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by Cristiano D'Adamo

The submarine ACCIAIO was one of the 13 boats of the series “Platino” of the class 600. Some authors also refer to the "Platino" series as the class “Acciaio”, or “Metalli” (metals), but this should be considered inaccurate, as the “Platino” were definitely boats of the class “600”, series “Platino”.

The ACCIAIO was laid down on November 21st 1940 at the OTO shipyard of Muggiano, near the naval base of La Spezia. The boat was launched on January 22nd, 1941 and delivered to the Regia Marina on October 30th of the same year. Considering the difficulties brought about by shortages of material and Allied bombardments, the boat was completed in a relatively short period of time. Nevertheless, the author and submarine expert Alessandro Turrini notes that this series of submarines was already obsolete even before completion. Indeed, the Class 600, including the most up-to-date series, the “Platino”, lacked most of the latest technological improvements to submarine warfare, including the absence of a firing control system, snorkel, radar, and the ability to expel torpedoes without creating an air bubble.

The operational life of the submarine ACCIAIO was intense; it completed 9 patrols and 15 training missions. After the official delivery to the Navy, the boat underwent five months of intense training to prepare machinery and crew for the first war patrol, which took place north of Libya (Cirenaica) from March 29th, 1942 to April 4th under the command of Lieutenant Commander Ottorino Beltrami. During this mission, the new 700 HP diesel engine produced by FIAT developed serious problems and the boat was sent to the shipyard for over two months of refitting.

Service was resumed in June with a patrol north of Cape Caxine off the Algerian coast from the 6th to the 9th, followed by another one in the same general area from the 13th to the 18th. The third patrol, from July 24th to August 3rd took the boat south of the Balearic Islands. During the fourth patrol, from November 8th to the 11th, the ACCIAIO attacked a cruiser near Algiers, but failed the target. During the fifth mission, from January 1st to February 10th, 1943 while on patrol between Cape Carbon and Cape Bougaroni, the ACCIAIO sighted and sank the British A/S trawler HMT Tervani of 409 t. This would be the only success achieved by the ACCIAIO.

Again, from February 18th to the 29th, the ACCIAIO was on patrol off Cape Bougaroni. The following patrol took place north of Cape de Fer from the 4th to the 16th of April. At the end of this mission Captain Beltrami disembarked leaving the command of the boat to Lieutenant Vittorio Pescatore who would remain aboard until the loss of the submarine.

In June, from the 13th to the 18th, the ACCIAIO was on patrol southwest of Sicily, and later was moved to the Gulf of Philippeville until the 20th. During this period, the Allied landing on the European continent was imminent. Axis troops had surrendered in Tunisia and a leap over the Sicilian channel was inevitable. Many submarines, like the ACCIAIO, would be sent south in a desperate and futile attempt to stop the Allies. The ACCIAIO thus left for hit last patrol on July 10th from the naval base of La Maddalena in Northern Sardinia. Its mission was simple: cross the Strait of Messina and patrol off the western coast of Sicily.

Those days, while operation Husky (the landing in Sicily) was in full swing, Italian and German submarines were not the only boats patrolling the Mediterranean. British boats based in Gibraltar, the well-known 10th Submarine Flotilla, were very active in antisubmarine warfare. During this period many Italian boats were lost to British torpedoes. In many instances it was suspected that the British were aware of the presence of the Italian boats; nevertheless, the case of the sinking of the ACCIAO by H.S.M. UNRULY was purely coincidental. Actually, H.M.S. UNRULY, along with the closely positioned H.M.S. ULTOR were sent off the coast of Calabria to ambush the Italian battle fleet, which was expected south in defense of Sicily. The fleet never left port, but Italian and German submarines were sent in meaningless and suicidal missions against the overwhelming British and American fleets.

H.M.S. UNRULY was a relatively new boat of the U class, a small submarine of 630 t. with 4 torpedo tubes, and 8 torpedoes. Commissioned on November 3rd of the previous year, in summer 1943 the UNRULY was on her third patrol lasting from the 1st of July through the 24th. The two boats would meet off Cape Vaticano, a rocky promontory in the town of Ricadi (Vibo Valentia) near the renowned summer resort town of Tropea in Calabria, the night of Tuesday, July 13th, 1943. It was only three days before the full moon of July 16th.

As said, UNRULY had left Lazaretto’s harbor in Malta at 16:30 on July 1st with specific operational instructions received in orders S.10’s 143/05. The captain, Lieutenant Fyfe was to attack only large military ships. After a few days at sea, the boat reached Cape Vaticano (north of the Strait of Messina on the northern cost of Calabria) in the early hours of July 6th and dove 8 miles from the coast navigating underwater up to 3 miles from the rocky promontory. At 11:25, the British crew sighted a destroyer of the “Orsa” class; later a few schooners and transport aircraft. At 21:41, Lieutenant J.P. Fyfe ordered the boat to the surface to recharge the batteries and replenish the air supply.

On the 7th, at 4:38 AM with daylight soon to appear behind the coastline, UNRULY dove again. During the day there were further sightings and at 20:45 the ship made radio contact with H.M.S ULTOR while still submerged, and at 21:40 broke to the surface. The 8th went just like the day before. The boat dove at 04:32 and resurfaced at 21:42. That night the crew noticed heightened activity with intense launch of flares and the brilliant light of a ship burning all night. It was the VALFIORITA (6,200 t.), an Italian ship of 8,000 t. that had fallen victim to Captain Hunt’s H.M.S. ULTOR sank 8 miles from Cape Milazzo.

The 9th went without much to report, but on the 10th at 03:00 H.M.S. UNRULY sighted a merchant vessel on ballast escorted by two destroyers. Since orders received before departure instructed Captain Fyfe only to attack loaded vessels heading south, the submarine broke contact. The same day, the ACCIAIO left La Maddalena to probably cross the Thyrrenyan Sea and then follow the coastline south. With the Allies in total control of the air, the boat was forced to submerge during the day and navigate at night, and the night in July is very brief.

On the 11th, at 14:35, UNRULY sighted the first Italian submarine but the position was not good for an attack, thus UNRULY signaled the presence of the Italian boat to H.M.S. ULTOR at a position slightly to the south. A little bit later, at 15:50, the British submarine sighted what was believed to be a German submarine and began firing the first torpedo at 16:05 and 52 seconds, followed by three more, with the last one exiting the ship at 16:06 and 10 seconds. The crew clearly heard one explosion, then another and was surprised that the two remaining weapons did not go off. The weapons failed the target and exploded against the coast, while two failed to explode altogether.

At 21:38 the boat came to the surface sighting, two hours later, a small convoy. One of the escorts, probably a corvette, fired three star shells which were well placed over the British boat forcing it to dive. UNRULY surfaced again at 00:14 on the 12th, and at 2:00 sighted the lighthouse of Cape Rasocolmo near Milazzo. Past 4:00 AM, as usual, the submarine dove again to remain submerged for the rest of the day. Late that evening, at 20:02, UNRULY sighted what was believed to be two German submarines and carried out a false attack since standing orders called for the torpedoes to be reserved for larger ships, such as cruisers. That night the crew noticed heavy aerial activity over Messina, and at 22:15 with signal S.10’s 12.172 the submarine command lifted all restrictions on the use of torpedoes.

As usual, at 4:33 the morning of the 13th UNRULY dove; this was the day it would meet the ACCIAIO. At 20:36 the British crew sighted a submarine closing Cape Vaticano and exchanging signals with the local station. At the same time there was some activity from a different ship and the British captain assumed that the Italians had become aware of his presence. At 20:44 the two submarines were getting closer and the British changed the original attack plot for a new one. At 20:49 and 8 seconds the first torpedo jumped out of the hull, soon followed by three more.

What followed was devastating for the Italian boat: at 20:51:08, two minutes after the launch, the first explosion occurred followed by another one at 20:52:59, and another one at 20:53:03, and a last one at 20:53:14. Considering that the first torpedo was heard to explode only two minutes after launch and the other ones well over three minutes after launch, it should be assumed that only the first weapon reached the intended target while the remaining torpedoes exploded against the shore.

The loss of the ACCIAIO was instant. The boat sank to the bottom of the sea, more than 300 meters below, leaving behind light wreckage and fuel oil and taking along the 46 crewmembers. UNRULY remained in the area two more days, until the 15th, and then was ordered to Bizerta. As reported by the captain, the launch of the four weapons caused the British boat to lose trim, thus the result of the attack could not be observed. After reviewing the report, the commander of the 10th Submarine Flotilla wrote an opinion in which he stated, “… the torpedoes were fired at an Italian U-boat and did not hit…” Unfortunately, he was awfully mistaken.

To ascertain the exact time of the attack, one should consider that the ship’s log recorded the time of the attack as 20:49, while a report completed on October 13th, 1943 indicates that the time of the attack was 18:49.

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