DESCO Mark V Mod. 1 U.S. Navy Diving Helmet

The DESCO U.S. Navy Mark V Diving helmet has been in continuous production from 1942 up to today. It started as, and still remains an authentic classic piece of military and commercial diving equipment. It conforms to the Bureau of Ships drawings which we still have in our files.

DESCO's production of the U.S. Navy Mark V Diving Helmet began in mid 1942. War contract manufacturers were issued drawings prepared by the U.S. Navy Bureau of Ships. Mark V Helmets produced by the various manufacturers were to adhere to these drawings so parts could be interchanged when necessary. DESCO helmets were and are still made using these drawings and specifications. We still manufacture the helmets in the same way. Bonnet shells are spun copper, NOT HYDRO FORMED, and the breastplates are formed by hand  in the original 1940's mandrels, NOT MACHINE STAMPED. These methods give each helmet its hand crafted individuality.

Pre 1945 DESCO Mark V Helmets had a football shaped nametag marked "Diving Equipment and Salvage Co. Inc\" which was a different shape than called for in BuShips drawings. When the company name changed to Diving Equipment and Supply Co. in late 1945 the tag was changed to an oval shape to conform to the BuShips drawings. ( info )

The DESCO Mark V Mod. 1 HEO2 U.S. Navy Diving Helmet

This is the standard U.S. Navy Helium/Oxygen Mixed Gas Helmet based on the standard Mark V Helmet. The main feature of this helmet is the canister mounted on the rear of the helmet and a venturi system allowing for recirculation of breathing gas to conserve Helium. The canister was filled with a scrubbing agent to remove Carbon Dioxide from the breathing mix.

The breastplate is the same as a normal Mark V except the lock assembly is located in front in place of the spitcock. All other parts are the same as a standard Mark V except for the omission of the spitcock valve, and the addition of a extra communications elbow which the Navy used to connect electrically heated underwear to a power source.

The canister can be removed and with the canister elbows capped the helmet can function as a normal Mark V. Standard finish is Tin plate but the helmet is also available polished. Shipping weight with canister approximately 93 lbs.

The U.S. Navy Mark V Helium Helmet is available in two versions. DESCO can produce either style of this helmet. ( info )

Double Exhaust Valve (The Later Version)
The newer style incorporates a Double Exhaust Valve on top of the helmet. It was found that when salt water leaked back through the exhaust valve and got into the scrubbing agent Chlorine gas formed. This would result in serious injury or death to the diver. A secondary exhaust valve was fitted to stop leak back. This change was made in the early 1950's. Also added is a top lifting ring due to the extra weight of this rig. Original single exhaust Helium helmets did not have a lifting eye (as shown in the drawings below). Desco offers the lifting eye as an option on both styles of USN Helium Helmets.  ( info & images )

Single exhaust Valve (The Early Version) The early version has the exhaust tube extending to the back of the helmet. ( info & images )

DESCO ‘Buie’ Mixed Gas Diving Helmet

During WW II pressure was kept on manufacturers to develop new and better equipment. Not just rifles, or planes, or tanks but in every area. DESCO was tasked with making continual advances in diving equipment to meet the challenges that arose daily during the war. The Navy had been experimenting for years with Helium diving using converted Mark V helmets. This was a practical approach as they were well familiar with the helmet and they were readily available. When the war broke out the status quo changed and this allowed for experimentation on a level not dreamed of before. U.S. Navy diver E.D. Buie came to DESCO to work on a low volume mixed gas helmet for the Navy to use clearing mines ( info )

DESCO Military Diving Helmets, Masks and Rebreathers

DESCO's production of the U.S. Navy Mark V Diving Helmet began in mid 1942. War contract manufacturers were issued drawings prepared by the U.S. Navy Bureau of Ships. Mark V Helmets produced by the various manufacturers were to adhere to these drawings so parts could be interchanged when necessary. During the war subcontractors supplied parts and sub assemblies to speed war production. Mark V manufacturers (DESCO, Morse, Schrader, and Miller Dunn) used exhaust valve assemblies made by Batteryless Telephone Equipment Company. After the war these parts were made in house at DESCO for their helmets. info

U.S. Navy diver Emerson D.Buie

A variation of the DESCO ‘Buie’ Mixed Gas Diving Helmet

This helmet design may have been developed concurrently with the Buie, or as a follow on design. This canister configuration makes the helmet more streamlined and less complicated to build and maintain. There are less protrusions creating potential snagging hazards. The concept may have been proposed by Buie himself or the DESCO designers as the helmet was being designed for mine clearance duties. Reducing the risk of snagging on a mine cable would be a practical goal. The canister is permanently soldered to the helmet shell so it was intended to be used as a gas hat only. The Buie helmet canister could be removed and the elbows capped and it would work like a normal free flow helmet. ( images & info )

First type of the DESCO ‘Buie’ Mixed Gas Diving Helmet ( with a curved window )

The first low volume mixed gas helmets had a curved window. The canister was much smaller than the Mark V Helium canister and in fact the whole helmet weighed less than half of the Mark V Helium (104lbs to 43lbs). The smaller and lighter rig was needed for mine clearance work. Not many units were made.  ( info scans are from ‘MINE DISPOSAL BULLETIN No. 22 July 1, 1943. David L.Dekker library )

Second type of the DESCO ‘Buie’ Mixed Gas Diving Helmet ( with a faceted window )

The second version of the Buie helmet. The basic design in the form of the shell, air inlet, and canister remained constant. The main difference in the later Buie helmets is the front window. A curved helmet can cause distortion in the field of vision underwater. This would not be good while working on a mine. Later Buie helmets have a faceted window presenting flat surfaces to the water. The secondary exhaust valve was changed from the original design and the helmet was given a support to keep it better in place at the divers shoulders. ( images & info  )

DESCO B-Lung This is the unit first developed for the OSS and U.S. Navy during WWII. The first units used a oval mask with a nose bump out. ( images & info  )

DESCO B-Lung first type

DESCO B-Lung second type. These later units were fitted with a modified Jack Browne mask. B-Lungs were produced until the early 1960's. ( images & info  )

DESCO B-Lung second type

The DESCO ‘Browne’ Full Face Diving Mask ( The standard Navy mask, first version )

This is the mask that started it all. The Navy needed a lightweight utility mask for jobs where heavy gear wasn't necessary or practical. DESCO developed the Browne Mask to meet this need. It was also the basis for a diving outfit. ( images & info  )

The first version of this US Navy mask had the unique feature of a 3 way valve attached to the breather bag. Air is fed through a non-return valve, and a three-way inhale valve which permits use of an optional breather bag assembly. The bag was intended to reduce air demand and ease breathing. It didn't function as well as hoped and eventually fell out of use. DESCO even stocked a cap to block the bag port. Air is exhausted on the left side of the mask through a rubber-disc exhaust valve ( images & info  )

The second version of this mask was simply a free flow mask ( images & info  )

The DESCO ‘Browne’ Full Face Diving Mask ( The standard Navy mask, second version )

DESCO Military Rebreathers

DESCO began producing equipment for the U.S. Navy in 1942 to support the war effort. The Office of Strategic Services (forerunner to the CIA) needed rebreathers for covert operations. DESCO was contracted to design and produce the needed units. After that contract was completed subsequent units were sold to the Navy. With the end of WW II DESCO applied the technology to commercial and sport diving. The B-lung was the unit that DESCO developed during the war and was aimed at the commercial diver.


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