Driving A Western
Driving a Western Class 52
Contrary to popular belief it is not harder for a driver
to drive a diesel hydraulic locomotive than a diesel electric type. Controls are
basically similar in respect of desk location and functions.
Once the driver
has seated in his position, and the engines are running, his first task is to
put his Master Key in the Master Switch and turn the key on. This releases the
direction selector allowing the driver to chose the appropriate direction.
Initially he will select an Engine Only position. Then, once the locomotive
straight air brake has been applied and the locomotive is secure, he will open
the train brake valve to start charging the brake pipe (to 72½ psi/5 BAR).
There is a short time delay of around 1 minute before the brake pipe starts to
charge.
He will then
operate the 'change end switch' located by his left foot on the floor. This lets
the locomotive know from which cab the driver will be driving and sets up the
signalling AWS system for that cab. Once the switch is operated a 'Caution' AWS
alarm sounds which the driver acknowledges, by cancelling the AWS by the reset
button on the desk directly in front of him. Once the brake pipe is fully
charged the locomotive is now ready to move.
On the Master Switch, unlike diesel electric locomotives
which have four positions, on a Western there are five positions; (R to L)
Reverse Engine Only, Reverse, Off, Forward and Engine Only Forward. These
additional Reverse/Forward Engine Only positions allow the driver to select
Engine Only without the transmission reversers throwing into neutral from the
selected direction. If the locomotive is moving the Master Switch direction
selector MUST be in Forward or Reverse and the Deadmans pedal depressed. In any
other position the brakes will automatically apply. This is a safety mechanism
to ensure that the driver is in position and alert when the locomotive is in
motion.
On opening the power controller three clicks can be
heard. The first is the power controller moving to the 'On' position. Then two
relays, 'CP' and 'CPR', energise, the first only energises if the locos safety
circuits are correctly set (AWS is 'in', Brake pressures are at normal, DSD is
'set' etc.), the second relay proves the transmission converters have filled
with oil. From this point onwards the engine speed is controlled by air pressure
to the engine governor which gives the driver total control over the engines.
This air pressure operated system is called 'infinitely variable', allowing the
driver to chose his desired engine speed rather than having electronic equipment
give the driver options of various pre-designated settings like modern class
66/67's.
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The
driving position in a Western cab is quite compact with everything a
driver needs to perform his duties with ease. The gauges on the desk angle
show the air pressures in the brakes, on the locomotive and on the train,
road speed and that end engines speed in rpm. A group of five fault lights
in front of the driver indicate the general health of the locomotive (Blue
= normal / Red = warning).
To
the drivers left are the train brake handle and locomotive brake handle,
centrally in front of him are the AWS acknowledgement reset button and
warning horn, to the right are the Master Switch direction selector and
power handle. The yellow/black striped indicator in the windscreen corner
is a visual reminder to the driver of the aspect of the last signal he
passed; all black indicates a clear aspect, yellow/black indicates a
caution aspect.
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