Japanese vessels taken to Pearl for inspection, torpedoed off coast

Navy Lt. Cmdr. Allen B. "Buck" Catlin, who served in the Pacific during World War II, had a hand in the sinking of five Japanese submarines.

Catlin has to take postwar credit for the kills, which occurred off Barbers Point in 1946, but he says it had to be, without a doubt, one of the most interesting chapters of his 20-year Navy career.

The subs, including three big aircraft-carrying versions, were rounded up at the end of the war, brought to Pearl Harbor for inspection, and then sent to the deep by U.S. torpedoes.

Catlin, who's now 91, said he was in charge of sinking them all.

"That was kind of an interesting exercise to go out there," the California man said by phone. "I would take each one of them out there and then we would leave with a small boat and the American submarine would come in."

During the war, it was unusual to see a ship actually sink, said Catlin, who had been executive officer of the submarine USS Hoe in the Pacific.

"They'd see it explode, but they would never see what would happen next," Catlin said. "The most amazing thing with those I-201 and I-203 (Japanese) boats — they were thin skinners — and when the torpedo hit, after the explosion, they had just disappeared."

The United States brought back to Hawai'i the I-201 and I-203, which were designed to run at high speeds, as well as the mammoth I-400 and I-401, each of which was designed to disgorge three Aichi M6A Seiran aircraft.

The 400-foot-long subs, three times the size of an average contemporary submarine, had rails and a catapult to launch the aircraft that were stored in big watertight bays.

When the I-401 surrendered, U.S. sailors were astounded at its size. Sixty years later, the I-401 would astound again, when a crew in a Hawai'i Undersea Research Laboratory submersible discovered a section of the sub, sitting upright five stories tall, in 2,854 feet of water off Barbers Point.

The Japanese submarines never got to fulfill a mission of bombing the Panama Canal. Steve Price, a submersible technician and co-pilot with the undersea research lab, said aircraft from a smaller Japanese sub did drop incendiary bombs in Oregon.

A third aircraft-carrying sub, the 372-foot I-14, also was brought to Pearl and sunk.

The U.S. Navy boarded at least 24 Japanese submarines at war's end, but to keep the technology out of the hands of the inquisitive Soviets, most were loaded with explosives and sunk off Nagasaki.

The five brought to Pearl "were the only ones that were left after we had sunk all the rest of them," Catlin said.

The subs were sailed to Hawai'i via Guam, and Catlin, a class of 1942 Naval Academy grad, said he became division commander for all of them.

The I-201 and I-203 "were high-speed (submarines), more like ours, and those things were fast," Catlin recalled. "They had 4,500 batteries on them. A U.S. sub would have 256."

Although the I-400 and I-401 were big boats, the bunks were small, only about 5 feet 6 inches long, Catlin said. The submarines also didn't have galleys, and a lot of food was cooked in boilers.

Catlin said at the time the American Mk-4 torpedo had a magnetic exploder, which was supposed to detonate beneath a ship.

"But it was a failure, and the guys would shoot and they'd see the torpedo go under the target and it didn't go off," he said. "So they decided to use those (Japanese) submarines to fire those torpedoes and see what was wrong."

The Cabezon, Queenfish and Caiman are among the U.S. submarines credited with sinking the Japanese subs in the spring of 1946. Catlin said the subs were taken out to a spot about 20 miles south of Barbers Point, and with some modifications, the Mk-4 torpedoes worked as designed.

"The big 'I' boats, the 400 and 401, they stayed afloat for a long time," Catlin said.

Catlin retired from the Navy as a commander in 1961.

"It was an interesting episode," Catlin said of the sinkings. "All of them are somewhere south of Pearl Harbor."

Reach William Cole at wcole@honoluluadvertiser.com.