Heavy Artillery had been effective as long-range weapons during the First World War. However, they were of little use against the Blitzkreig tactics employed by the German Army during the early stages of the Second World War.
Heavy guns were used to protect important harbours and coastal fortifications against attacks from the sea but were unable to cope against modern warships and aircraft and as a result coastal batteries failed to defeat any large-scale assaults throughout the war.
Germany spent large sums of money in improving long-range suns that could be used to shell mainland Britain from the French coast. The K12E was developed by Krupp and began firing shells at Kent in 1940. However, these had no military significance and were abandoned soon afterwards.