Training commenced at their base in La Spezia, located on the western shore of northern Italy, and a target date of the attack was scheduled for the night of Dec. 17. The battery-powered maiales the operators would use in the attack were 6.7 meters (22 feet) long, had a top speed of 2.5 miles per hour, a range of 10 nautical miles, and a submersion depth of 30 meters (about 98.5 feet). The warhead, located in the bow, weighed 300 kilograms (about 661 pounds). The crew rode in the midsection. A toolbox, located behind the second diver who sat behind the pilot, contained such necessary equipment as net cutters, net lifters, magnetic clamps to attach explosives, and additional rope.
Real-time intelligence on which ships were in the harbor and their position would be transmitted to the Sciré from Athens once it had reached its launch point.
The maiales and their crews would be transported to the launch site by the submarine Sciré, which had been fitted with three large tubes, one forward, two aft, designed to hold the maiales. To allow the crews the maximum amount of training time, crews and submarine would rendezvous at the Dodecanese island of Leros located off the coast of Turkey. From there the Sciré would travel submerged to Alexandria. Real-time intelligence on which ships were in the harbor and their position would be transmitted to the Sciré from Athens once it had reached its launch point.
The Sciré, captained by Lt. Cmdr. Borghese, departed La Spezia on Dec. 3. Six days later the submarine arrived at Port Lago in Leros, where technicians made a final check of the maiales. After a pre-mission leave that allowed them to be with their families, the crews departed La Spezia in aircraft on Dec. 10 and arrived at the island two days later. This was followed by three days of intensive final preparations that included intelligence updates. On Dec. 14, the Sciré departed Leros and headed south for Alexandria.
The two earlier missions had failed because enemy aircraft had spotted and attacked the transport submarines during the transit phase. To reduce that risk, the Sciré traveled underwater at maximum depth during the day. The Sciré surfaced only at night to replenish cabin air and recharge batteries. A heavy storm on Dec. 16 almost forced Borghese to abort the mission because he had to keep the submarine submerged well past normal endurance limits for the crew. Instead, it only caused him to delay the attack by one day. The Sciré reached its launch point at the northern end of the harbor on the night of Dec. 18. When he surfaced to “outcrop level” (only the conning tower above water, the transport chambers submerged), Borghese discovered, “The weather was perfect: it was pitch-dark; the sea very smooth and the sky unclouded. Alexandria was right ahead of me, very close … [T]o my great satisfaction I found that we were within a meter of the pre-arranged point.” To have done so after traveling more than 1,700 miles, most of it underwater and relying on dead-reckoning navigation, was an incredible achievement. More good luck was to follow. Coded messages from Athens revealed that among the ships in the harbor were the British battleships Queen Elizabeth and Valiant and the French battleship Lorraine. One message also congratulated Bianchi on becoming a new father. The crews took this as another good omen.
One message also congratulated Bianchi on becoming a new father. The crews took this as another good omen.
The British battleships and the tanker Sagona were selected as targets. Though both British battleships were heavily armored at the water line and on deck, their flat bottoms were lightly armored and thus vulnerable to attack by explosives placed directly below.
At 2100 hours, the reserve crew, in full diving gear as the maiale chambers were underwater, emerged to perform the physically exhausting task of opening the chamber hatches. The operational crews then boarded their torpedoes and headed south for the harbor’s entrance. The launch went smoothly, but Spaccarelli had over-exerted himself and collapsed unconscious on the submarine’s deck. It was only by accident that Feltrinelli discovered the inert man. Spaccarelli was quickly brought into the submarine. A greater danger to Sciré was the fact that Spaccarelli had left the exit chamber ajar, and the submarine was taking in water. With the Sciré’s role in the mission accomplished, Borghese retired as quickly as he could, fighting to retain trim underwater. When he had reached a safe distance away from Alexandria, he surfaced and had the chamber hatch properly secured. Miraculously, though feared dead, after three and a half hours, Spaccarelli began showing signs of life. By the time the Sciré reached Leros, he was almost fully recovered.