North Sea mine lock
The North Sea Mine Barrage (Engl. North Sea Mine Barrage ) was a big minefield that during the First World War from the east of the Orkney Islands up to Norway from the US Navy (supported by the British Royal Navy ) was placed. The purpose of this mine barrier was to block the sea routes from Germany towards the North Atlantic for German submarines . A total of 70,177 mines had been laid by the end of the war, and British Admiral Lewis Clinton-Baker , commander of the mine-laying associations of the Royal Navy, described the North Sea mine lock as the largest mine-laying operation in world history after the First World War. In the Second World War, however, even larger minefields were laid.
Plans for such a closure had been in existence for some time, but there were neither enough old-type mines with contact detonators (of which the need was estimated at 400,000 for the 250 nautical miles between Scotland and Norway), nor were there enough ships available as mine-layers because they instead were needed for convoy protection . In 1917, a new type of mine with an electric ignition mechanism was developed in the USA : copper wires expanded from the mine and triggered the detonation on contact with a submarine. The original idea came from the American inventor Ralph Browne, who submitted it to the Naval Ordnance Bureau as part of a depth charge; the head of the mines section, Commander SP Fullinwider, recognized the potential for a sea mine. This meant that only 100,000 mines were required, each with 150 kg of TNT .
The June 1917 proposal was approved in November, and mining began eight months later, in June 1918. Admiral Joseph Strauss was in charge of the American side, who did the main work, and operations at sea were under the command of Captain Reginald R. Belknap. The deployment of the mines (around 1000 per day) in the rough North Sea was dangerous and required great precision. In the end, the barrier was not quite finished: it was 230 nautical miles long and 15 to 35 nautical miles wide, each with staggered rows of mines, some of which were irregularly arranged. The distances between the individual mines were around 60 m (the pressure wave could destroy a submarine at a distance of 20 to 30 m and the mines had to be a minimum distance from each other so that they would not detonate the neighboring mines if they detonated). The sea depth there was 50 to 150 fathoms (on average 80). The mines were anchored on the sea floor and had to cover various depths up to the then maximum submarine diving depth of around 100 m.
From the middle of August to the end of October 1918, four German submarines are said to have fallen victim to the lock, two likely and two possibly destroyed.
The lock was cleared by the majority between April 1 and November 30, 1919, the remainder then in 1920 by the Royal Navy and the United States Navy . The Royal Navy used a total of 421 small ships with a crew of 15,600.
See also
literature
- VE Tarrant: West course. The German submarine offensives 1914-1945 , Motorbuch Verlag, 1998, ISBN 978-3613-0154-25 .
- Reginald Rowan Belknap: The Yankee mining squadron; or, Laying the North Sea mining barrage . United States Naval Institute, 1920
- Josephus Daniels: The Northern Barrage and other Mining Activities . Government Printing Office, Washington, 1920