Chidori-class Torpedo Boat

The was an Imperial Japanese Navy class of torpedo boats that were built before and served during the Second World War. The design initially proved to have too much armament for its small displacement, and the capsizing of shortly after completion in heavy weather resulted in a scandal which called into question the basic design of many Japanese warships of the time. After extensive modification, the class became satisfactory sea-boats and saw service in the Battle of the Philippines and the Dutch East Indies campaign as escorts and continued in that role for the rest of the war. Three were sunk during the war and the fourth was seized by the British at Hong Kong after the end of the war, where it was scrapped later.

Background

Per the terms of the 1930 London Naval Treaty, the Imperial Japanese Navy was constricted on the total tonnage of destroyers it was allowed to construct. In response, Japanese naval planners designed a 600-ton class vessel (which was small enough not to be limited by the treaty), but planned to arm it with half the armament of a destroyer. The new vessels were designated "torpedo boats" to further ensure that they would not be considered as "destroyers". Four vessels were ordered as part of the 1931 Maru 1 Programme, out of a planned twenty.

Description

As initially completed the ''Chidori''-class torpedo vessels displaced at standard load, but displaced at full load. They were long overall, had a beam and an average draft of .Whitley, p. 208 Two Kampon geared turbines drove two shafts. They were powered by two Kampon water-tube boilers and produced a total of . They were rated at and had a range of at or at using the of fuel carried.

The ''Chidori''-class were exceedingly heavily armed for their size. The main battery consisted of three Type 3 guns mounted in a single-gun power-driven gun turret placed on the forecastle, ahead of the bridge, and a power-driven twin-gun turret aft. Sources are contradictory on her anti-aircraft armament, Whitley says that they had a single license-built Vickers 40 mm (2 pounder pom pom) and others credit them with a single machine gun. Two sets of twin torpedo launchers were mounted abaft the single funnel. In total these weapons represented 22.7% of the displacement. One Type 94 depth charge launcher was also carried.

After the lead vessel ''Chidori'' was completed, it was discovered during trials that her center of gravity was too high and that she was overweight. To compensate, bulges fitted to the rest of the class. However, this proved to be insufficient. The ''Tomozuru'' Incident of March 12, 1934, resulted in an extensive redesign in which the Type 3 guns were replaced by smaller single 12 cm/45 3rd Year Type naval guns and one of the twin torpedo launchers was removed. An additional 100 tons of ballast also helped lower the center-of-gravity, but also meant the top speed was reduced to 28 knots.

In 1944, the rear gun was removed and replaced with a twin-mount ''Type 96'' 25mm AA gun. Another twin-mount was located in front of the bridge and six single-mounts were added in various locations. The number of depth charges carried was also increased over the course of the war to 48.Whitley, p. 209

The ''Tomozuru'' Incident

On 12 March 1934, shortly after completion, sailed in company with her sister and the light cruiser for night torpedo training. The weather worsened during the exercise and it was called off at 0325; the ships returning to port. ''Tomozuru'' never arrived and a search was launched. She was spotted at 1405 that same day, capsized and inverted, but still afloat. Thirteen of her 113-man crew were rescued. She was towed to Sasebo and docked, where she was rebuilt and returned to service.

Consequences

This disaster forced the Imperial Japanese Navy to review the stability of every ship recently completed, under construction or still being designed. The ''Chidori-class was forced to reduce its armament load and the bridge structure was cut down by one level. The bulges were removed, but displacement increased to with the addition of ballast. Their speed dropped to and range decreased to at . The remaining 16 vessels planned for the class were cancelled, and replaced by the torpedo boats, which were redesigned to reduce the top-heaviness that caused ''Tomozuru'' to capsize.

Service

In 1937, the four sisters were organized into ''Torpedo Flotilla 21'' and made a sortie for the Battle of Shanghai. All four saw action in the Battle of the Philippines and the Dutch East Indies campaign. ''Chidori'' and ''Manazuru'' returned to home waters after ''Torpedo Flotilla 21'' was disbanded in the spring of 1942 and were on escort duties for the rest of the war. ''Hatsukari'' and ''Tomozuru'' remained in that area for most of the rest of the war on escort operations. ''Tomozuru'' returned to Japan late in the war, but ''Hatsukari'' entered Hong Kong on 21 May 1945 and was engaged in anti-aircraft battles until the end of war. Following Japan's surrender, the ''Hatsukari'' was seized by the Royal Navy, and later scrapped.

Ships in class

Notes

Books

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*'', History of Pacific War Vol.62 Ships of The Imperial Japanese Forces'', Gakken (Japan), January 2008,
*''Collection of writings by Sizuo Fukui Vol.5, Stories of Japanese Destroyers'', Kōjinsha (Japan) 1993,
*''Collection of writings by Sizuo Fukui Vol.10, Stories of Japanese Support Vessels'', Kōjinsha (Japan), December 1993,
*''Model Art Extra No.340, Drawings of Imperial Japanese Naval Vessels Part-1'', Model Art Co. Ltd. (Japan), October 1989
*''Model Art Ship Modelling Special No.25, Genealogy of Japanese Destroyers Part-2'', Model Art Co. Ltd. (Japan), August 2007
*''The Maru Special, Japanese Naval Vessels No.39 Japanese torpedo boats'', Ushio Shobō (Japan), May 1980
*''The Maru Special, War ship mechanism 4, Japanese destroyers'', Ushio Shobō (Japan), November 1982

External links

{{WWII Japanese ships

Torpedo boat classes