The Americans has a submarine flotilla based in Fremantle. The subs were doing fifty day patrols up north into sea lanes where enemy ships were moving between Singapore and Japan. The sub crew were complaining that in tropical waters when at just below the surface, the conning tower became unbearably hot, while below, the sub was fully air-conditioned.
A Perth firm – Sandovers, made and fitted small air-conditioning units in the tower which were connected down the periscope well to the main carrier unit and so solved the problem.
I was allowed a 90-day leave from my army engineering unit to work on and install the units. Needless to say the crew were very appreciative.
After the last sub was completed they arranged to have a second lot made and sent to their other group in Townsville, Queensland.
We often wondered what the comment would be when the subs all returned to the US navy base.