The RF replacement lightweight contenders

This page created 21st September 2004, completed 19th October 2005.

Even before production of London Transport's RFs was complete there was thought about its successor. The prodigious weight (7ton 17cwt for the Greenline version) and tank-strength construction of the RF were cause for concern, and a number of relative light-weights were considered: a Saunders Roe-bodied Leyland Tiger Cub, a borrowed Bristol L5SG and AEC's new Monocoach were all evaluated by London Transport in 1953.

Tiger Cub/SARO drawing

Leyland Tiger Cub

PTE 592 was a Leyland Tiger Cub PSUC1/1 with a Leyland O350 5/76litre 90bhp engine. Transmission was a four-speed RV16 direct-selection air-operated gearbox The bus carried very smooth-looking Saunders-Roe Rivaloy bodywork. This tipped the scales at 5ton 12cwt. It was delivered to London Transport in Greenline livery in April 1953.
AEC Monocoach drawing

AEC Monocoach

AEC's Monocoach was an integral vehicle, with AEC running units in a Park Royal body. It weighed 5tons 11cwt (5.55 tonnes). It had a preselector gearbox of the RT type, and a AH470 6.75 litre engine, in an integral 45-seat bus body built by Park Royal.

The prototype bus was finished in LT green, with Greenline fleetnames, and went to London Transport in May 1953.
LS5G drawing

Bristol LS

PHW 918 was a Bristol LS5G with ECW bus bodywork, a standard British Transport Commision vehicle. It was owned by Bristol Tramways & Carriage Co., but was delivered to London Transport in Greenline livery in April 1953. It was powered by a five cylinder 96bhp Gardner engine, driving through a five speed syncromesh gearbox. Weight was 6tons 7cwt: only a ton and a half less than the RF.

After the trials it went to its rightful home at Bristol.

The trials

Reigate received all three evaluation vehicles, and used them on bus route 447 (Redhill - Reigate - Earlswood - Redhill - Merstham - Caterham - Woldingham) and then on Green Line 711 (Reigate - London - High Wycombe).

The trio was moved in December to Dalston, for Central Area evaluation. There they worked on the twisting and busy route 208 (Clapton Pond - Bromley-by-Bow). They retained green livery, but in deference to Greenline's sensitivities they were given London Transport fleetnames.

Trials lasted until April 1954, when the buses were returned to their owners. It was fairly obvious by now that the standard RFs were reliable, and likely to last forever, while the lack of the expected 1950's growth in traffic meant that replacements for the non-standard single-deckers would be found from within the RF fleet.

Further trials with the Monocoach

But for NLP635 that was not the end of its LT history. It was fitted with AEC's Monocontrol gear selector, and returned to Reigate and the 447 for more trials between January 1956 and May 1957, more of the gear selection gear than the bus. This trial formed part of the experience that went into the Routemaster automatic transmission. Then the trials concluded, and NLP 635 went to join its sister at West Monmouthshire Omnibus, where it served for another ten years.

RF Contents lightweights bus histories photo references