A J Morse & Son US Navy Helium Helmet w/Single Exhaust Valve

Product Features

A.J. Morse & Son Was one of three Mark V helmet manufacturers building the Helium helmet variant. We have never seen or heard of a US Navy Helium Helmet being made by Miller Dunn. The design was introduced just before WWII. The early version had an exhaust tube running from a Mark V exhaust valve assembly to the back of the helmet just above the canister. It was found that any leakage back into the helmet through the exhaust could allow salt water to mix with the carbon dioxide scrubber media. This would cause a chemical reaction which could injury or kill a diver. This problem gave the helmet the nickname widow maker. We don't know how many divers wives were made widows but given it was a new type of helmet being used under the pressures of wartime it seems a bit unjust. Many brand new innovations being field tested under battle conditions had similar issues. 

In the early 1950s the Navy designed a secondary exhaust valve with two rubber flapper disks stacked in a housing at the end of the duct. Those flapper disks were from the exhaust valve of the Jack Browne Mask exhaust. Today double exhaust valves are standard on diving helmets to protect divers form exposure to contaminated water.

The base helmet for this Helium helmet is the AJMS Mark V. It is built using the US Navy plans from 1942. 

DESCO has not yet constructed the single exhaust version of the single exhaust AJMS Navy Helium Helmet. The photos are a front view of a AJMS Double Exhaust Helium Helmet and the back view is of DESCO USS Squalus Commemorative US Navy Helium Helmet showing the exhaust tube outlet.