No.31-class patrol boat

Background

In 1939, the IJN was liberated from London Naval Treaty, and they built many s. On the other hand, aging of the Momi-class destroyers was serious. Their boilers were degraded due to the operating conditions present in destroyers. Some Momi-class destroyers were not able to show 30 knots speed. The Navy General Staff made the Confidential Document No. 456. It was an order to rebuild them into patrol boats - about four s and six Momi-class destroyers. The IJN chose nine Momi class and one Wakatake class. Three Momis and one Wakatake were increased, because two Minekazes were decreased.

Rebuilding

• Ten vessels were sent to dockyards for rebuilding. "Q" turret, all of torpedo tubes and one boiler were removed in 1940.
• In the second half of 1941, the IJN rebuilt them once again for war preparations. They were rebuilt to the landing craft carrier. The Y turret was moved to a place of the "Q" turret. Furthermore, a slope for was installed to their stern, and added deck house for one company of Navy Landing Force. As for the No. 31 and the No. 46, those rebuilt were not done.

Service

• 10 and 23 December 1941: Sortie for the Battle of Wake Island. (No. 32 and No. 33) (both were lost in Battle of Wake Island)
• 12 December 1941: Sortie for the invasion of Legazpi. (No. 34, No. 35 and No. 36)
• 20 December 1941: Sortie for invasion of Davao. (No. 36 and No. 37)
• 25 December 1941: Sortie for invasion of Jolo. (No. 36 and No. 37)
• 11 January 1942: Sortie for the Battle of Tarakan. (No. 36, No. 37 and No. 38)
• 11 January 1942: Sortie for the Battle of Manado. (No. 34, No. 1 and No. 2)
• 31 January 1942: Sortie for the Battle of Ambon. (No. 34 and No. 39)
• 20 February 1942: Sortie for invasion of Kupang. (No. 39, No. 1 and No. 2)
• 1 March 1942: Sortie for invasion of Surabaya. (No. 34, No. 36, No. 37, No. 38 and No. 39)
• 31 March 1942: Sortie for the Battle of Christmas Island. (No. 34 and No. 36)
• (after): The IJN which finished First Phase Operations allotted them to the convoy escort operations. Only No. 36 was survived war.

No 36 was the only one to survive the WW2.

Ships in classes

''No. 31'' class

''No. 46'' class

No. 40 to No. 45 were a space to the vessels numbers. These numbers were going to be given to all of Wakatakes.

Photos

Image:Japanese No31-class patrol boat.jpg|No. 31-class in September 1942 Image:Japanese patrol boat PB31.jpg|No. 31 on 30 March 1944 at Palau Image:Japanese patrol boats 32 and 33.jpg|No. 32 and No. 33 at Wake Island (left to right) Image:USMC-M-Wake-17.PNG|No. 33 at Wake Island Image:Japanese Patrol Boat No.39 sinking after being torpedoed on 23 April 1943.jpg|No. 39 on 23 April 1943 Image:IJN No46 patrol boat in 1940.jpg|No. 46 in 1940 at Kure Naval Arsenal

Footnotes

Bibliography

• , History of Pacific War Vol.62 Ships of the Imperial Japanese Forces, Gakken (Japan), January 2008,
• Ships of the World special issue Vol.45, Escort Vessels of the Imperial Japanese Navy, , (Japan), February 1996
• The Maru Special, Japanese Naval Vessels No.49, Japanese submarine chasers and patrol boats, (Japan), March 1981

References

1. About the time of their entering a dock, correct historical materials were not left.
2. {{nihongo. 第三十一号哨戒艇. Dai 31 Gō Shōkaitei. The same shall apply hereinafter.
3. 1 April 1940, Notice No. 72, ''Reclassified old destroyers to auxiliary boat.'' (昭和十五年四月一日 海軍大臣官房達第七十二号 ''舊驅逐艦ヲ特務艇籍ニ編入シ左ノ通命名ス'' 海軍大臣 吉田善吾), Minister's Secretariat, [[Ministry of the Navy of Japan. Ministry of the Navy]]. The same shall apply hereinafter.