The birth of the 2 bolt diving helmet.

The danish 2 bolt divers helmet was invented by Peter Hansen Hessing. As a diver working for the danish salvage company ‘Svitzer’ he had learned to dive with the antique ‘Sadler’ diving equipment. The Sadler was in fact an open helmet with a jacket attached to it, based on the very first design of diving equipment. Peter Hansen Hessing used the Sadler helmet as the base for his own helmet and improved the design by giving it a breastplate which could be built to a ‘one piece’ suit with the use of a neck ring and 2 bolts. He patented his helmet in 1907, he never built any helmets himself but designed them and had them built by local craftsmen.

The postcard here above shows Peter Hansen Hessing himself, in the harbor of Kopenhagen about to be dressed with the Sadler diving equipment (see also the chapter ‘Sadler’ on this website)

At the left an original Sadler helmet, next to it (middle) a Sadler which was converted into a 2 bolt helmet. And at the right a 2 bolt helmet Peter Hansen Hessing designed and had built. It is not impossible that the helmet in the middle is the very first 2 bolt helmet ever made(!)                             Photographs David L.Dekker

The original blue print showing the 2 bolt helmet design. Blue print collection Dykkehistorisk Selskab Danmark

From a Franz Clouth brochure: the diver is dressed (in a suit made by Franz Clouth) and Peter Hansen Hessing himself is about to place the helmet on his head. Document: collection Dykkehistorisk Selskab Danmark

The single oval neck ring is placed inside the suit, the helmet over it. When tightening the bolts this provides a water tight connection.  Photograph: Dykkehistorisk Selskab Danmark


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