Italian Auxiliary Ship Olterra - First Incursion

First Incursion

By the end of the autumn of 1942, the Olterra was ready for her mission. The workshop works were completed and all the supplies smuggled from Italy had reached Spain without raising any suspicion. On 6 December 1942, after taking part in Operation Torch, a naval squadron consisting of the battleship HMS Nelson, the battle cruiser HMS Renown, the aircraft-carriers HMS Furious and HMS Formidable and a number of escort units entered Gibraltar. Visintini planned a three manned torpedoes mission, each of them carrying 2 divers: the leading torpedo, driven by Visintini himself and Petty Officer Magro, the second by 2nd Lieutenant Cella and Sergeant Leone and the third by Midshipman Manisco and Petty Officer Varini. The targets were designated in the following order: for Visintini, Nelson, for Manisco, Formidable and for Cella, Furious.

The assault craft departed from the Olterra during the early hours of 8 December. At 2:15 AM, the first human torpedo reached the area of the boom defences. The motor launches and sentries inside the British base were quietly active and alert, conscious of the danger of a potential attack on the fleet at anchor. One of the security measures taken by the Royal Navy after the summer incursions of combat swimmers was the deployment at Gibraltar of an underwater bomb disposal unit, under the command of Lieutenant Lionel Crabb. A pattern of depth charges was dropped by the motor barges at an interval of three minutes between each one. The craft of Visintini and Magro was apparently hit by one of the charges and destroyed when they were trying to find a breach in the steel net protecting the harbour. Their bodies were recovered by the British some days later and buried at sea with full honors. The second “pig” also endured the strong response of British defences after being uncovered by a searchlight. After an endless chase by anti-submarine boats, the Italian crew decided to scuttle their craft and took shelter on board an American freighter. They discarded their swimsuits before submitting themselves to Gibraltar authorities. The last manned torpedo was caught in the middle of the general alarm across the stronghold, but managed to slip beneath the waters and fool the submarine chasers. The copilot, Leone, became missing during the pursuit and was never found; Cella, meanwhile, abandoned the craft elsewhere, thinking that he was still near Gibraltar or, in the best case, stranded close to the Spanish coast. With the idea of becoming a prisoner of war or being arrested and interned by Spanish authorities in mind, Cella surfaced, only to find that he was just a few meters away from the Olterra. His torpedo was recovered by the Italians the following day. The two divers captured by the British told their interrogators that the attack was launched by submarine, successfully deceiving Allied intelligence. Nevertheless, the first human torpedoes mission ended in failure.