Cross-Channel guns in the Second World War

During the Second World War, cross-Channel guns were long-range coastal artillery pieces placed on the English Channel coasts of Kent, England, and the Pas-de-Calais, France, at the point at which England was closest to continental Europe, with which to bombard enemy shipping in the Channel and towns and military installations.

History
The successful German offensive in early 1940 placed Calais and its environs under the control of an enemy of the United Kingdom for the first time since the end of the Napoleonic Wars 125 years earlier. The possibility of closing the Strait of Dover to Royal Navy warships and merchant convoys by use of land-based heavy artillery became readily apparent to Hitler and the German High Command. Even the Kriegsmarine’s Naval Operations Office deemed this a plausible and desirable goal, especially given the relatively short distance, 34 km (21 mi), between the French and English coasts. Orders were therefore issued to assemble and begin emplacing every Army and Navy heavy artillery piece available along the French coast, primarily at Pas-de-Calais. This work was assigned to Organisation Todt and commenced on 22 July 1940.

German guns
The first such guns to be put in place were Wehrmacht guns on the French coast, which began to be installed around the end of 1940. First came Siegfried Battery at Audinghen, south of Cap Gris Nez, with one 38 cm (15 in) gun (later increrased to 4 and renamed Todt Battery), shortly followed by:
 * Three 30.5 cm (12 in) guns at Friedrich August Battery, to the north of Boulogne-sur-Mer
 * Four 28 cm (11 in) guns at Grosser Kurfürst Battery at Cap Gris Nez
 * Two 21 cm (8.3 in) guns at Prinz Heinrich Battery just outside Calais
 * Two 21 cm (8.3 in) guns at Oldenburg'' Battery in Calais
 * Three 40.6 cm guns (from among the so-called Adolf Guns) at Lindemann Battery between Calais and Cap Blanc Nez. The battery was named after the fallen commander of the battleship Bismarck, Kapitän zur See Ernst Lindemann.

By early August, Siegfried Battery and Grosser Kurfürst Battery were fully operational as were all of the Army’s railway guns. Seven of the railway guns, six 28 cm K5 guns and a single 21 cm (8.3 in) K12 gun with a range of 115 km (71 mi), could only be used against land targets. The remainder, thirteen 28 cm (11 in) guns and five 24 cm (9.4 in) guns, plus additional motorised batteries comprising twelve 24 cm guns and ten 21 cm guns, could be fired at shipping but were of limited effectiveness due to their slow traverse speed, long loading time and ammunition types. 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 ship. 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 Batterie Todt) - a total of eleven guns, with the firepower of a battle-cruiser. 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 40 km (25 mi), 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.

Perhaps the most remarkable gun was the 21 cm K 12 (E), which had an effective range of 45 km, but it was designed as a replacement for the Paris gun and is said to have had a maximum range 115 km (75 miles). Shell fragments from the gun were found near Chatham, Kent, 88 km (55 miles) from the nearest point on the French coast. There were two of these guns (Artillerie-Batterie 701 (E)) and they remained on the Channel Coast for the rest of the war.

The guns started shelling the Dover area during the second week of August 1940 and continued firing until 1944.

British response
Having successfully withdrawn in the Dunkirk evacuation and winning the Battle of Britain, the British did not have an immediate answer to this threat, but the high ground to either side of the Port of Dover was fortified on the personal order of Prime Minister Winston Churchill (who had visited to see the situation in person), and large calibre guns dug in there. The only British cross-Channel guns already in place were Winnie (named after Churchill) and – later in 1940 – Pooh (named after the story book character Winnie the Pooh who in turn was named for "Winnipeg" the bear at the London Zoo.). These were two 14 inch (35.6 cm) guns positioned behind St Margaret's. They were spares taken from the stock of guns of the battleship King George V. One used a mounting from HMS Furious (47) and the other a mounting from a test range; neither was turret-mounted. They were operated from a separate firing-control room, and manned by 25 men of the Royal Marine Siege Regiment. These boosted morale – Winnie fired Britain's first shell onto continental Europe in August 1940 – but were slow and ineffectual compared to the German guns. They attacked the German guns (though they were too inaccurate and slow to fire on ships), and were protected from German aerial attack by anti-aircraft emplacements. Their separate and well-camouflaged cordite and shell magazines were buried under deep layers of earth and connected to the guns by railway lines.

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 for that purpose:
 * Three 6 in guns (15.2 cm) with a range of 25000 yd, at Fan Bay Battery
 * Four 9.2 in (23.4 cm) guns with a range of 31000 yd at South Foreland Battery
 * Two 15 in (38.1cm) guns with a range of 42000 yd at Wanstone Battery, known as Clem (after Clementine Churchill) and Jane (after the pin-up).

These were later joined by Lydden Spout Battery. Also, three BL 13.5 in Mk V naval guns from the First World War (named Gladiator, Sceneshifter and Peacemaker) were brought out of retirement in 1939 and mounted on railway chassis.

"Hellfire Corner"
This gunnery duel, along with heavy German shelling and bombing of Dover strait and the Dover area, led to this stretch of the Channel being nicknamed Hellfire Corner and led to 3,059 alerts, 216 civilian deaths, and damage to 10,056 premises in the Dover area and much damage to shipping. Much British shipping, perforce, had to pass through the bottleneck of Dover strait to transport essential supplies, particularly coal; Britain's road and rail network was not then able to handle the volume of traffic that had to be handled.

The British guns fired on the German battleships Scharnhorst, Gneisenau and Prinz Eugen during their 1942 Channel Dash, but were unable to stop them. On 26 September 1944, the last day of shelling, during the Anglo Canadian Operation Undergo 50 shells landed, killing five people, the last of whom was 63 year-old Patience Ransley, killed by a shell from the Lindemann Battery while sheltering in the 900 ft long "Barwick's Cave" reinforced cliff tunnel. Accurate bombardment however from the British heavy guns at Dover was effective and disabled the Batterie Grosser Kurfurst at Floringzelle, thus ending the duels.

Today
Between Calais and Boulogne-sur-Mer considerable parts of the concrete gun emplacements and associated bunkers remain, in accessible although often somewhat dangerous condition. One of the casements of the Todt Battery can be visited at the Musée du Mur de l'Atlantique, the Atlantic Wall Museum, at Audinghen. One of the Krupp K5 guns is now also located there.

Since 1954 a section of painted armour plating taken as a war trophy from one of the Lindemann Battery's turrets has been on display on Dover's seafront.