After the
Fall of France in June 1940,
Adolf Hitler personally discussed the possibility of invasion with
Großadmiral (Grand Admiral)
Erich Raeder, the Commander-in-Chief of the
Kriegsmarine (German Navy) on 21 May 1940. Almost a month later on 25 June he ordered
Oberkommando der Wehrmacht (
OKW, supreme command of the armed forces) 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. '' 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 (15-inch) gun (later increased to 4 and renamed
Todt Battery), 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
Prinz Heinrich Battery just outside
Calais • Two guns at
Oldenburg Battery in Calais • Three
40.6 cm SK C/34 (16-inch) guns (from among the so-called
Adolf Guns) at
Lindemann Battery between Calais and
Cap Blanc-Nez. The battery was named
Lindemann after the
fallen captain of the battleship
Bismarck. These guns were supplemented by a number of
railway guns operated by the
German Army (
Heer). These comprised 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 (E) 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 (E), 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 (and can be larger, with more ammunition stowage) 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 (measured in rounds per hour or even rounds per day), makes it difficult for them to hit moving targets. Another problem with super-heavy guns is that their barrels (which are difficult to make and expensive to replace) 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 (later renamed
Todt) – 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==