Churchill had a electric powered turret traverse control, the turret
being capable of complete rotation in 14 to 16 seconds (provide
the gun was not depressed in which case a slower speed was automatically
applied). The control unit was operated by the gunner using his
left hand. The trigger was first pressed then the handle rotated
- the turret moving in the same direction. The control was proportional
in nature - the further the handle was turned from vertical the
faster the rotation. There was no movement at 4 degrees either way
of vertical, a gradual increase thereafter up to 12 degrees, full
speed being obtained above 42 degrees. The photograph above shows
this operating range marked underneath the scale.
stop turret rotation the handle was returned to the central position
but the trigger still had to be pressed. If the trigger was released
prematurely, the braking effect on the motor would be lost resulting
in overrun. Apparently this system was somewhat noisy and operators
guides make reference to the fact that the "shrill noise"
is normal and doesn't indicate any defect!
power for the traverse system was provided by a generator, driven
directly from the engine. Unfortunately this implementation meant
rotation speed would drop if the tanks speed was slow and should
the driver depress the clutch for any length of time, power was
lost to the traverse system altogether!