Routemasters With Air Suspension an Service
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A IR suspension is being fitted to the rear axles of 50 of London Transport's new Routemaster doubledeck buses. Thirty modified vehicles are in service
already. They are based on the Poplar garage. The remainder will be brought into use as they become available.
As the running units of the Routemaster are mounted on detachable sub-frames,it is not difficult to replace the coil springs at the rear axle with air-suspension units. Four different types of air-suspension equipment are being tried, and they have been designed so that any rear sub-frame can carry coil or air springs without modification.
Dunlop and Firestone are supplying the air-suspension components. Two types of Dunlop equipment are in use. One is the Pneuridc triple-convolution spring, which works with a large surge tank to give' a total deflection of 7 in. and a natural frequency of 80 cycles per second.
It is to be fitted to 20 buses. The other system on five vehicles is the new Dillow' design. This has a two-convolution bellows, the lower convolution of which rolls over a .metal ring to give a rollingdiaphragm effect. A small surge tank is used and this spring also has a frequency of 80 cycles per second.
The same frequency is provided by the Firestone Type 1 rolling-diaphragm spring on 20 Routemasters, In this design, the surge tank is connected to a pedestal by a sealed rubber skirt, the tank rolling over the pedestal under deflection. Five buses have the Firestone Type 2 equipment, which incorporates a pedestal of different shape to give a frequency of 70 cycles per second. Both designs give a total deflection of 7 in.
The air-supply system for all types of spring is the same. Air is taken through the usual one-way and restrictor valves from the reservoir for the air-operated gearbox. A levelling valve is fitted, and this has a delay setting of nine seconds to prevent loss of air through road shocks. It reacts to a minimum change in load of l-1passengers.
TURKISH ORDERS FOR LEYLAND
TWO shipments of goods-vehicle chassis and buses from the Leyland group have left Britain for Turkey. They are part of a £300,000 order received since the Turkish market was reopened to vehicle imports.
The shipments consist of 85 Leyland and Albion goods-vehicle chassis. and 15 Leyland underfloor-engined buses. Five of the buses, for the Eskisehir municipality, are Tiger Cubs, with •M.C.W. 40-seat two-door bodies. The remainder are Leyland Worldmaster 60-seaters with M.C.W. bodies.
The lorries will have locally built timber bodies with hinged sides, suitable for carrying tobacco, fruit and cereals.