This was interrupted by the Second World War, and he was called up to the Royal Navy and became a research assistant at the physiological laboratory Vernon II at HMS Dolphin in Gosport, where he was involved in experimental work assessing the effects of explosions on immersed personnel.
In 1946 he was employed at the Wellcome Physiological Research Laboratory in Beckham, Kent, where he worked on chemotherapeutic agents for the treatment of pertussis infections.
[1] In 1949 he rejoined Vernon II, which had become the Royal Naval Physiological Laboratory, as a scientific officer, and was soon involved in the development of decompression tables.
Further work involved decompression from greater depths to develop the Royal Navy's capacity for rescue from disabled submarines.
[3] The critical volume concept was developed by T. R. Hennessy and Hempleman who formulated a simple mathematical condition linking the dissolved gas and the safe ascent pressure: Where Ptissue represents the dissolved gas tension, Pambient, the ambient pressure and two coefficients, a and b.