Operation Harpoon (Battle of Pantelleria (Battaglia di Mezzo Giugno [Battle of mid-June]) was part of Operation Julius, two simultaneous Allied convoys sent to supply Malta in the Axis-dominated central Mediterranean Sea in mid-June 1942, during the Second World War.
Operation Vigorous was a west-bound convoy from Alexandria and Operation Harpoon was an east-bound convoy from Gibraltar. Vigorous was driven back by the battle fleet of the Regia Marina after massed attacks by Axis aircraft. Two of the six ships in the Harpoon convoy completed the journey, at the cost of several Allied warships.
News of the two operations had been unwittingly revealed to the Axis by the US Military Attaché in Egypt, Colonel Bonner Fellers, who had been submitting detailed military reports on British activities to Washington. The American code was later revealed by Ultra intercepts to have been broken by Italian military intelligence (the Servizio Informazioni Militare).
Background
Malta
Siege, 1942
In 1942, Axis bombing of Malta smashed the docks, ships, aircraft and airfields by the end of April 1942. Axis bombing was switched to targets preliminary to invasion: camps, barracks, warehouses and road junctions. After 18 April, German bombing suddenly stopped and Italian bombers took over, regularly bombing with small formations of aircraft. During the month, Axis aircraft flew more than 9,500 sorties against 388 by the Royal Air Force (RAF) all but 30 of which were fighter sorties. The British lost 50 aircraft, 20 shot down in combat against 37 Axis losses incurred during the dropping of 6,700 long tons (6,808 t) of bombs, three times the March figure, 3,000 long tons (3,048 t) on the docks, 2,600 long tons (2,642 t) on airfields. The bombing demolished or damaged 11,450 buildings, 300 civilians were killed and 350 seriously wounded. Good shelters existed but some of the casualties were caused by delayed-action bombs.
As Malta was running short of supplies, Convoy MW 10 sailed from Alexandria on 21 March. The convoy was the subject of a half-hearted attack by the Italian Fleet; the Italians intercepted the convoy and inflicted much damage on several escorts in the Second Battle of Sirte but the weaker British force fended off the Italian squadron. The attack on the convoy meant that the convoy reached Malta in the morning and not at night as expected, leaving the merchant ships exposed to Axis air attack. In the following 48 hours, all the merchant ships were sunk off Malta or destroyed inside the port; barely 5,000 long tons (5,100 t) of supplies were unloaded.
Rations of meat, fats and sugar were cut further and on 5 May, the bread ration was reduced to 10.5 oz (298 g) per day, enough to last until late July; pasta rations had already been stopped and there had been a poor winter potato harvest. Three destroyers, three submarines, three minesweepers, five tugs, a water carrier and a floating crane were sunk in port and more ships damaged. The island continued to function as a staging post but the Axis bombing campaign neutralised Malta as an offensive base. Two boats of the 10th Submarine Flotilla had been sunk, two were damaged in harbour and on 26 April the flotilla was ordered out because of mining by small fast craft, which were undetectable by radar and inaudible during the bombing; the surviving minesweepers were too reduced in numbers to clear the approaches. Three reconnaissance aircraft remained and only 22 bomber sorties were flown, with eleven more by Fleet Air Arm (FAA) aircraft during the month. By the start of June, only two Fairey Albacores and two Fairey Swordfish were left.
Offensive operations
From December 1941, Luftwaffe bombing neutralised Malta, decrypts of Italian C 38m cipher messages showed more sailings and fewer losses and on 23 February 1942, an Italian convoy, led by the battleship Duilio, reached Tripoli. By the end of February, 11 ships had crossed without escort and a blackout caused by a change to the C 38m machine, in early March, made little difference to the British for lack of means. After the British broke back into C 38m, 26 Axis supply journeys had been made by May, only nine being spotted by air reconnaissance. On 14 April, five Malta aircraft were shot down and the submarine HMS Upholder was lost. On 10 March, the cruiser HMS Naiad was sunk by a U-boat and on 10 May, three of four destroyers were sunk by the Luftwaffe. In February and March, Axis losses were 9 per cent of supplies sent, in April less than one per cent and May losses were 7 per cent.
The Axis was able to reinforce North Africa sufficient for General Erwin Rommel to try to attack before the British. In late April, the British Chiefs of Staff ruled that there would be no convoy to Malta in May, because the Italian fleet could be expected to sail and convoy would need battleship and aircraft carrier cover, which was not available. An operation to fly Spitfires to Malta succeeded and anti-aircraft ammunition was to be supplied by fast minelayer, with which Malta must hold on until mid-June, when the situation in the Western Desert should have been clarified. If Martuba or Benghazi in Cyrenaica had been captured by the Eighth Army, a westbound convoy from Alexandria might survive without cover from battleships and aircraft carriers. It would also be known if Luftwaffe aircraft had been diverted to the Russian Front and if the crisis in the Indian Ocean had abated, sufficient for ships to escort a fast convoy from Alexandria.
Unternehmen Herkules
Operation Hercules (Operazione C3) was an Axis plan to invade Malta and during 1942, reinforcement of the Luftwaffe in Sicily and the bombing campaign against the island led to speculation that it was the prelude to invasion. Gleanings from prisoners of war and diplomatic sources led to a certain apprehension about the meaning of troop movements in southern Italy. The absence of evidence from signals intelligence and air reconnaissance led to a conclusion that an invasion was not imminent but the need to protect the source of information meant that this was not disclosed by the British. That preparations were being made were revealed on 7 February through the decryption of Luftwaffe Enigma messages but by 23 March the invasion scare had died down and more bombing was expected. By 31 March the progress of the Axis bombing campaign led to a prediction that the attempt would be made in April but this was soon discounted.
Although the bombing increased from 750 long tons (762 t) in February, to 2,000 long tons (2,032 t) in March and 5,500 long tons (5,588 t) in April, Enigma decodes showed that there were still 425 Luftwaffe aircraft in Sicily, not the 650 aircraft originally intended, because aircraft were detained in Russia by the Soviet winter offensive. On 26 April, Enigma revealed that Fliegerkorps II was being withdrawn. By 2 May, a Luftwaffe bomber group and a fighter group had been withdrawn with more to follow, which explained the lull. Hitler was lukewarm about the operation, in case the Italian navy let down the Fallschirmjäger (parachute and glider troops) but the Axis capture of Tobruk in mid-June made it appear that an invasion was redundant. Hitler and Mussolini agreed to Panzerarmee Afrika pursuing the British into Egypt for the rest of June and into July, which meant cancelling Hercules.
Western Desert Campaign
After the success of Operation Crusader (18 November – 30 December 1941), the Eighth Army advanced 800 km (500 mi) westwards to El Agheila in Libya, capturing airfields and landing grounds to provide air cover for Malta convoys. The British misjudged the speed of Axis reinforcement and expected to attack well before the Axis but Panzerarmee Afrika forestalled the Eighth Army by beginning an offensive on 21 January 1942. By 6 February, the British had been defeated, forced to retreat east of the Jebel Akhdar back to the Gazala line just west of Tobruk, where the Panzerarmee had begun its retirement seven weeks earlier. At the Battle of Gazala (26 May – 21 June), Panzerarmee Afrika attacked first again but appeared close to defeat until 11 June. The Allied Operation Julius began on the same day as the Afrika Korps broke out and by 14 June, forced the British to retreat towards Tobruk. The Axis forces pursued the British into Egypt and the Desert Air Force lost the Libyan landing grounds from which to cover Malta convoys.
Prelude
Operation Julius
Two weeks before the convoys, the carrier HMS Eagle began operations to deliver 63 Spitfires to Malta, which increased the number to 95 serviceable fighters. Air operations for the two convoys began on 24 May, when Wellington bombers of 104 Squadron from Malta began bombing airfields and ports in Sicily and southern Italy. On 11 June, the Wellingtons were withdrawn to accommodate six Wellington torpedo bombers of 38 Squadron, Beaufort torpedo-bombers of 217 Squadron and Baltimore reconnaissance aircraft of 69 Squadron. Aircraft from Gibraltar, Malta and Egypt began reconnaissance flights on 11 June, searching for the Italian fleet. Twelve Beauforts of 39 Squadron were based at Bir Amud in Egypt, near the Libyan border, five B-24 Liberator bombers of 160 Squadron and about 24 aircraft of the Halverson Detachment United States Army Air Forces (USAAF) at RAF Fayid, were also made available.
Short-range fighters based in Palestine, Egypt, Cyrenaica and Malta were to provide air cover and as the convoy moved out of range, protection would be taken over by Kittyhawks of 250 Squadron equipped with long-range fuel tanks, Beaufighters from 252 Squadron and 272 Squadron and Beaufighter night fighters from 227 Squadron. Air cover from Cyrenaica could not overlap with coverage from Malta leaving a gap but Wellingtons of 205 Group and the light bombers of the Desert Air Force would attack Axis airfields in North Africa. No. 201 (General Reconnaissance) Group was to provide maritime reconnaissance and anti-submarine sorties and a small sabotage party was to land on Crete and attack Axis aircraft on the ground.
Operation Vigorous
Vigorous was planned as a joint Royal Navy–RAF operation, to be conducted from the headquarters of 201 (General Reconnaissance) Group by Vice-Admiral Henry Harwood and Air Marshal Arthur Tedder, with Rear-Admiral Philip Vian in command of the convoy and escorts (Force A). If a larger Italian force attacked, Vian was to protect the convoy with smoke and the escorts were to repulse the attackers with torpedoes and try to inflict early casualties against two of the Italian ships using gunfire. The success of the convoy would depend on the Italian fleet being damaged by air and submarine attack before it could close on the ships, rather than on surface action because the battleships HMS Queen Elizabeth and Valiant were still out of action. Force A comprised four Dido-class 5.25-inch light cruisers and an anti-aircraft C-class cruiser, three 6-inch Town-class cruisers and 26 destroyers, four corvettes, two minesweepers, four Motor Torpedo Boats (MTB) and two rescue ships. The old battleship HMS Centurion was pressed into service to masquerade as a contemporary battleship. Two submarine flotillas were to send nine boats to screen the convoy and to patrol areas that the Italian fleet was likely to be found.
Convoy
12 June
Convoy MW4 left Gibraltar on 12 June 1942, with the British Troilus, Burdwan and Orari, the Dutch Tanimbar, the American Chant and the tanker Kentucky that carried 43,000 short tons (39,000 t) of cargo and oil. The convoy was escorted by Force X, the anti-aircraft cruiser HMS Cairo, nine destroyers, the fast minelayer HMS Welshman and smaller ships. Distant cover was provided by the battleship HMS Malaya, the aircraft carriers Argus and Eagle, the cruisers HMS Kenya, Charybdis and Liverpool, with several destroyers. Eagle carried 16 Sea Hurricanes of 801 Naval Air Squadron (801 NAS) and 813 NAS and four Fairey Fulmars of 807 NAS. Argus had two more Fulmars of 807 NAS and 18 Swordfish of 824 NAS.