Airfield_under_the_sea_rs2

AIRFIELD UNDER --- THE GOOGLE VVVV
SEA Pictures at JAPAN’S SUBMERSIBLE I-400 AIRCRAFT CARRIERS
His Imperial
Japanese Majesty’s
“Sensuikan Toku”
[Special Submarines].
Designed specifically to
attack the Panama
Canal.
JAPAN’S SUBMERSIBLE I-400 AIRCRAFT CARRIERS In many ways HIJMS I-400 was decades ahead of her time. She was the world’s largest
submarine with a length of 400-ft and a surface displacement of 3,530 tons. Above her main
deck rose a 115-ft. long, 12-ft diameter, hangar housing three torpedo-bombers. These float
planes were rolled out through a massive hydraulicAirfield_under_the_sea_rs2

door onto an 85-ft pneumatic catapult, where they
were rigged for flight, fueled, armed, launched,
and after landing alongside, lifted back aboard
with a powerful hydraulic crane. The I-400 was
equipped with a snorkel, radar, radar detectors,
and capacious fuel tanks that gave her a range of
37,500 miles: One and a half times around the
world. She was armed with eight torpedo tubes, a
5.5-in 50-cal deck gun, a bridge 25mm antiaircraft
gun, and three triple 25 mm A/A mounts atop her
hangar. The advent of guided missiles and atomic
bombs transformed her from dinosaur to an
overspecialized undersea menacing strategic
threat.
The I-400 was originally designed so that it
could travel round-trip to anywhere in the world,
and it was specifically intended to destroy the U.S.
controlled Panama Canal. A fleet of 18 boats was
planned in 1942, and work on the first one was
started in 1943 at the Kure, Hiroshima arsenal. Within a year the plan was scaled back to five,
and four (I-400, I-401, I-14 and I-13) were completed.
The I-400's had
aircraft storage and
catapult for three M6A1
Seiran (Storm from a
Clear Sky) torpedobombers.
These speciallydesigned
float planes had
a length of 35-ft, a
wingspread of 40-ft, a
range of 654 miles, and a
munitions payload of
1800-lb. Additional fuel
and bombs could be
carried by jettisoning the
floats on one-way missions where the pilots and planes were to be expended.. The sleek Seiran
bombers, built by Aichi
Kokuki at Nagoya, were
stowed in the hangar
compartment with floats
detached and wings and
tails folded. Actually with
the stabilizers folded
down, and the top of the
vertical stabilizer folded
over the overall profile of
the aircraft was within the
diameter of its propellor.
A trained team could rig a
floatplane for launch with
fuel and armament in as short a time as seven minutes, in fact that trained
same trained team could prepare all three planes, and have them in the air
in under 45 minutes time. The planes were launched from a 120 foot
catapult on the deck of the giant submarine.
Accommodations for a crew of 145 were designed into the
capacious twin hulls, but on most occasions was much
higher....somewhere in the 200+ range. The reason for the high number
was to facilitate speedy submarine and aviation operations at sea. Even
though the sub could surface, the trained crew could in fact could break
out, assemble, fuel, arm, and catapult all three aircraft..........more men
was an “assurance” of that. Also the I-400's had great cruising range
which enabled them to launch her three bombers within striking distance
of targets as far from Japan as San Francisco, the Panama Canal,
Washington, or New York. All of these missions were considered by the Tokyo Naval
Strategists.
Below the hangar in the starboard twin hull was a special compartment equipped to
conduct aircraft engine overhaul and test. An adjacent magazine stored four aircraft torpedoes,
15 bombs, and gun ammunition; more shells were stored topside in pressure-proof, ready-use
lockers handy to the guns. Each of the two engine rooms housed a pair of 1900-hp diesels linked
through Vulcan hydraulic couplings to drive the twin propeller shafts.
A 1200-hp electric motorgenerator
on each shaft drew
electricity form her storage batteries
to drive her submerged. With a clean
bottom this propulsion plant gave her
a top speed of 18.7 knots on the
surface and 6.5 knots below snorkel
depth.
Meals for her oversize crew
were prepared in a galley in the
starboard hull, where large steam
kettles turned out great quantities of
rice. As in all long range submarines,
a four month supply of food was
stowed in every cranny, including a
layer of crates laid out on deck which
the crew walked on until they’d eaten
their way through. Supernumeraries slept on the deck wherever they could find a nook, being
used to a floor and tatami mat.
OPERATIONAL HISTORY
Several surviving Japanese
submariners have described the
hopes that accompanied the
completion of the top secret boats in
late 1944. As they became available
the four giant submarines were
assigned to a newly created SubRon
One, a ten-bomber strike force.
For their first mission V.
Adm. Jisaburo Ozawa, Vice Chief
of the Navy General Staff, selected
Operation PX, a top secret plan to
use SubRon One’s ten aircraft to unleash bacteriological warfare on populous areas of the
American west coast and Pacific Islands. Infected rats and insects would be dispersed to spread
bubonic plague, cholera, dengue fever, typhus and other plagues. General Ishii’s infamous
medical laboratory at Harbin, Manchuria, had developed the virulent germ warfare agents and
confirmed their lethality by infecting helpless Chinese and Caucasian prisoners.
On 26 March 1945, this sinister mission was cancelled by Gen. Yoshijiro Umezu, Chief
of the Army General Staff, who declared that, “Germ warfare against the United States would
escalate to war against all humanity.” As an alternative the staff considered bombing San
Francisco, Panama, Washington or New York, and decided to launch a surprise air strike against
the Panama Canal’s Gatun Locks. Destroying these locks would empty Gatun Lake and block
the passage of shipping for months.
For the 17,000 mile
round trip to Panama each
submarine needed 1600-tons
of diesel fuel, which was
unavailable at Jure. I-401
was therefore despatched to
Dairen, Manchuria, to bring
back the needed oil. On 12
April she grazed a B-29 laid
mine off Hime Shima
Lighthouse in the Inland Sea
and had to return for repairs.
In her place I-400
successfully carried out the
undersea tanker mission.
By early June all four boats were fueled, armed, equipped with new snorkels, and
disguised with false funnels. They sailed north through Tsushima Strait and the Sea of Japan to
Nanao Bay on the west coast of Honshu near Takaoka. Training there was hampered by B-29
laid mines. American submarines penetrating their training areas, and shortages of aviation
gasoline, material and aircraft, but SubRon One managed to launch a number of simulated air
strikes on a full scale model of the Gatum Locks erected at Tayama Bay.
While the
submersible carriers
were perfecting
their tactics to
cripple the Panama
Canal, the position
of the Japanese
Navy was steadily
deteriorating.
Before the
submarines could
set sail for Panama
more than 3,000
Allied warships and
transports had
reached the Pacific
for Operation
Olympic, the
forthcoming invasion of Japan. This growing threat forced Tokyo strategists to reconsider the
attack on distant Panama, which now appeared a questionable diversion. The I subs was ordered
to abandon there carefully rehearsed canal strike and attack instead American Naval forces at
Ulithi Atoll.
In response to
the new orders I-13
proceeded on 4 July,
to the Ominato Naval
Base on the northern
tip of Honshu. There
she loaded two crated
Nakajima C6N2
Ayagumo (Colored
Cloud) long range
reconnaissance
aircraft, then sailed
into the Pacific
through Tsugaru
Strait bound for
Japan’s island
stronghold of Truk.
After repairing a hot propeller bearing I-14 followed on 14 July. On the 23rd, I-400 and I-401
departed Ominato on separate tracks far to the east for a rendezvous at sea southeast of Ulithi in
three weeks.
Suddenly, on 15 August, Emperor Hirohito
broadcast direct from the Imperial Palace this
dramatic decree ending hostilities. The I-boats crews
were thunderstruck; their combat careers ended just as
they reached the attack rendezvous. After a council
of war meet, the shattered ComSubRon One
reluctantly carried out Tokyo’s orders to cease
hostilities, hoist a black flag, and return on the surface
to home port. The captains of the I-boats were
ordered to jettison all documents and munitions, fire
all torpedoes, and catapult all aircraft into the sea.
When I-401 surrendered to an American
destroyer, the U.S. Crew was astounded at its size.
The commander of the submarine fleet, Captain
Ariizumi, apparently decided on suicide rather than
surrender to the Americans. He requested that his
body we wrapped in the Japanese flag and buried at
sea and shot himself. His body was never presented
as proof of his death.
The U.S. Navy boarded and recovered 24
submarines including the four I-400 subs, taking them
to Sasebo Bay to study them. While there, they received a message that the Soviets were sending
an inspection team to examine the submarines. To keep the technology out of the hands of the
Soviets, Operation Road’s End was instituted. Most of the submarines were taken to a position
designated as Point Deep Six, about 40 miles west from Nagasaki and off the island of Goto-
Retto, were packed with charges of C-2 explosive and destroyed. They are today at a depth of
200 meters.
Four remaining submarines (I-400, I-401, I-201 and I-203 which achieved speeds double
those of American submarines), were sailed to Hawaii by U.S. Navy technicians for further
inspection. Upon completion of the inspections, the submarines were scuttled in the waters off
Kalaeloa near Oahu in Hawaii by torpedoes from American submarine USS Cabezon on May 31,
1946. The reason for the scuttling is apparently that Russian scientists were again demanding
access to the submarines. The wreckage of I-401 was re-discovered by the Pisces submarines
deep-sea submarines of the Hawaii Undersea Research Laboratory in March 2005 at a depth of
820 meters.
END

 

Japanese I 400 Aircraft carrying Subs WWII


I-400 class submarine - Wikipedia, the free encyclopediaI-400: Japan's Secret Aircraft-Carrying Strike Submarine. Hikoki Publications, 2006. ... Japanese naval ship classes of World War II. Aircraft carriers ...
en.wikipedia.org/wiki/I-400_class_submarine - Cached - Similar

Pacific Wrecks Review: I-400 Japan's Secret Aircraft-Carrying ...Jan 30, 2011 ... Japan's Secret Aircraft-Carrying Strike Submarine: Objective Panama Canal. The Japanese Navy built the largest fleet submarines of WWII, the I-400 Class. ... the US Navy personnel involved with the sub after its capture, ...
Pacific Wrecks Review: I-400 Japan's Secret Aircraft-Carrying Strike Submarine: Objective Panama Canal - Cached - Similar

http://www.youtube.com/watch?v=KdytwjZXt_Q

 

I saw something about these on Disc. or the History channel a while ago, still very interesting.

 

One of the aircraft is on display at Smithsonian air and space museum at Dulles airport

 

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