Attack on Convoy BN 7
The Attack on Convoy BN 7 was a naval engagement in the Red Sea during the Second World War between a British force defending a convoy of 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 Italian destroyer Francesco Nullo 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 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 for a lack of aggression but leaving the convoy defenceless to chase ships at night and in misty weather was risky. The Italians made another fruitless sortie on 3 December, cancelled one in January 1941 after the destroyer Daniele Manin was damaged by a bomb and on 24 January sortied again with no result.
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 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 half way between Suez and the Bab-el-Mandeb Strait. 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 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 ; 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 which had been fortified and lay behind numerous islands and reefs with mined approaches; there was a smaller base at Assab. The scout cruisers Pantera and Leone 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 pom-pom anti-aircraft guns, four machine-guns, four torpedo tubes and The Sauro-class destroyers had an armament of four guns, two pom-poms, two machine-guns, six torpedo tubes and 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 Regia Aeronautica 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 Galileo Galilei sank the Norwegian tanker James Stove, sailing independently about south of Aden. On 19 June, Hobart sent its Supermarine 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° Squadriglia flew a long range reconnaissance sortie over southern Sudan and the Red Sea and was attacked by a Vickers 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 Cesare Battisti and Francesco Nullo came to nothing. Guglielmotti sortied from 21 to 25 August, Galileo Ferraris, Francesco Nullo and Nazario Sauro from 24 to 25 August and the destroyers Pantera and Tigre failing to find ships, despite agent reports and sightings by air reconnaissance. On 4 September, Italian bombers attacked SS Velko and inflicted serious damage and on the next day, five SM.79s attacked Convoy BS 3A. A Blenheim IVF convoy escort attacked the bombers but was damaged. 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 Nazario Sauro 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 BN 4 but Guglielmotti torpedoed the Greek tanker Atlas 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 was damaged in an Italian air attack, one man was killed and the ship was towed to Aden and beached for repairs. On 19 September five SM.79s attacked a convoy and outpaced two Gloster Gladiator fighters which tried to intercept them. On the next day, Italian bombers were driven off by Blenheim fighters. On 15 October three SM.79s attempted to attack a convoy but were prevented by two Gladiators 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 Norwegian, French, Greek and Turkish merchant ships. The escort consisted of the light cruiser , the destroyer Kimberley, the Egret-class sloop Auckland, the Grimsby-class sloops and Indus and the Hunt-class minesweepers 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 List of ships of the Free French Naval Forces, 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 Nazario Sauro and Francesco Nullo. Section II, the slower, more heavily armed Pantera and Leone were to divert the convoy escort and would 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. 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. 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 and at 02:45, opened fire with 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 salvoes.
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 Nullos gyrocompass and gunnery director. At 02:51, Leander lost contact in the haze and ceased fire. 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.
Battle of Harmil Island
In the early hours of 21 October, Kimberley continued 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 range. 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 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 aground on the island. Nullo was then hit by the second of two torpedoes at 06:35, which broke it in two. At 06:15 the four 120 mm guns on Harmil Island engaged Kimberley and hit the engine-room, wounding three men and holing the steam pipes. While adrift from the shore battery, Kimberley silenced two of the guns and wounding four gunners with 45 HE shells from No. 3 mount.
Kimberley managed to get under way, its speed reduced to and the shore battery ceased fire when Kimberley was away. Kimberley had fired 596 rounds of Semi-Armour Piercing and 97 High Explosive shells. Leander left the convoy and at 06:54 increased speed to. By 07:34, Leander was making and soon after, Kimberley reported that it was steaming east at on one engine. At 08:25, Leander was east by north of the Harmil South beacon and slowed to. Leander circled near Kimberley to keep freedom of manoeuvre, in case Italian bombers appeared. Kimberley had lost water in its boilers and Leander sent a boat with three shipwrights and an engine-room artificer; a wounded rating was transferred to the cruiser for medical attention. At about 10:00, Leander took Kimberley in tow.