The third hall is dedicated to the Royal Danish Navy. At the entrance is a photomontage of the catastrophe that overtook the regular ship service to Copenhagen on 11th June 1948. On that day the liner S/S KJØBENHAVN struck a magnetic mine, even though she followed a mine-swept channel. 48 passengers and crew members were killed. Magnetic mines detonate when influenced by the magnetic field of a passing ship, thereby creating blast waves which ”break the back” of the passing ship. During World War II Allied aircraft dropped large numbers of mines into Danish waters by parachute. Below the photomontage you see such a magnetic mine.
In the first part of the hall our decompression chambers and various diving gear are placed. The large decompression chamber, among the first to be built in Europe, was constructed in 1902 at the Royal Dock Yard in Copenhagen. It was used by the Navy until 1990, first at the Naval Diving School, Copenhagen until 1960 and later at the new Naval Base in Frederikshavn. The chamber has been modified several times. In 1960 a so-called ”NATO lock” was welded to the chamber, making it possible to connect it to a portable pressure tank. The smaller portable decompression chambers in the collection were all privately owned and cannot be connected to the larger chamber.
Decompression chambers are used in the treatment of decompression sickness (also known as the bends), which is caused by the development of nitrogen bubbles in the blood of a diver who surfaces too quickly. In the chamber, the pressure can be regulated to simulate the depth from which the diver surfaced. During the treatment in the chamber, the diver is given oxygen, which removes the nitrogen from his blood. A doctor will usually be present in the chamber during the treatment. Next to the decompression chambers gear for skin-diving as well as for deep sea diving are exhibited.