Operation Chastity
Encyclopedia
Operation Chastity was a World War II
plan by the Allies to construct an artificial harbor in Quiberon Bay
, France
, to support Allied operations in Northern France in 1944. It was never implemented because by the time that the surrounding territory had been seized, the main front had advanced hundreds of miles from Normandy and Antwerp, with its port facilities intact, had been captured.
A vital factor in the conception of Operation Overlord
, the invasion of Northern France, was rapid capture of deep-water ports. These were considered essential to handle the large quantities of reinforcements and supplies needed for the campaign. Operation Chastity was devised in April 1944 to fulfill this need, by rapidly constructing a complete new port at Quiberon Bay, and was the final major revision to the invasion plan.
Quiberon Bay is a large anchorage, between Lorient
and St. Nazaire on the southwest coast of the Brittany Peninsula
, sheltered by the Quiberon peninsula and a line of small islands and containing four small ports. The Auray
river drains into the bay near one of the ports, Locmariaquer
, and has scoured a 3000-yard-long 80 feet (24.4 m)-deep pool just offshore, between 30 and 300 yards wide with nearly vertical sides.
Operation Chastity would have seen the construction of floating piers in the pool, allowing large ships to tie up alongside, with bridges to carry the cargo and troops to the shore. The plan was berths for offloading five ships simultaneously, providing a capability of 2,500 tons of supplies per day directly onto vehicles. A further 7,500 tons per day could be offloaded using lighters carrying supplies directly to the shore from 30 further ships moored in the pool.
This was seen as a very efficient scheme, since the two Mulberry
prefabricated ports constructed on the Normandy beaches provided 6,000 tons of supplies a day at a construction cost of 120,000 man-months, whilst Operation Chastity facility would provide 10,000 tons per day (compared to 26,000 tons per day through Normandy and Cherbourg) but would only need 4,000 man-months to construct the prefabricated facilities. A further advantage was the ready access to local rail facilities and the relatively undamaged rail network away from the Normandy region.
The scheme required the rapid capture of Brest
and Lorient, since shipping would be liable to attack as it passed these German-held ports on the way around the peninsula from the United Kingdom. The plan was approved on 22 April 1944 and the capture of Quiberon Bay accorded a high priority.
Cherbourg was the first major objective of the invasion, its capture originally scheduled for 14 June (D+8) but moved back to 21 June just before the invasion. However, it was only captured on 27 June, and the capture of further Brittany ports was further delayed, and the assault on Brest did not start until 25 August.
By the time that Quiberon Bay was on the point of being captured, the Allies had already seized Antwerp (on 4 September) with its port facilities intact. On 9 September, Eisenhower abandoned all plans for further exploitation of Brittany ports, including Operation Chastity, which were now seen as irrelevant since, unlike Antwerp, they were now hundreds of miles from the front of the Allied advance.
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
plan by the Allies to construct an artificial harbor in Quiberon Bay
Quiberon Bay
The Baie de Quiberon is an area of sheltered water on the south coast of Brittany. The bay is in the Morbihan département.-Geography:The bay is roughly triangular in shape, open to the south with the Gulf of Morbihan to the north-east and the narrow peninsular of Presqu'île de Quiberon providing...
, France
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...
, to support Allied operations in Northern France in 1944. It was never implemented because by the time that the surrounding territory had been seized, the main front had advanced hundreds of miles from Normandy and Antwerp, with its port facilities intact, had been captured.
A vital factor in the conception of Operation Overlord
Operation Overlord
Operation Overlord was the code name for the Battle of Normandy, the operation that launched the invasion of German-occupied western Europe during World War II by Allied forces. The operation commenced on 6 June 1944 with the Normandy landings...
, the invasion of Northern France, was rapid capture of deep-water ports. These were considered essential to handle the large quantities of reinforcements and supplies needed for the campaign. Operation Chastity was devised in April 1944 to fulfill this need, by rapidly constructing a complete new port at Quiberon Bay, and was the final major revision to the invasion plan.
Quiberon Bay is a large anchorage, between Lorient
Lorient
Lorient, or L'Orient, is a commune and a seaport in the Morbihan department in Brittany in north-western France.-History:At the beginning of the 17th century, merchants who were trading with India had established warehouses in Port-Louis...
and St. Nazaire on the southwest coast of the Brittany Peninsula
Brittany
Brittany is a cultural and administrative region in the north-west of France. Previously a kingdom and then a duchy, Brittany was united to the Kingdom of France in 1532 as a province. Brittany has also been referred to as Less, Lesser or Little Britain...
, sheltered by the Quiberon peninsula and a line of small islands and containing four small ports. The Auray
Auray
Auray is a commune located in the Morbihan department of Brittany in France. Inhabitants of Auray are called Alréens.-Geography:The city is surrounded by the communes of Crac'h to the south and west, Brech to the north and Pluneret to the east. It is crossed by the Loch, a small coastal river...
river drains into the bay near one of the ports, Locmariaquer
Locmariaquer
Locmariaquer is a commune in the Morbihan department in Brittany in north-western France.It lies south of Auray by road.-Coat of arms:This coat of arms was created 30 years ago by the local artist Jean-Baptiste Corlobé...
, and has scoured a 3000-yard-long 80 feet (24.4 m)-deep pool just offshore, between 30 and 300 yards wide with nearly vertical sides.
Operation Chastity would have seen the construction of floating piers in the pool, allowing large ships to tie up alongside, with bridges to carry the cargo and troops to the shore. The plan was berths for offloading five ships simultaneously, providing a capability of 2,500 tons of supplies per day directly onto vehicles. A further 7,500 tons per day could be offloaded using lighters carrying supplies directly to the shore from 30 further ships moored in the pool.
This was seen as a very efficient scheme, since the two Mulberry
Mulberry harbour
A Mulberry harbour was a British type of temporary harbour developed in World War II to offload cargo on the beaches during the Allied invasion of Normandy....
prefabricated ports constructed on the Normandy beaches provided 6,000 tons of supplies a day at a construction cost of 120,000 man-months, whilst Operation Chastity facility would provide 10,000 tons per day (compared to 26,000 tons per day through Normandy and Cherbourg) but would only need 4,000 man-months to construct the prefabricated facilities. A further advantage was the ready access to local rail facilities and the relatively undamaged rail network away from the Normandy region.
The scheme required the rapid capture of Brest
Brest, France
Brest is a city in the Finistère department in Brittany in northwestern France. Located in a sheltered position not far from the western tip of the Breton peninsula, and the western extremity of metropolitan France, Brest is an important harbour and the second French military port after Toulon...
and Lorient, since shipping would be liable to attack as it passed these German-held ports on the way around the peninsula from the United Kingdom. The plan was approved on 22 April 1944 and the capture of Quiberon Bay accorded a high priority.
Cherbourg was the first major objective of the invasion, its capture originally scheduled for 14 June (D+8) but moved back to 21 June just before the invasion. However, it was only captured on 27 June, and the capture of further Brittany ports was further delayed, and the assault on Brest did not start until 25 August.
By the time that Quiberon Bay was on the point of being captured, the Allies had already seized Antwerp (on 4 September) with its port facilities intact. On 9 September, Eisenhower abandoned all plans for further exploitation of Brittany ports, including Operation Chastity, which were now seen as irrelevant since, unlike Antwerp, they were now hundreds of miles from the front of the Allied advance.