The Ko-hyoteki (??? ,Ko-hyoteki?, "Type 'A' Target") class was a class of Japanese midget submarines used during World War II. They had hull numbers but no names. For simplicity, they are most often referred to by the hull number of the mother submarine. Thus, the midget carried by I-16 was known as "the I-16 midget". The midget submarine hull number began with the character "HA", but is visible only on the builder's plate inside the hull. Fifty were built. The "A Target" name was assigned as a ruse—if their design was prematurely discovered by Japan's foes, the Japanese Navy could insist that the vessels were battle practice targets. They were also called "tubes" and other slang names. The first two, Ha-1 and Ha-2, were used only in testing. They did not have conning towers, which were added to the later boats for stability underwater. Ha-19 was launched by I-24 at Pearl Harbor. Most of the other fifty are unaccounted for, although three were captured in Sydney (Australia), and others in Guam, Guadalcanal, and Kiska Island, accounting for some of the other hull numbers. The submarines were each armed with two 450 mm torpedoes in muzzle-loading tubes one above the other on the port bow. In the Pearl Harbor attack, the specially designed Type 97 torpedo was used, but problems with the oxygen flasks[clarification needed] meant that all later attacks used a different torpedo. Some have stated that a version of the Type 91 torpedo, designed for aircraft launching, was used, but other reports indicate that the Type 97 torpedo was modified to the Type 98, otherwise known as the Type 97 special. There is no definitive information that the Type 91 was used. The Type 98 was later supplanted by the Type 02 torpedo. There was also a demolition charge which it has been suggested was large enough to enable the submarine to be used as a suicide weapon, but there is no evidence that it was ever used as one. Each submarine had a crew of two men. A junior officer conned the boat while a petty officer manipulated valves and moved ballast to control trim and diving. Five of these boats participated in the Pearl Harbor attack, with at least one actually making it into the harbor. Of the five used at Pearl Harbor, HA-19 was captured where it grounded on the east side of Oahu. During World War II, HA-19 was put on tour across the United States to help sell War Bonds. Now a US National Historic Landmark, HA-19 is on exhibit at the National Museum of the Pacific War. A photograph taken from a Japanese plane during the Pearl Harbor attack appears to show a midget submarine inside the harbor firing torpedoes at Battleship Row. According to analysis conducted by the United States Naval Institute in 1999, the midget submarine may well have scored a direct hit on West Virginia. Alternatively, the submarine in the photo may be the same one which fired its torpedoes at Curtiss and Monaghan. Both of those torpedoes missed and are believed to have hit a dock at Pearl City and the shore of Ford Island. This submarine was sunk by Monaghan at 0843 7 December and later recovered and used as fill during construction of a new landside pier at the Pearl Harbor submarine base.

My Flickr account has just come up for renewal....and I have decided...that you are stuck with me for another Year. Many thanks to all those that have commented, faved or even critised my work. It seems clear to me that I have grown in skill this last year, but I have a long way to go. For those of you that have been my companions on this journey, I can only say it has been a pleasure watching your skills grow. I have had many good friends leave flickr and they shall be missed but as in life new friends come along for those who look. Enough dribble..lol. Camera: Canon EOS 400D Digital Exposure: 0.01 sec (1/100) Aperture: f/7.1 Focal Length: 105 mm ISO Speed: 1600