Submarine snorkel
Encyclopedia
A submarine snorkel is a device which allows a submarine
Submarine
A submarine is a watercraft capable of independent operation below the surface of the water. It differs from a submersible, which has more limited underwater capability...

 to operate submerged
Underwater
Underwater is a term describing the realm below the surface of water where the water exists in a natural feature such as an ocean, sea, lake, pond, or river. Three quarters of the planet Earth is covered by water...

 while still taking in air from above the surface. Navy personnel often refer to it as the snort.

History

Until the advent of nuclear power
Nuclear submarine
A nuclear submarine is a submarine powered by a nuclear reactor . The performance advantages of nuclear submarines over "conventional" submarines are considerable: nuclear propulsion, being completely independent of air, frees the submarine from the need to surface frequently, as is necessary for...

, submarines were designed to operate on the surface most of the time and submerge only for evasion or for daylight attacks. In 1940, at night, a U-boat
U-boat
U-boat is the anglicized version of the German word U-Boot , itself an abbreviation of Unterseeboot , and refers to military submarines operated by Germany, particularly in World War I and World War II...

 was safer on the surface than submerged because ASDIC sonar could detect boats underwater but was almost useless against a surface vessel. However, with continued improvement in methods of radar detection as the war progressed, the U-boat was forced to spend more time underwater running on electric motors that gave speeds of only a few knots and with very limited endurance.

An early submarine snorkel was designed by James Richardson, an Assistant Manager at Scotts Shipbuilding and Engineering Company
Scotts Shipbuilding and Engineering Company
Scotts Shipbuilding and Engineering Company Limited, often referred to simply as Scotts, was a Scottish shipbuilding company based in Greenock on the River Clyde.- History :...

, Greenock, Scotland as early as 1916, during World War I
World War I
World War I , which was predominantly called the World War or the Great War from its occurrence until 1939, and the First World War or World War I thereafter, was a major war centred in Europe that began on 28 July 1914 and lasted until 11 November 1918...

. 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 Royal Navy
Royal Navy
The Royal Navy is the naval warfare service branch of the British Armed Forces. Founded in the 16th century, it is the oldest service branch and is known as the Senior Service...

 submarines.
In November 1926 Capt. Pericle Ferretti of the technical corps of the Italian Navy
Regia Marina
The Regia Marina dates from the proclamation of the Kingdom of Italy in 1861 after Italian unification...

 ran tests with a ventilation pipe installed on the ex submarine, which Italy had received as part of the World War I settlement. The tests were largely successful and a similar system was designed for the Sirena class, but was eventually scrapped, hence the following snorkel systems were not based on Ferretti's design.

Germany defeated the Netherlands
Battle of the Netherlands
The Battle of the Netherlands was part of Case Yellow , the German invasion of the Low Countries and France during World War II. The battle lasted from 10 May 1940 until 14 May 1940 when the main Dutch forces surrendered...

 in 1940; their capture of O-25 and O-26 was a stroke of luck for the German Kriegsmarine
Kriegsmarine
The Kriegsmarine was the name of the German Navy during the Nazi regime . It superseded the Kaiserliche Marine of World War I and the post-war Reichsmarine. The Kriegsmarine was one of three official branches of the Wehrmacht, the unified armed forces of Nazi Germany.The Kriegsmarine grew rapidly...

. The Dutch had been working on a device named snuiver (sniffer). The Dutch navy had been experimenting as early as 1938 with a simple pipe system on the submarines O-19
HNLMS O-19
The O 19 was an in the Royal Netherlands Navy that saw service during World War II. The O 19, along with her sister ship HNLMS O 20 were the first submarines in the world to be equipped with a submarine snorkel that allowed the submarine to run its diesel engines while submerged.The submarine was...

 and O-20 that enabled them to travel at periscope depth operating on its diesels with almost unlimited underwater range while charging the propulsion batteries. The system was designed by the Dutchman J.J. Wichers.

The Kriegsmarine
Kriegsmarine
The Kriegsmarine was the name of the German Navy during the Nazi regime . It superseded the Kaiserliche Marine of World War I and the post-war Reichsmarine. The Kriegsmarine was one of three official branches of the Wehrmacht, the unified armed forces of Nazi Germany.The Kriegsmarine grew rapidly...

 first viewed the snorkel as a means to take fresh air into the boats but saw no need to run the diesel engines underwater. However, by 1943 more U-boats were being lost, so the snorkel was retrofitted to the VIIC and IXC classes and designed into the new XXI and XXIII types.

The first Kriegsmarine boat to be fitted with a snorkel was U-58
German submarine U-58 (1939)
German submarine U-58 was a Type IIC U-boat of the German Kriegsmarine that served in the Second World War. She was produced by Deutsche Werke AG, Kiel. Ordered on 17 June 1937 she was laid down later that year on September 29th as werk 257. She was launched 12 October 1938 and was commissioned on...

 which experimented with the equipment in the Baltic Sea
Baltic Sea
The Baltic Sea is a brackish mediterranean sea located in Northern Europe, from 53°N to 66°N latitude and from 20°E to 26°E longitude. It is bounded by the Scandinavian Peninsula, the mainland of Europe, and the Danish islands. It drains into the Kattegat by way of the Øresund, the Great Belt and...

 during the summer of 1943. Boats began to use it operationally in early 1944, and by June 1944 about half of the boats stationed in the French
France
The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...

 bases had snorkels fitted.

On Type VII U-boats the snorkel folded forward and was stored in a recess on the port side of the hull, while on the IX Types the recess was on the starboard side. The XXI and XXIII types both had telescopic masts that rose vertically through the conning tower
Conning tower
A conning tower is a raised platform on a ship or submarine, often armored, from which an officer can con the vessel; i.e., give directions to the helmsman. It is usually located as high on the ship as practical, to give the conning team good visibility....

 close to the periscope.

Technical details

Snorkels created several problems for their users. A U-boat with a snorkel raised was limited to six knots to avoid breaking the tube, and its sound-detection gear was useless with the diesel engine running. Most dramatically, snorkels were equipped with automatic valves to prevent seawater from being sucked into the diesels, but when these valves slammed shut the engines would draw air from the boat itself before shutting down, causing a partial vacuum which was extremely painful to the ears of the crew and sometimes even ruptured eardrums. This problem still exists in later model diesel submarines, but is mitigated by high-vacuum cut-off sensors that shut down the engines when the vacuum in the ship reaches a pre-set point.

Modern snorkel induction masts use a fail-safe design using compressed air
Compressed air
Compressed air is air which is kept under a certain pressure, usually greater than that of the atmosphere. In Europe, 10 percent of all electricity used by industry is used to produce compressed air, amounting to 80 terawatt hours consumption per year....

, controlled by a simple electrical circuit, to hold the "head valve" open against the pull of a powerful spring. Seawater washing over the mast shorts out exposed electrodes on top, breaking the control circuit. This vents the compressed air and allows the head valve to slam shut. When the electrodes are again clear of the water, the circuit is re-energized and the valve reopens.

External Links

"New Subs Are Undersea Aircraft" , June 1949, Popular Science detailed drawing at bottom of page explaining the new Guppy Class's snorkel system
The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
x
OK