The image above shows the port guns in their reloading position, trained to Red 85 degrees. The guns are fully run in (retracted) and are elevated to 13 degrees.
The external loading rams are raised. In the sister ship to Colossus, HMS Edinburgh, loading rams were fixed in the raised position.
The armour plating base of the turret is also depicted in this image. Two access holes cut in the armour at the rear of the turret allow the loading rams access. Although not shown, there may also have been hatches to close the holes when not actually loading.
The armoured turret base also carried gearing that connected to gear wheels driven by two hydraulic turning engines situated in the bunker space below. It is probable that the turret could be trained through 360 degrees in about one minute.
(double-click the image to right to see the engine in action)