Italian submarine Gemma

Gemma

Company type	Submarine
Industry	Naval military vessel
Founded	September 7, 1935 (1935-09-07) in Monfalcone, Italy
Headquarters	Monfalcone , Italy
Products	Perla-class submarine

Italian submarine Gemma was a Perla-class submarine constructed for the Royal Italian Navy (Regia Marina) during the 1930s. The name Gemma translates from Italian as a gemstone or jewel.

Design and description

The Perla class submarines were largely based on the earlier Sirena class design, with most changes being incremental upgrades. These enhancements included enlarging the conning tower, updating the engines to more modern models, and fitting a radiogoniometer operable from within the vessel. Additional improvements involved installing advanced air conditioning systems, which slightly increased the displacement. Furthermore, greater fuel capacity extended their operational range compared to their predecessors. Their intended full load displacement was approximately 695 metric tons (684 long tons) when surfaced and around 855 metric tons (841 long tons) submerged, though these figures varied according to specific units and shipyards. The submarines measured 197 feet 6 inches (60.20 m) in length, with a beam of 21 feet (6.4 m), and a draft ranging between 15 feet (4.6 m) and 15 feet 5 inches (4.70 m).

For propulsion on the surface, these submarines utilized two diesel engines, each connected to a separate propeller shaft, delivering a combined output between 675–750 hp (503–559 kW). When submerged, each propeller was powered by an individual electric motor rated at 400-horsepower (298 kW). Their maximum speeds were approximately 14 knots (26 km/h; 16 mph) on the surface and 7.5 knots (13.9 km/h; 8.6 mph) while underwater. Surface cruising range was about 5,200 nautical miles (9,600 km; 6,000 mi) at a speed of 8 knots (15 km/h; 9.2 mph), whereas submerged endurance was limited to roughly 74 nmi (137 km; 85 mi) at 4 knots (7.4 km/h; 4.6 mph).

Armament included six internal torpedo tubes measuring 53.3 cm (21.0 in), with four located at the bow and two at the stern. Each tube had one reload torpedo available, totaling twelve torpedoes carried onboard. Surface combat capabilities were provided by a single 100 mm (3.9 in) deck gun. Defensive anti-aircraft weaponry consisted of one or two twin mounts of [[Breda Model 1931 Machine Gun|13.2 mm (0.52 in)]] machine guns.

Construction and career

The submarine Gemma was constructed by CRDA at their Monfalcone shipyard, with the keel laid on 7 September 1935. She was launched on 21 May 1936 and officially completed by 8 July 1936.

Following her commissioning, Gemma was assigned to the 35th Squadron within the III Submarine group, stationed at Messina. After a short training period, she undertook an extended endurance cruise in the Dodecanese during autumn 1936, which she repeated in 1937.

Between August 27 and September 5, 1937, under the command of Captain Carlo Ferracuti, Gemma conducted a covert operation in the Strait of Sicily amid the Spanish Civil War. Although she attempted three attacks during this mission, no engagements occurred due to the inability to definitively identify targets. After completing this assignment, she returned to Augusta.

In 1938, Gemma along with Perla was deployed to the Red Sea base at Massawa, Eritrea. The following spring of 1939 saw both submarines embark on a voyage into the Indian Ocean to evaluate their performance under tropical conditions and during monsoon weather. The outcomes were unfavorable; rough seas hindered the use of onboard weaponry and made maintaining periscope depth challenging. Additionally, issues arose with the air conditioning system, including reported leaks of chloromethane. Later that year in autumn, Gemma returned to the Mediterranean and was assigned to the 14th Submarine Squadron (I Submarine group) based at La Spezia. In 1940, she was transferred to the 13th Submarine Squadron (I Submarine Group), operating from Leros.

Upon Italy's entry into World War II, Gemma, commanded by Guido Lanza Cordero di Montezemolo, was deployed for patrol duties off Chios. She returned to base on June 15 without encountering any enemy vessels.

From June 30 to July 8, 1940, she patrolled near Sollum but did not detect any hostile ships. Similarly, during her patrol off Crete between August 7 and August 16, no enemy contacts were made.

On September 30, 1940, Gemma proceeded to her operational zone in the northern part of the Strait of Kasos, just east of Crete. Meanwhile, Amethyst was stationed south of her in the central strait area, and further south near Karpathos was Tricheco, commanded by Captain Alberto Avogadro di Cerrione. Arriving on October 1, Gemma was scheduled to remain on patrol until October 8; however, orders received on October 3 redirected her to patrol further east between Rhodes and Karpathos. A subsequent command on October 6 instructed her to return to base but due to a communication failure this message never reached her, resulting in her staying at her post. On October 7, Tricheco, dealing with an ill crew, began returning to Leros, navigating close to Karpathos’s eastern shore—an area where Gemma was stationed. Due to delayed communication and lack of notification regarding Gemma's position, Tricheco was unaware of her presence.

At approximately 1:15 on October 8, during nighttime conditions, Tricheco spotted a surfaced submarine silhouette. Since identification at night was impossible and standard protocol dictated treating unidentified submarines as hostile unless otherwise informed, at 1:21 two torpedoes were fired at close range. Both torpedoes struck Gemma amidships causing her immediate sinking near coordinates 35°30′N 27°18′E, just off Karpathos’s coast. Captain Cordero di Montezemolo along with four officers and thirty-nine crew members perished with the vessel.

Initially, it was believed that British anti-submarine operations had caused Gemma's loss; radio reports on October 8 mentioned two enemy submarines sunk with survivors captured, providing hope for families. However, it soon became evident that the timing of Trichecos attack coincided exactly with Gemmas disappearance. Consequently, Gemma was officially declared lost and her entire crew presumed dead rather than missing.

References

• Bagnasco, Erminio (1977). World War Two Submarines. Annapolis, Maryland: Naval Institute Press. ISBN 0-87021-962-6.
• Chesneau, Roger, ed. (1980). Conway's Complete Fighting Ships 1922–1946. Greenwich, UK: Conway Maritime Press. ISBN 0-85177-146-7.
• Rohwer, Jürgen (2005). Naval Warfare Chronology 1939–1945: The History of World War Two at Sea (Third Revised ed.). Annapolis, Maryland: Naval Institute Press. ISBN 1-59114-119-2.
• Giorgerini, Giorgio (2002). Men Beneath the Surface: History of Italian Submarines from Origins to Present (Second ed.). Mondadori. ISBN 8804505370.
• Pollina, Paolo (1963). Italian Submarines 1895–1962. Rome, Italy: SMM.