Lambertsen Amphibious Respiratory Unit
The Lambertsen Amphibious Respiratory Unit 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 and in 1944.
Etymology
The LARU is what the initials SCUBA originally meant; Lambertsen changed his invention's name to SCUBA in 1952; but later "SCUBA", gradually changing to "scuba", came to mean any self-contained underwater breathing apparatus.History
Lambertsen designed the LARU while a medical student and demonstrated the LARU to the Office of Strategic Services in a pool at the Shoreham Hotel in Washington D.C. in 1942 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.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.
- 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