The CB class was a group of midget submarine

Midget submarine

A midget submarine is any submarine under 150 tons, typically operated by a crew of one or two but sometimes up to 6 or 8, with little or no on-board living accommodation...

s built for the Italian Navy

Regia Marina

The Regia Marina dates from the proclamation of the Kingdom of Italy in 1861 after Italian unification...

 during World War II

World War II

World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...

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Design

The boats were designed as coast defence units with diesel electric propulsion. There was a mini conning tower to aid navigation. The armament consisted of two torpedoes mounted externally which could be reloaded without removing the craft from the water.

Boats

Seventy two boats were ordered from Caproni of Milan, but only 22 were laid down. 12 boats were completed before the Armistice and nine after. Six boats were transferred to the Black Sea

Black Sea

The Black Sea is bounded by Europe, Anatolia and the Caucasus and is ultimately connected to the Atlantic Ocean via the Mediterranean and the Aegean seas and various straits. The Bosphorus strait connects it to the Sea of Marmara, and the strait of the Dardanelles connects that sea to the Aegean...

 by rail and fought the Soviets sinking two submarines. After the Italian Armistice, the five survivors were transferred to the Royal Romanian Navy

Romanian Naval Forces

The Romanian Navy is the navy branch of the Romanian Armed Forces; it operates in the Black Sea and on the Danube.-History:-Development of the Romanian Navy:The Romanian Navy has been founded in 1860 as a river flotilla on the Danube...

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Boat	Completed	Service / Fate
CB 1	27 January 1941	Transferred to the Black Sea, To Romania 1943, Scuttled August 1944, raised by USSR and commissioned as TM-4, scrapped 1945
CB 2	27 January 1941	Transferred to the Black Sea, To Romania 1943, Scuttled August 1944, raised by USSR and commissioned as TM-5, scrapped 1945
CB 3	10 May 1941	Transferred to the Black Sea, To Romania 1943, Scuttled August 1944, raised by USSR and commissioned as TM-6, scrapped 1945
CB 4	10 May 1941	Transferred to the Black Sea, To Romania 1943, Scuttled August 1944, raised by USSR and commissioned as TM-7, scrapped 1945
CB 5	10 May 1941	Transferred to the Black Sea, sunk by Soviet aircraft near Yalta Yalta Yalta is a city in Crimea, southern Ukraine, on the north coast of the Black Sea.The city is located on the site of an ancient Greek colony, said to have been founded by Greek sailors who were looking for a safe shore on which to land. It is situated on a deep bay facing south towards the Black... , 13 June 1942
CB 6	10 May 1941	Transferred to the Black Sea, To Romania 1943, Scuttled August 1944
CB 7	1 August 1943	Captured by Germany at Pola Pula Pula is the largest city in Istria County, Croatia, situated at the southern tip of the Istria peninsula, with a population of 62,080 .Like the rest of the region, it is known for its mild climate, smooth sea, and unspoiled nature. The city has a long tradition of winemaking, fishing,...  September 1943- transferred to the Italian Social Republic Italian Social Republic The Italian Social Republic was a puppet state of Nazi Germany led by the "Duce of the Nation" and "Minister of Foreign Affairs" Benito Mussolini and his Republican Fascist Party. The RSI exercised nominal sovereignty in northern Italy but was largely dependent on the Wehrmacht to maintain control... , cannibalised for spare parts
CB 8	1 August 1943	Surrendered to Britain 1943, Scrapped 1948
CB 9	1 August 1943	Surrendered to Britain 1943, Scrapped 1948
CB 10	1 August 1943	Surrendered to Britain 1943, Scrapped 1948
CB 11	24 August 1943	Surrendered to Britain 1943, Scrapped 1948
CB 12	24 August 1943	Surrendered to Britain 1943, Scrapped 1948
CB 13	Late 1943 ?	Captured by Germany 1943, Transferred to Italian Social Republic, Sunk by Allied aircraft 23 March 1945
CB 14	Late 1943 ?	Captured by Germany 1943, Transferred to Italian Social Republic, Sunk during air raid
CB 15	Late 1943 ?	Captured by Germany 1943, Transferred to Italian Social Republic, Sunk during air raid
CB 16	Late 1943 ?	Captured by Germany 1943, Transferred to Italian Social Republic, Sunk during air raid
CB 17	Late 1943 ?	Captured by Germany 1943, Transferred to Italian Social Republic, Sunk by Allied aircraft 3 April 1945
CB 18	Late 1943 ?	Captured by Germany 1943, Transferred to Italian Social Republic, Sunk 31 March 1945
CB 19	Late 1943 ?	Captured by Germany 1943, Transferred to Italian Social Republic, Broken up 1947
CB 20	Late 1943 ?	Captured by Germany 1943, Transferred to Italian Social Republic, Captured by Yugoslav Partisans in Pola at the end of the War, In active service in Yugoslav Navy Yugoslav Navy The Yugoslav Navy was the navy of Yugoslavia. It was essentially a coastal defense force with the mission of preventing enemy landings along the Yugoslavia's rugged 4,000- kilometer shoreline or coastal islands, and contesting an enemy blockade or control of the strategic Strait of Otranto...  till 1959. as P-901 On display at the Technical museum Technical Museum, Zagreb Technical Museum is located at 18 Savska Street in Zagreb and it exhibits numerous historic aircraft, cars, machinery and equipment.-The Museum features:...  Zagreb Zagreb Zagreb is the capital and the largest city of the Republic of Croatia. It is in the northwest of the country, along the Sava river, at the southern slopes of the Medvednica mountain. Zagreb lies at an elevation of approximately above sea level. According to the last official census, Zagreb's city...
CB 21	Late 1943 ?	Captured by Germany 1943, Transferred to Italian Social Republic, rammed and sunk by a Marinefährprahm in the Adriatic 29 April 1945
CB 22		Captured by Germany in 1943, taken to Pola and abandoned at the end of the war. Wreck salvaged and preserved in Trieste