The Routemaster double-deck bus was designed in the 1950s by London Transport, AEC (the engine and chassis maker) and PRV (Park Royal Vehicles, the body maker) to replace the AEC Regent RT type. Experimental vehicles took to the road in 1954, and full production began in 1959.
The bus used the AEC AV590 or Leyland O.600 diesel engine, an automatic gearbox by SCG (Self-Change Gears Ltd), power hydraulic brakes by Lockheed or Clayton Dewandre, and electrical equipment by CAV and Simms. A total of over 2700 were built in several variants, apart from the standard RM: the longer RML, coach versions RMC and RCL for the London Country operations, and the forward-entrance RMA for the London-to-Heathrow Airport shuttle service (a similar type being operated in Newcastle by Northern General Transport).
Heavy overhauls were carried out at Chiswick and Aldenham Works until these facilities closed. Surplus London Routemasters began to be sold in the 1980s, but in 1993 the remaining fleet was extensively refurbished, with new Cummins or IVECO engines, fluorescent lighting and other improvements. After the RM's 50th Anniversary celebrations in 2004 the number of Routemasters in service was reduced to just a handful, currently (2018) running on Route 15.
I worked for Colin Curtis from 1973 until his retirement from London Buses in 1988 - from the trials and tribulations of the Daimler Fleetline, through the development of the Metrobus and Titan, to the refurbishment of his beloved Routemaster. For most of that time Colin managed the Development Office at Chiswick, instilling, by turns, enthusiasm and scepticism for his projects and experiments. But for all his single-minded, some would say 'workaholic', support for the RM, he was always a jovial and likeable man, full of boyish glee at every victory.
In the mid-1950s he had nursed the four prototype Routemasters into service, and helped turn the concept into a production-ready design. That experience convinced him of the superiority of light-weight, sub-frame based, simple vehicles, and of the benefits of hydraulic braking over the air brakes of the time. Observing the weaknesses of the Fleetline and others in London conditions he worked tirelessly with MCW and with Leyland to design the next generation of one-man double-deckers. The robustness and light weight particularly of the Leyland Titan were due as much to Colin's efforts as those of the manufacturer's engineers. Unfortunately the troublesome hydraulic braking systems on both buses were also at his insistence; but in fairness their serious leakage problems arose through manufacturing quality-versus-price arguments rather than failures of design principles.
Colin remained convinced of the advantages of hydraulic power, and experimented with hydraulic drives for alternators, doors, and even windscreen wipers. But it was the more mundane work of solving day-to-day maintenance and reliability problems that occupied most of Colin's time - gearbox piston seal materials, brake lining alternatives to asbestos, fire and accident investigations, amongst many others. He and his team (along with the highly-skilled Experiment Shop fitters, who were remarkably tolerant of some of our more outlandish schemes) struggled against old Spanish customs and accountants to raise the standards of design and maintenance across manufacturers, garages and in Chiswick Works, with at least a modicum of success: I doubt very much if the Routemaster would have survived as far as refurbishment without Colin Curtis' hand on the wheel.
Graham Walker, former Mechanical Engineer - Development, London Buses. © G. L. Walker 2012.
www.routemaster.org.uk - The Routemaster Association
The AEC Bus Site - Neil Gow
AEC Southall - Neil Fraser
Park Royal Vehicles - Graham Hill
The Classic Buses Website - Dick Gilbert
RT3236 and Friends - Eric Scott
Ian's Bus Stop
The British Bus Club - dedicated to those who love British Made Buses
Mostly Food & Travel Journal - Food, Book Reviews, everything for the enthusiastic eater!