© 2006-2010 Bob Hackett and Sander
Midget Submarines at Sydney, Australia
11 December 1941:
Lt ( j.g.) Akieda Saburo sends a memo to the Kure Torpedo
facility suggesting that nine Type A midget
submarines be rebuilt according to an improved standard ("Kai 1”).
18 December 1941:
The Combined Fleet staff authorizes planning of a
second midget submarine operation designated as "Shinki No. 2" (Divine Turtle
3 January 1942:
Lt (j.g.) Matsuo Keiu and Cdr (Rear Admiral,
posthumously) Ariizumi Tatsunosuke, liaison officer from the Naval General
Staff, participants in the planning conference for Divine Dragon Operation No. 1
- the midget submarine attack on Pearl Harbor - arrive aboard flagship NAGATO to
discuss details of the pending operations with Admiral (Fleet Admiral,
posthumously) Yamamoto Isoroku (former CO of AKAGI), CINC, Combined Fleet.
6 January 1942:
The third and the fourth midget submarine crew courses
begin extensive training in the Inland Sea. Special emphasis is placed on night
operations, negotiating narrow straits and penetrating net defenses.
31 January 1942:
Hashirajima anchorage, Hiroshima Bay. In mid-morning,
Admiral Yamamoto accompanied by his Chief of Staff, Rear Admiral (later Vice
Admiral) Ugaki Matome, arrive on Yamamoto's launch from flagship NAGATO. They
are piped aboard Captain (Vice Admiral, posthumously) Harada Kaku's (former CO
of HOSHO) tender CHIYODA to inspect midget submarines and their crews that are
engaged in training exercises in Hiroshima Bay. Yamamoto and Ugaki the observe
midget submarines being lowered from CHIYODA's stern and launched in gale
weather conditions, then return to NAGATO at Hashirajima.
CHIYODA in Inland Sea, Nov 1938
(Imperial War Museum)
31 January -2 March 1942:
Hiroshima Bay. The midget submarine crews
continue to engage in daily training exercises from CHIYODA.
2 March 1942:
Aki Nada. During training, Lt (j.g.) Kanda Akira's
midget submarine HA-13 sinks. Captain (later Rear Admiral) Komazawa Katsumi's
(former CO of CHOGEI) tender NISSHIN and destroyer YAKAZE attempt unsuccessfully
to locate and rescue Kanda and his crewmen Ensign Mifu Shozo and PO1C Oishi
Takaji. The next night, divers locate HA-13, but there is no response from her
16 April 1942:
Hashirajima. Vice Admiral, the Marquis, Komatsu
Teruhisa (former CO of CA NACHI), CINC, Sixth Fleet (Submarines), Captain (later
Rear Admiral) Ishizaki Noboru (former CO of HYUGA), ComSubRon 8, and their
staffs with Captain Komazawa of NISSHIN, Captain Harada of CHIYODA, Rear
Admiral-Retired (Vice Admiral, posthumously) Okamura Masao of AMC/supply ship
AIKOKU MARU and SubRon 8's midget submarine crews pay a courtesy call on Admiral
Yamamoto aboard flagship YAMATO.
Yamamoto wishes the young midget submariners well in their forthcoming
missions in the southern latitudes. That same day, CHIYODA, with a number of
Type A Kai 1 midget submarines and their crews embarked depart Hashirajima to
support Operation "MO" - the Invasion of Port Moresby, New Guinea. NISSHIN
departs that same day for Penang, Malaya.
24 April 1942:
CHIYODA arrives at Truk and disembarks the midget
submarines and their crews. 
27 April 1942:
Truk. I-21, with ComSubDiv 3 Captain (later Rear
Admiral) Sasaki Hankyu embarked, and I-27 depart for Noumea.
30 April 1942:
I-29 departs Truk.
4 May 1942: Operation "MO" - The Invasion of Port Moresby:
Admiral (Vice Admiral, posthumously) Kajioka Sadamichi's (former CO of NAGARA)
Port Moresby Attack Force departs Rabaul escorting Rear Admiral (later Vice
Admiral) Abe Koso's (former CO of HIEI) Transport Force of 12 transports and a
5 May 1942:
Rear Admiral (later Admiral) Frank J. Fletcher's Task
Force 17 sinks light carrier SHOHO.
8 May 1942:
SBD dive-bombers from YORKTOWN (CV-5) and LEXINGTON (CV-2)
damage carrier SHOKAKU. Carrier ZUIKAKU's air group also suffers heavy losses.
The Japanese damage YORKTOWN and LEXINGTON. Later, aviation gasoline vapors
ignite and massive explosions cause LEXINGTON to be abandoned and scuttled. The
Battle of the Coral Sea halts the Japanese thrust toward Port Moresby and they
are forced to cancel Operation MO.
(Naval Historical Center)
11 May 1942:
I-22, I-24, I-27, I-28 are ordered to return to Truk.
17 May 1942:
S of Truk. Early in the morning, LtCdr Joseph H.
Willingham's USS TAUTOG (SS-199) attacks two I-class submarines, including I-24,
unsuccessfully. Two hours later, TAUTOG sinks I-28 that was heading towards Truk
on the same course.
Truk. I-22, I-24 and I-27 of Captain Sasaki’s Eastern Advanced
Detachment’s Special Attack Unit each embark a midget submarine and its crew
that were carried to Truk aboard seaplane/submarine carrier CHIYODA (later
converted to a carrier). I-21 and I-29 are also assigned to the force and each
carries an E14Y floatplane for reconnaissance. I-22, I-24 and I-27 depart Truk.
18 May 1942:
I-24 surfaces to begin a battery charge and carry
out maintenance on her midget submarine. At 1831 (JST), when Lt (j.g.) Yamaki
Teiji enters the midget submarine, followed by PO1C Matsumoto Shizuka, there is
a strong smell of chlorine. Matsumoto turns on the interior light to
investigate. A terrific explosion blows him overboard! Despite a long search,
his body is never recovered. Lt ( j.g.) Yamaki is badly burned, so Cdr Hanabusa
returns to Truk.
20 May 1942:
Australia. I-29's floatplane reconnoiters Sydney.
23 May 1942:
At dawn, I-29's floatplane reconnoiters Sydney and
Newcastle. On landing, it is damaged and cannot be used again, but the pilot
reports the presence of one WARSPITE-class BB in the harbor and another in
drydock in Sydney's Port Jackson harbor. They are heavy cruisers USS CHICAGO
(CA-29) and HMAS CANBERRA, old light cruiser HMAS ADELAIDE, destroyer USS
PERKINS (DD-377), tender USS DOBBIN (AD-3), minelayer HMAS BUNGAREE, armed
merchant cruisers KANIMBLA and WESTRALIA, corvettes HMAS WHYALLA and HMIS
BOMBAY, minesweeper GEELONG, accomodation ship HMAS KUTTABUL and Dutch submarine
I-29 radios a report of the sighting to Headquarters, Sixth Fleet at
Kwajalein. The report is relayed to Captain Sasaki in I-21 who is then
reconnoitering Auckland, New Zealand. The transmission is picked up by the
RAN/USN Fleet Radio Unit, Melbourne (FRUMEL) communications-intelligence unit
and is partially decoded.
24 May 1942:
Kwajalein. Vice Admiral Komatsu, aboard his flagship
light cruiser KATORI, orders Captain Sasaki's Eastern Detachment to attack
29 May 1942:
Komatsu and Sasaki send out messages of encouragement to
the Eastern Detachment's submarines and their midget submarine crews. These
transmissions are also picked up by FRUMEL, although it is unclear what, if any,
action is taken by the RAN at Sydney based on these warnings.
35 miles NE of Sydney, Australia. WFO Ito Susumu is launched from I-21 to
reconnoiter Sydney harbor in his E14Y. At 0420, it circles twice over the harbor
near where the heavy cruiser USS CHICAGO (CA-29) is anchored. Ito returns to
I-21 and reports sighting a "battleship" in the harbor. Captain Sasaki orders an
attack on Sydney harbor by his midget submarines on 31 May 1942.
30 May 1942:
I-22, I-24 and I-27 arrive off Sydney.
IJN Midget Submariners who Attacked Sydney and Diego Suarez 
(Australian War Memorial)
31 May 1942: The Attack on Sydney:
At 1721, I-22 launches M-22b (HA-21), a
Type A midget submarine, piloted by Lt Matsuo Keiu with PO2C Tsuzuku Masao about
7.2 miles ESE of Sydney Harbor.
At 1740, I-24 launches midget submarine M-24b piloted by Lt (j.g.) Ban
Katsuhisa with PO Ashibe Mamoru about 7.5 miles E of Sydney. 
At 1758, I-27 launches midget submarine M-27b (HA-14) piloted by Lt Chuman Kenshi
with PO1C Omori Takeshi about 6 miles ESE of Sydney Harbor. The plan calls for
M-27b to enter the harbor first, about 20 minutes after moonrise at 1833.
At 2001, M-27b enters the harbor, but by 2005, becomes entangled in the
steel netting of an anti-torpedo boom laid across the harbor entrance between
Georges Head and Watson's Bay. A watchman spots and reports an object thought to
be a mine caught in the net. Harbor patrol boat HMAS LOLITA, a converted yacht,
arrives, spots M-27b and drops three depth charges that fail to explode in the
At about 2200, Lt (j.g.) Ban's midget submarine M-24b enters the harbor,
Ban follows a Manly ferry through the boom defences, avoids the nets and slowly
makes his way. M-24 b maneuvers around the harbor and is sighted several times.
At 2207, all vessels in the harbor are alerted of the presence of an
enemy submarine. CHICAGO spots Ban's M-24b and fires on it with its 20-mm AA
(U. S. Navy)
At 2235, as patrol boat HMAS YARROMA arrives at the anti-torpedo boom and
prepares to drop her four depth charges, M-27b's crew detonate the midget's
35-kilogram scuttling charge to prevent capture. The charge kills Chuman and
Omori and blows off M-27b's forward section. 
At 2252, Lt Matsuo's midget submarine M-22b is spotted by auxiliary
patrol boat HMAS LAURIANA after it enters the harbor. Off Potts Point, Lt (j.g.)
Ban's midget submarine M-24b is spotted by an Electrician’s Mate aboard CHICAGO
and fired on by her AA guns, but not hit. At 2254, patrol boat HMAS YANDRA tries
unsuccessfully to ram Matsuo's M-22b. At 2310, minesweeper HMAS GEELONG opens
fire on an object, probably Ban's M-24b, but fails to score a hit.
1 June 1942:
At 0007, YANDRA attacks Matsuo's M-22b with depth
charges, but M-22b survives.
At 0029, Lt (j.g.) Ban's M-24b fires her two 17.7-inch torpedoes at
CHICAGO, but both miss. One torpedo passes under Dutch submarine K-IX and
explodes under and sinks accommodation ship HMAS KUTTABUL (an old ferry) killing
21 sailors and damaging K-IX beyond repair. The other torpedo runs aground on
Garden Island and fails to explode. 
About 0300, CHICAGO leaves the harbor for the open sea. Her lookouts spot
a "submarine” entering the harbor. This may have been Lt Matsuo’s M-22b. At
0301, a harbor indicator loop registers an "inward crossing” as well. At 0350,
armed merchant cruiser HMAS KANIMBLA opens fire on Lt Matsuo's M-22b near
Bradley’s Head. At 0450, ASW vessel HMAS DOOMBA's ASDIC sonar detects M-22b off
Robinson’s Point. Her lookouts spot a "submarine” entering the harbor. This may
have been Lt. Matsuo’s M-22b. At 0301, the harbor indicator loop registers an
inward crossing as well.
Taylor Bay. At 0500, minesweeper HMAS GOONAMBEE picks up Lt Matsuo's
HA-21. The midget submarine is then attacked by harbor patrol boats HMAS
YARROMA, SEA MIST and STEADY HOUR with depth charges for about an hour. Matsuo
and PO Tsuzuku shoot each other. Later that day, STEADY HOUR drags her anchor
and snags the midget submarine. Divers find M-22b disabled on the harbor floor
with both torpedoes jammed in their tubes, motor running and propellers still
3 June 1942:
S of Port Hacking, Sydney. The “mother” submarines
linger on the surface to recover their midget submarines, but they fail to
9 June 1942:
Sydney's Eastern Suburbs' Crematorium. The Australian
Government allows the bodies of the four crewmen recovered from the two midget
submarines sunk during the attack to be cremated. At 1100, their remains are
accorded full naval honors. Later, the Japanese ambassador, Tatsuo Kawai, takes
their ashes back to Japan aboard KAMAKURA MARU. On his arrival at Yokohama, he
hands them over to relatives of the midget submariners. Radio Tokyo calls their
return a chivalrous act that "greatly impressed" Japan.
Midget Submarine Raised at Sydney
(Australian War Memorial)
Bungan Head, Newport, Sydney, Australia. Seven
recreational scuba divers called 'No Frills Divers' find a midget submarine on the seabed 2 km/1.25 miles N of
Long Reef, about 20 km/ 12.5 miles N of Sydney Harbor at 33-40-21S, 151-22-58E.
The midget submarine is sitting upright on its keel in 54m/175 feet of water, but heavily
encrusted with barnacles and weed. Both tubes are empty of their torpedoes confirming
the identification of the vessel as I-24's midget submarine, the only midget to successfully
fire its two torpedoes. The upper tube has been torn off the vessel back to a substantial
bulkhead and lies almost totally buried in sand adjacent to the bow on the port quarter.
On top of the hull, the divers find what looks like 20-mm bullet holes, possibly fired by
USS CHICAGO. The remains of Lt (j.g.) Ban and PO Ashibe are probably still inside.
1 December 2006:
Based on an inspection by divers of the Royal
Australian Navy and advice from the Navy Heritage Collection, the Australian
Government’s Environment and Heritage Minister confirms that the midget
submarine discovered recently off Sydney is the Japanese “M-24b". A comparative
analysis with the midget submarine at the Australian War Memorial in Canberra
is also conducted. The government provisionally declares the sub wreck to be a
"historic shipwreck" to give it legal protection from damage, disturbance or
removal. A protected zone around the site extends 500 meters in each direction
to ensure protection of this wreck, its relics and any human remains. Diving is
prohibited in the zone.
14 December 2006:
The discovery of the midget submarine M24b off Sydney brought mixed emotions for Dr Ban Kazutomo, 74, a retired doctor, and brother of Sub-Lieutenant Ban Katsuhisa. Dr Ban, who lives in Hekinan, 40 kilometres from Nagoya, told the press “I feel relieved that we now know the exact place he died, [but] now I think we should leave him to rest in peace.” But Itsuo Ashibe, 84, brother of the other submariner who died on board, says he is “filled with a hope” that the vessel will be raised. “I know it is likely that nothing remains, but nonetheless...if there were just something, a shoe, perhaps, or ...a rusted piece of the sub that I could bury inside my brother’s grave, I would be happy.” he said.
30 July 2009:
Australian maritime investigators confirm the presence of unexploded explosives aboard M-24 (probably scuttling charges). The wreck is believed to contain more than 50 kilograms of highly-unstable T-N-T, posing a major risk to any recovery operation.
 The three crew members of HA-13 are each promoted one
 Captain Sasaki led the midget submarine attack on Pearl Harbor.
 The two-man crews of each midget are shown with the Commanding
Officer seated in the front row with his crewmember behind him.
FRONT ROW –
OFFICERS, FROM THE RIGHT:
LtCdr Iwase Katsusuke - Died in the Diego Suarez
Lt (j.g.) Ota Masaharu - A member of the Diego Suarez Attack Group,
but did not participate because of a malfunction of his submarine
Keiu - Died in the Attack on Sydney
Lt Akieda Saburo - Died in the Diego
Lt Chuman Kenshi - Died in the Attack on Sydney
Teiji - A member of the Sydney Attack Group, but did not participate because of
the death of his crewman in a training accident before the operation
Lt (j.g.) Ban
Katsuhisa - Lost, Presumed Dead in the Attack on Sydney
BACK ROW - CREW MEN, FROM THE RIGHT;
PO2C Takada Kozo - Died in the
Diego Suarez Attack
PO1C Tsubokura Daiseiki - A member of the Diego Suarez
Attack Group, but did not participate
PO2C Tsuzuku Masao - Died in the Attack
PO1C Takemoto Masami - Died in the Diego Suarez Attack
Omori Takeshi - Died in the Attack on Sydney
PO1C Matsumoto Shizuka - Killed
in a battery explosion aboard I-24 during training before the Attack on Sydney
PO1C Ashibe Mamoru - Lost, Presumed Dead in the Attack on Sydney
 Some sources claim that Lt (j.g.) Ban's "M-24b" was HA-17, but this
has not been confirmed.
 M-27b's two Type 97 torpedoes are later captured and examined.
 M-27b and M-22b were salvaged and cannabalized to build the single
midget now at the Australian War Memorial's ANZAC Hall, Canberra, one of four
Type A midgets on display around the world. The salvaged conning tower of M-22b
is on display at the Naval Heritage Center, Garden Island Naval Base, Sydney.
Composite Type A Kai 1 at the Australian War Memorial
-Bob Hackett and Sander Kingsepp
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