Japanese torpedo boat Tomozuru
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{{Infobox ship image |Ship image= Japanese torpedo boat Tomozuru-1934.jpg |Ship caption= Tomozuru in 1934 }} {{Infobox ship career |Hide header= |Ship country= Empire of Japan |Ship flag={{shipboxflag|Empire of Japan|naval}} |Ship name=Tomozuru |Ship namesake= |Ship ordered= |Ship builder= Maizuru Naval Arsenal |Ship laid down= |Ship launched= 1 October 1933 |Ship completed= 24 February 1934 |Ship acquired= |Ship commissioned= |Ship decommissioned= |Ship in service= |Ship out of service= |Ship struck= |Ship homeport= |Ship honours= |Ship fate= Sunk 24 March 1945 |Ship notes= }} {{Infobox ship characteristics |Hide header= |Header caption= as built |Ship class= {{sclass|Chidori|torpedo boat}} |Ship displacement=*{{convert|535|LT|t|0}} standard
|Ship length= {{convert|82|m|ftin|abbr=on}} |Ship beam={{convert|7.4|m|ftin|abbr=on}} |Ship draught={{convert|2.5|m|ftin|abbr=on}} |Ship propulsion= |Ship speed= {{convert|30|kn|mph km/h|lk=in}} |Ship range= |Ship complement=113 |Ship armament=*1 × 2, 1 × 1 - 12.7 cm/50 Type 3 naval gun L/50 guns
|Ship armour= |Ship notes= }} {{Infobox ship characteristics |Hide header= |Header caption=after rebuilding |Ship class= |Ship type= |Ship tonnage= |Ship displacement=*{{convert|600|LT|t|0|abbr=on}} (standard)
|Ship length= |Ship beam= |Ship height= |Ship draught= |Ship draft={{convert|2.38|m|ftin|abbr=on}} |Ship depth= |Ship hold depth= |Ship decks= |Ship deck clearance= |Ship ramps= |Ship ice class= |Ship power= |Ship propulsion= |Ship sail plan= |Ship speed={{convert|28.0|kn|mph km/h|lk=in}} |Ship range={{convert|1600|nmi|km|lk=in|abbr=on}} at {{convert|14|kn|mph km/h|abbr=on}} |Ship endurance= |Ship test depth= |Ship boats= |Ship capacity= |Ship troops= |Ship complement= |Ship crew= |Ship time to activate= |Ship sensors= |Ship EW= |Ship armament=*3 × 1 - 12 cm 11th Year Type naval gun L/45 guns
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{{nihongo|Tomozuru|友鶴}} was one of four {{sclass|Chidori|torpedo boat}}s of the Imperial Japanese Navy (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, the Tomozuru fought in the Battle of the Philippines and in the Dutch East Indies campaign 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.
- 01:00, 12 March 1934, Tomozuru departed from Sasebo for a night torpedo exercise with the light cruiser {{ship|Japanese cruiser|Tatsuta|1918|2}} and torpedo boat {{nihongo|Chidori|千鳥}}.
- 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 Chidoris 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 trials 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 sea trials.
=Consequences=
The cause of Tomozuru capsizing was a low metacentric height. 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 : {{ship|Japanese aircraft carrier|Ryūjō||2}}
- Cruisers : {{sclass|Mogami|cruiser|4}}
- Destroyers : {{sclass|Fubuki|destroyer|5}}, {{sclass|Akatsuki|destroyer (1931)|5}} and {{sclass|Hatsuharu|destroyer|4}}es
- Submarine tenders : Taigei
- Minelayers : {{ship|Japanese minelayer|Yaeyama||2}}, {{ship|Japanese minelayer|Shirataka||2}}, {{ship|Japanese minelayer|Itsukushima||2}} and the {{sclass|Natsushima|minelayer|5}} and {{sclass|Tsubame|minelayer|4}}es
- Minesweepers : {{sclass|No.1|minesweeper (1923)|5}} and {{sclass|No.13|minesweeper|4}}es
- Subchasers : {{sclass|No.1|submarine chaser|4}}
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 {{sclass|Mogami|cruiser|2}}s were significantly altered.
Service
File:Japanese torpedo boat Tomozuru sinking 1945.jpg
The ship was later repaired and saw service against China and in World War II. It was part of the naval support force for the invasion of Netherlands New Guinea 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 charges carried was also increased over the course of the war to 48.Whitley, p. 209
Tomozuru was sunk 220 km north-west of Okinawa on 24 March 1945 by U.S. carrier-based aircraft.
Notes
{{Reflist|2}}
References
- {{cite magazine|last=Brown|first=David K.|editor=Antony Preston
| title=Weather and Warship Casualties 1934-1944
|publisher=Conway|location=London|magazine=Warship |year = 2009|pages=143–53|isbn=978-1-84486-089-0 |issn=0142-6222}}
- {{cite book|last=Whitley|first=M. J.|title=Destroyers of World War 2|publisher=Cassell Publishing|year=1988|isbn=1-85409-521-8}}
External links
- [https://web.archive.org/web/20070310190253/http://shippai.jst.go.jp/en/Detail?fn=0&id=CB1011021& Failure knowledge database]
- [http://www.combinedfleet.com/tomozu_t.htm IJN Tomozuru: Tabular Record of Movement]
{{Japanese torpedo boats in WWII}}
{{1934 shipwrecks}}
{{March 1945 shipwrecks}}
{{coord|28|25|N|124|32|E|source:kolossus-eswiki|display=title}}
{{DEFAULTSORT:Tomozuru}}
Category:Chidori-class torpedo boats
Category:Ships built by Maizuru Naval Arsenal
Category:World War II shipwrecks in the Philippine Sea
Category:World War II naval ships of Japan
Category:Ships sunk by US aircraft
Category:Torpedo boats sunk by aircraft
Category:Maritime incidents in 1934