Royal Navy’s HMS Cattistock clears mines around Oslo

The waters around Norway’s capital are considerably safer after a two-week hunt by the crew of Royal Navy’s HMS Cattistock.

Experts from the Portsmouth-based minehunter found more than ten WW2 mines and torpedoes during a concerted search for unexploded wartime bombs with a NATO task group, the navy said.

Norway was occupied by the Nazis between April 1940 and the war’s end, with the RAF making repeated attempts to disrupt shipping between Oslo and Germany – an operation codenamed ‘gardening vegetables’, with Oslofjord itself also given the cover name ‘onions’.

Twin-engine Hampden bombers, or four-engine Lancasters and Halifaxes dropped between one and two dozen mines at a time, just one or two seconds apart from a mere 600ft over the fjord.

Around 1,500 British ‘A’ mines were sown in the fjord and its many inlets – some triggered by a ship’s magnetic field, others by the noise vessels made as they passed overhead, according to the navy.

While the major sea lanes were cleared in the immediate aftermath of the war, the fjord covers 1,984 square km with countless lesser inlets, estuaries and the like.