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Editor’s Note: The following is a letter written in 1984 by Dr. Paine to CDR Compton-Hall of the British Submarine
Museum. Both were experienced World War II submariners and both men were well known to the submarine community during the Cold War. While still on active duty in the Royal Navy, Richard Compton-Hall served in New London with the Development Group. In retirement he wrote a number of submarine-related books, contributed frequently to these pages, and spoke to the League’s Annual Symposium.

Dr. Paine also kepi up his interest in submarine matters through a distinguished technical career during which he
directed a major laboratory, headed NASA. and served as President of Northrop. Part of his continuing interest involved collecting books about submarining and after Iris death in the 1990s his library of over three thousand volumes was given to the Naval Academy’s Nimitz Library as one of its special collections. In addition, he put together a Submarine Registrv which listed every submarine built anywhere up to J 992, and included an annotated bibliography of about eight thousand books and articles about submarines.
A note from RADM Joe Vasey, USN(Ret) about Tom Paine and how his letter to Richard Compton-Hall came to be in the
Submarine Archives:
I am the one who gave a copy of Tom Paine’s letter with material on the 1-400 to the Bowfin museum in the mid-1980s. We were good friends with a mutual interest in submarines and both WW2 SubVets.
Tom Paine served as Board Chairman of Pacific Forum 83-87, a non-profit foreign policy institute I founded in the
70’s to focus on US-Asian relations. All the while, he was President of Northrop Aircraft Corporation.

On a couple of my visits to his Northrop office on Wilshire Blvd. He showed me his Submarine Warfare Library maintained in a large adjacent room as a separate entity and not involved with Northrop. There he pursued his fascinating hobby during rest periods and at the end of the day. He was proud of his invaluable collection and with good reason. It contained a wealth of material on submarining and submarines worldwide. The 1-400 project is typical. I don’t think there is anything comparable anywhere else.
At that time I don’t believe the collection was nearly as large as the final one, but obviously growing.
In 1984 he sent me a copy of his illuminating letter to Compton-Hall and later I gave it to the Bowfin Submarine
Museum requesting it be maintained as a WW2 historical item.
Commander Richard Compton-Hall MBE, RN, (Ret)
Director – the Submarine Museum
HMS Dolphin
Gosport, Hampshire, U.K.
Dear Commander Compton-Hall:
Here is the material I’ve been able to assemble for you on Japan’s secret SENSUIKAN TOKU (Special Submarine) aircraft carriers. I’m delighted that you’re writing about these undersea giants, and only wish I had more to send you.
In many ways HUMS 1-400 was decades ahead of her time, with a range of 37,500 miles at 14 knots, snorkel, radar detectors, and a 115 foot long, 12 foot diameter hangar opening onto an 85 foot long catapult. Like Germany’s Type XXI U-boat she was too late to influence World War II, but the advent of the atomic bomb and guided missile transformed her overnight from an ineffective curiosity to a major strategic threat. A 400 foot long, 3530 ton
monster of a boat, the 1-400 could have stowed several of your XCraft below as cargo, but as Executive Officer of her U.S. Navy prize crew I grew fond of her ponderous ways.

Not knowing what material you already have or exactly what kind of book you ‘rewriting, I’m not sure what information would be most useful to you. The U.S. Navy was still under security wraps in 1945, and the Japanese deep sixed their papers before surrendering, so I don’t have any unpublished photos, diagrams or technical manuals
from my own records to send you. At the risk of telling you more than you want to know, and duplicating information you already have, I’ll try to give you a feeling for these remarkable submarines, an account of how I became a Japanese submarine officer, and a narrative of the I-400’s transpacific voyage from Sasebo to Pearl Harbor. I’ll throw in extra material because I’ve always wanted to write a journal recording my experiences in the Occupation of Japan; anything you don’t need can be filed in your museum archives for future researchers.


There was a unique asymmetrical cross section of the 1-400 class, with the bridge and conning tower offset seven feet to port of the centerline and the hangar offset two feet to starboard. A Japanese quartermaster told me that because of this he had to use a seven degree starboard helm to steer a straight course at periscope depth, resulting in a larger submerged turning circle to starboard than to port. A flooded conning tower would have posed an interesting stability problem, requiring quick lateral compensation by blowing a port tank.
The long vertical trunk outside the hangar from the conning tower down to the control room is another noteworthy design feature. With a diving time of 56 seconds, spectacular action followed “Clear the Bridge!” as the lookouts dropped into the conning tower and then hurtled 25 feet down this tube to man their diving stations in the control room below. To cushion the landing impact a three foot thick canvas hassock was positioned at the foot of the ladder. This was so filthy that we finally heaved it overboard. Afterwards an unfortunate Japanese sailor who hadn’t got the word dropped down from the conning tower and struck the steel deck with a mighty crash. Although he must have been in great distress, he staggered off without a sign … no weakness would be shown in front of the
The I-400’s four 1900 horsepower diesels drove two propellor shafts through Vulcan hydraulic couplings, with a 1200 horsepower electric motor on each shaft. These gave her a top speed of 18. 7 /6.5 knots. Her athwartships twin pressure hulls did not extend the entire length of the boat. The crew compartment aft reverted to conventional single pressure hull/double hull design, while forward the twin torpedo rooms were stacked vertically, with four 21″ tubes and ten torpedoes in each. This arrangement permitted a reasonably fair external hull shape with good stability on the surface and a reasonable draft of 23 feet. The test depth of the pressure hull was 328 feet (80% of her 400 foot length).
Below the hangar in the starboard hull was a special compartment well equipped for aircraft engine overhaul and test, and a magazine to stow four aircraft torpedoes and fifteen bombs to arm her three M6A l Seiran (Mountain Haze) twin float planes. These planes were 35 feet long with a wingspread of 40 feet and could be flown without floats on missions where they were to be expended. Manufactured by Aichi Kokuki K. K., they were stowed aboard with floats detached and wings and tail folded. A SEIRAN could be rigged for flight by a trained team of skilled technicians in as short a time as seven minutes. The magazine also stored ammunition for the 5.5” 50 Caliber deck gun, the bridge 25mm A/A gun and the three triple 25mrn Antiaircraft mounts atop the hangar, which also had ready use ammunition lockers on deck.
The I-400’s round-the-world cruising range made possible air raids with three bombers against targets as distant as San Francisco, Panama, Washington or New York, and all of these missions were considered. Accommodations for a crew of 145 were designed into the big hulls, but her wartime complement was nearly 200, and a Japanese officer told me that they’d actually carried as many as 220 men to facilitate rapid submarine and aviation operations at sea. This
made it possible to unstow, assemble, arm and catapult all three aircraft within 45 minutes after surfacing. Meals for this big crew were prepared in a galley in the starboard hull where great steam kettles turned out huge quantities of rice. A four month supply of food was stowed in every cranny (as in all submarines), including a
layer of crates laid out on the decks which the crew walked on until they’d eaten their way through. Supernumeraries slept on the decks (as you and I have done); they were accustomed to a deck and tatami
mat. The oriental style heads were just holes in the decks above
sanitary tanks … one did not linger there.

You would have recognized most of the fittings and general layouts of the torpedo rooms, engine rooms, motor rooms, auxiliary machinery compartments, control room, battery compartments, conning tower, and bridge. These and the tankage, piping and electrical systems followed fairly standard submarine practice, so it didn’t take us long to master the boat despite the lack of plans and manuals. With much gesticulating, sketching and exchanges of
broken Japanese and English we and the Japanese petty officers traced every system and operated all of the gear, tying descriptive tags on critical valves and switches until we got to know them. For a while the interior looked like an inside-out Christmas Tree festooned with dangling paper ornaments. I still remember some of the Japanese submarine terminology: Barasuto Tanku “” Ballast Tank, Gyorai = Torpedo, Hatsudenki To .,. Electric Light, Benjo =
Head, Sembokyo (imde1water looking mirror) a: Periscope. Actually the feature that I found hardest to adjust to was the very existence of the two Siamese-Twin pressure hulls and giant hangar compartment. When you walked aft through the port hull your experience told you that you were inspecting an entire submarineyou passed through a torpedo room with four tubes, chiefs’ quarters, radio shack, capacious wardroom (beautifully fitted with fine wooden cabinet work, a shrine and comfortable staterooms), large control room with conning tower trunk in the overhead, engine room with two 1900 HP diesel engines, motor room with a 1200 HP electric motor, and crew compartment with raised wooden decks varnished like a dance floor (you removed your shoes before walking
there). You had to remind yourself that welded to the large submarine you’d just inspected were two other big hulls. You’d only checked a third of your boat- and had better keep going because every compartment in all three hulls required manning, rigging for sea, maintenance, etc. I kept a particularly wary eye on the enormous hydraulic door opening into the hangar; you can imagine the devastating effect of a loss of buoyancy and a 115 foot long free
water surface so high above her metacenter (shades of HMS M-2).

Abaft the periscope shears is the rather crude snorkel fitted as an afterthought with its exhaust piping branching over the hangar to reach the starboard hull engine room. The horn-shaped surface search radar is forward of this. The very large pressure proof binoculars in massive mounts port and starboard at the forward end of the bridge reflected the inadequate perfonnance of Japanese radar.
The submarine had a hydraulic deck valve that opened and shut our big hangar door. We enjoyed majestically swinging open this rumbling portal to expose our cavernous hangar to astonished visitors, or raising, operating and lowering our massive seaplane crane (to impress VIPs we fired our pneumatic catapult).


Commander Mochitsura Hashimoto, IJN (1-58), and Captain Zenji Orita, IJN (J-47), have written valuable commentaries on the development, training and operation of the 1-400 class boats from the perspective of contemporary Japanese submarine commanders. An interesting recent reference is Richard O’Neill’ s Suicide Squads: W.
, 299 p., illust., St. Martin’s Press, New York 1981. These references describe the organization of the giant boats into Sub Ron 1, a special ten-aircraft strike force:
Submarine Squadron One – Captain Tatsunoke Ariizumi, IJN

  • HJJMS 1-13 (2 Bombers) -Commander Ohashi, IJN
  • HUMS 1-14 (2 Bombers) – Commander Shimizu, IJN
  • HUMS 1-400 (3 Bombers) – Commander Utsunosuke Kusaka, I.JN
  • HJJMS 1-401 (3 Bombers) – Commander Shinsei Nambu, IJN

SubRon I commenced training in early 1945 for a bomb and torpedo strike against the Panama Canal’s vital Gatun Locks. Each of the 1-400 class submarines required 1600 tons of fuel for the 17,000 mile round trip to Panama, which was more than the total then available at Kure. The 1-401 was therefore dispatched to Dairen, Manchuria, in mid May to bring back the needed oil, but she was damaged by a mine and forced to return. The 1-400 made the trip
instead, after which all four boats, newly equipped with snorkels and false funnels for disguise, moved north through the Sea of Japan to the Ominato Naval Base at the northern tip of Honshu. There they were still hampered by B-29 laid mines, U.S. submarines penetrating their training areas, and shortages of fuel, material and aircraft, but they nevertheless managed to launch their bombers for simulated attacks on a full scale model of the Gatun Locks erected at Toyama Bay.
While SubRon 1 was training at Ominato the position of the Japanese Navy was steadily deteriorating. By June, 1945, there were more than 3000 American warships and transports already in the Pacific preparing to invade Japan, so the distant raid on Panama began to appear a questionable diversion. Despite Captain Ariizumi’s violent disagreement he was ordered to abandon his carefully rehearsed attack on Panama and strike instead the American task forces at Ulithi Atoll. Captain Orita relates how Sixth Fleet staff in Tokyo told the protesting ComSubRon I “A man does not
worry about a fire he sees on the horizon when other flames are licking at his kimono sleeve!” Sixth Fleet staff planned to coordinate the air strike with a suicide torpedo attack by Kaiten carrying
submarines. The 1-13 departed Ominato on 5 July and sortied through Tsugaru Strait into the Paci fie. I-14 left next, followed on the 15th by the 1-400 and the I-40 l sailing on separate tracks far to the east for a rendezvous at sea southeast of Ulithi. The 1-14 docked at Truk on 4 August to unload two long range Ayagumo scout aircraft for a reconnaissance flight over Ulithi in preparation for the air strike by the 1-400 and 1-401 planned for 17-25 August.
Bypassed Truk had become a practice bombing range for new USAAF B-29 crews flying from Guam, and as a result no long range reconnaissance aircraft were still intact there, although a few other planes were operational. (I speak from personal experience, having been Officer of the Deck of USS POMPON (SS267) on lifeguard station off Truk on 5 July when a circling plane we thought friendly suddenly dove at us; the orange meat balls on her wings convinced us we’d better eat our breakfast down at 150 feet).
Commander Hashimoto reports that Captain Ariizumi still hoped to strike the Panama Canal if he could recover his planes after a dawn raid on Ulithi, but other sources say a Kamikaze strike was intended. Suddenly on August 6’b the Atomic Bomb devastated Hiroshima, followed on the IS’b by the Emperior’s dramatic radio address accepting defeat. With the combat careers of his giant submarines over before they’d begun, ComSubRon 1 reluctantly carried out his new orders to cease hostilities, hoist the black flag and return on the surface to his home port in northern Honshu.
Admiral Lockwood recounts the interception and surrender of the giant boats east of Honshu on 28 August, and the American Navy’s astonishment at their size. His statement accurately reflects our feelings at the time, including elation that the war had finally been won and rage and disgust over the enemy’s ill treatment of the pitifully few survivors from our lost submarines. I was one of the officers at Guam detailed by Admiral Lockwood to meet and
interrogate released submarine P.O.W.s as they were flown down from Japan. We needed to prepare quickly a complete muster list of the known survivors from all of our lost submarines to ensure that we recovered every prisoner still alive. We also wanted to establish how each boat had been sunk – many were simply “Long Overdue
and Presumed Lost.”
It was a sobering experience. Many of my friends and former shipmates were missing in action, and I was grieved to find none among the human wreckage we recovered. We directed the Japanese Naval Staff to prepare a list specifying the time, place and circumstances of every U.S. submarine sunk by Japanese ASW forces during the war, but the hand written document proved of little use since it described some 500 confirmed sinking’s against our loss
of 52 boats. (I did note with satisfaction my certain destruction on at least three occasions following some rude act by USS POMPON.)
After the 1-400 struck her colors to Commander Hiram Casserly, USN he became her first Prize Crew Captain. I’d known Hi as skipper of the old SEARA VEN (SS-196), and considered him quite a character. Although never fortunate in tonnage sunk, he’d rescued 31 RAAF personnel from Timor in a bold two-night operation in 1942, and picked up a record 31 U.S. airmen from the sea off Honshu in 1945 in the new Tigrone (SS-419). He didn’t last long as the I-400’s skipper, running afoul of Admiral Halsey for disregarding orders about taking swords as souvenirs. Hi thus became the first U.S. naval officer to be relieved of command of a Japanese submarine. I remember him for another first though: when he died his ashes were placed in a canvas covered metal box which was fired from a forward torpedo tube of USS BARRACUDA (SSK l) in deep water off Key West…a unique submarine Viking funeral.
Admiral Lockwood recounts the saga of the recalcitrant Japanese Squadron Commander who shot himself rather than surrender; this was the above mentioned ComSubRon I, Captain Tatsunoke Ariizumi. Neither Admiral Lockwood nor the Japanese authors mention that as Commander of the J-8 operating out of Panang in the Indian Ocean on 26 March, 1944, Captain Ariizumi had methodically collected from the water and then massacred 98 unarmed survivors of the big Dutch merchantman TJISALAK he’d sunk south of Colombo. He was repeating this brutal performance with 96 bound prisoners from the American JEAN NICOLET in the Maldives on 2 July when he was forced to dive, leaving 35 survivors
on deck, 23 of whom managed to untie themselves and swim until rescued next day. These atrocities may have contributed to Captain Ariizumi’s decision to commit suicide as his squadron was being escorted by U.S. Naval vessels to Yokosuka.


I’d joined the Naval Reserve with a brand new engineering degree in 1942 and after 90 Day Wonder midshipman training at Annapolis had been commissioned Ensign. I volunteered for The Silent Service because I’d always been fascinated by submarines. My father, the late Commodore George T. Paine OBE, USN, was an M. l.T. naval architect who specialized in the design and construction of submarines and destroyers. Boyhood memories of being allowed to peer through the periscopes of S-Boats and V-Boats sold me on subs- that’s what the big guys did. My father had begun his naval career doing the deep submergence testing of the World War One RB oats built in San Francisco, so it seemed appropriate that my first submarine was the USS R-14 (SS 91). (Appropriate to me, not to him – he thought it foolhardy to dive those old rust buckets!)
The R-14 was then performing Clockwork Mouse duties for the Fleet ASW School at Key West, Florida. As you know, diving and surfacing all day long to give sonar operators experience in submarine detection provides ideal training for Makee Learn submarine officers. When we weren’t operating rusty kingston valves or starting balky air injection diesels we were putting the low pressure pump on the main drain and practicing surfaced and submerged ship handling. We learned the boat by tracing and drawing all of the piping and electrical lines, hull openings, duct keel and other mysteries of R boat design. In early 1943 this was repeated at the Submarine School at New London, and repeated again after graduation when I was ordered to the fleet submarine USS POMPON as Radar and Assistant Engineering Officer. I reported aboard her at the principal U.S. Submarine Base in the Southwest Pacific,
which consisted of the submarine tender PELIAS (AS 17), a converted merchantman moored to North Wharf in Fremantle,
Western Australia. Quickly learning our way around the Japanese submarines we took over in 1945 was thus standard operating procedure.
As the war drew to a close in July, 1945, I was Engineering and Diving Officer of the POMPON refitting at Guam after my seventh war patrol. We didn’t realize that the war was almost over; our hopeful slogan was The Golden Gate in ’48. I did note, though, that Japanese shipping had been almost completely driven from the seas, and the B-29 raids had become such milk nms that ComSubPac had to issue a stern letter forbidding submariners from hitching
sightseeing rides on the night raiders. I was impressed every evening when our Marianas Armed Forces Radio Station switched from English to Japanese for fifteen minutes to broadcast a warning to Japanese civilians to flee the next cities marked for destruction by fire bombs. While a voice of doom slowly read the list of specific cities targeted for tonight I could hear outside the roar of B-29 engines as the long stream of heavily laden bombers rose into the
night. This broadcast was not an act of humanity- there is no humanity in setting cities aflame- but a contemptuous display of America’s overwhelming air/sea power. As powerful propaganda it
surely beat Tokyo Rose.
Suddenly within an eventful eight days, dread mushroom clouds rose over Hiroshima and Nagasaki, Russia declared war on Japan, and the Emperor’s own voice told his stunned subjects that Japan was defeated and hostilities must cease. When the shouting died away I was transferred to the submarine tender USS EURY ALE (AS 22) for intensive training in the Japanese language as the U.S. Navy prepared to demilitarize the Japanese Submarine Force.

I had a large lump in my throat when I waved goodbye to the homeward bound POMPON as she backed out from the nest of boats alongside the tender, sounding a prolonged blast on her whistle and streaming a long commissioning pennant held aloft by balloons. I wasn’t sure she could dive safely without me, but I wasn’t ready to head back to the states yet because I was detennined to marry and carry home with me the smashing WAAAF I’d fallen for in Perth. I wanted to head south, not east, and north at least kept me on the right longitude. On 16 September EURY ALE set sail for Kyushu via Okinawa. On arrival we took care to enter Sasebo Harbor with all watertight doors dogged shut steaming in the wake of our escorting minesweeper right down the middle of the swept channel. The burnt out city and oily harbor littered with wrecked naval vessels was an unforgettable sight, underscoring the tragedy of World War II for Japan.
I landed at the naval base in the first boat with orders to seize samples of every model of Japanese torpedo, complete with chests of spare parts and special tools for each. We had learned to respect Japanese torpedoes, which substantially outperfonned our own. Of course our first hours in Japan were very tense- no one really knew
what to expect, and we were fully prepared to deal with kamikaze resistance from diehard fanatics. One patrol boat crew threatened trouble, but this was decisively handled by the Japanese, and everyone on both sides was relieved when an orderly local surrender took place. I soon found myself with a Japanese officer’s sword and a detail of Japanese naval personnel to help me assemble my collection of torpedoes and ordnance equipment.

Since your interest is in their submarines, I’ll just say that after many days sloshing through the mud in dark, dripping caves piled high with rusting gear I did find all of the requested ordnance specimens for shipment back to the states. Do you remember the large Japanese torpedoes on display at the Submarine School when you were in New London? They were part of my collection. A point that may interest you is the procedure the Japanese torpedo officer used to bleed the pure oxygen charge from an oil-coated midsection of a Long Lance torpedo. I didn’t see how this could be done safely in view of the obvious fire and explosion hazard of oil and oxygen, but it proved to be simple. The torpedo was carted to the middle of an open field where a junior rating was handed a spanner with
instructions to open the oxygen valve after the rest of us had retreated to a safe distance. In response to a shouted order he spun open the valve and darted to safety as high pressure oxygen whistled out around the greasy torpedo-no explosion- no casualties- that time. Of course it was far safer to go into combat armed with the mighty Japanese oxygen torpedo than with our Bureau of Ordnance’s poorly designed, inadequately tested Mark 14 (which sank at least two of our own submarines).
My torpedo collecting was just a sideline to our primary mission, which was to locate and disarm the Japanese submarine fleet, interrogate the crews, study the material and, when ordered, scuttle the boats. The duty of Boarding Officer was rotated, and I happened to be on watch when the giant 1-402 appeared offSasebo from Kure requesting clearance to enter harbor in accordance with U.S. Navy orders. She was told to heave to, and a group of us shoved off to board her in a whaleboat. Our armed detail included an interpreter, ChiefTorpedoman, Gunners Mate, Signalman, and Radioman. This was my first experience aboard an 1-400 class submarine, and I recall my mixed emotions as we pulled alongside her towering hull and clambered up her superstructure over the degaussing gear and onto her foredeck. I was excited to be carrying out a Boarders Away! operation, wary of the impassive Japanese who stiffly greeted us, curious about the unfamiliar aircraft handling equipment all around us, delighted to be directly involved in this historic finale of the undersea war, and concerned about both the technical and human problems involved in carrying out our orders to disable her torpedo, ordnance and radio gear before bringing her in.
That’s a lot of excitement for a notoriously phlegmatic submariner, but you must bear in mind that I was only 23 years old. Joseph
Conrad’s Youth captures my emotions perfectly:

“And then I saw the men of the east – they were looking at me …. I have known its fascination since; I have seen the mysterious shores, the still water, the lands of brown nations, where a stealthy nemesis lies in wait, pursues, overtakes so many oft he conquering race. who are proud of their wisdom, of their knowledge, of their strength. But for me all the East is contained in that vision of my youth. It is all in that moment when I opened my young eyes 0n it. I came upon it from a tussle with the sea – and I was young – and I saw it looking at me …. Ah! The good ole time – the good old time. Youth and the sea. Glamour and the sea!”

A stiffly fonnal Japanese officer conducted us aft alongside the catapult, up the port ladder to the top of the hangar, aft and up onto the bridge, whose bizarre offset position distracted me. I exchanged proper salutes and introductions with the Captain, stating slowly in what I hoped was impeccable Japanese: “Watakushi wa Beikoku no Kaigun no Sensuikan shoko, Painu Tai, des!” He looked blank and unhappy, and mumbled something in reply which neither I nor our interpreter caught. Eventually we made ourselves understood, though, and arranged for his petty officers to conduct our specialists to the designated compartments, with our interpreter to facilitate communications and report back. This left me surrounded by the non-English speaking officers and bridge watch, who clearly didn’t realize that I was speaking Japanese. This was somewhat disheartening after all those studious hours aboard EURY ALE, but I just raised my voice and plunged on.

The l-402’s navigator kept insistently repeating something like Hobby Sea Toy, which I struggled to link to some English or Japanese nautical phrase. Then it came to me: “Haben Sie deutsch?” -he must have made one of those Penang to Germany I-boat voyages. “Ja, Ja, Herr Leutnant, aber mein deutsch ist nicht sehr gut! Kanne Sie mein Nihon verstehen, bitte? Anata wa Watakushi no Nihon wakarimaska?” I asked hopefully. “Ah, so! Sehr gut, sehr gut!”, he replied with a bow, telling me nothing, but conveying to everyone else on the bridge the impression that two great linguists had established communication.

Fortunately word was soon passed up that all was secure below, and we managed to muster enough fractured Japanese/English/Gennan among us to bring her safely in to her moorings. Later, when I’d gotten to know the Japanese officers better, I learned that part of our problem was that our interpreter instructors had been taught by elderly Japanese-American ladies who spoke only old fashioned, very honorific Japanese. Thus, instead of barking out orders in proper quarterdeck style I’d been most respectfully and politely requesting. The puzzled Japanese must have thought that we were a boarding party from HMS PINAFORE under instructions from Sir Joseph Porter, KCB:
“For I hold that on the seas.
The expression ‘If you please’,
A particularly gentlemanly tone implants,
And so do his sisters and his cousins and his aunts … ”
Although Sasebo was our home port, the EURYALE (fondly known as Urinal Mant to her crew) also sailed around Kyushu and up through the Inland Sea to Kure to pick up a number of surviving boats there. All of the mines in the harbor had not yet been swept, but Hiro Wan was clear so we anchored well out from the burned out Navy Yard and put our ship’s boats in the water to ferry our boarding parties to the Japanese submarines moored around the harbor. I remember that first boat trip on a sunny autumn afternoon past picturesque pine clad islands right out of a Hiroshige print – except for the blackened hulks of burned out warships canted at rakish angles littering the oily shores. Rounding the awash deck of the wrecked battleship HARUN we drew alongside the anchored HUMS 1-58, a large Kaiten carrier with six suicide torpedo launching racks visible on her decks.
The deck watch announced our approach and tended our lines as a group of officers clambered out of her hatches and lined up on deck to meet us. Because our scarce interpreters were assigned elsewhere, I climbed aboard the 1-58 with only a non-Japanese speaking fellow submariner and a naval intelligence officer, hoping we’d find someone aboard who spoke better English than my halting Japanese. We were in luck as the Commanding Officer introduced himself in highly accented but understandable English as Commander Mochitsura Hashimoto, IJN. He invited us to accompany him below to conduct our business, and led us down the forward torpedo room hatch and aft through a bulkhead into the wardroom.There we sat down across the wardroom table from Commander Hashimoto and several of his officers; on the table Jay his sword.

That dramatic scene in the 1-58 wardroom from 39 years ago is very clear in my mind’s eye today. Since I don’t want to spin this yam out beyond your interest, or stray too far from your topic of giant submarines, I’ll just recount the high spots of this first U.S. Navy contact with the I-58. After I refused to accept his proffered sword, explaining that I had come aboard specifically to issue disarmament instructions and to learn about the J-58’s operational career, he said proudly that of course he’d been expecting us since “This is the submarine that sank the U.S. navy warship that carried the atomic bomb.”

We were thunderstruck at this statement, and exchanged looks of consternation- what ship was he talking about? Atomic weapon information was Ultra Secret – we had never been told which ship had transported atomic bombs. As we fired questions at him he drew out a chart for us and described precisely how he’d recently sighted, approached, attacked and sunk USS INDIANAPOLIS. He told us that he’d manned his Kai ten human torpedoes, but with a clear
moonlit night, a calm sea, a target proceeding at moderate speed without zigzagging, an advantageous position forward of her beam, and no sonar transmissions or escorts detected, he’d decided that conventional torpedoes were adequate for this elementary attack. We knew of the sinking of INDIANAPOLIS, and the tragic loss of life that ensued when a bungling staff failed to note her absence while her survivors battled exposure and sharks for days. We had no idea that INDIANAPOLIS had carried the components for the first atomic bomb to Tinian, though. How did commander Hashimoto know this? Did a P.O.W. from one of the final B-29 raids reveal it? Was there a news release we’d missed? Or could the 1-58 have picked up and interrogated an unknown survivor from INDIANOPOLIS? This still remains a mystery to me.
While we were at Kure I went over the hill to see Hiroshima. Both cities were utterly devastated, with rubble and ashes stretching as far as you could see. Once it was decided to destroy the cities I couldn’t see that it made much difference how the flames had been lit. The destruction and casualties were the same; the difference was only the number of aircraft employed- and the frightening implications for the future.

By the end of October we’d gathered together in Sasebo enough operational Japanese submarines to require some administration, so on 2 November I received Memorandum No. 4-45 from ComSubDiv 131 organizing the boats for which we were responsible into four divisions:
Japanese Submarine Division I – LCDR F. B. Tucker, USN

  • HUMS 1-158
  • HUMS 1-162
  • HUMS 1-201
  • HUMS 1-202
  • HUMS 1-203

1-158 (8 Torpedo Tubes) and 1-162 (6 Tubes) were older 1640 ton, 20 knot Kaigun Dai (large Fleet) Submarines with 4. 7 inch deck guns and test depth of 200 feet. Launched in 1927/30 as 1-58 and 1-62, they were renumbered and retired to training duty in 1942, then refitted in 1945 to launch five Kaiten torpedoes against the expected U.S. invasion fleet. The 1-201to203 Sensuikan Taka (Fast Submarines) were modem 1070 tonners designed for mass production with four torpedo tubes and 360 foot test depth. Like the German Type XXI they were true submarines with streamlined hulls, great battery capacity and 5000 HP motors that have them a top submerged speed at the one hour rate of 19 knots, enough to show a clean pair of heels to many escorts. I wanted to try one out in underwater exercises with a U.S. ASW team, and grumbled when our high command rejected this as too risky – it was hard for me to readjust to such a sensible peacetime decision.

Japanese Submarine Division 2 -Comdr. J.P. Currie, USN

  • HUMS Ha-103 Lt. Y. Murayama, IJN
  • HUMS Ha-105 Lt. T. Kiuchi, IJN
  • HIJMS Ha-106 Lt. T. Tatiyama, IJN
  • HUMS Ha-107 Lt. S. Takezaki, IJN
  • HUMS Ha-I 08 Lt. 0. Oshiro, IJN
  • HIJMS Ha-109 Lt. Kunihiro, JJN (Senior Captain)
  • HUMS Ha-111 Lt. Ono, IJN

The Ha-10 I Class Sensuikan Yu Sho (Small Supply Submarines) were simple 3 70 ton boats without torpedo tubes designed to transport aviation gasoline from Singapore to Japan or to carry 60 tons or l 03 cubic meters of cargo to bypassed garrisons within a radius of 3000 miles. The Ha-100 class was equipped with snorkel and radar. Their top speed from a single 400 HP diesel was 10 knots, submerged endurance at 2.3 knots 20 hours, test depth 300 feet,
armament one 25mm gun, and complement 21 officers and men. Later, when I got to know these officers better, they confided that their initial reaction to news of Japan’s defeat had been to sail at once on a mass suicide mission. Fortunately they’d soon simmered down and turned back.

Japanese Submarine Division 3 – Lt. Comdr. P.R. Schratz, USN

  • HUMS Ha-201
  • HUMS Ha-202
  • HUMS Ha-203
  • HUMS Ha-205
  • HUMS Ha-21 O

The Ha-201 Class Sensuikan Taka Sho (Small Fast Submarine) was a new 320 ton coastal defense boat with a test depth of 350 feet. Designed for mass production, they were armed with two torpedo tubes and had a snorkel range above 5000 miles. Their streamlined hull and 1250 HP motor gave them an underwater speed above 13 knots and great maneuverability. In skilled and determined hands they might have given our ASW force a hard time. The Sasebo Navy Yard was full of additional Ha-201 Class hull sections in various stages of completion. I wondered how I could sail one home- the ideal yacht for a retired submariner.

Japanese Submarine Division 4 – Lt. Comdr. J.D. Mason, USN

  • HUMS Ro-50
  • HUMS 1-156
  • HUMS 1-157
  • HUMS I-159
  • HUMS I-366

Ro-50 was a Kaigun Chu (Medium Navy) 960 ton, 19.7 knot submarine of 1944 vintage with an 11,000 mile radius of action, four torpedo tubes and a three inch deck gun. The 1-156, 157 and 159 were sister ships of the 1-158, but with slightly different bow shapes.

1-366 was a 1440 ton, 13 knot Type D.l Cargo Submarine built in 1944 to transport 82 tons of cargo 7500 miles. She had a 5.5 inch gun and no torpedo tubes, but with the invasion looming she was refitted in 1945 to launch five Kaiten torpedoes. We lost one of her sister ships, 1-363, to a mine while enroute to Sasebo on 29 October off my old patrol area in the Bungo Suido. With the war ended this struck me as a particularly tragic loss, yet a few weeks before I’d have worked desperately to sink her. Sanity was returning.

I list the names of the Ha-100 boat skippers in Japanese Sub Div 2 because I later became acting Division Commander- the peak of my naval career! A short boat ride each morning brought me to my nest of seven submarines, where I was greeted formally by the Commanding Officers. Since Lieutenants Murayama and Takezaki spoke some English, and my Japanese was improving with practice, our daily joint inspection proceeded smoothly. After each boat had been methodically checked the seven skippers and I sat around the wardroom table of one of the boats to resolve any problems that had arisen (an ill quartermaster, next weeks rations, a hot engine bearing, detachment orders, etc.). When business was over a warm bottle of sickly sweet orange beverage was produced (U.S. Navy regulations against alcohol were strictly enforced- for obvious reason) and informal conversation followed. Topics discussed ranged from professional naval subjects to the complexities of the game of Go.

Our extreme curiosity about each other’s submarine combat experiences quickly broke through our initial reserve, and I learned a lot about the war patrols of the boats in the harbor, emotions on launching Kaiten torpedoes, midget submarine effectiveness, hazards of supply runs (they never suspected that we were decoding their rendezvous messages), their respect for American radar and contempt for our torpedoes, etc. These discussions were essentially
verbal patrol reports in Homeric style. Even the decrepit old 1-158 had a story to tell. While patrolling 300 miles north of Singapore on 10 January, 1942, she’d sighted and fired at HMS Prince of Wales and Repulse. The torpedoes missed, but her contact report brought in the 22nd Naval Air Flotilla, which sank the two capital ships before dark, dooming Malaya. Ha-I 06 had supported a desperate long range air strike from Kanoya, at the southern tip of Kyushu, against Ulithi Atoll. Lacking sufficient range for the round trip, the bombers had ditched on the way home off Minami Daito Shima, 200 miles east of Okinawa, where Ha-106 waited to pick up the aircrews. A number of the Ha-100 boats had patrolled the Bungo Suido and served as submarine tenders for hundreds of Kairyu (SEA DRAGON) two-man midget submarines being prepared to repulse the U.S. invasion fleet. Ro-50 had had several brushes with U.S. carrier task forces, and was credited with sinking a carrier and destroyer 150 miles northeast of Lamon Bay in
the Philippines on 25 November, 1944 – but the U.S. Navy recorded no such attack. She was more successful 300 miles southeast of Surigao Strait on 10 February, 1945, when she torpedoed and sank USS LST-577.

The venerable l-157’s saga included running hard aground at 14 knots on Little Sitkin Island in the fogbound Aleutians, from which she escaped only by throwing overboard everything movable, firing all torpedoes, pumping all tanks, and breaking up and jettisoning over one hundred battery cells. 1-366 had released three Kaiten torpedoes against an American convoy 500 miles north of Palau on the evening of 11 August, 1945, and was credited with three
sinking’s, but the three explosions she’d heard had only marked the ends of the torpedo runs- and of three brave young pilots. Within a few days I was startled to note that when the Japanese officers and I discussed submarine attacks and ASW counter-measures we used the terms us and them to refer to Submarines and Surface Ships, not to Americans and Japanese. I was surprised how quickly bonds of mutual interest developed based on our shared experience in a hazardous, demanding, professional enterprise.

By mid November most of the operational Japanese submarines slated for scuttling off Goto Shima were moored in Sasebo harbor awaiting orders. It was decided that the unusual design features of the giant boats and their implications for the atomic age merited more detailed study in the United States. U.S. Navy Prize Crews were therefore ordered to prepare the 1-14, 1-400 and J-401 for a transpacific voyage to the Submarine Base, Pearl Harbor. Thus, I received orders to leave my roomy stateroom aboard EURY ALE and report to Commander J.M. McDowell USN, the Officer-in-Charge of the Prize Crew of ex-HIJMS 1-400, for duty as Executive Officer and Navigator of that vessel.


After the I-400 was taken over from the Japanese on her way home from patrol you can imagine that she required a massive cleanup from stem to stern. The field day started one night with all hands moving aboard the tender, after which cylinders of fumigating gas were opened in every compartment and the boat sealed. Next morning bushel after bushel of dead rats and cockroaches were swept up. I’d noted with some disgust on our Japanese boats the occasional rat leaping through a hatch from compartment to compartment, and hordes of scurrying roaches when a light was switched on. I had no idea that so many verminous shipmates went on patrol in these boats, though. If the 1-400 had been rigged for dive when the rats and roaches were thrown overboard the Diving Officer would have had to order Flood two hundred pounds to Auxiliary Tank from sea.

Sailing across the Pacific to Pearl Harbor(orthrough space to the moon) requires a sound plan for fitting out, manning and supplying your ship. The 1-400 had no blueprints or Machinery History describing her equipment, no crew’s Watch, Quarter & Station Bill, and no Standard Allowance lists of tools, spares and supplies. It was clear that we’d have to improvise, so we were given wide latitude by the powers that be in readying and supplying our unusual boat for her transpacific voyage. EURYALE’s workshops and stores were put at our disposal, and we were authorized to salvage any Japanese spare parts and supplies we wanted from the warehouses and caves I’d explored around the Sasebo Navy Yard.

An experienced submariner like you can imagine the results of opening a trove of untended Japanese stores to the crew of a homeward bound submarine equipped with a cavernous hangar and a 12 ton crane. Yes, the 1-400 quickly became history’s first Undersea Interisland Trader. Overnight our hangar became an armory suitable for a major gun running operation, with stacks of rifles and bayonets from a relatively dry cave I’d spotted. From Japanese uniform buttons and rating badges to rubber stamps and a sampan, down our capacious hatches they went to stock our Submarine War Surplus Store.

The prize crew which had brought the 1-400 from Yokosuka had maintained her well, and it didn’t take us long to put her in shipshape seagoing condition, with vital machinery inspected, overhauled and tested by a responsible crew member. Since we had no plans to dive the boat before a complete overhaul at Pearl Harbor we didn’t worry about an inoperative snorkel, stiff diving gear or minor defects like leaky hatch gaskets. By the end of November we were able to report the I-400 in all respects ready for sea.

Our squadron of giant I-Boats got under way for Pearl Harbor via Guam on 11 December, shepherded by the submarine rescue vessel USS GREENLET (ASR 22). She had escorted them from Sagami Wan a month before and was well equipped to support us, including deep sea towing gear- just in case. The minesweeper that escorted us to the end of the channel blinked Bon Voyage! Instead of Good Hunting!; the Pacific was again pacific.

Falling in astern of the 1-14 we made turns for an easy 12 knots on a southerly course clear of the unswept minefields west of Kyushu. We kept a sharp lookout for floating mines, but the Officer of the Deck’s main concern became precise station keeping. It seemed unnatural not to be constantly alert, meticulously sweeping the horizon for enemy mastheads or smoke, the sky for ASW aircraft, and the sea for periscopes. When I climbed up to the bridge
at twilight to get my evening star sights I felt a strong urge to douse the running lights. My unease soon passed, however as the pleasures of peacetime submarine cruising began to sink in. It was perfectly safe to be running so casually here on the surface – we owned it!

The shallow East China Sea grew choppy, and we found that the I-400’s high freeboard, broad beam, deep draft and ample bow buoyancy tank gave her a dry bridge and an easy roll and pitch. She was a comfortable boat in a seaway. Her 130 foot long gun platform atop the hangar gave us a promenade deck worthy of the Queen Mary, while our small prize crew spread out luxuriously in the spacious compartments below. For peacetime surface cruising she couldn’t be beat. As the 1-13 demonstrated, however, in combat submerged, such a huge, low speed target with a shallow test depth would not last long against a modern ASW team. Her best strategy would probably be a bold offensive against ASW vessels, taking her chances with aircraft while staying at periscope depth and rapidly firing and reloading her eight torpedo tubes. Down the throat shots are sporty, though, and you can understand why the Japanese turned next to small, fast, handy deep diving submarines.

We passed uneventfully through the Tokara Gunto, and I enjoyed the contrast with my last wartime passage against vigilant ASW patrol craft and planes equipped with radar and magnetic airborne detectors. Now the I-400’s 1700 horsepower diesels pounded steadily on, driving us southeast on the 1200 mile leg of our voyage across the Philippine Sea. Soon we were sailing through tropic seas, where we discovered a culinary failing of the 1-400: fewer fresh flying fish on deck each morning for breakfast than we’d have collected on a lower freeboard fleet submarine. Overall, though, I can report to you that our giant submarine liner proved to be a fine sea boat throughout our transpacific voyage.

The 1-400’s 23 foot draft was not so handy, though, as we led the division up the harbor toward the Submarine Base at Guam. In submarine fashion we’d taken no pilot, and I was surprised when we suddenly came upon a new pipeline from a SeaBee dredge crossing the shallow channel under our route. It was unmarked on our charts, and I grew increasingly nervous about our clearance. It was too late to take the way off our ponderous bulk, though, so we ploughed on and slipped across. I assured my skeptical skipper that I knew every inch of the muddy bottom of that harbor, having strolled around with lead shoes, canvas suit and brass helmet getting my deep sea diver’s rating there. He hissed that I’d damn well better be right, gripping the bridge coaming with white knuckles until the division commander made it also in our wake.

Our trials were quickly forgotten as we threw our heaving lines across to the tender at the Submarine Base. We were met with a tumultuous welcome-whistles blowing, bands playing and VIPs lining up to board our esoteric squadron. In the six months since the end of the war Guam had become a dull backwater as Operation Magic Carpet ferried its once great Navy and Air Force population back to the states. For the rear echelon personnel still there the arrival of our giant I-Boats flying the stars and stripes over the rising sun provided a stimulating release from their boredom and Island Fever. Visitors of all ranks swanned aboard. In the comer of your Submarine Museum is a busy souvenir stand offering everything from ash trays and emblazoned mugs to tea towels and tee shirts. In every comer of the 1-400 were Japanese artifacts liberated by our crew from the deteriorating caves of Sasebo. You trade souvenirs for money; being outside the cash economy we bartered for goods. The receding tides of war had left
Guam’s quonset huts as crammed with unneeded supplies as Sasebo’s caves, and our crew quickly opened our floating flea market for infonnal trading. I can’t give you the texts verbatim, but all over the Naval Operating Base Guam you might have heard:
“Could you use a couple of these rifles, Chief? I need two
16mm projectors and some good movies – good movies.”
“This bayonet used to belong to Tojo, Swabbie, but we’d
swap it for a new automatic Silex Coffee Maker – OK?”
“My guys won’t eat no more lousy Spam, Cookie. Now I
figure your wife and kids would like to flash this genuine
Japanese stuff around back home to show how you won the
war; we need some canned hams and prime steaks – is it a
The transformation of the 1-400 had begun.

These yarns may be historically significant when future underwater archeologists diving on the 1-400 where she lies in deep water off Hawaii wonder why every scuttlebutt was equipped with a General Electric refrigerated fountain. What was the reason for installing in her galley all of that gourmet cooking equipment (including an ice cream machine)? Why deluxe porcelain plumbing fixtures in all of the heads? Who decided to mount such crude electronic gear topside and then wire every bunk below for music from a juke box with flashing colored rights? You have the

Of course all of this cumshaw dealing was bound to lead to trouble, and it came in the form of an irate marine officer stonning on board demanding that the 1-400 return his motor scooter. Discreet inquiry pointed to the culprit being a swindling motor pool sergeant, but our Chief of the Boat reassured me “Don’t worry, Mr. Paine,
we’ll take care of that gryrene, and they won’t find any motor scooter in this boat.” That was not quite the same as saying that the motor scooter was not aboard our labyrinthine craft, but I believed him: it would never be discovered. Clearly it was time to crack down on our I-Boat bazaar, so we lowered the boom on our pirates while, in the fine tradition of your Queen Elizabeth I, enjoying the fruits of their buccaneering.

I’d hoped that the submarine command at Guam might be able to help me get back to Perth to settle my personal affairs, but with all U.S. Navy operations in Australia being terminated there wasn’t a chance. Barbara would have to come to America, and I’d better get back stateside. I was happy therefore when our now lavishly equipped and well stocked I-400 set sail from Guam with her squadron for the I 000 mile trip to Eniwetok Atoll in the Marshall Islands. Running east by south we had fine tropical weather with occasional drenching rain squalls. We took advantage of these in submarine style with a bar of soap and towel sent up to the bridge, even though the I-400’s fresh water capacity was ample to provide showers for our small crew.

Christmas Eve found us cruising through tropic seas approaching Eniwetok, relying on the GREENLET’s radar to pick up low lying atolls. Despite our superstructure’s rubberized anti-radar coating Santa Claus had no trouble detecting our little squadron, and small presents were distributed to all. The greatest gift, of course, was the one our surroundings reminded us of: a world at peace. Christmas dinner was a magnificent feast, testifying to both the culinary and bartering skills of our submarines cooks. That’s what the old hands called Shipping Over Chow, asking “Where would you get a meal like that on the beach?” When I run into an old 1-400 shipmate now we say of her fondly: “She weren’t no looker, but she were a feeder!”

Our stop in Eniwetok was short, paralleling our experience at Guam. This time, however, it was the mysterious disappearance of the Island Commander’s jeep on the eve of our departure which brought wrath down upon all hands. Our buccaneers were all innocence, and a thorough search of all three submarines and the GREENLET failed to tum up a clue. We were granted reluctant permission to sail- and told not to come back or they’d open fire on
us. I still don’t know what happened to that jeep, except that the 1-401 crew did acquire a newly-painted one in Pearl Harbor, said to have been purchased by their welfare fund.

New Year’s Eve found us steaming eastward across the International Date Line for Pearl Harbor on a course laid out to take us close to Johnson Island in case one of our boats needed repairs. Submarine tradition requires that the deck log entry for the last watch of the year be written in rhyme- is this also an RN custom? I liked Stringfellow’s deathless poetry so well that not only did I keep a copy, but I set the calendar back a day, so after entering 1946 we went back into 1945 and at midnight he had to consult his muse again.

Ploughing along on the last leg of our voyage to Pearl Harbor we began to prepare a list of the work that should be done when we arrived at the Submarine Base to put the I-400 in good condition for diving. I went over this in detail with each department to make sure we included everything essential for reasonably safe submerged operations, but nothing extra that might make it too costly to refit her. After a thorough personal inspection of the boat with our petty officers I boiled the list down to three pages containing thirty nine items.

On 6 January, 1946, our unique squadron sailed triumphantly into Pearl Harbor, dipping our American and Japanese ensigns in salute as we slowly glided by the gutted hulk of USS ARIZONA on our way up the loch to moor at the Submarine Base. We were again given a lively reception by the Submarine Force, with many senior submariners showing great interest in our unconventional boats. One division commander expressed particular interest in our Japanese navigation gear, which I proudly demonstrated for him. Then, when my back was turned, the son of a bitch walked across the gangplank carrying my beautiful sextant. I knew all submariners were pirates at heart- I paid the price for failure to stay alert. To anyone who would listen I argued the case for refitting the 1-400 for submerged operation and evaluation. I was convinced that we should find out how such a huge submarine handled submerged, how her automatic trim system worked, what lessons her Japanese naval constructors had incorporated into her design from their long experience with large submarines, and all of the other things she could teach us. Decisions had slowed to a peace time tempo, though; we were to stand by for further orders.

The time had come for me to think seriously about my own future, and it was clear that I’d already had the peak experiences of life in submarines. I’d liked to have been skipper of my own boat, but peacetime training operations would be an inevitable letdown (I didn’t foresee the nuclear submarine). I decided that the next phase of my life should be in the exciting new science and technology developments that had emerged from the war. I’m sure it was the right decision, but I made it reluctantly, and I’ll never forget my fascinating youthful experiences in the submarine navy. We were indeed the last of the corsairs.

I caught a homeward bound fleet submarine back to San Diego, enrolled for a doctoral degree at Stanford, and married my lovely W AAAF cutting our wedding cake with my Japanese sword. The giant 1-400 was taken out to sea off Hawaii and torpedoed- welt, at least the damn things worked for once.

With very best wishes for your book,
Thomas 0 . Paine
Lieutenant, USNR (Ret)
Ex-Executive Officer – Ex-HUMS I-400 Prize Crew.

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