The Leyland Atlantean was a model of double-decker bus built by Leyland in the United Kingdom from 1958 to 1986. It pioneered the design of rear-engined, front entrance double deck buses in the UK, allowing for the introduction of "one person operated" buses, dispensing with the need for a conductor.

The prototypes
In the years immediately following the Second World War bus operators in the UK 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 deckers, these problems were amplified, causing the overall height of the vehicle to increase, or an inadequate interior height.

In 1952 Leyland began experimenting with ideas for a rear engine double decker. A prototype was built with a SARO body to the maximum permitted width of 7ft 6in, 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 sidemembers. An automatic clutch and self change gearbox were also fitted. The vehicle, numbered 530001, registered STF90 was designated the PDR1 (R for 'Rear-engined').

In 1956 a second prototype, XTC684 (No. 542209) was constructed with a MCCW body, but this time fitted with the more powerful O.600 engine fitted across the frame, with a centrifugal clutch, pneumatic cyclic gearbox and angle drive. This vehicle was 13ft 2.75 inches in height, with a 16ft 2.875 inches wheelbase and overall length of 29ft 10 inches, 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.

Leyland Atlantean. (2007, August 14). In Wikipedia, The Free Encyclopedia. Retrieved 15:51, August 22, 2007