LT superbus !
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LONDON TRANSPORT's search for "the bus of the future" comes a step nearer with the completion of an hydraulically driven Daimler Fleetline for trial service.
This has a fluid pump in place of the gearbox and fluid driven motors at each rear wheel.
LT already has an advanced chassis – the eight-wheeled Moulton design with hydragas suspension – and has only been waiting for a suitable transmission to be developed for the project to get into top gear.
But introduction of the new superbus is still said to be ten years or more away.
The trial Fleetline was handed over earlier this year by LT to the National Engineering Laboratory at East Kilbride, for conversion.
NEC has been working on hydraulic transmissions since 1962. Project leader Mr Sinclair Cunningham told CM that the standard chassis presented some problems for conversion.
"We were stuck with the standard axle, so we couldn't try independent suspension on this bus," he said.
In LT's view, one of the main advantages of the hydraulic transmission is that the engine and pump can be placed anywhere on the chassis, and the drive taken by fluid lines to the wheel motors. The gearbox is, of course, disposed of altogether.
Although 3001b was saved on the axle by removing the differential and installing hydraulic wheel motors, this weight was added again by the heavier hydraulic pump fitted in place of the Daimler semiautomatic gearbox.
"The hydraulic transmission shouldn't be any less efficient than the old transmission," said Mr Cunningham.
Obtaining cash backing from the government funds had not been easy. London Transport had been working in close collaboration with NEC since 1972.