Operation Judgement (i)

This was the British carrierborne air attack, within the context of ‘MB8’, on units of the Italian fleet in Taranto harbour as the world’s first all-aircraft versus warship naval battle in history (11/12 November 1940).

Otherwise known as the Battle of Taranto, ‘Judgement’ (i) pitted British carrierborne aircraft of Admiral Sir Andrew Cunningham’s Mediterranean Fleet against some of the Italian naval strength commanded by Ammiraglio di Squadra Inigo Campioni. In ‘Judgement’ (i), the British undertook the first all-aircraft ship-to-ship naval attack in history, flying a small number of obsolescent Fairey Swordfish biplane torpedo bombers from the fleet carrier Illustrious in the Mediterranean Sea to the south of the ‘instep’ of the Italian ‘foot’. The attack struck the Italian battle fleet in the harbour of Taranto using air-launched torpedoes despite the shallow depth of the harbour’s water. The damage inflicted by the carrierborne attackers on the large Italian warships marked the true beginning of the ascendancy of naval aviation over the battleship as the arbiter of naval warfare.

Long before the start of World War II, the Italian navy had developed Taranto as its primary southern base, and the British had drafted plans for countering the power of the Italian navy in a Mediterranean conflict: indeed, plans for the seizure of Taranto had been considered as early as the Italian invasion of Abyssinia in 1935.

In 1940/41, Italian operations in North Africa from their bases in Libya required the establishment of a higher-capacity line of communications across the Mediterranean from Italy. The British forces fighting in North Africa from their bases in Egypt suffered from considerably more difficult supply problems: supply convoys to Egypt had either to traverse the length of the Mediterranean from Gibraltar via Malta, which necessitated the passage of the Sicilian narrows and thus a close approach to the coast of Sicily, or otherwise steam all the way around the Cape of Good Hope, up the whole east coast of Africa, and then through the Suez Canal, to reach Alexandria. Since the latter was very long and therefore very lengthy in terms of time, this put the Italian fleet in an excellent position to interdict the delivery of British supplies and reinforcements. The passage along the length of the Mediterranean made British convoys vulnerable to sea and air attacks from Sardinia, Sicily, mainland Italy and the Italian-held Dodecanese islands group, while the passage round Africa made them vulnerable to air and sea attacks from Italian East Africa.

However, in the early stages of their war against the Italians, the British had won several naval actions, considerably upsetting the balance of power in the Mediterranean, and the Italians, believing in the concept of the ‘fleet in being’ as the core of their naval strategy, usually kept their major warships in harbour as a threat would could, so the concept suggested, be unleashed as and when needed. The Italian fleet at Taranto was powerful: six battleships, of which five were combat-capable, seven heavy cruisers, two light cruisers and eight destroyers. This was sufficient to make the threat of a sortie against their maritime lines of communication a serious and realistic problem for the British.

During the Munich crisis of 1938, as a result of which the British and French abandoned the Sudetenland of Czechoslovakia to Germany for the illusory promise of ‘peace in out time’, Admiral Sir Dudley Pound, then commanding the Mediterranean Fleet, became concerned about the survival of one of his primary assets, the elderly fleet carrier Glorious in the face of Italian opposition in the Mediterranean, and instructed his staff to re-examine all plans for an attack of the Italian fleet base at Taranto. He was advised by the captain of Glorious, Captain Arthur L. St G. Lyster, that the carrier’s Swordfish bombers were capable of a night attack with air-launched torpedoes. At the time the Fleet Air Arm was the only naval aviation arm possessing such a capability. Pound took Lyster’s advice, and ordered the start of training for such an undertaking under conditions that were so secret that no written records were kept. Just one month before the war began, Pound advised Cunningham, his successor, to consider the possibility, and this was the proximate spur for ‘Judgement’ (i).

The fall of France in June 1940 and the consequent loss of the French fleet in the Mediterranean as a British ally made essential the redress of the naval balance of power in the Mediterranean. For this Eagle, an older carrier now part of the Mediterranean Fleet, was ideal as she possessed a very experienced air group composed entirely of Swordfish aircraft. Three Gloster Sea Gladiator biplane fighters were added for the operation for defensive purposes. Firm plans were drawn up after the Italian army had halted its first offensive toward Egypt at Sidi Barrani, where it started to dig entrench itself during September, and this freed the Mediterranean Fleet to consider other plans.

‘Judgement’ (i) was just a small part of the overarching ‘MB8’ operation, and was originally scheduled for 21 October 1940, but a fire in the auxiliary fuel tank of one of the Swordfish warplanes imposed a delay. This 60-Imp gal (273-litre) auxiliary tank replaced the usual third crewman to extend the operating range of the Swordfish sufficiently to operate against Taranto, and the minor fire in one aeroplane spread into something more serious which destroyed two of the Swordfish aircraft. Eagle then suffered a breakdown in her fuel system, and had therefore to be eliminated from the plan. Her place was taken by the new fleet carrier Illustrious, which took on board five of Eagle’s Swordfish aircraft and launched the strike alone.

The complete British task force, commanded by Lyster who was now a rear admiral, comprised Illustrious, heavy cruisers Berwick and York, light cruisers Glasgow and Gloucester, and destroyers Hasty, Havelock, Hyperion and Ilex. The 24 Swordfish aircraft were machines of Nos 813, 815, 819 and 824 Squadrons, and there was some concern that the small number of attacking warplanes would merely alert and enrage the Italian navy without achieving significant results. Illustrious also had on board the Fairey Fulmar two-seat fighters of No. 806 Squadron to provide air cover for the task force, a task enhanced by the carrier’s possession of radar and fighter control systems.

Half of the Swordfish aircraft were armed with torpedoes to serve as the primary attack aircraft, and the other half carried bombs and flares with which to carry out diversions. The torpedoes were fitted with magnetic/contact exploders, which were extremely sensitive to the effects of rough water as attacks on the German battleship Bismarck had showed in May 1941 during the later stages of ‘Rheinübung’. There were also worries the torpedoes would strike the harbour’s bottom after entering the water but before they could level themselves. The bombers’ loss rate was expected to be in the order of 50%.

Several reconnaissance flights by Martin Maryland aircraft of the RAF’s No. 431 (GR) Flight from Malta confirmed the presence of the Italian fleet in Taranto, and also yielded photographs on which Illustrious’s intelligence officer spotted previously unforeseen barrage balloons. The plan was the attack was then changed to accommodate this new factor. To make sure the Italian warships had not sortied since the Maryland flights, the British also despatched a Short Sunderland flying boat on the night of 11 November, just as the carrier task force was coming into formation about 200 miles (320 km) from Taranto off the Greek west coast island of Kephaloniá. This reconnaissance flight alerted the Italian forces in southern Italy, but as they lacked radar they could do little but wait for events to start maturing. The Italian warships could conceivably have put out to sea in search of British naval force, but this ran counter to the naval philosophy espoused by the Italians between January 1940 and September 1943.

At the time of ‘Judgement’ (i), Taranto accommodated Campioni’s 1a Squadra with the modern battleships Littorio and Vittorio Veneto of Ammiraglio di Divisione Carlo Bergamini’s 9a Divisione Navi di Battaglia, older battleships Caio Duilio (recommissioned on 7 July 1940 after a reconstruction) and Andrea Doria (recommissioned on 20 October 1940 after a reconstruction but not considered operational), older battleships Conte di Cavour and Giulio Cesare of the 5a Divisione Navi di Battaglia, heavy cruisers Pola, Zara, Gorizia and Fiume of Ammiraglio di Squadra Angelo Iachino’s 1a Divisione Incrociatori, heavy cruisers Trento, Trieste and Bolzano of the 3a Divisione Incrociatori, light cruisers Luigi di Savoia Duca degli Abruzzi and Giuseppe Garibaldi of the 8a Divisione Incrociatori, and destroyers Giosué Carducci, Vittorio Alfieri, Alfredo Oriani, Vincenzo Gioberti, Lampo, Baleno, Folgore and Libeccio, and seaplane tender Giuseppe Miraglia. There were other destroyers in the inner harbour.

The complexity of ‘MB8’, with its various forces and convoys, succeeded in deceiving the Italians into thinking only normal convoy operations were under way, and this was a major factor in the success of ‘Judgement’ (i).

The first wave of 12 aircraft led by Lieutenant Commander M. W. Williamson of No. 815 Squadron lifted off the flight deck of Illustrious just before 21.00 on 11 November, and was followed by a second wave of nine aircraft some 90 minutes later. Of the aircraft of the second wave, one turned back with an auxiliary fuel tank problem, and another took off 20 minutes late after emergency repairs had been effected to damage sustained in a minor taxiing accident, so only eight aircraft of the second wave made it to the target.

The first wave of 12 attackers, comprising equal numbers of aircraft armed with torpedoes and bombs, was split into two sections after three of the bombers and one torpedo bomber had strayed from the main force while flying through thin cloud. The smaller group continued to Taranto independently. The main group approached the Mar Grande outer harbour at 22.58. A flare was dropped to the east of the harbour, then the flare dropper and another aeroplane made a dive-bombing attack to hit and ignite the base’s oil tanks. The next three aircraft, led by Lieutenant Commander K. Williamson of No. 815 Squadron, attacked over the island of San Pietro, which was built into the harbour’s northern mole, and struck the older battleship Conte di Cavour with a torpedo whose detonation blew a 27-ft (8.2-m) hole in the battleship’s side below the waterline. Williamson’s aeroplane was then shot down by the Italian battleship’s 3.93-in (100-mm) anti-aircraft guns. The two remaining aircraft in this sub-flight continued, dodging barrage balloons and receiving heavy anti-aircraft fire from the Italian warships and shore batteries, to press home an unsuccessful attack on the older battleship Andrea Doria. The next sub-flight of three aircraft attacked from a more northerly direction, attacking the newer battleship Littorio, hitting her with two torpedoes and launching one torpedo at the flagship, the newer Vittorio Veneto, which failed to hit its intended target. The bomber force led by Captain O. Patch of the Royal Marines was the next to attack but, finding the targets difficult to identify, attacked two cruisers from 1,500 ft (460 m), and then another of the aircraft straddled four destroyers with its bombs.

The second wave of nine aircraft, led by Lieutenant Commander J. W. Hale of No. 819 Squadron, was now approaching the target area. Two of its four bomb-armed aircraft also carried flares, and the other five carried torpedoes. The flares were dropped shortly before 24.00. Two aircraft targeted Littorio and gained a single hit. Despite being hit twice by anti-aircraft fire, one of the aircraft aimed a torpedo at Vittorio Veneto but missed. Another aeroplane scored a torpedo hit on Caio Duilio, blowing a large hole in her hull and flooding the magazines of the two forward main armament turrets. The aeroplane flown by Lieutenant G. W. L. A. Bayly was shot down by the anti-aircraft fire of the heavy cruiser Gorizia after its attack on Littorio, and this was the only loss among the aircraft of the second wave. The final aeroplane to arrive, 15 minutes behind the others, made a dive-bombing attack on an Italian cruiser in the face of heavy anti-aircraft fire, and then made a safe departure to return to Illustrious at 02.39.

Of the two aircraft shot down, the two men of the first were taken prisoner, and the two men of the second were killed.

The Italian battleships suffered significant damage. Conte di Cavour had a hole measuring 39 by 26 ft (12 by 8 m) in her hull: in the six hours following the attack all the attempts to prevent her from sinking failed and she settled on the bottom. The ship was later raised, but was still undergoing repairs when Italy switched sides in September 1943, so she did not return to service. Caio Duilio had hole only a slightly smaller, at 36 by 23 ft (11 by 7 m), in her hull and was saved by being run aground. Littorio suffered considerable flooding as a result of being hit by three torpedoes. Despite the underwater protection provided by the ‘Pugliese’ system, which was standard in all Italian battleships, the damage was extensive, and the ship also lost 32 men killed and many more wounded. She was holed in three places: the single opening on the port side measured 23 by 5 ft (7 by 1.5 m), and the two holes on the starboard side measured 49 by 33 ft (15 by 10 m) and 39 by 30 ft (12 by 9 m). This ship too was saved by being run aground but, despite this, by the morning the ship’s bow was totally submerged.

The Italian land batteries had fired 13,489 anti-aircraft rounds during the course of the British attack, and the ships had also fired several thousands of rounds. The anti-aircraft barrage was formidable, for it was fired by 101 guns and 193 machine guns. There were also 87 balloons, but strong winds caused the loss of 60 of them. There were only 2.6 miles (4.2 km) of anti-torpedo nets, up to 33 ft (10 m) in depth, largely round the heavy cruisers Gorizia, Zara and Fiume, but adequate defence required 8 miles (12.8 km) of nets. The defences also included 13 listening stations and 22 searchlights.

Littorio was repaired as a high-priority matter by the use of all available resources, but the repair of the older Conte di Cavour and Caio Duilio, with a main armament based on 12.6- rather than 15-in (320- rather than 381-mm) guns, proceeded considerably more slowly (seven months for Caio Duilio and as noted above never completed for Conte di Cavour).

Two Italian aircraft were also destroyed by the bombing. Two bombs, neither of which detonated, hit the heavy cruiser Trento and destroyer Libeccio, and near-misses damaged the destroyer Emanuele Pessagno.

Meanwhile the cruisers of Rear Admiral H. D. Pridham-Wippell’s British ‘X’ Force attacked an Italian convoy in the Strait of Otranto while on passage from Valona in Italian-occupied Albania to Brindisi in south-eastern Italy. This force had the light cruisers Ajax, Orion and Australian Sydney, and the destroyers Mohawk and Nubian. Just after 24.00 the British force met and destroyed the 4,391-ton Capo Vado, 2,429-ton Catalani, 5,691-ton Antonio Locatelli and 4,427-ton Premuda, and damaged the torpedo-boat Fabrizi as the auxiliary cruiser Ramb III fled.

Cunningham and Lyster wished to attack Taranto once again on the following night with 15 Swordfish aircraft in the form of six torpedo-bombers, seven bombers and two flare dispensers, but bad weather prevented the action.

‘Judgement’ (i) had cost the Italian fleet half of its capital ships in one night, and on the following day the Italians transferred their undamaged ships from Taranto to Naples to protect them from similar attacks. The Mediterranean balance of power had swung strongly to the Mediterranean Fleet, which now enjoyed considerably greater operational freedom: while previously forced to operate as one unit to match the Italian capital ship strength, it could now operate as two battle groups each built around one carrier and two battleships. Cunningham initially estimated that Italians would now be unwilling to risk their remaining heavy units, but was quickly proved wrong as only five days after ‘Judgement’ (i), Campioni sortied with two battleships, six cruisers and 14 destroyers in ‘Gaudo’ designed to disrupt the ‘White’ aircraft and supply delivery operation to Malta. The follow-up to this operation led to the Battle of Cape Spartivento on 27 November 1940.

However, when measured against its primary task of disrupting Axis convoys to Africa, ‘Judgement’ (i) had very little effect. In fact, Italian shipping to Libya increased between the months of October 1940 and January 1941 to an average of 49,435 tons per month, up from the average of 37,204 tons over the previous four months.

Up to this time air-launched torpedo proponents in all modern navies had believed that torpedo attacks against ships required water at least 75 ft (23 m) deep. Taranto harbour had a depth of only about 39 ft (12 m). However, the British had developed a new method to prevent torpedoes from diving too deep. A drum was attached beneath the nose of the aeroplane, from which a roll of wire led to the nose of the torpedo: as the torpedo dropped, the tension from the wire pulled up its nose before the wire broke so that the weapon landed flat in the water rather than in a shallow dive.

It is worth noting that the staff of the Imperial Japanese navy carefully studied the Taranto raid during its planning for the ‘Ai’ attack on Pearl Harbor which, like Taranto, had shallow water. Lieutenant Commander Takeshi Naito, the assistant naval attaché in Berlin, flew to Taranto to make a first-hand investigation of the attack. He probably wrote a report, but no copy of such a report has ever been found. Naito subsequently had a lengthy conversation with Commander Mitsuo Fuchida about his observations in October 1941, and it was Fuchida who led the Japanese attack on 7 December 1941. More significant, perhaps, was a Japanese military mission to Italy in May 1941. Japanese navy officers visited Taranto and had lengthy discussions with their Italian navy opposite numbers. However, the Japanese had been working on shallow-water torpedo solutions since a time early in 1939 with a view to attacks on ships moored in the shallow water of ports such as Manila, Singapore and Vladivostok as well as Pearl Harbor. In the early 1930s, the Japanese were using a break-away wooden nose to soften the torpedo’s impact with the water, and by the middle of 1941, regardless of any contribution made by study of the Taranto attack, the Japanese had perfected break-away wooden fins for added aerial stability.

The Japanese air attack on Pearl Harbor on 7 December 1941 was a considerably larger operation than Taranto, with six fleet carriers each carrying an air wing which was more than double the size of the group carried by a British carrier. ‘Ai’ therefore caused far greater devastation, sinking or disabling seven US battleships, and seriously damaging other warships. However, the Japanese raid on the US Pacific Fleet did not alter the balance of power in the Pacific in the same way that the attack on Taranto had in the Mediterranean Sea. The leaders of the US Navy were forced rapidly into a modernisation of their thinking and made aircraft carriers, which had been absent from Pearl Harbor, their capital ships in naval warfare planning. Compared with the Italian battleships which were a threat in the narrow confines of the Mediterranean, the US battleships which survived the ‘Ai’ raid proved to be of use in the vast expanse of the Pacific Ocean mainly as fire support platforms to aid amphibious landings as they were too slow to escort the carriers.