Once France was occupied in 1940, Hitler begun quickly  the preparatives to invade Great Britain, this plan would be code named "Operation Sea Lion". Nevertheless, it never was carried out. As a precondition, Hitler specified the achievement of both air and naval superiority over the English Channel and the proposed landing sites. But German forces did not achieve this at any point during the war.

In summer 1940,  the possibility of closing the Strait of Dover to Royal Navy warships and merchant convoys by the use of land-based heavy artillery became readily apparent, both to the German High Command and to Hitler. 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.

Different types of heavy batteries and guns were installed along French coast. Among them, all of the Army’s railway guns. Seven of these weapons, six 28 cm K5 pieces and a single 21 cm (8.3 in) K12 gun with a range of 115 km (71 mi). They were installed on the English Channel coast to target British shipping in the Channel, but proved unsuccessful at this task. The presence of these batteries was expected to greatly reduce the threat posed by British destroyers and smaller craft along the eastern approaches as the guns would be sited to cover the main transport routes from Dover to Calais and Hastings to Boulogne. 

Photo Credit

However, despite firing on frequent slow moving coastal convoys, often in broad daylight, for almost the whole period between 1940-1944 (there was an interlude in 1943), there is no record of any vessel being hit by them, although one seaman was killed and others were injured by shell splinters from near misses.

Source: 

World War 2: The Lost Footage (Youtube) | www.one35th.com | Wikipedia
1

WW2 Timeline: 

Language: 

No votes yet