Operation Corkscrew or the invasion of Pantelleria (11 June 1943) saw the British occupy this fortified Italian island without a shot being fired, after the garrison was subjected to a heavy aerial bombardment.
Pantelleria is located half way between the south-western tip of Sicily and the North Africa coast, and had been portrayed by the Italians as their equivalent to Gibraltar or Malta, a strong fortress that would be very difficult to assault. No foreigners had been allowed to visit the island for some time, so nobody was sure how strong it actually was. The island was lined by cliffs, and the only suitable place for an invasion was at the town of Porto di Pantelleria in the north-west of the island.
The Italians had fortified the island. There was a large airfield at the northern end of the island, capable of taking four engined bombers and operating up to eighty fighters, and with a 1,100ft long underground hanger to its south-east. There were over 100 gun emplacements on the island, some dug out of the local rock, others built from concrete. These covered the harbour at Porto di Pantelleria and all other possible landing points. There were also a large number of pillboxes and machine gun positions built across the island. There was also a Freya radar base on the island. Allied intelligence estimated that the Italians had 10,000 men on the island. After the invasion the Allies took 11,000 prisoners of war.
On 9 May Eisenhower ordered Tedder to direct the full strength of the Northwest African Air Forces against Pantelleria, offering him the support of the heavy and medium bombers of the Northwest African Air Forces. Tedder thus had around 1,000 operational aircraft at his disposal for the attack. This included four groups of B-17s, two groups of B-25s, three groups of B-26s, three groups of P-38s and two wings of RAF and SAAF Wellingtons from the Strategic Air Force.
The operation was to be jointly commanded by General Spaatz of the USAAF, Major General W. E. Clutterbuck from the British 1st Infantry Division and Rear Admiral R. R. McGrigor, RN. The date was set for 11 June, but the three commanders had the authority to postpone the attack if they decided that more preliminary attacks were needed.
The air attack began on 18 May. The initial plan was to carry out fifty medium bomber and fifty fighter bomber sorties per day against the island from then until 5 June. Porto di Pantelleria and the airfield were the initial targets. Combined with a naval blockade, this meant that the island was soon isolated and besieged. By the end of May all aircraft on the airfield had been knocked out.
The heavy bombers joined the attack on 1 June, when the emphasis moved onto the coastal batteries and gun emplacements. On 1 June the B-17s, P-38s and P-40s dropped 141 tons ob bombs on the island. On 3 June the A-20 Bostons joined the attack. On 4 June a force of B-17s, B-25s, B-26s, Wellingtons, P-38s and P-40s dropped more than 200 tons of bombs on the island. Between 18 May and 6 June the NAAF flew around 1,700 sorties against Pantelleria, and had dropped 900 tons of bombs on the port and airfield and 400 tons on gun positions.
The air attack moved into a second, even more intensive, phase on 6 June. On 7 June 600 tons of bombs were dropped, mainly against the coastal batteries. This rose to 700 tons on 8 June, 800 tons on 9 June and a massive 1,571 tons on 10 June, when 1,100 aircraft took part in the attack! Between 1-10 June the Allies carried out 3,647 sorties against Pantelleria, dropping 4,844 tons of bombs. This massive air attack was carried out at comparatively low cost. The Northwest African Air Forces lost four aircraft destroyed, ten missing and sixteen damaged over the island, while carrying out a total of 5,285 sorties.
The German and Italian air forces did make some efforts to protect the island. The first concentrated fighter attacks came on 6-7 June. The peak of activity came on 10 June, but these efforts had little impact. Axis loses were estimated as 60 aircraft on 1-10 June, four times the Allied losses.
The island was also attacked from the sea. Between 31 May and 5 June small British forces, normally made up of one cruiser and two destroyers, carried out a series of raids. On 8 June five light cruisers, eight destroyers and three torpedo boats bombarded Porto di Pantelleria. Encouragingly the Italian response was weak, suggesting that the bombardment was working.
The Allies gave the Italians two chances to surrender before the invasion. The first came on 8 June, after the naval bombardment. Three fighters dropped the surrender message, followed by thousands of leaflets, but there was no response. The same happened on 10 June.
The invasion itself was carried out by the British 1st Infantry Division, which had been trained in amphibious warfare and wasn’t allocated to the invasion of Sicily. This quickly proved to be overkill. The division embarked on three convoys on the night of 10-11 June, two fast and one slow. The fast convoys were in place off Pantelleria by daybreak on 11 June and moved into position eight miles off the harbour, where the troops moved from the transports to their landing craft.
At the same time the air forces carried out a final round of attacks on the Italian gun positions, which ended at 1000 on 11 June. The landing craft then began to move towards the island at 1030. At this point the Luftwaffe made an attempt to intervene, sending a large force of Fw-190s against the fleet and five Bf-109s against the landing craft. Both attacks were driven off without success.
At 1100 the 15th Cruiser Squadron carried out a final naval bombardment. This was followed by one last attack by the B-17s. At this point the Italians had finally had enough. Between 1130 and 1200 a destroyer and several aircraft sighted a white flag flying on a height named ‘Semaphore Hill’ by the Allies. The landing craft touched down at 1155, and encountered almost no resistance. There was some small arms fire on one beach, but that soon stopped. Elsewhere one British soldier was bitten by a donkey, becoming the only Allied casualty of the attack.
As the troops were approaching the shore, news arrived from Malta that Vice Admiral Gino Pavesi, the military governor of Pantelleria, had asked to surrender, having first gained permission from Mussolini. Pavesi informed Rome that the Allied bombing could no longer be endured, while the official excuse was a lack of water. At 1330 General Clutterbuck moved ashore, and at 1735 the formal surrender of the island was signed in the underground aircraft hanger.
Nearby Lampedusa was also theoretically strongly defended, with a garrison of 4,300 troops, two platoons of tanks, 33 coastal and AA guns and a network of fortifications, as well as minefields protecting all landing zones. However the island’s defenders were just as eager to surrender as on Pantelleria. White flags were displaced late on 12 June and the Island was officially occupied on 13 June.
Much of the damage to the airfield was quickly repaired by the 2690th Air Base Command, which came ashore soon after the surrender. By 26 June it was possible for the 33rd Fighter Group to move onto the island, in time to take part in Operation Husky, the invasion of Sicily.
The Allies learnt the wrong lessons from the quick surrender of Pantelleria. Although the aerial bombardment had done plenty of damage, the main reason was that the defenders had no interest in fighting for Mussolini. However the leaders of the Allied air forces took it as an example of how air power could defeat even the strongest of defended positions, without the need to coordinate the air attacks with an actual land attack. This was proven not to be the case during the Second battle of Cassino, which began with a massive aerial attack on the Benedictine monastery that was carried out independently of the ground troops. As a result the Germans were given time to recover from the bombing before the infantry attacked, and were able to hold their ground.