Sutton's Locomotive Workshop British Railways Sulzer Type 2 Operating Manual - page 21
TRAIN HEATING: Ever wondered what that diesel loco is doing on the end of a
steam-hauled special? Or marshalled inside, behind another leading locomotive?
A common reason was and is to provide train heating of the type required by
the stock being hauled if the lead loco did not possess the correct equipment. In
fact, this was a common occurrence when Class 24s were loaned to the Southern
Region in the early 1960s, when they were employed as the only way to steam-heat
coaching stock that was to be hauled by new Class 33s (equipped with electric train
heat only).
You can simulate the use of your Class 24 in this way quite easily. You will need
to speed match the loco with any other loco in the train, and use your preferred
method of ‘consisting’ to operate them together. Your Class 24 will be providing
motive power, of course, but it is possible to lock the engine sound in ‘idle’ to prevent
it changing with speed or load. Before driving off, engage F6. By default, F6 plays
the engine ‘on’ sound. If you wish to ‘hold’ a higher engine sound specifically for
this role, change the value CV375 to 2, 3, 4, 5. For normal use, remember to revert
back to the default setting, CV375 = 1. This method could be used to simulate the
operation of the later Class 25 ‘ETHEL’ units.
Two redundant Class 24s were actually converted to static carriage pre-heating
units in 1976. The conversions saw the generator output used to provide an electric
train heat supply via jumpers and cables. These departmental locos had their
traction motors isolated, but obviously the engine needs be running to provide
power. This method of static operation can be replicated using the manual power
handle positions described on the previous page.
Global commands
Lighting: The main lighting switch (F0) has been programmed by default to reflect
the most common working arrangement, i.e. when the locomotive is at the head of a
train. This will show illuminated marker lights (white) behind the headcode discs in
the direction of travel only. Tail lights (red) are switched off, since the rule book states
there should always be an illuminated red lamp at the rear of the train. In contrast,
light engine movements should show white markers to the front and red tail lights
to the rear, and this arrangement is possible by selecting special lighting function
F21. A third lighting function (F22) additionally allows the interior lighting to be
operated in the cab facing in the forward direction.
Shunting mode: Pressing F20 will temporarily remove all inertia settings and reduce
speed by up to one half and is great for precise control during shunting. Release the
button to immediately restore normal operation.
Live volume control: This new feature replaces the mute button and gives you the
ability to adjust the sound level coming from your model without the requirement to
go into programming mode and adjust CVs. The live volume control should only be
FULL: Everything available! Used to lift heavy trains and for brisk acceleration.
May be required in any load condition on steep gradients to start off or maintain
speed. The driver will use anticipation, his knowledge of the road and his driving
experience to vary the position of the control lever to maintain the correct speed.
Despite what many enthusiasts believe, good driving practice requires relatively
gentle movement of the power handle until FULL is reached. With a heavy train ‘on
the hook’, a driver will always have one eye on the ammeter to prevent overloading.
To the outside observer, little of this is visible, but the engine sounds and exhaust
note can be heard to vary greatly, irrespective of track speed. The power required
(and therefore the engine note at any given speed) will vary depending upon
gradient, loading, environmental factors, track conditions, signals and speed limits.
The Throttle Response, Throttle ‘Plus’, Coasting
and Notching-back
features of this ZIMO decoder will enable you to simulate this behaviour in most
circumstances simply by use of the throttle on your chosen DCC controller.
Since our aim is to provide you with the facility to simulate every eventuality, and
to satisfy the needs of those who prefer full manual control, you will find that the
power handle positions are replicated on a series of F-buttons. Please note that the
use of these buttons is entirely at your discretion; the project will work correctly
without their use at all, though the ‘ON’ position (F7) will add to the prototypical
experience before moving off.
These are the F-buttons used. For correct operation, they each must be ‘latched’:
F7 = ‘ON’ F23 = ¼ Power F24 = ½ Power F25 = ¾ Power F26 = Full Power
Each button can be used in isolation. That is to say pressing F24 will cause the
engine sound to accelerate up to ½ Power in a single sweep and remain there.
Disengaging it will cause the engine sound to spool down, in a single sweep, to idle.
They can also be used progressively - activate F23 to ramp-up to ¼ Power, followed
by F25 will transition engine sounds directly to ¾ Power and so on.
Because these actions are fully integrated into the driving scheme, it is possible
to mix throttle and F-button controlled sounds if you wish. For example, you want
the engine sound to ramp up to ½ Power and maintain that sound until the actual
track speed of the loco requires a transition to ¾ Power. Engage F24 and sound will
transition to ½ Power. Drive the loco with your controller. When speed exceeds the
internal threshold to trigger ¾ Power, the sound will automatically ramp-up.
Deceleration will cause the engine sound to spool down, but will hold steady at
½ Power unless F24 is disengaged. Remember that ‘Notch down’ and ‘Coasting’ by
use of the throttle remains active throughout, but any ‘power handle’ button will act
as a floor beyond which the engine sounds will not drop.
SLW Class 24 Operating Manual
Page 41
Page 40
SLW Class 24 Operating Manual