Submarine snorkel

A submarine snorkel is a device which allows a submarine to operate submerged while still taking in air from above the surface. British Royal Navy personnel often refer to it as the snort. A concept devised by Dutch engineers, it was widely used on German U-boats during the last year of World War II and known to them as a Schnorchel. Until the advent of nuclear power, submarines were designed to operate on the surface most of the time and submerge only for evasion or for daylight attacks. Until the widespread use of radar after 1940, at night a submarine was safer on the surface than submerged, because sonar could detect boats underwater but was almost useless against a surface vessel. However, with continued radar improvement as the war progressed, submarines (notably, the German U-boats in the Battle of the Atlantic) were forced to spend more time underwater, running on electric motors that gave speeds of only a few knots and very limited range. An early submarine snorkel was designed by James Richardson, an Assistant Manager at Scotts Shipbuilding and Engineering Company, Greenock, Scotland as early as 1916, during World War I. Although the company received a British patent for the design, no further use was made of it—the British Admiralty did not accept it for use in the Royal Navy. In November 1926 Capt. Pericle Ferretti of the technical corps of the Italian Navy ran tests with a ventilation pipe installed on the submarine H 3. The tests were largely successful, and a similar system was designed for the Sirena class, but was eventually scrapped; subsequent snorkel systems were not based on Ferretti's design. Germany defeated the Netherlands in 1940; their capture of O-25 and O-26 was a stroke of luck for the German Navy, the Kriegsmarine. The Dutch O-21 class were equipped with a device named a snuiver (sniffer). The Royal Netherlands Navy had been experimenting as early as 1938 with a simple pipe system on the submarines O-19 and O-20 that enabled diesel propulsion at periscope depth, while also charging the batteries.