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LIGHTING
This is a 24 volt system and the saloon lighting units are spaced to give good
illumination over the whole area of the car, particularly at the doorways. Marker
lights and headlamps are fitted accordingly to requirements.
UNDERFRAME
This is designed as a lightweight steel unit consisting of mild steel channel
section electrically welded together. the whole being stiffened with diagonal
members and generously gussetted.
WHEELS AND AXLE BOXES
The lightweight rolled steel disc wheels are mounted on two axles carried in
self-aligning roller bearings in cast steel axle boxes.
UNDERFRAME SPRINGING
Springing between the axle box and the underframe is by means of rubber
shear-compression units specially designed for this purpose. These units consist
of rubber, moulded and bonded to steel plates of chevron shape. Each axle box
carries two units the former being specially designed to accommodate same. The
two units are mounted at an angle relative to each other; this angle determining
the ratio of shear to compression. Stiffness in the horizontal direction is very
high due to the rubber being mainly in compression in this direction. Lateral
stiffness is given by the chevron formation of the units.
BRAKES
Brakes of normal clasp type are employed operated by a straight air system
incorporating an emergency feature.
POWER UNIT &
TRANSMISSION
This equipment comprises a British United Traction 150 h.p. 6-cylinder horizontal
diesel engine capable of providing a maximum speed of 50-55 m.p.h., driving through
a fluid fly-wheel, thence through a free wheel unit to a 4 speed epicyclic gearbox.
A universal joint shaft takes the drive to the final drive unit mounted centrally on
one of the axles. The torque reaction being taken by an arm attached to the
underframe and incorporating rubber buffers to absorb shock loads. The final drive
unit also incorporates the forward and reversing gears. Engine throttle, gearbox
and forward-reverse gear are all operated through electro-pneumatic valves, the air
supply being drawn from the system after the brake reservoirs have reached a
pre-determined pressure. Combustion air for the engine is taken through a large air
filter and thence to the manifold by flexible pipe.
The engine cooling water is taken through a large radiator mounted at the side of the underframe. The fan is driven by a universal joint from the engine and is enclosed in a cowl attached to the radiator body. A header tank incorporating a filler is mounted above the engine to ensure that no steam locks form in the cooling system. This tank also incorporates a low water level switch.
FUEL TANK
This is suspended on one end of the underframe and the filler is located to be easily
accessible from rail level. The capacity of the tank is 50 gallons and the fuel is
fed through a filter after leaving the tank.
COMPRESSION
The compressor of 15 cu.ft. minute capacity is driven through vee belts from the input
end of the gearbox. Air is drawn through a filter and anti-freezer and connections to
and from the compressor are flexible to allow for belt adjustment and vibration.
GENERATOR AND CONTROL PANEL
This is of J. Stone manufacture and the generator is also driven from the input end of
the gearbox. It should be noted that in this position it is unaffected when the car is
coasting my means of the free wheel.