The Leyland Atlantean is a predominantly double-decker bus chassis manufactured by Leyland Motors between 1958 and 1986. Only 17 Atlantean chassis were bodied as single deck from new.

It pioneered the design of rear-engined, front entrance double deck buses in the United Kingdom, allowing for the introduction of one man operation buses, dispensing with the need for a bus conductor.

The prototypes In the years immediately following World War II, bus operators in the United Kingdom faced a downturn in the numbers of passengers carried and manufacturers began looking at ways to economise. A few experimental rear-engined buses had been produced before the war but none successfully made it beyond the prototype stage. The need to minimise the intrusion of the engine into passenger carrying space was a priority, leading to several underfloor-engined single-deck designs. However, such designs raised the height of the floor of the vehicle, forcing additional steps at the entrance. On double decker buses, these problems were amplified, causing either an increase in the overall height of the vehicle or an inadequate interior height.

In 1952, Leyland began experimenting with ideas for a rear-engined double-decker bus. A prototype was built, STF 90, with a body by Saunders-Roe, to the maximum permitted width of . It was fitted with a turbocharged version of the Leyland O.350 engine, which was transversely mounted at the rear of the sub-frame. The chassis was a platform-type frame of steel and light alloy with deep stressed side-members. An automatic clutch and self change gearbox were also fitted. The vehicle was designated the PDR1 (R for "Rear-engined").

In 1956, a second prototype was constructed, XTC 684, this time with a Metro-Cammell body and, again equipped with an O.350 engine fitted across the frame. It had a centrifugal clutch, Pneumocyclic gearbox and angle drive. This vehicle was in height, with a wheelbase and overall length of and had a seating capacity of 78. Leyland christened this prototype the Lowloader.

Though two prototypes were thoroughly tested, the same problem of a front-engined bus remained, they had rear entrances with the space alongside the driver being wasted.

PDR1/PDR2

An amendment to the Construction and Use Regulations in 1956 saw the maximum length for double-deckers increased to , allowing a wider entrance to be located ahead of the front axle. This was initially to allow the driver to supervise boarding whilst the conductor collected fares, but quickly it became apparent that the design would allow for one man operation. Leyland took advantage of the new regulation to launch the first prototype Atlantean at the 1956 Commercial Motor Show at Earls Court Exhibition Centre.Rear Engine in New Double-decker Commercial Motor 7 September 1956Latest at Earls Court Commercial Motor 21 September 1956 Though it featured the front entrance design that would redefine the bus industry, several factors prevented the bus going on the market. The main problem was the high level of engine noise inside the lower saloon, as the engine was still inside the body, with the compartment being used for bench seating.

Mechanically, the prototype Atlantean was similar to the Lowloader with an O.600 engine transversely mounted at the rear with a pneumo-cyclic gearbox situated in the rear offside corner providing drive in a straight line from the engine. The Atlantean had a light and strong fabricated frame. Light alloy floor plates were rivetted directly to the framework, fulfilling the dual purpose of reinforcing the frame and providing a foundation for the saloon floor. The platform-type sub-frame concept from the Lowloader was retained for the prototype. A drop-centre rear axle allowed the flat floor, only one step up from ground level, to continue for the full length of the bus.

The prototype was demonstrated around the country to various operators. It also had an unregistered sister vehicle, which was used as a testbed. Both were subsequently scrapped.

By 1958, Leyland had overcome most of the problems and moved the engine to a rear-mounted compartment outside the main body and the first production Atlantean PDR1/1, with a wheelbase, was launched at the 1958 Commercial Motor Show. It had simpler mechanical specification than the prototype, with conventional front and rear axles, leaf springs all round and a channel section frame. Glasgow Corporation, James of Ammanford and Wallasey Corporation each put their first example of the type into service in December 1958.The Atlantean Gets Down to Business Commercial Motor 5 September 1958

From 1964, a drop-centre rear axle was available as an option for the Atlantean; the Atlanteans with drop-centre rear axles became known as the Atlantean PDR1/2 and, for the later version, the Atlantean PDR1/3. In 1967, Leyland launched the Atlantean PDR2/1 which could be fitted with .Larger Leyland Atlantean Commercial Motor 9 September 1966Manchester Orders 33-footers from Daimler and Leyland Commercial Motor 13 January 1967

In 1965, London Transport purchased a fleet of 50, initially operating on routes 7, 24, 67 and 271 before being transferred to Croydon.Routes for LTB Atlanteans Commercial Motor 18 June 1965LTB Atlanteans entering service Commercial Motor 5 November 1965LT's first o-m-o double decker Commercial Motor 14 November 1969LT to sell its Atlanteans Commercial Motor 12 January 1973

Though some operators initially continued to buy front-engined vehicles for reliability, the Atlantean gained multiple orders. Though the National Bus Company and the Scottish Bus Group favoured the Bristol VR and Daimler Fleetline respectively, the Atlantean was bought by many municipal operators. Aberdeen, Bournemouth, Glasgow, Edinburgh, Newcastle, Manchester, Liverpool, Newport, Nottingham and Plymouth Corporations purchased large numbers of the type.

In 1968, three Atlanteans were bodied by Marshall as single deck buses for Great Yarmouth Corporation.First single-deck Atlanteans Commercial Motor 15 March 1968 Portsmouth had 12 Atlantean chassis with single deck bodywork from Seddon Pennine, and lastly Birkenhead ordered three Northern Counties bodied single deck Atlanteans, albeit delivered to Merseyside in Birkenhead colours.

By 1972, over 6,000 Atlanteans had entered service.Leyland Atlantan PDR1 Bus Fleet Lists on the WebLeyland Atlantean PDR2 Bus Fleet Lists on the Web

AN68/AN69

In February 1972, Leyland announced the AN68 series to replace the PDR1/PDR2.New model Atlantean Commercial Motor 4 February 1972 The new chassis provided a wider entrance and several new safety features were included. An audible and visible alarm discouraged engine overheating by giving the driver due warning. A fail-safe parking brake was introduced, while the steering box and brake controls were protected against damage from severe head-on collision and stainless steel air-piping gave greater resistance to corrosion.New from Leyland - the AN68 Atlantean Commercial Motor 4 February 1972

Two models were offered: AN68/1R (9.4m in length) and AN68/2R (10.2m in length). Power assisted steering was standard on the AN68/2R and optional on the AN68/1R. The steering pump was power driven, which replaced the early belt driven system, while the only available engine was the Leyland O.680. A wide variety of body styles from various manufacturers continued to be offered, allowing the Atlantean to be tailor-made to requirements from operators ranging from the small independent to the large city corporation.

In 1978, Leyland started to offer the AN69 with Leyland O.690 (a turbocharged variant of the O.680 engine), all were sold to overseas operators.Leyland Atlantean AN69 Bus Fleet Lists on the Web However one AN69 with the 0.690 engine ended up with now defunct operator J. Fishwick & Sons of Leyland, the vehicle having been intended for export to Baghdad.

The Atlantean continued to sell in large numbers, with many operators proving loyal to it.Leyland Atlantean AN68 Bus Fleet Lists on the Web London Transport however, chose the Daimler Fleetline over the AN68 for its first large rear-engined double-deck order. Though over 2,000 Fleetlines would be purchased, reliability problems led to their very premature withdrawal.

The formation of British Leyland in 1968 saw rivals Daimler and Bristol merge with Leyland, bringing the two competing rear-engined chassis (Daimler Fleetline and Bristol VR) together with the Atlantean. Though the Bristol brand was retained, Daimler was dropped and products were re-badged as Leylands. After the re-organisation, Leyland set out to develop a new rear-engined double-deck bus for the London market to replace the troublesome Fleetlines. This new vehicle, the Titan B15 spawned a simpler, non-integral offshoot, the Olympian, which debuted in 1980. Though the Olympian was meant as a direct replacement for the VR, Fleetline and Atlantean, the venerable AN68 continued in production alongside the Olympian until 1986. The last Atlantean for the domestic market rolled off the production line in 1984, the last of a batch for Merseyside PTE, while the export version remained in production for a further two years, with deliveries to the city operator in Baghdad, Iraq.

By the end of production, over 15,000 Atlanteans had been built. Greater Manchester PTE (and its predecessors) was the largest operator of the Atlantean with 'Greater Manchester Standard' bodies from Northern Counties and, to a lesser extent, Park Royal. Second was Glasgow Corporation/Greater Glasgow PTE all of which were bodied by Walter Alexander. Third was Merseyside PTE who took approximately 800 Atlanteans mostly bodied by Walter Alexander and East Lancs although there were smaller batches with MCW and Willowbrook bodies.

Exports

Singapore

In 1977, Singapore Bus Services (SBS) received 20 Leyland Atlantean AN68s with BACo and Metal Sections bodywork on a trial to test their suitability on Singapore roads. These were Singapore's first double deck buses after an AEC Regent was deployed in 1953. They were first deployed on route 86, which plied between Hougang South and Shenton Way and thereafter redeployed to other routes. These buses were withdrawn and sold to China in 1990.£1.1m sale Commercial Motor 8 September 1978New buses for old in Singapore Commercial Motor 1 December 1979

Satisfied with the trial, SBS ordered 200 Leyland Atlanteans in 1978. Half of this intake were fitted with a Metal Sections body by Soon Chow and the other half an Alexander L body by SBS Woodlands Depot. They were deployed between 1979 and 1980 and all units were retired by 1993. All 100 of the Alexander-bodied buses were sold to Citybus of Hong Kong for use on Network 26 and 37 of the Metal Sections-bodied buses to Shanghai, China, where they would continue revenue service. The Citybus' buses would be refitted with a modified Alexander R front and served as the bulk of their training fleet.Leyland Atlantean AN68A/2R Bus Datafile"Hong Kong Buses Part 2: Citybus Limited" Fleetline issue 248 May 1997 page 94 These buses were scrapped by the mid-1990s, with a handful sold to South Africa.Exporting to survive Commercial Motor 5 July 1980 although one of them (Citybus fleet number A633) was a rare survivor and underwent restoration works in mid-2019.城巴亞特蘭大古董巴士A633由拖車運走 hkitalk.net

In 1982, SBS ordered another 100 units of Leyland Atlantean, all of which were imported from the UK completely built up with the Alexander L bodywork although there was a cancelled plan to fit one of them with an Eastern Coach Works body. Some of these buses were equipped with blind changing advertisement boards, dubbed as "Flexvision". These buses entered revenue service that same year and 1983 and all units were withdrawn by 1995.