Japanese cruiser Sakawa

Agano class light cruiser

Sakawa (酒匂 ) was the last of four light cruisers built for the Imperial Japanese Navy (IJN) during World War II. Fuel shortages crippled the IJN's operations by the time the ship was completed in late 1944 and she never left Japanese waters. After the war, Sakawa was used to ferry Japanese troops home until she was selected in early 1946 to be expended for nuclear weapon tests during Operation Crossroads. The ship was used as a target during the first bomb test on 1 July and sank the following day.

The Agano class ships were intended to replace the obsolete light cruisers built in the 1910s and 1920s as flagships of destroyer flotillas. The ships measured long overall with a beam of and had a draft of They displaced at standard load and at deep load. Sakawa had a crew of 55 officers and 750 enlisted men; assignment as a flagship added 3 officers and 16 more sailors. The Agano class had four geared steam turbine sets, each driving a single propeller shaft, using steam provided by six Kampon Ro Gō water tube boilers. The turbines were designed to produce a total of and give the ships a speed of They carried enough fuel oil to give them a range of at a speed of .

The main armament of the Agano class consisted of six 41st Year Type guns in three twin gun turrets, two in front of the superstructure and one aft. The secondary armament included four 98th Year Type anti aircraft (AA) guns in two twin turrets amidships. Sakawa, being the last built ship of her class, had the strongest suite of light anti aircraft weapons which included 10 triple and 18 single mounts for Type 96 AA guns. The ships also had two quadruple torpedo launchers for Type 93 (Long Lance) torpedoes on the centerline and had a reload system with eight spare torpedoes. They were equipped for anti submarine warfare with two depth charge chutes for 18 depth charges and could also carry three mines. The Agano class ships were also fitted with a pair of Aichi E13A floatplanes and a catapult. To detect submarines, the Aganos were equipped with a Type 93 Model 2 hydrophone installation and, unlike her sisters, Sakawa had a Type 3 Model 1 sonar, based on a German design. The ship was completed with Type 13 and Type 21 early warning radars as well as a Type 22 surface search radar. The latter system had received a modification that allowed it to be used for fire control as well.

Sakawa, named after the Sakawa River, was laid down on 21 November 1942 at Sasebo Naval Arsenal. The ship was launched on 9 April 1944 and completed on 30 November. On commissioning, she was assigned directly to the Combined Fleet. On 15 January 1945 Sakawa became flagship of Destroyer Squadron 11, training with new destroyers in the Inland Sea, and participating in a series of tests of a new anti radar submarine coating. On 1 April, the squadron was assigned to Operation Ten Go, the suicide mission against the American invasion forces at Okinawa. They were originally scheduled to accompany the battleship Japanese battleship Yamato and her sister ship Japanese cruiser Yahagi, but there was no fuel available for the squadron to participate in the mission. On 26 May one of Sakawas propellers struck a rock in the Kanmon Straits between Kyushu and Honshu, but only had its tips partly bent. The ship was later transferred to the Maizuru Naval District and arrived there on 19 July. She was attacked by aircraft from the aircraft carrier Yorktown six days later, but was not damaged. When Japan surrendered on 2 September, Sakawa was docked at Maizuru. The second weapons test, Baker, was an underwater shot on 25 July about 500 feet (152 m) away from the sunken Sakawa. It blew most of the remaining forward superstructure off the ship and further damaged the wreck. Sakawa is mostly upright on the sandy bottom, but there is very little surviving aft of the forward gun turrets.