Diving Helmet

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Object detail

Siebe Gorman Diving Helmet, c. 1905-1908
12 bolt, 3 light (window). Standard Diving Dress Helmet; Admiralty Pattern.
MARITIME TECHNOLOGY Diving Diver's helmet
Production date
Production place
Height 460mm (measured from base of corselet to highest point on bonnet)
Width 378mm (measured between two widest points of of the bonnet and corselet included)
Depth 421mm (measured between the most forward projection of the bonnet/corselet and the furtherest rear projection of the bonnet/corselet)
Media/Materials description
copper, brass, glass, lead solder, leather plastic
Manufacturer's name plaque (centre front of corselet):
-10227 is stamped on the outer rim of the front light (viewing window).
SIEBE GORMAN & Co LTD FRONT FRONT LONDON is stamped into the front brails (from left to right).
History and use
Siebe Gorman Ltd is a British company, which developed diving equipment and breathing equipment, and worked on commercial diving and marine salvage projects. The company advertised itself as 'Submarine Engineers' and was founded by Augustus Siebe and his son-in-law, Gorman. The company was particularly notable for developing the 'closed' diving helmet of the standard diving dress and associated equipment. As the helmet was sealed to the diving suit, it was watertight, unlike previous 'open' helmet systems. The new equipment was safer, more efficient and revolutionised underwater work from the 1830s.

Siebe Gorman manufactured the 12 bolt helmet continuously from 1837 to 1975. It takes its name from the number of bolts, which project from the breastplate or corselet piece. The rubber and canvas diving suit would be tightly clamped in place on these bolts, making a watertight seal. The top of the helmet could then be screwed in place and the diver allowed to descend.

This 12 bolt 'closed' diving system was copied by many manufacturer's from around the world, including Korea, Japan, China and Italy. Versions of it are still produced in some countries today. Its simplicity and robust reliability meant that divers could be quickly and easily trained in its use, and for many years it wast eh workhorse of the diving world.
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