AEC-PRV Routemaster

Looking at the three third generation designs, let’s begin with the AEC-PRV Routemaster – surely Britain’s, if not the world’s, most famous bus.

The heart of the design and development of the Routemaster was London Transport’s Chiswick works. The project was led by A A M Durrant, with Eric Ottoway as chief engineer. Durrant had already been a leading figure in the development of the RT in the late 1930s.

The RT was intended to rid London Transport of its bewildering variety of pre-war bus types with a highly standardised product, and also enable it to close down its antiquated (if much loved) tram system.

The Routemaster fleet was set to replace what had quickly become the world’s largest trolleybus system, with over 1,800 vehicles operating across a kind of horseshoe shaped network than enveloped but did not penetrate central London.

After five years of weighing up different configurations and approaches a 27 foot long, open rear platform, 64-seater was settled upon as the most practical for London. Any design involving doors was rejected as hampering rapid passenger flow. London’s troubled experiences with the side-engined AEC Q type, and the high floor necessitated by an underfloor-mounted engine, led to the safe choice of a front-mounted engine.

The new bus would be made in aluminium alloy and be of integral construction to save weight, and hence fuel, tyre and other expenses. A target operating life of 18 years was anticipated.

Work began in earnest in 1951. AEC and Park Royal Vehicles were heavily involved throughout although the intellectual property in the vehicle belonged to London Transport.

AEC (the Associated Equipment Company) had grown out of the London General Omnibus Company – a predecessor of London Transport. It had been building most of London’s bus chassis for decades.

Park Royal Vehicles (PRV) was formed in 1930 out of a previous bodybuilding firm. It became part of the Associated Commercial Vehicles (ACV) group in 1949 alongside AEC, by which time it was already an important supplier of bus bodies to London Transport on AEC and other chassis.

With LT at Chiswick, AEC at Southall and PRV at Park Royal (a district in north London) the development teams were just a few miles apart from each other.

The prototype was unveiled at the Commercial Motor Show at Earls Court in 1954. London bus types had not previously had a model name, only nick-names like the ‘Bluebird’ LTs or the ‘Diddler’ trolleybuses. But London Transport wanted plenty of publicity for its new creation and the name Routemaster was announced. That led to the type code RM, and the first prototype being called RM 1.

Three other prototypes followed, including one with a Weymann body and one with an Eastern Coach Works body. Both companies hoped to secure orders to build production Routemasters but all the work went to Park Royal. Three of the prototypes were placed in service to build up operating experience.

RM 2 endured the most testing, including stints at the Motor Industry Research Association at Nuneaton, and – believe or not – the Fighting Vehicles Research Establishment at Chobham. Two more slave chassis units were built for development work.

The design of the Routemaster was optimised so that the appearance of first production bus, RM 5, was noticeably different from RM 1, especially at the front.

The first batch of production buses entered service in November 1959, to replace trolleybuses out of Peckham and West Ham garages. Labour disputes at PRV had constrained manufacture, so substantial in-service mileage of a small fleet could not be obtained to tease out teething problems. Retirement of the trolleybuses would not be delayed.

Consequently, the introduction of dozens of brand-new buses into daily service led to hundreds of faults. Many were serious – steering column fractures, gear selector failures, electric system problems. It was 1963 before the rapidly growing fleet was running satisfactorily.

This sorry situation was probably a combination of design faults, manufacturing and supplier quality issues, and problems arising from learning how to build a vehicle radically different from anything before.

Seeking more bus capacity on heavily-patronised routes, in 1961 London Transport decided to insert a 28-inch module in the centre of the body to add four more seats downstairs and four upstairs. The version was christened the RML. This stretch would match the length of the trolleybuses, and give plenty of capacity on busy routes. All Routemasters built after 1965 were of this type, and they made up about one fifth of the total build for LT.

A more luxurious Routemaster was built in 27- and 30-foot-long variants for Green Line limited-stop services.

In the early 1960s London Transport produced its Bus Reshaping Plan. It envisaged that long single-deckers with driver-only-operation and lots of space for standees were the future, so Routemaster production ended at 2,760 units in 1967. That was well short of the 7,000 or so examples of the RT family that were built up to 1954.

However, the Routemaster story had quite some time to run. The big single-deckers were a disaster – as unpopular as they were unreliable.

Falling passenger numbers and rising costs meant the running down of London Transport’s extensive in-house design and development capability. So it turned to outside manufacturers to supply buses that were modified versions of equipment sold in large numbers elsewhere.

Government regulations effectively ended the market for front-engined buses, because they would not attract the purchase subsidies in place from the late 1960s. It was therefore inevitable that London would go rear-engined for future double-deckers. It bought over 2,500 Daimler Fleetlines, which struggled in the capital’s extremely intensive operating conditions. The Fleetlines were scrapped by the hundred while the Routemasters soldiered on.

Leyland then developed the entirely new rear-engined Titan, ostensibly for the wider market but with London heavily in mind. MCW produced a London version of its Metrobus. Both were much better than the Fleetlines, but the dependability, ease of maintenance and sheer staying power of the Routemasters meant they were being withdrawn at a much slower rate than would be expected.

Even by 1997, when the youngest would be thirty years old, there were significant numbers in daily service. The very last finally went in December 2005, except for a handful running heritage routes for a few more years.

Outside London, there were ready buyers. Bus service deregulation in 1986 saw lots of operations start up that needed cheap, reliable buses, and the Routemaster was the perfect answer – even if you still had to pay a conductor.

Plenty of others found work as sightseeing buses around Britain, often having their roofs largely removed. Their reputation as a symbol of London saw lots being exported all over the world for similar work. Needless to say, dozens have been preserved.

Were the Routemasters a good buy? One analysis suggests that had they only lasted 18 years, the whole programme would have lost money. This was because of the high costs of development, the extensive early service problems, and LT’s failure to secure the kinds of productivity deals with its labour force that would have made running them more efficient.

But by lasting far longer, they more than paid their way, and certainly put the economics of some of their intended replacements to shame.