UMP227, trialled by London Transport in 1950-1.  This high-floored bus had a centrally mounted underfloor engine, again laid on its side.  The flat front and front entrance (as previously seen on some of the Q-class) gave maximum internal space (as well as the potential for future one-man operation).  The trial, based at St Albans was a success and the RF was born.
 
The RF's AEC chassis carried a 9.6 litre diesel engine under the floor with access via detachable panels on the offside.  Apart from changes arising from being laid on its side, this engine was essentially similar to that carried by the RT.  Bodywork was provided by Metro-Cammell of Birmingham, previously a supplier of trolleybus bodies but not buses.  This came about because Park Royal and Weymann were still busy with RT orders; their output was originally to be complemented by 1,000 Metro-Cammell bodies of the same design for the Leyland-engined RTL, but delays caused a change of plan, with the 700 RF bodies being substituted for a reduction of 550 in the order for RTL bodies. 
 
Metro-Cammell bodywork had an excellent reputation for durability and the RF has proved to be one of the most robust buses ever built. 
 
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Part 2 - Diversity

Part 3 - Into service

Part 4 - Rejuvenation

Part 5 - Maturity