HOW WE LEARNED TO OPERATE I-400

Since 06-25-05

From TOM PAINE'S JOURNAL: JULY 1945 TO JANUARY 1946

Despite the absence of plans and manuals our prize crew soon produced their own working drawings of the fittings and general layouts of the I-400's torpedo rooms, engine and motor rooms, auxiliary machinery compartments, conning tower, control room, battery compartments, and bridge. This wasn't difficult, since we'd been required to familiarize ourselves with new boats to earn our submarine dolphins. Japanese submarine design, including diesels, tankage, piping and electrical systems, followed fairly standard submarine practice.

With sign language, exchanges of broken Japanese and English, and wild gesticulation our prize crew traced every system, including trim and drain, vent and blow, hull openings, electric power, communication circuits, hydraulic and pneumatic lines, steering, depth control, engine cooling and fuel oil, fresh water, hull and battery ventilation, high and low pressure air piping, torpedo tubes, and other systems. Under the critical eyes of Japanese petty officers we operated engines, motor-generators, pumps, air compressors, ventilation blowers, gyros, sonar, fathometer, radar, radios, and other equipment. We hung so many descriptive colored labels on essential valves and switches that the I-400's interior began to look like an inside-out Christmas Tree festooned with paper ornaments.

Japanese submarine terminology still sticks in my mind:

• Okii Sensuikan (Big Submarine),
• Barasuto Tanku (Ballast Tank),
• Gyorai (Torpedo),
• Hikoki (Airplane),
• Hatsudenki To (Electric Light),
• Benjo (Toilet),
• Sembokyo Periscope (in calligraphy "underwater looking mirror").

This 1945 vocabulary is not helpful today at Tokyo's Hotel Okura.

I soon felt at home in I-400, with the exception of the two "Siamese-Twin" pressure hulls and huge hangar - the giant submarine's proliferation of compartments was hard to get used to. Walking aft through the port hull my submarine experience told me that I was inspecting the whole boat. I'd duck through the hatch from a large torpedo room with four tubes into the chiefs' quarters, then through the radio shack, capacious wardroom (featuring fine wooden cabinet work, a shinto shrine, and officers' staterooms), large control room with conning tower trunk in the overhead, engine room with two 1900 HP diesels, motor room with a 1200 HP electric motor-generator, and into the aft crew compartment with raised wooden decks polished like a dance floor (you took your shoes off before walking there).

At that point I had to remind myself that I hadn't yet finished checking all compartments, that welded to the large pressure hull I'd just checked were two others, and I'd better keep going because every compartment in all three hulls required close attention. I kept a particularly wary eye on the enormous hydraulic door opening into the I-400's spacious hangar. A loss of buoyancy here, with a 115 foot long free water surface sloshing around above her metacenter, would have had a devastating effect on stability. I remembered how the Royal Navy had lost the experimental aircraft-carrying submarine H.M.S. M-2 in 1932 by flooding through her hangar door.

We liked to astonish visitors by majestically opening this rumbling portal to expose our cavernous hangar, or by raising and lowering our towering 12 ton seaplane derrick. To entertain top brass we fired our noisy pneumatic catapult. Our crew took pride in our mastery of this remarkable submarine.

TRANSPACIFIC VOYAGE OF THE I-400

After she was taken over from the Japanese on her way home from patrol you can imagine that the I-400 required a massive clean-up from stem to stern. The field day started with all hands moving aboard the U.S.S. Proteus, 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 revulsion on the Ha-boats the occasional rat leaping through a hatch from compartment to compartment, and hordes of scurrying roaches when a light was switched on, but I'd no idea that these boats carried so many verminous shipmates on patrol. If the I-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.

My friend Admiral Joe Vasey, who was "Junior" McCain's Exec on the U.S.S. Gunnel, sent me this description of the condition of the I-400 when the U.S. Navy took over.

While you were at Sasebo I was in Yokosuka with the Proteus group. When the I-400 entered Yokosuka I was detailed, along with a few marines, to accompany the squadron doctor for a medical inspection of the boat. This was quite an experience - as you so eloquently described in your report. The sub was incredibly filthy, with a layer of grease and left-over food on the decks and rats running freely in every compartment. The stench was almost unbearable, particularly near the heads where one of our party lost his breakfast as he was hovering over the sanitary tank opening.

Despite the unhygienic conditions we witnessed, the physical appearance of the crew was remarkably good. Everyone seemed to be lean and alert. I think that in the closing weeks of the war, the Japanese submarine crews realized the collapse of the Empire was imminent and morale dropped sharply. Incidentally, when we questioned the ship's officers as to the total complement, the reply was 187. By our count it was 213, I believe.

The next morning, the crew was ordered on deck and the fumigation commenced. If my memory is correct it was conducted under Joe McDowell's supervision and resulted in about a dozen gunny sacks full of dead rats.

Sailing across the Pacific to Pearl Harbor (or through space to the moon) requires a sound plan for fitting out, manning and supplying your ship. The I-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. The Euryale's workshops and stores were put at our disposal, and we were authorized to salvage any Japanese spare parts and supplies we needed from the warehouses and caves I'd explored around the Sasebo Navy Yard.

Experienced submariners 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 12 ton crane. Yes, the I-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 I-400 from Yokosuka had maintained her well, and it didn't take 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 her malfunctioning snorkel, stiff diving gear or minor defects like leaky hatch gaskets or an inoperative automatic trim system. To conserve the Euryale's supplies we loaded provisions for only 14 days to carry us through the first leg of our passage to Guam, where we'd reprovision for the rest of the voyage to Hawaii. By the end of November we were able to report the I-400 "in all respects ready for sea."

Our squadron of three giant I-Boats got under way for Pearl Harbor on 11 December, 1945, escorted by the submarine rescue vessel U.S.S. Greenlet (ASR-10). She had shepherded 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 a jaunty Bon Voyage! instead of our traditional Good Hunting! The Pacific was again pacific.

Falling in astern of the I-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 dangerous and 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 and would have had no difficulty rounding the stormy southern capes. Her 130 foot long gun platform atop the hangar gave us a promenade deck worthy of the RMS Queen Mary, while our small prize crew spread out luxuriously below in the spacious twin hulls. For peacetime surface cruising our submarine liner couldn't be beat, but as I-13 demonstrated, in combat submerged such a huge, low speed, low endurance target with a shallow test depth would not last long against a modern ASW team. Her best tactic would probably have been a bold offensive against ASW vessels, staying at periscope depth and taking her chances with aircraft while rapidly firing and reloading her eight torpedo tubes. Those "Down the throat" shots at charging escorts are sporty, though, and you can understand why the Japanese turned next to small, handy, fast, deep diving submarines.

We passed uneventfully through the Tokara Gunto, and I enjoyed the contrast with my last tense wartime passage against vigilant ASW patrol craft and planes equipped with radar and magnetic airborne detectors. Now the I-400's 1900 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 drawback of the I-400: fewer fresh flying fish on deck each morning for breakfast than we'd have collected with a fleet submarine's lower freeboard. Overall, however, I can attest that the I-400 proved to be a fine sea boat throughout our transpacific voyage.

Her 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 that muddy bottom, having slogged around down there with lead shoes, canvas suit and brass helmet getting my deep sea diver's rating. He hissed that I'd damn well better be right, gripping the bridge coaming with white knuckles until the Division Commander also made it in our wake.

My piloting worries were quickly forgotten as we threw our heaving lines across to dock at the Submarine Base. We were met with a tumultuous welcome - whistles blowing, bands playing and VIPs lining up to board our colorful squadron. In the six months since the end of the war Guam had become a dull back-water as Operation Magic Carpet ferried its once large Navy and Air Force population back to the states. For the rear echelon personnel still there the arrival of our esoteric I-Boats flying the stars and stripes over the rising sun provided a stimulating release from boredom and "Island Fever." Visitors of all ranks swarmed aboard.

In every corner of the I-400 we had Japanese artifacts "liberated" by our crew from the deteriorating caves of Sasebo. Being outside the cash economy, we exchanged our government-owned souvenirs for government-owned goods rather than for money. The receding tides of war had left the quonset huts of Guam as crammed with unneeded supplies as Sasebo's caves, and our crew quickly opened our floating flea market for informal trading. Of course I can't give you the texts verbatim, but all over the Naval Operating Base Guam you might have heard conversations along these lines:

Say, Chief, could you use these rifles? I need two 16mm projectors and some good movies - good movies.

This bayonet used to belong to Tojo, Swabbie, but I'll 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 could flash this genuine Japanese stuff around back home to show how you won the war, and we got to have canned hams and prime steaks - is it a deal?

The complete transformation of the I-400 had begun.

These yarns may be historically significant when future underwater archaeologists diving on the I-400 in deep water off Hawaii wonder why her scuttlebutts were equipped with General Electric refrigerated fountains. Why did her galley feature gourmet cooking equipment (including an ice cream machine)? Why deluxe porcelain plumbing fixtures in the heads? Why crude military electronics topside, while bunks below were wired for music from a deluxe jukebox with flashing colored lights? You have the explanation.

Of course all this "cumshaw" dealing was bound to lead to trouble, and it came in the form of an irate marine lieutenant storming on board to demand that the I-400 return his motor scooter. Discreet inquiry pointed to the real culprit being his double-dealing motor pool sergeant, but our Chief of the Boat reassured me; "Don't worry, Mr. Paine, we'll take care of that swindling gyrene, and nobody is going to find any motor scooter in this boat." That was not quite the same as saying that the lieutenant's motor scooter was not aboard our labyrinthine craft, but I believed our chief: nobody was going to find it. Clearly the time had come to crack down on our I-Boat bazaar, though, so we lowered the boom on our pirates while, in the fine tradition of Queen Elizabeth I, enjoying the fruits of their buccaneering.

I'd hoped that the submarine command at Guam might be able to help me find a way to return to Perth to marry Barbara, but with all U.S. Navy operations in Australia being terminated there wasn't a chance. She'd have to come to America, so I'd better get back stateside. I was happy therefore when our now lavishly stocked and well equipped I-400 set sail from Guam with her squadron for the next 1000-mile leg of our trip to Eniwetok Atoll in the Marshall Islands. Running east by south we enjoyed 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 was able to find our little squadron, and small presents were distributed to all hands. The greatest gift, of course, was the one our unique surroundings reminded us of: A World at Peace. Each of us had his own memories, emotions and reflections on that Christmas, 1945. Our hard-bitten captain was moved to express his feelings in this poetic Christmas Greeting he posted in the Control Room for the I-400 crew:


CHRISTMAS AT SEA, 1945

A Merry Christmas, which I know
Is better here than in Sasebo!
Next Christmas, and the ones to come
I hope all hands will spend at home.
Let's hope and pray that ne'er again
Must we spend Christmas killing men,
That peace will reign beyond our time,
No guns compete with Christmas chimes.
Let's offer thanks for where we are,
For Christmas time not spent at war,
And honor those who gave their lives,
While we head home toward our wives.

-- Commander J. M. McDowell, U.S.N.
Commanding Officer, ex-H.I.J.M.S. I-400.

For several days our large galley had been bustling with elaborate preparations for Christmas Dinner. It proved to be a magnificent feast, testifying to both the culinary and cumshaw talents of our submarine cooks. [table below] shows both sides of our menu, which I kept as a souvenir.

That's what the old hands called "Shipping-Over Chow," asking "Where would you get a meal like that on the beach?" Old I-400 shipmates still say of her: "She weren't no looker, but she were a feeder!"

Our stop in Eniwetok was short, paralleling our experience at Guam, but not brief enough to keep us out of hot water. This time it was the mysterious disappearance of the Island Commander's jeep on the eve of our departure which brought official wrath down upon the I-Boat Buccaneers. Our crew was all innocence, and a thorough search of the three submarines and the Greenlet failed to turn up a clue. We were granted reluctant permission to sail - told, in fact, to get the hell out and not come back or they'd open fire on us. I don't know what happened to that jeep, but the I-401 crew flaunted a newly-painted one in Pearl Harbor they said they'd purchased with their welfare fund (the I-400 crew thought our racy motor scooter had more class.)

Ploughing along on the last leg of our voyage I had every petty officer prepare a list of the design features in his area that he considered superior to those in U.S. fleet submarines. These included items like a recording fathometer that facilitated navigation using soundings, and a shallow depth gauge with a cross section of the ship's hull painted on the scale from the waterline to the tip of the periscopes to tell the Diving Officer at a glance how much of his superstructure was still exposed while submerging.

We prepared a list detailing the work that should be done when we arrived at the Submarine Base to put the I-400 in satisfactory shape for diving. I went over every item carefully with each department to make sure that we included everything essential for safe operation, but nothing extra that might make the Com-SubsPac staff decide that it would be too costly to refit her for diving tests. After a thorough personal inspection of the boat with our petty officers I boiled the list down to three pages containing 39 items:


WORK TO BE DONE ON I-400 (Cont'd)

Free up all bulkhead flappers and test for proper operation.

Blank off topside voice tubes.

Check packing on representative number of valves. Renew as found necessary.

Calibrate depth and sea pressure guages. Install one US type deep guage for parallel operation.

Check and repair as necessary all battery disconnect switches.

Make complete check of hydraulic system. Repair as necessary.

Check automatic trimming system and place in operation if at all possible.

Test trim system for proper operation.

Repack all shafting through hull above waterline.

Install hull opening indicator panel.

Overhaul Japanese type 7MC system. If it cannot be placed in working condition make temporary installation of American system using present wiring.

Install three grove reducers in place of present Japanese type.

Install bathythermograph.

Install pressure proof running lights.

Inspect hull for improperly sealed openings. Ship reports that several openings have insufficient welds. Weld any openings to American standards.