Operation Mascot (i)

'Mascot' (i) was an unsuccessful British carrierborne air attack on the German battleship Tirpitz at her anchorage in the Kaafjord, a spur of the Altafjord, in northern Norway (17 July 1944).

The attack was one of a series of attacks on the battleship undertaken from aircraft carriers between April and August 1944, and was initiated after Allied intelligence established that the damage the ship had sustained during the 'Tungsten' raid on 3 April had been repaired.

A force of 44 British dive-bombers and 40 fighters took off from three aircraft carriers in the early hours of 17 July. German radar stations detected these aircraft while they were on their way to the Kaafjord, and Tirpitz had been shielded by a smoke screen before the British attackers reached the scene. Few of the British airmen were able to spot the battleship, and their attacks inflicted only insignificant damage. German losses were limited to a patrol vessel, and three British aircraft were destroyed or damaged beyond repair by the Kaafjord’s defenders. A group of U-boats tried without success to intercept the carrier force as it returned to base, two U-boats being sunk near the carriers by British patrol aircraft and several others being damaged.

From a time early in 1942, Tirpitz had been a significant threat to the Allied convoys delivering matériel through the Norwegian Sea to the USSR. Operating from fjords on the northern part of the Norwegian coast, the battleship was capable of overwhelming the close escort forces assigned to the Arctic convoys, or indeed of breaking out into the North Atlantic to savage Allied transatlantic convoys plying to and from the UK. To counter this threat, the Allies were forced to maintain a powerful force of warships in northern waters as the Home Fleet, and capital ships accompanied most convoys part of the way to the USSR.

Several air and naval attacks were launched against Tirpitz during 1942 and 1943. On 6 March 1942, torpedo bombers flying from the aircraft carrier Victorious attacked the battleship while she was attempting to intercept the PQ.12 convoy, but achieved no hits. Land-based bombers of the RAF and Soviet air forces also attempted to strike Tirpitz in her anchorages on several occasions in 1942 and 1943, but did not inflict any damage. On 23 September 1943, two British 'X' class midget submarines penetrated defences around the battleship at her main anchorage in the Kaafjord during 'Source' and placed explosive charges in the water beneath her. This attack caused extensive damage to Tirpitz, rendering the ship non-operational for six months.

As the British considered that Tirpitz was still a major threat to Allied shipping, they continued their attempts to damage or destroy the battleship before she could re-enter service. Another midget submarine attack was considered impractical as the Kaafjord’s defences had been strengthened, and Air Chief Marshal Sir Arthur Harris, commander of RAF Bomber Command, refused to attempt heavy bomber raids against the battleship as he believed that such efforts were unlikely to be successful and would result in heavy losses. As a result, the Home Fleet’s aircraft carriers were considered the best means of attacking the Kaafjord, and the Admiralty directed the fleet to begin planning such a raid late in 1943. Following a preparatory phase of several months' duration, the Home Fleet’s first attack on the Kaafjord, which was designated 'Tungsten', was undertaken on 3 April 1944 and involved five aircraft carriers. The two strike forces of 20 Fairey Barracuda dive-bombers escorted by 40 fighters were not detected during their approaches to the Kaafjord, and the battleship was hit by 15 bombs. Tirpitz's crew suffered heavy casualties, but the ship was not badly damaged. Nevertheless, the damage inflicted on Tirpitz's superstructure, armament and engines was sufficient to put the ship out of service for several months as repairs were effected. The commander of the German navy, Grossadmiral Karl Dönitz, emphasised the necessity of returning the battleship to service as a primary 'threat in being' that would thus continue to pin Allied naval resources. However, Dönitz and other senior German officers recognised at this time that the threat of further air attacks meant that Tirpitz could no longer operate against Allied convoys.

British intelligence assessed that Tirpitz could be repaired within six months, and the Admiralty ordered further carrierborne attacks on the battleship. The First Sea Lord, Admiral Sir Andrew Cunningham, believed that the Barracuda was incapable of carrying weapons capable of sinking Tirpitz, but hoped that further attacks would increase the period the battleship was out of service and adversely affect her crew’s morale. The commander of the Home Fleet, Admiral Sir Bruce Fraser, initially resisted this order on the grounds that further carrier raids on the Kaafjord were unlikely to be successful as Tirpitz's defences would have been reinforced and weather conditions were likely to be worse than those encountered during 'Tungsten'. Following an argument with Cunningham, Fraser eventually agreed to create another attack on the Kaafjord. Despite the decision to make further attacks, many of the Home Fleet’s airmen were posted to other units following 'Tungsten' and this hindered subsequent operations against the German forces in Norway as the new aircrew were less experienced than the men they replaced.

Three raids on Tirpitz in April and May 1944 were cancelled after launch as a result of adverse weather. The first of these attacks was 'Planet', in which the Home Fleet sortied from its main base at Scapa Flow in the Orkney islands group on 21 April: the undertaking involved the same carriers as had been used in 'Tungsten' with the exception of the replacement of the escort carrier Fencer by her sister ship Striker. The British force reached the position from which its aircraft were to be flown off three days later, but the raid was cancelled when Allied agents in the Kaafjord area reported bad weather over the target area. The force then steamed to the south and attacked a German convoy near Bodø, sinking three merchant ships for the loss of six aircraft. The Home Fleet put to sea once again for an attack on Tirpitz during the middle of May in what was designated 'Brawn': an attack force of 27 Barracuda dive-bombers escorted by Vought Corsair and Supermarine Seafire fighters took off from the fleet carriers Furious and Victorious during the afternoon of 15 May, but encountered heavy cloud over the Kaafjord and therefore turned back without attacking. The next attack was 'Tiger Claw', which was launched late in May. The planned attack on the Kaafjord, which would have also involved aircraft operating from Furious and Victorious, had to be cancelled as to be cancelled as a result of bad weather on 28 May, and instead the carriers steamed to the south in search of German convoys. In a raid on 1 June, the carriers' aircraft sank four merchant vessels near Ålesund. No further attacks were attempted during June as the ships of the Home Fleet were needed to support the 'Neptune' (iii) landings for 'Overlord' in Normandy in that month.

Despite these setbacks, the Admiralty and Admiral Sir Henry Moore, who had assumed command of the Home Fleet on 14 June 1944, remained committed to attempting further carrier raids on Tirpitz. During June, the Admiralty received a number of intelligence reports suggesting that repairs to Tirpitz were progressing well and that the battleship would soon be ready for service once more. Late in that month, Allied agents spotted Tirpitz as she undertook steaming trials in the Kaafjord, and reported that she was capable of 20 kt and could traverse her main gun turrets. As a result, late in that same month the Admiralty directed that another aircraft carrier raid be conducted against the Kaafjord during the middle of July. It was intended that this attack would take place before the resumption of the Arctic convoys, which had been suspended since April 1944 to free ships for the invasion of France.

As detected by the British, repairs to Tirpitz after 'Tungsten' advanced quickly. Work on repairing the battleship had begun late in April, and 157 shipyard workers and special equipment had been transported from Kiel in northern Germany to the Kaafjord to accelerate the programme. Facilitated by the long hours of daylight at the Kaafjord’s latitude during the summer, three shifts of personnel worked on Tirpitz every day. The battleship was capable of moving under her own power by 2 June, and ready to begin gunnery exercises at the end of that month. The repair work came to an end in the middle of July, although the battleship’s starboard propeller shaft could only be used to drive her forward. Kapitän Wolf Junge assumed command of the battleship in May 1944, replacing Kapitän Hans Meyer, who had been wounded during 'Tungsten'.

As Victorious had been redeployed to the Indian Ocean in June, the carriers selected for 'Mascot' (i) were the recently commissioned fleet carrier Indefatigable (52 aircraft) as well as the veteran Formidable (42 aircraft) and Furious (35 aircraft). The carriers were escorted by the battleship Duke of York, the heavy cruisers Devonshire and Kent, the light cruiser Jamaica, the light anti-aircraft cruiser Bellona and the destroyers Milne, Marne, Matchless, Musketeer, Nubian, Scourge, Verulam, Vigilant, Virago, Volage, Canadian Algonquin and Canadian Sioux of the 3rd Destroyer Flotilla, and Burges, Bulldog, Hoste and Inman of the 20th Escort Group. Moore commanded the force in Duke of York, and the carrier group was led by Rear Admiral R. R. McGrigor in Indefatigable.

The attack force’s composition was essentially similar to that used in the earlier operations targeting Tirpitz. Formidable embarked No. 8 Torpedo Bomber Reconnaissance Wing, whose Nos 827 and 830 Squadrons each operated 12 Barracuda aircraft, as well as No. 1841 Squadron equipped with 18 Corsair fighters. Indefatigable carried No. 9 Torpedo Bomber Reconnaissance Wing, which was also equipped with 24 Barracuda aircraft divided between Nos 820 and 826 Squadrons, as well as the Seafire-equipped No. 894 Squadron and No. 1770 Squadron’s 12 Fairey Firefly fighters. In a change from her role in the previous attacks, Furious did not embark any Barracuda warplanes for 'Mascot' (i), and instead operated 20 Grumman Hellcat fighters of No. 1840 Squadron, three Seafire fighters assigned to No. 880 Squadron and three Fairey Swordfish anti-submarine aircraft of No. 842 Flight.

The defences of the Kaafjord had indeed been improved following 'Tungsten'. Before this attack, the defences comprised 11 batteries of Flak guns, several anti-aircraft warships and a system of smoke generators capable of hiding Tirpitz from aircraft. After the attack, additional radar stations and observation posts had been established and the number of smoke generators located around the battleship had been increased. The improved defences at the time of the 'Mascot' (i) attack included a cliff-top observation post near the Kaafjord, which was capable of directing the battleship’s anti-aircraft guns if necessary. Tirpitz's air defences were also strengthened during the period she was under repair: additional 20-mm cannon had been added, the 150-mm (5.91-in) guns of the secondary armament had been modified so they could be used in the anti-aircraft role, and the 380-mm (15-in) guns of the main armament had been provided with anti-aircraft shells.

As well as the German forces in the Kaafjord area, a patrol line of 12 U-boats of the 'Trutz' wolfpack had also been created around Jan Mayen island for the task of intercepting any British carrier forces that ventured into the Norwegian Sea. The submarines assigned to this force were U-347, U-361, U-365, U-387, U-636, U-716, U-742, U-921, U-956, U-965, U-992 and U-995.

The Luftwaffe had few fighters stationed at bases near the Kaafjord, and their operations were constrained by a shortage of fuel.

On 4 July, McGrigor issued an operational memo to the air units selected for 'Mascot' (i), this outlining how the attack was to be undertaken. Further orders for the raid were promulgated eight days later. In accordance with these instructions, the squadrons assigned to the three carriers undertook training exercises from their ships and shore bases from 4 July onward. 'Ultra' intelligence gained from the decryption of German radio traffic during early July, and photographs taken by a RAF aeroplane on 12 July, provided further evidence that the battleship was once again fully operational and possibly preparing to put to sea. The naval airmen were informed on 13 July that they would attack the Kaafjord in four days time.

The British force departed Scapa Flow as a single group on 14 July. During the voyage north, the airmen received detailed briefings on the attack plans and terrain around the Kaafjord, and were also issued with escape kits to use if they were shot down over Norway. Maintenance personnel also worked to ensure that as many aircraft as possible were serviceable. The 12 U-boats in the Norwegian Sea did not make contact with the British force as it streamed to the north. The weather for much of the passage was foggy, but the skies were clear when the British force reached its flying-off position to the north of the Kaafjord during the evening of 16 July.

The carriers began to launch their aircraft shortly after midnight on 17 July. The main attack force comprised 44 Barracuda dive-bombers, and the raid’s plan specified that No. 8 Torpedo Bomber Reconnaissance Wing’s aircraft would attack before those of No. 9 Torpedo Bomber Reconnaissance Wing. All but two of the dive-bombers were armed with powerful 1,600-lb (726-kg) armour-piercing bombs; the other aircraft each carried three 500-lb (227-kg) bombs. No. 1841 Squadron’s 18 Corsair fighters were assigned to provide protection against German fighters, and the 20 Hellcat and 12 Firefly fighter-bombers of Nos 1840 and 1770 Squadrons respectively had the task of suppressing the Flak defences,

The bombers and fighters formed in the air and began their flight to the Kaafjord at 01.35, flying at an altitude of only 50 ft (15 m) above the sea to evade German radar until they reached a point 10 minutes flying time from the Norwegian coast, at which time the Barracuda aircraft climbed to 9,000 ft (2745 m) and the fighters to higher altitudes. The weather was fine throughout the flight, but clouds were sighted as the aircraft neared the target area.

The British aircraft were detected by German radar stations when they reached a point 43 miles (69 km) from the Kaafjord at 02.00. It took four minutes to pass a warning to Tirpitz, whose protective smoke generators were in action by 02.13 and quickly covered the vessel in an artificial cloud. The battleship and shore-based Flak batteries started to fire a barrage toward the British aircraft at 02.19, and the Germans also began to jam the radios of the British aircraft once the latter came within 10 miles (16 km) of the Norwegian coast. The smokescreen frustrated the British attack, as the crews of only two of the Barracuda machines and a pair of fighters managed to spot Tirpitz during the raid.

The Hellcat and Firefly fighter-bombers were the first of the aircraft to attack, and strafed anti-aircraft positions as well as the destroyer Z 33 and the small patrol vessel VP 6307. The patrol vessel was forced aground and later declared a total loss. As a result of the thick smoke, the fighter pilots were able to locate targets only by aiming at the sources of tracer fire.

The Barracuda attack aircraft were targeted by heavy, but inaccurate, Flak fire as they arrived over the Kaafjord. Aside from the two aircraft whose pilots sighted Tirpitz, the 35 other dive-bombers attempting to attack the ship were forced to aim at her gun flashes. These attacks took 25 minutes to complete: seven near misses were achieved, but no damage was inflicted on Tirpitz. One of the other Barracuda aircraft attacked a Flak battery, another attempted to bomb a destroyer and a third scored a near miss on the tanker Nordmark. Three of the remaining four Barracuda aircraft found no targets, and while three of them jettisoned their bombs into the sea, the fourth was unable to drop its bomb as a result of a fault in its release mechanism.

Although German gunners fired a heavy Flak barrage throughout the British attack, they achieved little success. Only one British machine, a Corsair, was shot down near the Kaafjord, its pilot surviving and being taken prisoner. A damaged Barracuda was also forced to ditch near Indefatigable and its crew was rescued by the destroyer Verulam. Several other Barracuda machines and five Hellcat fighter-bombers were damaged during the raid and returned to their carriers, one of the latter being subsequently written off as judged to be beyond repair.

A second British raid, which had been scheduled to start from 08.00 on 17 July, was cancelled two minutes before the aircraft were to begin launching when fog began to build up near the carriers,and the British force turned to the south to return to Scapa Flow. Swordfish and Seafire aircraft flew protective patrols over the Home Fleet throughout the morning’s operations.

While the Kaafjord was under attack, the commander of the U-boats in the Norwegian Sea ordered the 'Trutz' wolfpack to take up new positions to the south-east of Jan Mayen island and intercept the British ships as they returned to Scapa Flow. The Admiralty had anticipated this redeployment, and maritime patrol aircraft from the RAF Coastal Command’s No. 18 Group were directed to sweep the Home Fleet’s route back to its base. The British patrol aircraft prevented the boats of the 'Trutz' wolfpack from attacking the Home Fleet. At 21.48 on 17 July, a Consolidated Liberator landplane of No. 86 Squadron detected and sank U-361, which went down with all hands. Eight minutes later a Consolidated Catalina flying boat of No. 210 Squadron piloted by Flying Officer John Cruickshank spotted U-347 on the surface. The U-boat’s Flak guns damaged the Catalina, killing the navigator and wounding Cruickshank as well as three other crewmen, but the pilot continued his attack and sank U-347 with depth charges. The Catalina managed to return to base, and Cruickshank was awarded the Victoria Cross.

That night the Home Fleet sailed through the gap in the German patrol line that had been opened by the sinking of the two U-boats.

Attacks on the U-boats continued for the next six days. On the morning of 18 July a German reconnaissance aeroplane sighted and reported the Home Fleet, but the German naval command in Norway assessed that it was heading north-east to launch another attack. The 'Trutz' wolfpack as therefore instructed to head to the north, and four more U-boats sortied from Narvik to guard the approaches to the Altenfjord and Vestfjord. In the evening U-968, one of the four boats that had sortied from Narvik, was attacked twice by Liberator aircraft: the boat’s guns shot down the first attacker but the boat was then damaged by the second and had to return to port. U-716 also suffered severe damage from a Liberator attack at 19.15 on 18 July but managed to return to Hammerfest. At about 23.00 on that same day, U-716 was seriously damaged by the attack of a Short Sunderland flying boat but also survived. Three other boats were attacked on 20 July but only one suffered any damage. Following these actions the commander of submarines in the Norway area decided to dissolve the 'Trutz' wolfpack as it was too vulnerable to air attack; all but four of the surviving submarines returned to port and the remaining boats were ordered to head to the north so that they were out of range of the British aircraft. The final attack on the boats of the former 'Trutz' wolfpack was made on 23 July when a No. 330 Squadron Sunderland damaged U-992 near the Vestfjord.

After the attack of 17 July, the British learned from intercepted German radio transmissions and reports provided by Secret Intelligence Service agents that Tirpitz had suffered no significant damage. Moore blamed the failure of 'Mascot' (i) on the inexperience of the aircrews, and criticised the leader of the attacking force for not selecting alternative targets after it became clear that Tirpitz could not be bombed with any accuracy. Moore also judged that further attacks on the Kaafjord with Barracuda aircraft would be futile, as the dive-bombers' slow speed gave the Germans time sufficient to cover Tirpitz with a dense smoke between the time the raid was detected and its arrival over the target area. The Admiralty was hopeful that a tactic of repeated attacks on the Kaafjord over a 48-hour period would wear down the defences, and Moore agreed to attempt another attack. Consideration was also given to flying fast and long-ranged de Havilland Mosquito bombers off the carriers in an attempt to achieve surprise, but none of these land-based aircraft could be spared from supporting the Allied bombing of Germany.

The next attack on the Kaafjord took place late in August. During this 'Goodwood' (ii), aircraft flying from three fleet carriers and two escort carriers conducted four raids between 22 and 29 August. The attackers again found Tirpitz covered in smoke on each occasion, and managed to inflict only slight damage. These unsuccessful attacks cost the British 17 aircraft and 40 airmen killed. The frigate Bickerton was torpedoed and sunk by U-354 during the operation, and the same boat also inflicted heavy damage on the escort carrier Nabob before being destroyed by a British aeroplane.

The Admiralty accepted that the Barracuda was too slow to be effective against the Kaafjord area following the failure of 'Goodwood' (ii). As a result, the task of attacking the battleship was transferred to RAF Bomber Command. The first heavy bomber raid against the Kaafjord was 'Paravane' on 15 September 1944, with the bombers flying from staging bases in northern Russia. This attack inflicted irreparable damage on Tirpitz, which was then transferred south to the Tromsø area to be used as an immobile coast-defence battery. The battleship was sunk there with heavy loss of life by Bomber Command’s 'Catechism' of 12 November.