Some naval sub history - Interesting!!

Vorkapitan · 08-13-08, 12:55 PM

Hi mates,
Thought you might be interested in this trivia!!
More info: http://en.wikipedia.org/wiki/I-400_class_submarine

"It was seven minutes before midnight on August 28, 1945, when a large unidentified object appeared on the radar screen of USS Segundo, a Balao-class submarine on patrol south of Japan. It had been 13 days since Japan’s surrender announcement, and Segundo’s commanding officer, Lieutenant Commander S.L. Johnson, was on the lookout for remnants of Japan’s naval fleet. Segundo was 18 days out from Midway, and except for an encounter with a Japanese fishing boat, the patrol had been uneventful.
Soon after Segundo changed course to intercept the blip, Commander Johnson and his men realized they were on the trail of a Japanese submarine. After tracking the sub for more than four hours, Johnson tired of the cat-and-mouse game and radioed for it to stop, receiving a positive acknowledgement in reply. But as Segundo closed in, Johnson and his crew were literally in for a big surprise.
The vessel 1,900 yards off their bow was not your average Japanese submarine; it was I-401, flagship of the I-400 class known as Sen-Toku, or special submarines. At the time I-400s were the biggest submarines ever built, and they would remain so for nearly 20 years after the war. The sub Commander Johnson intercepted simply dwarfed Segundo.
Johnson and his men were about to discover that they’d happened upon one of the war’s most unusual and innovative weapon systems. Not only was I-401 bristling with topside weaponry, the sub was also designed to carry, launch and retrieve three Aichi M6A1 Seiran floatplane attack bombers. In other words, I-401 wasn’t just a major offensive weapon in a submarine fleet used to playing defense—it was actually the world’s first purpose-built underwater aircraft carrier.
Japan’s I-400 subs were just over 400 feet long and displaced 6,560 tons when submerged. Segundo was nearly 25 percent shorter and displaced less than half that tonnage. Remarkably, I-400s could travel 37,500 nautical miles at 14 knots while surfaced, equivalent to going 1½ times around the world without refueling, while Segundo could travel less than 12,000 nautical miles at 10 knots surfaced. I-400s carried between 157 and 200 officers, crew and passengers, compared to Segundo’s complement of 81 men.
The I-400s boasted a maximum speed of 18.75 knots surfaced, or 6.5 knots submerged. They could dive to a depth of 330 feet, shallower than most U.S. subs at the time, and had a draft of 23 feet—fairly deep but hardly surprising given the sub’s size.
Nevertheless, the I-400s were to submarines what the Yamato class was to battleships. They carried Type 95 torpedoes, a smaller version of the Type 93 Long Lance torpedoes, the most advanced used by any navy in the war. The oxygen-powered 95s traveled nearly three times farther than the American Mark 14s, carried more explosive punch, left virtually no wake and were the second fastest torpedoes built during the war (Type 93s were the fastest). They were launched from eight 21-inch forward torpedo tubes, four on each side (two upper and two lower). Unlike U.S. subs, I-400s had no aft torpedo tubes, which could prove a shortcoming in certain situations, but topside they were all business, with one 5.5-inch rear- facing deck gun, three triple-barrel 25mm anti-aircraft guns on top of the aircraft hangar and a single 25mm gun on the bridge."

08-13-08, 12:55 PM	#1
Vorkapitan Samurai Navy Join Date: May 2006 Posts: 594 Downloads: 1367 Uploads: 0	Some naval sub history - Interesting!! Hi mates, Thought you might be interested in this trivia!! More info: http://en.wikipedia.org/wiki/I-400_class_submarine "It was seven minutes before midnight on August 28, 1945, when a large unidentified object appeared on the radar screen of USS Segundo, a Balao-class submarine on patrol south of Japan. It had been 13 days since Japan’s surrender announcement, and Segundo’s commanding officer, Lieutenant Commander S.L. Johnson, was on the lookout for remnants of Japan’s naval fleet. Segundo was 18 days out from Midway, and except for an encounter with a Japanese fishing boat, the patrol had been uneventful. Soon after Segundo changed course to intercept the blip, Commander Johnson and his men realized they were on the trail of a Japanese submarine. After tracking the sub for more than four hours, Johnson tired of the cat-and-mouse game and radioed for it to stop, receiving a positive acknowledgement in reply. But as Segundo closed in, Johnson and his crew were literally in for a big surprise. The vessel 1,900 yards off their bow was not your average Japanese submarine; it was I-401, flagship of the I-400 class known as Sen-Toku, or special submarines. At the time I-400s were the biggest submarines ever built, and they would remain so for nearly 20 years after the war. The sub Commander Johnson intercepted simply dwarfed Segundo. Johnson and his men were about to discover that they’d happened upon one of the war’s most unusual and innovative weapon systems. Not only was I-401 bristling with topside weaponry, the sub was also designed to carry, launch and retrieve three Aichi M6A1 Seiran floatplane attack bombers. In other words, I-401 wasn’t just a major offensive weapon in a submarine fleet used to playing defense—it was actually the world’s first purpose-built underwater aircraft carrier. Japan’s I-400 subs were just over 400 feet long and displaced 6,560 tons when submerged. Segundo was nearly 25 percent shorter and displaced less than half that tonnage. Remarkably, I-400s could travel 37,500 nautical miles at 14 knots while surfaced, equivalent to going 1½ times around the world without refueling, while Segundo could travel less than 12,000 nautical miles at 10 knots surfaced. I-400s carried between 157 and 200 officers, crew and passengers, compared to Segundo’s complement of 81 men. The I-400s boasted a maximum speed of 18.75 knots surfaced, or 6.5 knots submerged. They could dive to a depth of 330 feet, shallower than most U.S. subs at the time, and had a draft of 23 feet—fairly deep but hardly surprising given the sub’s size. Nevertheless, the I-400s were to submarines what the Yamato class was to battleships. They carried Type 95 torpedoes, a smaller version of the Type 93 Long Lance torpedoes, the most advanced used by any navy in the war. The oxygen-powered 95s traveled nearly three times farther than the American Mark 14s, carried more explosive punch, left virtually no wake and were the second fastest torpedoes built during the war (Type 93s were the fastest). They were launched from eight 21-inch forward torpedo tubes, four on each side (two upper and two lower). Unlike U.S. subs, I-400s had no aft torpedo tubes, which could prove a shortcoming in certain situations, but topside they were all business, with one 5.5-inch rear- facing deck gun, three triple-barrel 25mm anti-aircraft guns on top of the aircraft hangar and a single 25mm gun on the bridge." __________________ __________________________________________________ ________ __________________________________________________ ________ Joe Last edited by Vorkapitan; 08-13-08 at 01:15 PM.