Lambertsen Amphibious Respiratory Unit

The Lambertsen Amphibious Respiratory Unit (LARU) is an early model of closed circuit oxygen rebreather used by military frogmen. Christian J. Lambertsen designed a series of them in the US in 1940 (patent filing date: 16 Dec 1940) and in 1944 (issue date: 2 May 1944).^[1]

Etymology

The LARU is what the initials SCUBA (Self-Contained Underwater Breathing Apparatus) originally meant; Lambertsen changed his invention's name to SCUBA in 1952;^[2] but later "SCUBA", gradually changing to "scuba", came to mean (first in the USA) any self-contained underwater breathing apparatus. (Modern diving regulator technology was invented by Émile Gagnan and Jacques-Yves Cousteau in 1943 and was not related to rebreathers; nowadays the word SCUBA is largely used to mean Gagnan's and Cousteau's invention and its derivatives.)

History

Lambertsen designed the LARU while a medical student and demonstrated the LARU to the Office of Strategic Services (OSS) (after already being rejected by the U.S. Navy) in a pool at the Shoreham Hotel in Washington D.C. in 1942^[3][4] The OSS "Operational Swimmer Group" was formed and Lambertsen's responsibilities included training and developing methods of combining self-contained diving and swimmer delivery including the LARU.^[5][6]

Design

• Two large lengthways backpack mounted cylinders under a hard metal cover: the right cylinder is high pressure oxygen and the left is the cylindrical absorbent canister.
• Fullface mask with two small viewports like an old-type gasmask
• Two counterlungs, one on each shoulder.
• A breathing conduit of 4 lengths of large-bore corrugated breathing tubes in a loop: from the mask to one of the breathing bags to the canister to the other breathing bag to the mask.
• Its harness is a strong cloth jacket that enclosed the diver's chest.
• Mid front, a long zipped pocket: the diagrams do not show whether it was for kit or for diving weights.

Many diving rebreathers are descended from it. However, there were earlier underwater uses of rebreathers:

• Davis Escape Set for use in emergency by submariners from 1927 onwards
• Siebe Gorman Salvus invented in the 1900s and first used in mines and by firemen
• The rebreathers used by the Italian Decima Flottiglia MAS frogmen in World War II
• Rebreathers used by British frogmen and divers in World War II and led to the 1950s Siebe Gorman CDBA used by the British

See also

• Rebreather – Portable apparatus to recycle breathing gas

References

1. Lambertsen's patent in Google Patents^{[dead link]}
2. See Lambertsen's homage by the Passedaway.com website
3. Shapiro, T. Rees (February 19, 2011). "Christian J. Lambertsen, OSS officer who created early scuba device, dies at 93". The Washington Post. Retrieved 2013-05-16.
4. staff (2013-10-30). "'America's first frogman' dies in Bend at 95". KTVZ. Archived from the original on 2013-11-03. Retrieved 2013-11-02.
5. Vann RD (2004). "Lambertsen and O2: beginnings of operational physiology". Undersea Hyperb Med. 31 (1): 21–31. PMID 15233157. Archived from the original on June 13, 2008. Retrieved 2013-05-16.{{cite journal}}: CS1 maint: unfit URL (link)
6. Butler FK (2004). "Closed-circuit oxygen diving in the U.S. Navy". Undersea Hyperb Med. 31 (1): 3–20. PMID 15233156. Archived from the original on June 13, 2008. Retrieved 2013-05-16.{{cite journal}}: CS1 maint: unfit URL (link)

External links

• A long biography about him, and about the rebreather that he designed
• Images of his rebreather
• Image of Lambertsen rebreather's fullface mask, 1944, with eyeholes
• Front view of frogman swimming with Lambertsen rebreather, 1944
• Lambertsen rebreather with mouthpiece on neck strap, and eyes-and-nose mask, 1944
• Underwater Demolition Team Operations U.S. Navy video demonstrating the Lambertsen rebreather National Archives #76869