Adua-Class Submarine

Submarine Gondar

The Adua-class submarine Gondar undergoes conversion at the La Spezia Shipyards to replace Iride in late August 1940. The process involves removing the deck gun and its ammunition, two reserve torpedoes, three chain shackles, a kedge anchor, a towing cable, and other non-essential equipment. The submarine is fitted with three watertight metal cylinders to transport three Siluri a Lenta Corsa devices. Unlike Iride, these cylinders enable the submarine to operate at its maximum diving depth of 90 metres, addressing the severe limitations posed by deck-mounted saddles.

Manufactured by Odero-Terni-Orlando (OTO) in Muggiano, La Spezia, the cylinders weigh 2.8 metric tons each, with a seawater capacity of 21.75 tons and buoyancy of 23.3 tons when empty. Each cylinder is equipped with a watertight hemispherical hatch with a side hinge for inserting and extracting the Siluri a Lenta Corsa’s. Valves and pipes allow flooding and venting to be controlled from inside the submarine, and a ventilation and battery recharge system is installed to maintain the Siluri a Lenta Corsa ‘s during transit.

Trials conducted in Ligurian waters establish two main methods for deploying the Siluri a Lenta Corsa’s and their operators. When the submarine is resting on the seabed at depths of 8 to 15 metres, operators exit through the lock-out chamber using breathing apparatus, open the flooded cylinder hatches, extract the Siluri a Lenta Corsa’s, and reseal the cylinders to stabilise buoyancy. Alternatively, when the submarine is awash with only the conning tower exposed, operators exit through the upper hatch, descend to the deck, open the pre-flooded cylinder hatches, extract the Siluri a Lenta Corsa’s, and return to the submarine once the devices are deployed.

On September 21^st, 1940, Gondar, under the command of Lieutenant Francesco Brunetti, a survivor of the Iride sinking, departs La Spezia carrying three Siluri a Lenta Corsa’s for Operation GA 2. The Gondar reaches Messina on September 23^rd, 1940, embarking the operators.

On September 24^th, 1940, at 07:00 hours, the submarine Gondar departs Messina for Operation GA 2, a 1^a Flottiglia MAS mission targeting Alexandria. This operation represents the second attempt to breach the port’s defenses. The Gondar carries five officers, thirty-three ratings, and ten frogmen from Gruppo Gamma of the 1^a Flottiglia MAS, led by Capitano di Fregata (Mission Commander) Mario Giorgini. Other key personnel include Tenente di Vascello Alberto Franzini, Guardiamarina Alberto Cacioppo, Capitano del Genio Navale Elios Toschi, Sergente Palombaro Umberto Ragnati, Capitano di Artiglieria Navale Gustavo Stefanini, Sergente Palombaro Alessandro Scappino, Guardiamarina Aristide Calcagno, Sergente Palombaro Giovanni Lazzaroni, and Capo Elettricista di Seconda Classe Cipriano Cipriani.

On the night of September 29^th, 1940, the Australian destroyer H.M.A.S. Stuart is en route to Alexandria after a steam pipe malfunction. To avoid entering the harbour before daylight, the ship conducts an anti-submarine search at a speed of 30 km/h. At 22:15 hours, the ASDIC operator detects a contact at 2,700 metres. H.M.A.S. Stuart increases speed to 33 km/h.

The contact is Gondar, attempting to approach Alexandria. To evade detection, the submarine dives to 110 metres. At 22:20 hours, H.M.A.S. Stuart drops a pattern of six depth charges, followed by another five at 22:45 hours after slowing to 22 km/h (12 knots) to improve sonar accuracy. A single depth charge is dropped at 01:00 hours on September 30th, 1940, at maximum depth. Subsequent attacks are carried out at 02:00 and 03:50 hours with six and one depth charge, respectively. At 06:25 hours, H.M.A.S. Stuart executes a final barrage of five depth charges.

At 06:30 hours, a Sunderland flying boat (L.2166) from No. 230 Squadron, piloted by Flying Lieutenant Alington, arrives and circles the area. At 09:25 hours, the armed trawler H.M.T. Sindonis joins the hunt. At 09:30 hours, the aircraft releases a bomb 2,700 metres from H.M.A.S. Stuart. Ten minutes later, the Gondar surfaces on the starboard bow of H.M.A.S. Stuart and attempts to escape at 19 km/h (10 knots). H.M.A.S. Stuart opens fire, prompting the crew of Gondar to abandon ship. At 09:50 hours, internal explosions from scuttling charges rock the submarine, and Gondar sinks stern-first at position 32°02’N, 27°54’E.

H.M.A.S. Stuart rescues 28 survivors, while H.M.T. Sindonis picks up 19 more. One crew member, Luigi Longobardi, drowns and is posthumously awarded the Medaglia d’Oro. The survivors include Tenente di Vascello Francesco Brunetti, four officers, 33 ratings, and all ten frogmen. Among them is Capitano del Genio Navale Elios Toschi, a co-founder of X^a Flottiglia MAS alongside Teseo Tesei and Capitano di Fregata Mario Giorgini, the chief of the assault craft unit (then Sezione Armi Speciali) of the 1^a Flottiglia MAS. Among the group are four officers and four petty officers, three of whom belong to gruppo Gamma. The group also includes six operators and two reserves who were intended to deploy the three Siluro a Lenta Corsa.

The capture of such high-ranking personnel, along with specialized operatives and equipment, does not go unnoticed by British intelligence. The incident raises numerous questions, particularly regarding the role of the Gondar and the strategic intent behind her mission. The presence of specialized assault craft operatives hints at Italy’s covert naval operations, fueling Allied curiosity about the capabilities and objectives of the X^a Flottiglia MAS. This event marks a significant intelligence opportunity for the British in understanding and countering Italian special naval warfare efforts during World War II.

Submarine Sciré

The Adua-class submarine Sciré is converted in August and September 1940, at the La Spezia Shipyards to carry Siluri a Lenta Corsa devices. This includes installing three watertight cylinders for transporting the craft, lowering the periscope standards, and reducing the size of the conning tower. Over time, the submarine’s original dark iron-grey hull is repainted in various camouflage schemes, including a short-lived outline of a trawler on its conning tower. Later, it adopts a pattern of light brown triangles on a light ash-grey background.

Under the command of Lieutenant Commander Junio Valerio Borghese and later Lieutenant Commander Bruno Zelich, the Sciré undertakes six key missions, transporting and deploying assault craft to infiltrate heavily defended enemy ports.

On September 24^th, 1940, at 05:40 hours, Sciré departs La Spezia for Gibraltar with three Siluri a Lenta Corsa’s as part of Operation BG 1. The submarine carries human torpedoes, known as Siluro a Lenta Corsa (maiali), and three teams of operators tasked with piloting them, along with a reserve team.

The first team consists of Tenente di Vascello Gino Birindelli and Secondo Capo Palombaro Damos Paccagnini. The second team includes Capitano del Genio Navale Teseo Tesei and Sergente Palombaro Alcide Pedretti. The third team is made up of Sottotenente di Vascello Luigi Durand de la Penne and Secondo Capo Palombaro Emilio Bianchi. The reserve team comprises Tenente del Genio Navale Gian Gastone Bertozzi and Secondo Capo Palombaro Enrico Ario Lazzari.

The submarine makes its way toward Gibraltar, intending to position the Siluri a Lenta Corsa’s close to the harbour for a surprise attack. However, shortly before reaching its target, approximately 80 kilometres from Gibraltar, the mission is aborted. Intelligence reveals that Force H, the British naval task force stationed in Gibraltar, has departed. Without the primary targets in the harbour, continuing the operation is deemed too risky and strategically unnecessary.

In Operation BG 3 on May 26^th, 1941, Sciré embarks operators in Cadiz from the tanker Fulgor and releases the Siluri a Lenta Corsa’s in the Algeciras roadstead. Again, the mission fails due to equipment malfunctions.

On September 20^th, 1941, during Operation BG 4, Sciré achieves its first success. The submarine releases three Siluri a Lenta Corsa’s in the Algeciras roadstead, resulting in the sinking of two tankers and a motor vessel.

Operation GA 3 on December 18^th, 1941 is the most successful mission. Sciré releases three Siluri a Lenta Corsa’s near Alexandria Harbour, where the craft penetrate and sink or severely damage two British battleships, the H.M.S. Valiant and the H.M.S. Queen Elizabeth, a tanker, and a destroyer. This mission demonstrates the effectiveness of Italian underwater assault tactics.

On August 10^th, 1942, during Operation SL 1, Sciré departs for Haifa with ten Gamma operators aboard. Near the harbour entrance, it is detected by H.M.S. Islay and coastal defences. After being attacked with depth charges and gunfire, Sciré is sunk, with the loss of its entire crew and all X^a Flottiglia MAS operators aboard.

Submarine Aradam

During the summer of 1943 the Aradam enters the Genoa shipyard for conversion into a submarine capable of deploying Siluro a Lenta Corsa’s. As part of its conversion, Aradam is equipped with two watertight deck-mounted cylinders, one at the bow and another at the stern, designed to carry assault craft. This modification aligns with Regio Marina’s strategy to intensify the use of assault craft against Anglo-American naval forces. To this end, efforts focus on converting existing submarines, such as the Aradam, and adapting newly constructed vessels like the Murena, Grongo, and Sparide of the Tritone class. Still commanded by Lieutenant Carlo Forni (although some sources suggest Lieutenant Mario Tromba assumes command temporarily), the submarine is unable to sail. To prevent it from falling into German hands, the crew scuttles the vessel on September 9^th, 1943.

By December 1943, the RSI’s X^a Flottiglia MAS reconstitutes its SSB operational group, equipped with Siluro San Bartolomeo, advanced versions of the Siluro a Lenta Corsa used in earlier raids on Alexandria, Algiers, and Gibraltar.

The Germans salvage the Aradam and transfer the submarine the Marina Nazionale Repubblicana on January 25^th, 1944. The Aradam, already fitted with the necessary transport cylinders, is placed in dry dock for repairs on March 25^th, 1944. On April 29^th, 1944 is is transferred to Junio Valerio Borghese’s X^a Flottiglia MAS, which plans to repair and repurpose it for transporting assault units. Lieutenant Carlo Forni, having joined the Italian Social Republic, is appointed its commander.

There are no records of the Aradam undertaking any missions between January and September 1944. By August 18^th, 1944, the submarine Aradam is undergoing harbour trials in Genoa as part of its reconditioning to return to service. The vessel, salvaged and partially refitted as a carrier for Siluro a Lenta Corsa’s, is stationed alongside the submarines Grongo, Murena, and Sparide, which are also undergoing conversion or testing.

During this period, a bombing raid by 168 B-17 bombers of the United States Army Air Forces targets Genoa’s harbour. A total of 1,965 bombs, each weighing 227 kilograms, are dropped during the attack. The damage caused by the raid results in the sinking of the Aradam, as well as the Grongo, Murena, and Sparide.

The loss of these submarines ends efforts to restore them to operational status. The sinking of the Aradam also marks the disbandment of the X^a Flottiglia MAS Assault Vehicle Transport Group.

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