1942 1943 1944 1945 Associated articles Operation Tungsten was a Second World War Royal Navy air raid that targeted the German battleship Tirpitz.

The British decision to strike Kaafjord was motivated by fears that the battleship, upon re-entering service, would attack strategically important convoys carrying supplies to the Soviet Union.

[1] These convoys carried large quantities of war material from ports in the UK and Iceland, and were frequently attacked by the German air and naval units stationed in Norway.

[6] On 23 September 1943 two British X-class midget submarines succeeded in penetrating the defences around the battleship at her main anchorage at Kaafjord in northern Norway during Operation Source, and placed explosive charges in the water beneath her.

[13] By this stage of the war the Allies also had large numbers of anti-submarine and anti-aircraft escort ships available, and were able to assign strong forces to protect all of the Arctic convoys.

German submarines operating in the Norwegian Sea were rarely able to evade the convoy escorts, and few merchant vessels suffered damage from enemy attack.

Allied intelligence tracked the progress of work on the battleship using decrypted German radio signals, photo reconnaissance flights and eyewitness reports from agents in Norway.

Another submarine-borne raid was considered impractical as intelligence gathered from intercepted radio transmissions and field agents indicated that the battleship's underwater defences had been improved and more aerial reconnaissance patrols of the region were being flown.

Vice Admiral Bruce Fraser, the commander of the Home Fleet, was not optimistic about the prospects for success, and had to be persuaded to undertake the operation by First Sea Lord Sir Andrew Cunningham.

[22] The British considered cancelling Operation Tungsten in February as Victorious was also needed in the Indian Ocean to counter a build-up of Japanese warships at Singapore.

To enable the attack to proceed, the United States Navy agreed to temporarily transfer USS Saratoga to the Eastern Fleet so that Victorious could be retained in the North Sea.

Flying from RNAS Hatston in the Orkney Islands, aircrew practiced manoeuvring around this terrain to familiarise themselves with the tactics needed to avoid German anti-aircraft guns and successfully attack Tirpitz.

[21] The Royal Navy drew on intelligence on the defences of Kaafjord to make the exercise range as similar to the conditions around Tirpitz as was possible, and the aircrew were extensively briefed on the locations of German positions.

[30][31] The final decision to undertake Operation Tungsten was made in mid-March on the basis of a decrypted radio message that indicated that Tirpitz was almost ready for combat and would conduct high-speed trials on 1 April.

[33] From 1 April onwards, the Admiralty received hourly weather reports from a group of Norwegian Secret Intelligence Service agents in Alta, near Kåfjord.

[41] The German Air Force (Luftwaffe) had only a small number of fighters stationed at bases near Kaafjord, and their operations were constrained by a lack of fuel.

[41] Force One departed the Home Fleet's base at Scapa Flow in the Orkney Islands on 30 March, three days after JW 58 had sailed from Loch Ewe in Scotland.

Decrypted German signals indicated that Tirpitz's trials had been delayed until 3 April, and Fraser hoped that an attack on this date would catch the battleship away from her usual well-protected mooring.

Moreover, as JW 58's escorts were performing well and there was no indication that Tirpitz would sortie into the open sea, Fraser judged that Force One no longer needed to provide support for the transports.

The force approached the Altenfjord from the west, passing over the western end of the Langfjord before turning south, then looping to the north and attacking the battleship over the hills on the southern shore of Kaafjord shortly before 5:30 am.

The airmen found the defences and geography at Kaafjord to be very similar to the Loch Eriboll training range, and one of the post-attack reports stated that the operation had been "almost an exercise which they [the aircrew] had frequently carried out before".

[26] The official historian of the Royal Navy's role in the Second World War, Stephen Roskill, also judged that the strikes were "beautifully co-ordinated and fearlessly executed".

[77] The most important discrepancy between the plans for the operation and its execution was that many pilots dropped their bombs below the specified minimum altitude of 3,000 feet (910 m) in an attempt to improve their chances of hitting Tirpitz.

While the starboard turbine was knocked out by shock damage and two of the boilers were disabled after being contaminated by salt water used for firefighting, the battleship was still capable of steaming within Kaafjord.

[81][83] The British fighters also damaged four patrol craft and a large repair ship; the captain of an armed trawler died and 13 other sailors on board these vessels suffered wounds.

[83] Torstein Raaby of the Allied Secret Intelligence Service group in Alta reported a few hours after the raid, that no civilian casualties had resulted from the attack, and that the local population was "... extremely impressed by the bombing."

[76] While Cunningham did not believe that Barracudas could carry weapons capable of sinking Tirpitz, he hoped that further air strikes would increase the period the battleship was out of service and harm her crew's morale.

[88] Fraser initially resisted Cunningham's order, arguing that the prospects for a successful raid were poor as the Germans would have reinforced the defences around Tirpitz and weather conditions were likely to be worse than those encountered during Operation Tungsten.

[90] In late August it was decided that further Fleet Air Arm attacks should not be attempted as the Germans were now able to cover Tirpitz in smoke before Barracudas could reach the battleship, and these aircraft could not carry bombs large enough to inflict heavy damage.

[91] On 15 September a force of heavy bombers attacked Kaafjord after refuelling at bases in northern Russia and inflicted irreparable damage on the battleship.