Dover Strait coastal guns
The Dover Strait coastal guns were long-range coastal artillery batteries that were sited on both sides of the English Channel during the Second World War. The British built several gun positions along the coast of Kent, England while the Germans fortified the Pas-de-Calais in occupied France. The Strait of Dover was strategically important because it is the narrowest part of the English channel. Batteries on both sides attacked shipping as well as bombarding the coastal towns and military installations. The German fortifications would be incorporated into the Atlantic Wall which was built between 1942 and 1944.
German installations
After the Fall of France in June 1940, Adolf Hitler personally discussed the possibility of invasion with Großadmiral Erich Raeder, the Commander-in-Chief of the Kriegsmarine on 21 May 1940. Almost a month later on 25 June he ordered Oberkommando der Wehrmacht to begin preparation and feasibility studies, which had to be completed by 2 July, for the invasion of Britain. In an OKW directive on 10 July, operational coastal batteries under the control of the Kriegsmarine would support the invasion fleet.On 16 July Hitler issued Führer Directive 16 to have guns in place to support Operation Sea Lion:
Commencing on 22 July 1940, Organisation Todt began work on artillery positions primarily at Pas-de-Calais for every heavy artillery piece available; the batteries were required to be capable of withstanding the heaviest bombardments.
File:Bundesarchiv_Bild_146-1986-104-10A,_Atlantikwall,_Batterie_"Todt".jpg|thumb|Batterie Todt was part of the Atlantic Wall.
The first German guns began to be installed around the end of July 1940. The German batteries in order of construction were:
- Siegfried Battery at Audinghen, south of Cap Gris-Nez, with one 38 cm SK C/34 naval gun gun, shortly followed by:
- Three guns at Friedrich August Battery, to the north of Boulogne-sur-Mer
- Four guns at Grosser Kurfürst Battery at Cap Gris-Nez
- Two guns at Prince [Henry of Prussia (1862–1929)|Prinz Heinrich] Battery just outside Calais
- Two guns at Oldenburg Battery in Calais
- Three 40.6 cm SK C/34 guns at Lindemann Battery between Calais and Cap Blanc-Nez. The battery was named Lindemann after the fallen captain of the battleship Bismarck.
six K5 guns and a single K12 gun with a range of, which could only be used against land targets, and a further thirteen guns and five guns, plus additional motorised batteries comprising twelve guns and ten guns; these could be fired at shipping but were of limited effectiveness due to their slow traverse speed, long loading time and ammunition types.
The longest-ranged guns were two K12 railway guns, manned by the Army. These guns had an effective range of. Designed as successors to the World War I Paris gun, they had a maximum range of. Shell fragments were found near Chatham, Kent, about from the French coast. Both guns, which were operated by Artillerie-Batterie 701, remained on the Channel Coast until the Liberation of France in July 1944.
By early August, Siegfried Battery and Grosser Kurfürst Battery were fully operational as were all of the Army's railway guns. The first shells landed in the Dover area during the second week of August 1940.
Land-based guns have always been feared by navies because they are on a stationary platform and are thus more accurate than those on board ships. Super-heavy railway guns can only be traversed by moving the entire gun and its carriage along a curved track, or by building a special cross track or turntable. This, combined with their slow rate of fire, makes it difficult for them to hit moving targets. Another problem with super-heavy guns is that their barrels wear out relatively quickly, so they could not be fired often.
Better suited for use against naval targets were the four heavy naval batteries installed by mid-September: Friedrich August, Prinz Heinrich, Oldenburg and Siegfried – a total of eleven guns, with the firepower of a battlecruiser. Fire control for these guns was provided by both spotter aircraft and by DeTeGerät radar sets installed at Blanc-Nez and Cap d'Alprech. These units were capable of detecting targets out to a range of, including small British patrol craft near the English coast. Two additional radar sites were added by mid-September: a DeTeGerät at Cap de la Hague and a FernDeTeGerät long-range radar at Cap d'Antifer near Le Havre.
From their establishment in August 1940 and for the following two years one out of every five Channel convoys was fired upon, with an average of 29 rounds on each occasion. no convoys at all were fired on 1943, though shelling resumed sporadically in 1944. During the whole period up to the Normandy landings no ship was hit, though some damage was done by near misses.
Hewitt reports that the only success achieved by these batteries was in June 1944 when the Sambut was hit, and sank with the loss of 130 of the troops on board.
Some sources report a second ship, Empire Lough, from convoy ETC 17, was also sunk by gunfire on 24 June, though others attribute the loss to an attack by E-boats.
Most of the batteries continued firing until September 1944 when they were overrun during the clearing of the Channel Coast. By then more than a thousand rounds had been fired by the German coastal batteries against England and shipping.
British emplacements
Having withdrawn in the Dunkirk evacuation and winning the Battle of Britain, the British did not have an immediate answer to the threat posed by the German coastal batteries. However, the high ground to either side of the Port of Dover was fortified on the personal order of Prime Minister Winston Churchill and wanted large calibre guns dug in there. The only British cross-Channel guns already in place were two BL 14 inch Mk VII (35.6 cm) guns Winnie and – later in 1940 – Pooh at St Margaret's at Cliffe. Both guns were spares taken from the stock of guns of the battleship. One gun used a mounting from, while the other had a mounting from a test range; neither was turret-mounted. Their separate and well-camouflaged cordite and shell magazines were buried under deep layers of earth and connected to the guns by railway lines. Both batteries were camouflaged and protected from aerial attack by anti-aircraft emplacements behind and below St. Margaret's.Both guns were operated from separate firing-control rooms and were manned by 25-man troop of the Royal Marines Siege Regiment. Although Winnie fired Britain's first shell onto continental Europe in August 1940 boosting morale, the Mk VII naval guns were slow to reload and ineffectual compared to the German guns in the Pas-de-Calais. Both conducted extreme range counter-battery operations against the Germans' coastal guns but they were too inaccurate and slow to fire on enemy shipping.
Due to these guns' lack of success in targeting shipping, Churchill ordered three new heavy gun batteries to be built in Dover and manned by the Royal Artillery:
- Three BL 6-inch (152 mm) Mk VII guns with a range of, at Fan Bay Battery
- Four BL 9.2-inch (234 mm) Mks IX–X guns with a range of at South Foreland Battery
- Two BL 15-inch (381 mm) Mk I guns with a range of at Wanstone Battery, known as Clem and Jane.
The British coast batteries sank:Pentiver, 2,382 BRT, 2 March 1943Livadia 3,094 BRT, 4 October 1943Munsterland 6,315 BRT, 20 January 1944Recum 5,500 BRT, 20 March 1944S.184 sunk 5 September 1944: