The water supply was from a borehole where there was barely enough at the time for the population, so it was vital to give a continuous supply to the tower and later reservoir there. The water was raised by capping the well which had a pipe from the bottom up the tower and forcing compressed air in to the borehole. This was supplied from 2 engines. The newer of the 2 engines was a Dennis (Diesel) with a large flywheel of about 7 tons. Pictured to the right of Joe Woodward.
The main engine was a single cylinder diesel started by forcing in compressed air from a small compressor driven by and electric motor once it had started to rotate it was possible to switch over to diesel via a system of valves. This engine was sold to India but the Fly wheel was lost in transit strange as it was so large. Also another maybe 4 cylinder compressor driven by an electric motor used as a back up . This system was later replaced by a screw in the well driven by electric motor.
The above information and photo from Malc Woodward son of Cess Woodward.