Oskar Kummetz was given command of the warships stationed in Norway. By the time Scharnhorst arrived in Norway in March 1943, Allied convoys to the Soviet Union had temporarily ceased. To give the ships an opportunity to work together, Admiral Karl Dönitz, who had replaced Raeder in the aftermath of the Battle of the Barents Sea on 31 December 1942, ordered an attack on Spitzbergen, which housed a British weather station and refuelling base. Spitzbergen was defended by a garrison of 152 men from the Norwegian Armed Forces in exile. The two battleships, escorted by ten destroyers, left port on 6 September; in a ruse de guerre, Tirpitz flew the white ensign on the approach to the island the following day. During the bombardment, Tirpitz fired 52 main-battery shells and 82 rounds from her 15 cm secondaries. This was the first and only time the ship fired her main battery at an enemy surface target. An assault force destroyed shore installations and captured 74 prisoners. By 11:00, the battleships had destroyed their targets and headed back to their Norwegian ports. British attacks on Tirpitz Operation Source The British were determined to neutralise Tirpitz and remove the threat she posed to the Allied arctic convoys. Following the repeated, ineffectual bombing attacks and the failed torpedo attack in October 1942, the British turned to the newly designed X Craft midget submarines. The planned attack, Operation Source, included attacks on Tirpitz, Scharnhorst, and Lützow. The X Craft were towed by large submarines to their destinations, where they could slip under anti-torpedo nets and each drop two powerful two-tonne mines onto the sea bed under the target. Ten vessels were assigned to the operation, scheduled for 20–25 September 1943. Only eight of them reached Kåfjord in Norway for the attack, which began early on 22 September. Three of the vessels, X5, X6, and X7, successfully breached Tirpitzs defences, two of which—X6 and X7—managed to lay their mines. X5 was detected from the nets and sunk by a combination of gunfire and depth charges. The mines damaged the ship extensively. The first exploded abreast of turret Caesar, and the second detonated off the port bow. A fuel oil tank was ruptured, shell plating was torn, a large indentation was formed in the bottom of the ship, and bulkheads in the double bottom buckled. Some of water flooded the ship in fuel tanks and void spaces