The K5 gun was produced by Krupp (Essen) in collaboration with Hanomag. June 1944. The shooting range was approximately 62 km. In 1940; three railway batteries; each with two K5 guns; were transferred to the Channel coast for Operation Sealion. Battery E 712 took up position near Pointe aux Oies; E713 near Hydrequent and E 765 at first in the railroad yards of the harbor depot of Calais; later this battery was transferrd to Coquelles. After Operation Sealion the three batteries remained on the Channel. Along with the Navy's long range guns; the 28;3 cm railway guns dominated the Channel and the south coast of England. The guns could fire on any shipping traffic at the ports of Ramsgate; Dover and Folkstone. France.