Naval engagement in the Red Sea during WWII
The Attack on Convoy BN 7 (20–21 October 1940) was a naval engagement in the Red Sea during the Second World War between a British force defending convoyed merchant ships and a flotilla of Italian destroyers. The Italian attack failed, with only one merchant ship being slightly damaged. After a chase, the British destroyer torpedoed the which was beached on Harmil Island. "Kimberley" was hit, disabled by Italian shore batteries on the island and towed to safety by the cruiser .
Manoeuvring in two groups to increase the chance of intercepting the convoy had succeeded for the Italians but sacrificed the benefits of concentration against the escorts and a destroyer was lost for no result. The British command at Aden criticised the escorts (excepting "Kimberley") for a lack of aggression but leaving the convoy defenceless to chase ships at night and in misty weather would have been risky. The Italians made another fruitless sortie on 3 December, cancelled one in January 1941 after the destroyer was damaged by a bomb and conducted an abortive sortie on 24 January.
Background.
Red Sea.
The Red Sea is an area of high temperatures and humidity, its coasts vary from desert to high mountain ranges and navigation is fraught with danger from offshore reefs and false horizons caused by atmospheric refraction. From May to June 1939, French and British military officials met at Aden to devise a common strategy to retain control of the waters around Italian East Africa if Italy declared war. It was expected that Italy could close the Mediterranean to Allied traffic and that supplies to the Middle East would have to be transported via the Red Sea. Control of the Gulf of Aden, the Red Sea and the Gulf of Suez at the northern terminus and the maintenance of the bases at Aden and French Somaliland (Djibouti) was equally important but a withdrawal from French and British Somaliland had also be contemplated.
The British-controlled Port Sudan, lay on the west coast of the Red Sea, about halfway [] between Suez and the Bab-el-Mandeb Strait (, Gate of Tears). The Italian port of Massawa in Eritrea was about north and Aden about east of the Bab-el-Mandeb. The ports along the coast of Italian Somaliland and the entrance to the Red Sea were to be blockaded (Operation Begum) to prevent the Italians from receiving supplies and reinforcements. Allied merchant ships in the Indian Ocean and the Red Sea were to proceed in escorted convoys. Naval ships were to sweep mines, patrol the Gulf of Aden and the Bab-el-Mandeb to isolate the Italian Red Sea Flotilla and protect Aden from sorties by Italian ships; the Italian naval bases in Eritrea were to be attacked.
Red Sea Force.
In April 1940 the Royal Navy established the Red Sea Force with the light cruisers and (Senior Naval Officer Red Sea, Rear-Admiral Murray); (New Zealand Division) replaced "Liverpool" on 26 May. By September the Force comprised the cruisers "Hobart", "Leander", and the anti-aircraft cruiser ; the destroyers , and ; the sloops , , and ; , and ; and . Aden was the base for two minesweepers, two small Armed Merchant Cruisers and two armed trawlers. Ships attached temporarily included the light cruisers and , the 8-inch cruisers and .
Red Sea Flotilla.
The Italian naval and air bases in East Africa were convenient for attacks on shipping in the Red Sea and the Indian Ocean. Massawa was the home port of the Red Sea Flotilla () commanded by Rear-Admiral [] Mario Bonetti, from December 1940 to April 1941. Massawa had been fortified and lay behind numerous islands and reefs with mined approaches; there was a smaller base at Assab. The scout cruisers (, also s) and (Commander Paolo Aloisi) had an unusually powerful armament of eight guns, in four turrets on the centre line. Only two turrets could aim fore and aft but the eight-gun broadside was unique for destroyers.
The class also carried two 40 mm pom-pom anti-aircraft guns, four 20 mm machine-guns, four torpedo tubes and 60 mines. The s had an armament of four guns, two 40 mm pom-poms, two 13.2 mm machine-guns, six torpedo tubes and 52 mines. Once war was declared, the fuel stored for the Italian ships based at Massawa could only diminish under the British blockade. The accumulation of mechanical faults, fuel depletion and the enervating effect of the climate exercised severe constraints on the operations of the Red Sea Flotilla.
Prelude.
Red Sea convoys.
In June four of the eight Italian submarines based at Massawa were lost. The (Italian Royal Air Force) commenced operations over the Red Sea and on 11 June a Savoia-Marchetti SM.81 flew a reconnaissance sortie. On 16 June, the Italian submarine sank the Norwegian tanker "James Stove" (8,215 gross register ton [GRT]), sailing independently about south of Aden. On 19 June, "Hobart" sent its Walrus amphibian to bomb an Italian wireless station on Centre Peak Island between Massawa and the Arabian coast. On 2 July, Convoy BN 1, comprising six tankers and three freighters, assembled in the Gulf of Aden. On 8 July, an SM.81 of 10° flew a long range reconnaissance sortie over southern Sudan and the Red Sea and was attacked by a Wellesley. The SM.81 was damaged hit an island trying to force land, bounced into the air and flew on at wave top height, with the Wellesley flying above and to one side for its gunners to keep firing. After ten minutes the Italian aircraft hit the sea and shed its wings.
From 26 to 31 July, "Guglielmotti" failed to find two Greek merchantmen and a sortie by the torpedo boats and came to nothing. "Guglielmotti" sortied from 21 to 25 August, "Galileo Ferraris" (25–31 August), "Francesco Nullo" and "Sauro" from 24 to 25 August and the destroyers "Pantera" and (28–29 August) failing to find ships, despite agent reports and sightings by air reconnaissance. On 4 September, Italian bombers attacked SS "Velko", inflicted serious damage on it and on the next day, five SM.79s attacked Convoy BS 3A. A Blenheim IVF fighter on convoy patrol attacked the bombers and received damage by return-fire. On 6 September the convoy was attacked again by a SM.79. Convoy BN 4 was spotted by air reconnaissance and on the night of 5/6 September, "Cesare Battisti", "Daniele Manin" and sailed. The destroyers "Leone" and "Tigre" followed on 6/7 September but the destroyers found nothing.
The submarines "Galileo Ferraris" and "Guglielmotti" patrolling further to the north, also failed to find Convoy BN 4 but "Guglielmotti" torpedoed the Greek tanker "Atlas" (4,008 GRT) straggling behind the convoy south of the Farasan Islands. Air reconnaissance also found Convoy BN 5 of 23 ships but "Leone", "Pantera", "Cesare Battisti" and "Daniele Manin", with the submarines "Archimede" and "Gugliemotti" failed to find the convoy. MV "Bhima" (5,280 GRT) had straggled and was damaged in an Italian air attack, one man was killed; the ship was towed to Aden and beached for repairs. On 19 September five SM.79s attacked a convoy and outpaced two Gladiator fighters which tried to intercept them. On the next day, Italian bombers were driven off by Blenheim fighters. On 15 October, three SM.79 bombers were prevented from attacking another convoy by two Gladiator fighters and a Blenheim. Five days later, individual SM.79s attacked Convoy BN 7.
Convoy BN 7.
Convoy BN 7 was northbound through the Red Sea and consisted of 32 British, Norwegian, French, Greek and Turkish merchant ships. The escort consisted of the light cruiser (Commander James Rivett-Carnac), the destroyer "Kimberley" (Commander J. S. M. Richardson), the "Auckland", the s and "Indus" and the s and . Convoy BN 7 was nearing Perim, a volcanic island off the south-west coast of Yemen in the Bab-el-Mandeb, on the afternoon of 19 October, when an aircraft dropped four bombs close astern of one of the merchantmen. "Leander" and "Auckland" opened fire on the aircraft as it flew off to the west; shortly before dark, an undercarriage wheel of an Italian aircraft was picked up south of the island. Next morning, Italian aircraft dropped four bombs, two of which fell ahead of the convoy and two bombs harmlessly astern of the French liner , carrying New Zealand troops to Suez. At dusk "Leander" took station on the port beam of the convoy between it and the Italian base at Massawa, which flanked the line of advance; the convoy zig-zagged through the night.
Battle.
Italian sortie.
The Italian flotilla sailed on 20 October, the destroyers operating in pairs, Section I, comprised the faster "Sauro" (Commander Moretti degli Adimari) and "Francesco Nullo" (Lieutenant Commander Costantino Borsini). Section II, the slower, more heavily armed "Pantera" and "Leone" were to divert the convoy escort and then attack the convoy with torpedoes. At 21:15 the two sections separated and at 23:21, "Pantera" sighted smoke from the convoy. "Pantera" signalled "Sauro" and moved ahead of the convoy to intercept, with "Leone" following behind. The convoy was about north-north-west of Jabal al-Tair Island at 02:19 on 21 October, when "Leander" sighted two patches of smoke bearing north.
"Auckland" reported two destroyers off and "Leander" altered course to intercept, the captain assuming that they would run for home through the South Massawa Channel. After a challenge from "Auckland", "Pantera" fired over "Yarra" at the convoy, inflicting some splinter damage to a lifeboat on the convoy commodore's ship. "Auckland" opened fire and the Italian ships separated and turned away at full speed, west-south-west, towards Massawa, firing their aft guns. The destroyers were broad on the port bow of "Yarra" when "Pantera" fired two torpedoes at 23:31 and another pair at 23:34. "Yarra" avoided two torpedoes by turning towards them and combing their tracks. Observers in "Yarra" thought that the leading enemy vessel was hit by their fourth or fifth salvo.
"Sauro" and "Nullo" had been manoeuvring to a more favourable position after receiving the sighting report from "Pantera", turned towards the convoy and spotted "Leander" at 01:48 (21 October). "Sauro" fired a torpedo at "Leander" which missed and "Leander" opened fire but lost sight of "Sauro" after two minutes. "Sauro" made another torpedo attack at 02:07 and turned away towards Massawa. ("Nullo" was not able to attack after its rudder jammed for several minutes and it went round in circles, losing contact with "Sauro".) Borsini ordered "Nullo" towards the Italian batteries on Harmil Island off Massawa. When the gunfire ceased, "Leander" altered course to north-west to intercept the ships at the South Massawa Channel (the Harmil Island Passage) and at 02:45, opened fire with 6-inch HE and star shells on a ship that was firing red and green tracer. The range was increasing and the ship was lost to sight after the first salvos.
"Leander" altered course westwards to bring all guns to bear if the ships were making for the South Massawa Channel. At 02:20 "Leander" spotted "Nullo" by searchlight and exchanged fire for about ten minutes at about , "Leander" scoring several hits which damaged "Nullo"'s gyrocompass and gunnery director. At 02:51, "Leander" lost contact in the haze and ceased fire (having fired a hundred and twenty-nine 6-inch rounds). "Nullo" headed toward Harmil Island with "Leander" in pursuit and at 03:00, "Leander" challenged a destroyer which turned out to be "Kimberley", also in pursuit. After five minutes, the cruiser altered course east to rejoin the convoy, since the Italian ship was drawing away at the rate of and the convoy would still be vulnerable to attack during a pursuit.
Action off Harmil Island.
In the early hours of 21 October, "Kimberley" continued to sail at maximum speed and at 03:50 sighted smoke ahead, apparently from two ships retiring at high speed. At 05:40, off Harmil Island, lookouts on "Kimberley" and "Nullo" spotted each other at distance. Borsini assumed that the ship was "Sauro" and when "Kimberley" opened fire at 05:53, "Nullo" was taken by surprise, not returning fire for four minutes. "Kimberley" closed the range to and at 06:20, "Nullo" scraped a reef, which damaged a propeller and sprung a leak. As "Nullo" rounded Harmil Island at about 06:25, it was hit once in the forward engine room and once in the aft engine room.
"Nullo" lost all power; Borsini gave the order to abandon ship and steered towards Harmil Island. The upper works were hit by shell splinters and the crew abandoned-ship, while Borsini tried to run "Nullo"