Created By: Volunteer JW Boston
This is a Mark VI mine like the ones used in WWI in the largest and most rapid mine laying operation for it’s time called the North Sea Mine Barrage or the Northern Barrage. Larger fields with greater numbers of mines were laid during World War II. Within 5 months 56,571 mines such as this were planted by a joint effort from the Royal Navy and US Navy.
German U-Boats were terrorizing the seas and putting a halt to merchant shipping, even of relief supplies in the eastern Atlantic. A similar barrage had already been placed across the English Channel, which had resulted in U-boats diverting north around Scotland. The North Sea Mine Barrage was intended to close this alternative route, and it also made it hard for the U-boats to get supplies. The most famous of the U-Boat attacks was the sinking of the R.M.S. Lusitania, a passenger ship, resulting in 128 American deaths which began the dialogue that resulted in the entry of the United States into the War in April of 1917.
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The Royal Navy—and in particular Admiral Beatty as Commander in Chief of the Grand Fleet—was skeptical about the value of the operation and did not feel it justified the large logistical and manufacturing commitment required. The United States was altogether more enthusiastic about the operation, as the loss of trans-Atlantic shipping was a major domestic concern and this plan allowed the United States to play an active part in tackling this, while playing to their industrial strength and with minimal risk of American casualties. A minefield across the North Sea would require mining water 900 feet (270 m) deep, while no previous minefield had been established in waters more than 300 ft (91 m) deep. A minefield across the North Sea had been estimated to require 400,000 conventional anchored mines. An "antenna" mine developed in July 1917 was effective at the assumed maximum submarine depth of 200 ft (61 m), and 100,000 of these new Mk 6 mines would be adequate to form the North Sea mine barrage.
U.S. Mine Squadron One (Yankee Mining Squadron) was ordered to mine the 250 mile stretch of the North Sea from Scotland to Norway. The Squadron placed 56,571 mines (including a record 600 by a single ship in 2 hours) effectively protecting North Sea shipping lanes and resulting in the sinking of 22 German U-Boats.
The Mk 6 mine was a 34-inch-diameter (86 cm) steel sphere containing a buoyancy chamber and 300 lb (140 kg) of TNT. The mine was connected to its 800-pound (360 kg) anchor box by a wire rope mooring cable stored on a reel. The depth of the mine below the water surface was controlled by allowing the steel mooring cable to unwind from its reel as the mine was dropped from the minelayer until a sensor suspended beneath the anchor reached the bottom. The sensor locked the cable reel so the falling anchor would pull the buoyant mine below the surface; and the float extended the antenna above the mine. Each mine had two hydrostatic safety features intended to render the mine safe if it detached from its mooring cable and floated to the surface. The mines were intended to be safe at depths less than 25 ft. A ship's steel hull touching the copper antenna would form a battery, and seawater acted as an electrolyte completing a circuit with an insulated copper plate on the mine surface to actuate a detonating relay within the mine.
The mine barrage was within a belt 230 mi (200 nmi; 370 km) long and 15 mi (13 nmi; 24 km) to 35 mi (30 nmi; 56 km) wide divided into area B off the east coast of Orkney, area C near the Norwegian coast between Utsira and Bergen, and the longest central area A connecting the two coastal areas between 0° 50′ West and 3° 10′ East. The Royal Navy laid mines in areas B and C while the United States Navy mined area A. The design of the minefield meant there was a theoretical 66 per cent chance of a surfaced U-boat triggering a mine and a 33 per cent chance for a submerged U-boat.
Cleanup of the minefield was also a joint effort. Royal Navy minesweeping efforts involved 421 vessels manned by 600 officers and 15,000 men from 1 April to 30 November 1919. Twelve Lapwing class minesweepers and 18 submarine chasers were available for the first routine sweep of the United States minesweepers on 29 April 1919. Approximately one-third of the ships were damaged by exploding mines. Two men were killed in separate incidents while attempting to haul mines aboard to clear fouled sweeping kites. It had been assumed the Mk 6 mine hydrostatic safety devices would minimize the risks of this procedure, but sweeping gear losses increased after unreliability of these safety devices was recognized. Seven men drowned when the Richard Bulkeley was sunk by a mine detonation on 12 July. Most damaged ships were repaired, but SC-38 was declared a total loss. Three more men of the minesweeping force were killed in individual accidents involving sweeping gear before Strauss declared the barrage cleared on 30 September 1919. The minesweepers found only about 25 to 30 percent of the mines laid a year earlier; but it was assumed the others had either broken free, sunk to the bottom, or been destroyed by premature explosions. Strauss was recognized as a Knight Commander of St Michael and St George for his efforts; but doubts about effectiveness of the minesweeping effort persisted into the 21st century.
Late into 1919 losses of civilian ships to North Sea mines continued; the origin of the mine in these cases was often difficult to determine. In 1919, twenty crewmen drowned when the Swedish steamship Hollander sank, minutes after striking a mine in October; and the steamer Kerwood struck a mine and sank on 1 December.
This is one of the many connections of how America and Britain forgave the past and became allies during the World Wars, solidifying them into the prophesied Anglo-American World Power as described in Daniel.
-Source Links-
https://www.tourofhonor.com/pages/2013ma_boston.html
This point of interest is part of the tour: Boston and The Dual-Powered King of the South
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