During World War II, a team of scientists carried out more than 600 experiments on themselves to improve the safety of divers and submariners. In the 1940s, diving required bulky suits, large helmets and constant tethering to boats for air supply. Scientists were well aware of decompression sickness, a condition caused by nitrogen bubbles forming in the blood when divers ascended too quickly from deep dives. This condition could be fatal in severe cases.
The sinking of the submarine Thetis in 1939, where 99 people died of unknown causes, brought attention to the need for better breathing support equipment for underwater mobility. An investigation into the tragedy led scientist John Burdon Sanderson Haldane to conduct experiments on himself and colleagues in a high-pressure chamber. Their focus was on the effects of different gases and pressure levels on the human body.
Through their experiments, Haldane and his team discovered the dangers of excess CO2, oxygen toxicity, and nitrogen intoxication in high-pressure environments. They also worked to find the ideal mixture of oxygen and air for divers and submarine crews to breathe without side effects. These findings led to the development of breathing support equipment used by the British Navy during World War II.
The dangerous experiments conducted by Haldane’s group not only aided in the D-Day campaign but also contributed to the scientific foundations of modern scuba diving. Their work, although risky, paved the way for advances in underwater breathing technology that continue to save lives today.
