was one of four s of the

Imperial Japanese Navy The Imperial Japanese Navy (IJN; Kyūjitai: Shinjitai: ' 'Navy of the Greater Japanese Empire', or ''Nippon Kaigun'', 'Japanese Navy') was the navy of the Empire of Japan from 1868 to 1945, Potsdam Declaration, when it was dissolved followin ...

(IJN). It capsized in a storm on 12 March 1934, shortly after its completion. This incident forced the IJN to review the stability of all recently completed, under construction and planned ships. It was salvaged and put back into service after extensive modifications. During

World War II World War II or the Second World War (1 September 1939 – 2 September 1945) was a World war, global conflict between two coalitions: the Allies of World War II, Allies and the Axis powers. World War II by country, Nearly all of the wo ...

, the ''Tomozuru'' fought in the Battle of the Philippines and in the

Dutch East Indies campaign The Dutch East Indies campaign of 1941–1942 was the conquest of the Dutch East Indies (present-day Indonesia) by forces of the Empire of Japan in the early days of the Pacific campaign of World War II. Allied forces attempted unsuccessfully t ...

as an escort, and it continued to play that role for the rest of the war.

The ''Tomozuru'' Incident

In February 1934, ''Tomozuru'' joined the 21st Torpedo Flotilla at

Sasebo is a core city located in Nagasaki Prefecture, Japan. It is the second-largest city in Nagasaki Prefecture, after its capital, Nagasaki. , the city had an estimated population of 230,873 in 102,670 households, and a population density of 540 per ...

. *01:00, 12 March 1934, ''Tomozuru'' departed from

for a night torpedo exercise with the light cruiser and torpedo boat . *03:25, because of stormy weather, ''Tatsuta'' ordered the other two boats to return to base. *03:58, radio contact lost with ''Tomozuru''. Possible loss of power or radio capability. *04:12, ''Tomozuru''s lights disappeared, presumably this is when it capsized. *14:05, a rescue plane discovered the capsized ''Tomozuru'' drifting. *07:00, 13 March 1934, ''Tomozuru'' was towed by ''Tatsuta'' back to Sasebo. 100 crew were lost. The instability of the ''Chidori''s arose from Japanese efforts to circumvent the various naval treaties. They had designed small vessels of around 600 tons, but with the weaponry of a destroyer of twice the displacement. Weight had been saved by lighter construction but gun systems remained complex and heavy. After the launch of the lead ship, its high centre of gravity - even higher than feared - had been noted and efforts made to remedy this. High-speed

sea trial A sea trial or trial trip is the testing phase of a watercraft (including boats, ships, and submarines). It is also referred to as a "shakedown cruise" by many naval personnel. It is usually the last phase of construction and takes place on op ...

s showed it to be unstable, however, and further efforts were made to rectify the problem by adding bulges to the hull. Eventually ''Chidori'' satisfied the examiners and it was commissioned and the construction of the class, including ''Tomozuru'', proceeded. At the time of its loss, ''Tomozuru'' was low on consumables such as fuel or water that would have ballasted it and lowered its centre of gravity. On the other hand, munitions were fully loaded, so the situation was significantly worse than on its

Consequences

The cause of ''Tomozuru'' capsizing was a low

metacentric height The metacentric height (GM) is a measurement of the initial static stability of a floating body. It is calculated as the distance between the centre of gravity of a ship and its '' metacentre''. A larger metacentric height implies greater initial ...

. The IJN established a committee and inspected the stability of all vessels. As a result of the inspection, the IJN discovered a lack of rolling performance, among others, in the following vessels: * Aircraft carriers : * Cruisers : * Destroyers : , and es * Submarine tenders : ''Taigei'' * Minelayers : , , and the and es * Minesweepers : and es * Subchasers : The significance of this incident is that it severely challenged Japanese assumptions over the stability of their warships and prompted a major review of the design of all Japanese warships. Existing vessels had their superstructures reduced and ships planned and under construction were redesigned during 1934-35. In particular the s were significantly altered.

Service

Japanese torpedo boat Tomozuru sinking 1945

The ship was later repaired and saw service against China and in

. It was part of the naval support force for the invasion of

Netherlands New Guinea Dutch New Guinea or Netherlands New Guinea (, ) was the Western New Guinea, western half of the island of New Guinea that was a part of the Dutch East Indies until 1949, later an overseas administrative territorial entity, overseas territory of ...

in April 1942 and was present in the Banda Straits in July 1942. During the war the rear gun was landed and replaced with Type 96 25mm AA guns. A total of ten of these were carried by the end of the war. The number of

depth charge A depth charge is an anti-submarine warfare (ASW) weapon designed to destroy submarine A submarine (often shortened to sub) is a watercraft capable of independent operation underwater. (It differs from a submersible, which has more limited ...

s carried was also increased over the course of the war to 48.Whitley, p. 209 ''Tomozuru'' was sunk 220 km north-west of

Okinawa most commonly refers to: * Okinawa Prefecture, Japan's southernmost prefecture * Okinawa Island, the largest island of Okinawa Prefecture * Okinawa Islands, an island group including Okinawa itself * Okinawa (city), the second largest city in th ...

on 24 March 1945 by U.S. carrier-based aircraft.

Notes

References

* *

External links

Failure knowledge database
{{DEFAULTSORT:Tomozuru Chidori-class torpedo boats Ships built by Maizuru Naval Arsenal 1933 ships World War II shipwrecks in the Philippine Sea World War II naval ships of Japan Ships sunk by US aircraft Torpedo boats sunk by aircraft Maritime incidents in 1934 Maritime incidents in March 1945 de:Tomozuru-Klasse