Italian auxiliary cruiser Ramb II

Ramb II

Company type	Ship
Industry	Maritime transport, naval warfare
Founded	September 6, 1937 (1937-09-06) (launched)
Headquarters	Monfalcone , Italy
Products	Refrigerated cargo transport, auxiliary cruiser, auxiliary transport ship

Overview

The Italian auxiliary cruiser Ramb II originated as a pre-World War II refrigerated cargo vessel, specifically designed for transporting bananas. Constructed in 1937 at the Cantieri Riuniti dell' Adriatico (CRDA) shipyard located in Monfalcone, she initially operated under the Italian government. Early in the Second World War, she was converted into an auxiliary cruiser for the Regia Marina (Royal Italian Navy). Subsequently, during the later stages of her service, she was repurposed as an auxiliary transport ship by the Imperial Japanese Navy.

Details and construction

In the latter half of the 1930s, the Ministry of the Colonies of the Kingdom of Italy commissioned four vessels specifically designed to transport bananas from Mogadishu in Italian Somaliland to Naples. These ships required substantial cargo capacity and sufficient range to complete voyages without intermediate stops. The quartet of refrigerated ships was managed by the Regia Azienda Monopolio Banane (RAMB), headquartered in Rome. Two of these, including Ramb II, were constructed by CRDA at Monfalcone, while the other two were built at the Ansaldo shipyards located in Sestri Ponente. The keel for Ramb II was laid on December 14, 1936; she was launched on June 7, 1937, and officially handed over to RAMB on September 6, 1937.

Launch of RAMB II at Monfalcone (1937).

Although modest in size, these vessels were technologically advanced for their time. Each RAMB ship could transport roughly 2,400 tons of cargo along with twelve passengers. Passenger accommodations included a luxury suite with a bedroom, living room, and private facilities for two individuals, while ten additional passengers were housed in twin cabins. A dedicated deck area was reserved exclusively for passengers, separate from crew quarters. Amenities also featured a dining room with panoramic views and two verandas designated for smokers. All passenger areas were equipped with air conditioning.

The Ramb II measured 383 feet 2 inches (116.79 m) in length between perpendiculars and had a beam of 49 feet 9 inches (15.16 m). Her mean draft was 24 feet 8 inches (7.52 m). The vessel’s gross register tonnage was 3,685 GRT with a net register tonnage of 2,190 NRT. Constructed with a steel hull, propulsion was provided by two seven-cylinder, single-acting 2-stroke diesel engines, each with cylinders measuring 22+1⁄16 inches (56.0 cm) in diameter and a stroke length of 33+1⁄16 inches (84.0 cm). These engines powered twin screw propellers enabling speeds up to 18.0 knots (20.7 mph; 33.3 km/h).

Legislation mandated that these ships be built with convertible features allowing transformation into auxiliary cruisers if necessary. Deck space was reserved to mount four 120 millimetres (4.7 in) guns. The artillery pieces and related military equipment were stored at Massawa for two vessels and at Naples for the remaining pair.

Service

During her initial two years operating in peacetime, Ramb II transported bananas from Italian Somaliland to ports such as Venice, Naples, and Genoa, while returning with various goods destined for Mogadishu. An onboard explosion occurred on August 7, 1938, in Trieste, resulting in eight fatalities.

On April 9, 1940, the vessel was requisitioned by the Regia Marina and underwent conversion into an auxiliary cruiser at the Eritrean port of Massawa. Post-conversion armament included four 120⁄40 cannons and two 13.2 mm Breda anti-aircraft machine guns. Following Italy’s entry into World War II on June 10, 1940, Ramb II joined the Italian Navy’s Red Sea Flotilla.

Throughout her brief tenure as an auxiliary cruiser, Ramb II remained docked at Massawa due to limited allied merchant shipping activities and the strong presence of the British Royal Navy within the Red Sea theater.

Following the commencement of Operation Compass in North Africa and the Italian defeat at Sidi Barrani between December 9–12, 1940, it became evident that Italian forces in Libya could not break through to relieve their holdings in Italian East Africa. Fuel reserves were rapidly depleting and expected to run out by June 1941. In preparation for the anticipated fall of the colony, plans were implemented to dispatch as many vessels as possible to Japan or occupied France while scuttling any ships unable to make such journeys. Among those sent eastward were the colonial ship Eritrea, along with auxiliary cruisers Ramb I and Ramb II.

Departing Massawa on February 22, 1941—after Ramb I and Eritrea had left earlier—both auxiliary cruisers set course for Nagasaki while Eritrea headed toward Kobe. The trio navigated past Perim Island to avoid interception by Royal Navy ships and Royal Air Force aircraft stationed at Aden and Socotra before transiting through Bab el-Mandeb Strait into the Gulf of Aden and onward into the Indian Ocean.

On February 27, 1941, Ramb I was intercepted and sunk by HMNZS Leander, but both Ramb II and Eritrea successfully traversed the Indian Ocean and Sunda Strait to reach Japan safely.

Ramb II arrived at Kobe on March 23, 1941. The Italian government intended to employ her as a commerce raider targeting British merchant shipping within the Indian Ocean; however, Japan’s neutral status at that time led Japanese authorities to reject this proposal. Consequently, on March 24 she left Kobe to disarm her weapons in international waters before returning to Japan. In May 1941, her name was changed to Calitea II, and she was transferred under management of the Triestine Line.

Subsequently, Calitea II sailed to Tianjin where Admiral Carlo Balsamo—serving as naval attaché in Tokyo—inspected Italian merchant vessels available for transporting natural rubber from East Asia to occupied France. Due to her limited cargo capacity for such extended voyages, Calitea II was not selected for this mission.

In December 1941, Calitea II was chartered by Japanese authorities as a cargo ship but retained her Italian crew.

By September 1942 she had been formally commissioned into the Imperial Japanese Navy as a stores ship and underwent further refrigeration modifications at Kawasaki Heavy Industries’ shipyard. Her inaugural voyage under Japanese command commenced on November 30, 1942 from Kobe bound for Southeast Asia; she reached Surabaya on December 23.

Throughout 1943, Calitea II operated primarily on inter-island routes transporting supplies and troops when required. She returned to Kobe for repairs on August 24 that year. Following Italy’s signing of the Armistice of Cassibile on September 8, 1943, her Italian crew deliberately scuttled the vessel at Kobe to prevent capture by Japanese forces.

Service under Japanese control

After being salvaged by Japanese forces, Calitea II was renamed Ikutagawa Maru on October 3, 1943, and received the call sign JXBY. She was officially designated as an auxiliary transport vessel on November 30, 1943. Once her repairs were finalized in December, she sailed to Sasebo and was incorporated into the Southwest Area Fleet.

Ikutagawa Maru embarked on her inaugural voyage under Japanese command on January 7, 1944, departing from Moji as part of convoy No. 127. This convoy included seven other merchant ships and was escorted by the destroyer Karukaya and minesweeper W-27. On January 10, 1944, the US submarine Seawolf detected and launched an attack against the convoy near coordinates 27°32′N 127°25′E, resulting in the sinking of three vessels.

Throughout 1944, the ship continued to transport supplies to various island ports across Southeast Asia, including Makassar, Surabaya, Ambon, among others. On November 4, 1944, Ikutagawa Maru ran aground near Cape Agal but managed to free herself within a few hours and proceeded safely to Banggi Island. On January 5, 1945, she left Manila escorted by destroyers Momi and Hinoki. The following day, the convoy came under attack from the US destroyer Bennion, which inflicted damage on Hinoki, temporarily incapacitating her and forcing both escorting destroyers to retreat to Manila. Meanwhile, Ikutagawa Maru continued onward to Cap Saint-Jacques.

During Operation Gratitude on January 12, 1945—a component of the South China Sea raid aimed at supporting the liberation of Luzon in the Philippines—aircraft from the US Navy's Task Force 38 executed extensive air raids targeting ports, airfields, and military installations primarily around Saigon, Indochina. In this assault, Ikutagawa Maru, along with several other ships, was sunk near coordinates 10°20′N 107°50′E.

Bibliography

• Alton, Dave (2006). "Question 15/03: Italian Warship Losses". Warship International. XLIII (1): 32–33. ISSN 0043-0374.
• Dupuis, Dobrillo (2014). Forzate il blocco. 1940. L'odissea della marina militare italiana. Res Gestae. ISBN 978-8866970606.