Emerson MK 6 Semiclosed Rebreather

us

US Navy workhorse

Therebreathersite Emerson MK6 002

Emerson was a major influence in the development of US Navy UBA’s (underwater breathing apparatus) during the 1950-60’s, they collaborated with Dr Lambertsen to mass produce his Lambertsen Amphibious Respiratory Unit (LARU), the LARU (not to be confused with Draeger’s LAR V).  This developed into other units, such as the Emerson-Lambertsen, the Flatus II and the workhorse of the USN, the Mk 6.

Recently I received some nice pictures of the Emerson MK6 Semi closed rebreather. This very early design from the 70’s is little known in Europe but was used for many years in de US army. The Emerson rebreather was also called “the Green Death”. De rebreather is a constant flow mixed gas SCR. It uses a constant mass regulator  and a needle valve to set the flow. The manual says it is rated for 180 ft (55 mtr) with a premix of 32 % of oxygen resulting in a pO2 of 2,08 bar! The MK 6 was later to be replaced by the MK15.

Therebreathersite Emerson MK6 003
Therebreathersite Emerson MK6 004
Therebreathersite Emerson MK6 005
Therebreathersite Emerson MK6 006
Therebreathersite Emerson MK6 007
Therebreathersite Emerson MK6 008
Therebreathersite Emerson MK6 009
Therebreathersite Emerson MK6 010
Therebreathersite Emerson MK6 011
Therebreathersite Emerson MK6 012
Therebreathersite Emerson MK6 013
Therebreathersite Emerson MK6 014
Therebreathersite Emerson MK6 015
Therebreathersite Emerson MK6 016
Therebreathersite Emerson MK6 017
Therebreathersite Emerson MK6 018
Therebreathersite Emerson MK6 019
Therebreathersite Emerson MK6 020
Therebreathersite Emerson MK6 021
Therebreathersite Emerson MK6 022
Therebreathersite Emerson MK6 023
Therebreathersite Emerson MK6 024
Therebreathersite Emerson MK6 025
Therebreathersite Emerson MK6 026
Therebreathersite Emerson MK6 027
Therebreathersite Emerson MK6 028
Therebreathersite Emerson MK6 029
Therebreathersite Emerson MK6 030
Therebreathersite Emerson MK6 031
Therebreathersite Emerson MK6 032

First published may 20, 2004;

I want to thank all persons who sent the above pictures to make this publication possible!
A special thank you for Stefan Besier and Steam Machines Inc. !!

Courtesy Periscope Film
JW

Therebreathersite was founded by Jan Willem Bech in 1999. After a diving career of many years, he decided to start technical diving in 1999. He immediately noticed that at that time there was almost no website that contained the history of closed breathing systems. The start for the website led to a huge collection that offered about 1,300 pages of information until 2019. In 2019, a fresh start was made with the website now freely available online for everyone. Therebreathersite is a source of information for divers, researchers, technicians and students. I hope you enjoy browsing the content!