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Decima Flottiglia Mas and Operazione EA3: The Raid on Alexandria

Italian David vs. British Goliath

To even the most casual observer of global events in World War II, it was obvious the strategic situation during the first two weeks of December 1941 heavily favored the Axis powers of Germany, Japan, and Italy.

“We are having shock after shock out here. The damage to the battleships at this time is a disaster… One cannot but admire the cold-blooded bravery and enterprise of these Italians.”

-Adm. Sir Andrew Cunningham, commander in chief Royal Navy Mediterranean Fleet

Having conquered western continental Europe in 1940, in 1941 the armies of Adolf Hitler’s Germany turned east. The conquest of Yugoslavia and Greece, necessitated by a botched invasion of Greece by Italy, was followed by the invasion of the Soviet Union. In early December Hitler’s armies were approaching the outskirts of Moscow.

Alexandria Harbor

Map of Alexandria Harbor at the time of the Alexandria raid by Decima MAS. Map courtesy of John D. Gresham

Meanwhile, in the Pacific, because victories were happening so rapidly, Japanese success was even more breathtaking. The surprise and devastating Dec. 7 attack by the Imperial Japanese Navy on American military facilities in and around the U.S. Navy port at Pearl Harbor, Hawaii, was followed up with successful Japanese attacks and invasions ranging from Indochina and the Dutch East Indies (modern Indonesia) in the east and south to the Philippines in the north.

Only in the Mediterranean were the Allies, primarily in the form of the British Royal Navy under the command of Adm. Sir Arthur Browne Cunningham, holding their own – barely, and not without cost. Yet, through an inspiring combination of courage, leadership, and tenacity, the intrepid Scotsman, affectionately nicknamed “ABC” because of his initials, had managed to cow the larger and more powerful Italian Regia Marina. But despite the obvious threat posed by the Italian surface fleet, a much smaller unit of the Italian Navy would prove to be the greater – and more deadly – threat to the Royal Navy: Decima Flottiglia MAS (10th Light Flotilla), one of the most effective units in the history of special operations.

Italian naval commando operations had their origin in the final days of World War I, when two Italian naval officers in a modified torpedo boat successfully entered the Austro-Hungarian navy harbor at Pola on the Adriatic Sea in what is now Croatia and sank the battleship Viribus Unitis. In the interwar years, Italian Navy Majs. Teseo Tesei and Elios Toschi developed a manned torpedo they nicknamed “maiale,” (Italian for “pig”), and officially designated Siluro a Lenta Corsa (SLC – “slow running torpedo”). The Italian Navy high command was impressed and gave its approval. Specially designed motor torpedo boats were soon added, and a special operations unit, designated the 1st Light Flotilla, was formed in 1939. In 1941, it was reorganized into Decima Flottiglia MAS and split into two parts, with one sub-unit specializing in surface operations and the second sub-unit specializing in underwater operations.

In August 1940, Junio Valerio Borghese, a submarine commander, joined the 1st Light Flottiglia. Borghese’s first mission was a raid on the strategic British base of Gibraltar, located at the mouth of the Mediterranean Sea. Between September 1940 and September 1941, he conducted four raids on the base. The first was aborted, the next two failed, but the fourth, in September 1941, resulted in three merchant ships being damaged. For this action, he was promoted to lieutenant commander and put in command of the sub-surface unit of what was now Decima MAS.

The name of the mission was Operazione EA3 (Operation EA3), the “3” designating this as the third attack on Alexandria.

At the same time Borghese was planning his first Gibraltar mission, another underwater commando team was conducting its first raid on the Royal Navy’s primary operating base in the eastern Mediterranean at Alexandria. That raid, and a follow-up attempt, ended in failure. But the Italians were determined to return. Their chance to do so, with the potential of swinging the balance of power back to the Italian Navy, finally presented itself in the fall of 1941.

Through reports from agents in Alexandria and aerial reconnaissance flights, the Regia Marina had an accurate and detailed picture of harbor defenses at Alexandria, a formidable combination of minefields, net barriers, shore-based artillery and machine gun defenses, and constant patrols both on shore and water. A long sea wall extending from the peninsula at the north end of the harbor almost fully enclosed its protected waters. Its only opening was at the southern end, which was protected by an antisubmarine net that was only opened when authorized vessels entered. Passive defenses outside the harbor included a minefield 20 miles northwest of the harbor containing contact mines. Closer to the harbor were lines and rings of “lobster pots” – smaller mines that could be detonated manually via a radio signal.

Shortly after the successful Gibraltar mission, Cmdr. Ernesto Forza, who would be in overall command of the Alexandria raid from his base in Athens, called together a dozen of the most senior and experienced members of the underwater commandos and delivered what Borghese recalled was a brief speech: “[W]e want three crews for an operation in the very near future; all I can tell you about it is that it is differs from the Gibraltar operations in the fact that return from it is extremely problematical. Is there anyone who would like to take part in it?” To a man, they all volunteered. From that group, three maiale crews were selected: Lt. Luigi Durand de la Penne and Petty Officer/diver Emilio Bianchi (operating SLC 221); Engineer Capt. Antonio Marceglia and Petty Officer/diver Spartaco Schergat (operating SLC 222); and Gunner Capt. Vincenzo Martellotta and Petty Officer/diver Mario Marino (operating SLC 223). A backup crew, composed of Surgeon Sub-Lt. Spaccarelli and Engineer Feltrinelli, was added in the event that something happened to one of the primary crews. The name of the mission was Operazione EA3 (Operation EA3), the “3” designating this as the third attack on Alexandria.

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.


A photograph of the Italian submarine Scirè at La Spezia with the deck compartments that housed the maiales. Photo courtesy of John D. Gresham

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.

Meanwhile, the three manned torpedoes had arrived near the harbor’s entrance. The crews decided to take a brief break and eat some rations as they decided how they were going to breach the antisubmarine net stretching across the entrance. Then, to their surprise, they saw the net being pulled aside — the barrier was being opened to allow three arriving British destroyers into the harbor. Quickly the crews got into position behind the last destroyer and entered the harbor before the net closed. The crews soon separated and headed toward their respective targets.

The crews soon separated and headed toward their respective targets.

Because his dry suit had been leaking ever since he had left the submarine and the cold water was sapping his strength, de la Penne decided to take their torpedo over the netting surrounding the Valiant instead of submerging and cutting an entrance from the bottom. The maneuver was successful, and soon the torpedo was beside the hull of the battleship. Suddenly, the torpedo began sinking for some unaccountable reason. The divers rode the submarine to the bottom, 17 meters (about 55 feet) below the surface. The divers then struggled to get the torpedo into position under the battleship. The effort proved too much for Bianchi, whose breathing apparatus was not working properly. Feeling faint, he returned to the surface to get some fresh air. But, shortly after he surfaced, he lost consciousness. When he regained consciousness, he got rid of his malfunctioning breathing apparatus and swam to a nearby buoy to await capture.


An SLC (Siluro a Lenta Corsa) maiale at the Mueso Sacrario delle Bandiere delle Forze Armate inside the monument to Vittorio Emanuele II, Rome, Italy. Photo by Myrabella via Wikimedia Commons

When he discovered that Bianchi was gone, de la Penne went to the surface to find him. Failing to do so, de la Penne returned to the torpedo. Over the next 40 minutes, with agonizing slowness, he managed to get the torpedo directly below the middle of the battleship, and set the timers before swimming to the surface. He was soon discovered and, together with Bianchi, captured. The two frogmen were first taken aboard the Valiant, and briefly interrogated. They were then taken to a security hut ashore for a short time before being returned to the Valiant, where they were put in a cabin on the lowest deck of the ship.

Marceglia and Schergat reached their target, Queen Elizabeth, positioned their torpedo below its hull, and set the timers without experiencing any of the problems that de la Penne and Bianchi did. Marceglia and Schergat successfully evaded a shore patrol and got into Alexandria. The overall plan called for any commando who wasn’t captured to try and find a boat and rendezvous with the submarine Zaffro that had been dispatched for this purpose. But the two were captured three days later by Egyptian police for suspicious behavior.

By the time Martellotta and Marino reached their target, the tanker Sagona, Martellotta had become sick and was vomiting, the result of exposure and the inhaling of pure oxygen from his breathing apparatus. Martellotta had to remain on the surface while Marino positioned the torpedo beneath the tanker and set the timers. After Marino had done so, the two commandos reached shore and, like Marceglia and Schergat, were apprehended by the Egyptian police.

“The enemy were for some time unaware of the success of their attack. …”

The explosives of all three torpedoes had been set to detonate at 0600. At 0550, de la Penne asked to see the captain of the Valiant. He told the captain that his ship would shortly be blown up. De la Penne refused the captain’s demand for details, and for this refusal, was returned to his cabin. At 0600 the charge beneath the Valiant exploded, propelling Cunningham, standing on the quarterdeck, 5 feet into the air. De la Penne and Bianchi survived and were later taken to a prisoner of war camp. A few moments later the torpedoes beneath the Queen Elizabeth and Sagona blew up.

Cunningham imposed a complete news blackout in an attempt to mislead the Axis into thinking that the mission had failed. In a secret session of the House of Commons on April 23, 1942, Prime Minister Winston Churchill informed parliament of the attack and the Italian frogmen’s success. He concluded by saying, “Both [the Valiant and Queen Elizabeth were sunk] on an even keel, they looked all right from the air. The enemy were for some time unaware of the success of their attack. …”

But Churchill was wrong. On Jan. 8 and 9, the Italian high command issued two bulletins identifying that the Queen Elizabeth and Valiant had been heavily damaged. Naval power had now swung in the Regia Marina’s favor. Axis forces under German Gen. Erwin Rommel could now be easily supplied, and Italy was in a position to win the war in the Mediterranean. Yet, to Borghese’s disgust, it didn’t happen. He accused the German high command of refusing to allot enough fuel to the Italian air force and navy so it could exploit the opportunity. By the end of 1942, with Operation Torch in the west and the British 8th Army’s offensive in the east, the Allies had regained the initiative.

This article was first published in The Year in Special Operations: 2010-2011 Edition.


DWIGHT JON ZIMMERMAN is a bestselling and award-winning author, radio host, and president of the...