Operation Halberd

Force H rejoined the convoy at 07:10 27 September. Sixteen destroyers formed a curved screen ahead of the two columns of merchant ships. The port column was led by the cruiser Kenya, followed by Ajax, Clan MacDonald, Imperial Star, Rowallan Castle and City of Calcutta. The starboard column was led by the cruiser Edinburgh followed by Clan Ferguson, Dunedin Star, HMS Breconshire and City of Lincoln. Rodney took position behind the port wing of the screen followed by Prince of Wales. Nelson took position behind the starboard wing of the screen followed by Ark Royal in formation with the anti-aircraft cruisers Euryalus and Hermione. The cruiser Sheffield took position astern of the merchant ships, while the destroyers Piorun and Legion were astern of Ark Royal.^[5]

Italian aircraft identified Ark Royal at 08:10 and at 10:45 reported the convoy speed of 16 kn (30 km/h; 18 mph), which indicated that merchant ships were with the convoy. The battleships from Naples rendezvoused with the cruisers from Taranto at 10:40 and were joined by the 8th Cruiser Division at 11:48. The Italian fleet was faster than the battleships of Force H but was inferior in firepower. The Regia Aeronautica gave priority to fighter defence of bomber strikes, and the six fighters providing air cover over the Italian fleet could not travel more than 62 mi (100 km) from their base. Since Italian aircraft had reported only one British battleship, the Italian fleet received authorisation at noon to engage the British formation. The Regia Aeronautica was requested to provide increased air cover for the Italian fleet by 14:00.^[6]

The Regia Aeronautica launched a strike of 28 SM.79 and SM.84 torpedo-bombers with 20 Cr.42 fighter escorts. The convoy came under air attack at 13:00. The strike was met by Fulmars and massed anti-aircraft fire. Three bombers pressed through the barrage of starboard wing destroyers to launch torpedoes at Nelson. Nelson turned to comb the torpedo tracks and inadvertently steadied on the reciprocal course of a torpedo which struck the port side of the forecastle.^[a] Nelson slowed to 15 kn (28 km/h; 17 mph) but maintained position in the convoy. The Italian torpedo-bomber had released the torpedo at a range of only 450 yd (410 m) and endured concentrated anti-aircraft fire from Prince of Wales before being shot down by one of the Fulmars. Six more torpedo planes and a fighter failed to return from the strike. Friendly fire from Rodney and Prince of Wales shot down two Fulmars, and a patrolling Swordfish had been shot down by the Italian fighters before the strike ended at 13:30.^[6]

The Italian fleet was shadowed by British aircraft from Malta beginning at 13:07. At 14:30 the Italian fleet was about 40 nmi (74 km; 46 mi) from the convoy, but "...decided to return home around 14:30 on 27 September when..." it "... learned that the British had two battleships, a carrier and six cruisers at sea."^[8] Aircraft from Ark Royal shadowed the Italian fleet from 15:15 to 17:50. Cr.42 fighters arrived at 15:30 to provide air cover but the squadron leader of the first flight was shot down by an Italian destroyer. Two more Italian pilots were lost when another flight of ten C.200s ran out of fuel and ditched in the sea. At 14:46 Prince of Wales, Rodney, Sheffield, Edinburgh, and six destroyers steamed toward the Italian fleet but were recalled at 17:00 before making contact and rejoined the convoy at 18:30.^[9]

Nelson, Rodney, Prince of Wales and Ark Royal turned west to return to Gibraltar, escorted by Duncan, Fury, Gurkha, Lance, Legion, Lively. Garland, Piorun and Isaac Sweers. Euryalus fell in astern of the port column of merchant ships while Sheffield and Hermione joined the starboard column as the remaining destroyers closed into a night steaming formation. The formation was attacked by a few torpedo bombers and Imperial Star was struck by a torpedo; Oribi took the damaged freighter in tow. Italian Motoscafo armato silurante (MAS torpedo boats) in the Strait of Messina but failed to find the convoy.^[6]

Convoy GM 2 was the final revictualling operation to Malta in 1941 and showed that the Royal Navy had gained much experience in defending convoys under attack from surface ships, submarines and aircraft. The convoy arrived at the cost of a battleship damaged by a torpedo and the loss of Imperial Star for the Italian loss of the submarine Adua and 21 aircraft (ten aircraft ran out of fuel and ditched).^[11] In 2024, Andrew Boyd called this a fine achievement, that established Malta as an offensive base for the rest of the year. Boyd wrote that signals intelligence, air reconnaissance and staff work were excellent. The presence of an aircraft carrier was of the highest importance and even the Fulmar fighter could compete with the Italian Falco and accounted for about half of the Italia aircraft losses, causing much disorganisation amongst the rest. The Swordfish aircraft were permanent danger to Italian ships, seriously hampered Italian submarines and provided useful tactical reconnaissance during the operation. Ark Royal was unique in carrying 40 per cent more aircraft than the succeeding Illustrious-class aircraft carriers. Having been with Force H for a year, Ark Royal had reached a high pitch of efficiency and even without radar had set a standard of fighter direction not reached again until Operation Pedestal in August 1942.^[12]

Somerville was knighted in recognition of his command of Force H during Operation Halberd. It was the second time Somerville had received that honour, and it occasioned a memorable congratulatory message from Andrew Cunningham "Fancy, twice a knight at your age".^[13]

• Battle of the Mediterranean
• Malta Convoys