Flange helmet: The Mine Recovery Outfit

The MRS or the Mine Recovery Type Self-Contained Diving Apparatus was originally designed in wartime to enable divers to deal with magnetic mines in coastal waters. It is however a highly efficient self contained apparatus for general use for depths up to 40 meters or 120 feet. The breathing mixture used is nitrox which is a blend of 55% nitrogen and 45% oxygen which is carried in the cylinders on the diver's back. The use of this breathing gas mixture reduces the time required for decompression . The maximum duration of the apparatus is 60 - 90 minutes but this varies according to the depth the diver is operating at.

This is a Mine Recovery helmet. It used to be tinned, the previous owner had it removed and had the helmet polished........ 
At the rear you see the 2 connections for the CO2 scrubbing cannister. At the side are the telephone connection and the unusual exhaust. 
These helmets were worn with a 2 piece suit. Trousers with as rubber band around the waist and a jacket with the same rubber band, worn over the rubber band of the trousers. The jacket was glued over the breastplate so the diver entered the jacket and immediately had the helmet, all in one piece, on his head. 
Notice the hinged front window. 
Photo courtesy by our friend Rob Krul.

Royal Dutch Engineers on their way to work in the MRO

On this hat, the tinning is still intact. What about the weird looking breastplate?
Here you can see that the jacket was glued to the breastplate!
The owner of this helmet cut the jacket at the edges and never removed the remains from the breastplate.

One more for the road. On this jake you can see what the jacket looked like. 
The side nipples sticking through for the weights.
Another Mine recovery helmet displaying the bonded suit collar serial number 31The front window hinges downwards. There were telephone connectors fitted to this series of helmets.
The rear view show the 2 connectors for the hoses which went to the backpack containing the scrubber unit and the nitrox mixture. One of the connectors, the inlet has a non return valve whilst the
other the outlet is extended around the base of the helmet to a position in the front of the divers mouth. The back pacha has a third cylinder which is connected directly to the inlet for emergency use.
 
Side vies showing the weight nipples for the front weight and the rear backpack. The telephone connector can also be seen which was connected to the standard Admiralty 104M breastrope and lifeline
The exhaust valve is a different pattern to the standard diving helmet allowing any escaping air to pass through with very small bubbles so as not to cause acoustic interference.

Photos thanks to and courtesy of David Falcó Rodriguez
Director Tčcnic.

Commercial Diving & Marine Services
Diving Center
Centre d' Immersió Roses