Japanese Midget Submarines Attack Sydney Harbour on the night of May31/June 1, 1942

In wartime the element of suprise is forever paramount, and, to this end, over the period of 1939 -1945 that WW2 covered, four nations sought to exploit this fact by developing both Human Torpedoes and the use of Midget Submarines.

These countries were Britain, Italy, Japan, and Germany.

This work is but one thread, drawn from the fabric that was woven by these nations  seeking an advantage by using these unconventional weapons, and records the Japanese Midget Submarine Attack on Sydney Harbour over the night of May 31st/June 1st in 1942.

The approach to Sydney
On May the 11th. 1942, the Japanese 8th Squadron Submarines, I-22, I-27, and I-28, having been involved in the Coral Sea operation were ordered to Truk to embark Midget Submarines, it was planned to attack Naval targets at either Suva or Sydney.

Two seaplane carrying Submarines, I-21, and I-29, were proceeding to reconnoitre both Suva and Sydney.

I-28, did not reach Truk, she was sighted on the surface by the US Submarine Tautog, enroute from Pearl Harbour to Fremantle Western Australia, two of her torpedoes despatched the Japanese boat.

The other three I class with midgets clamped to their decks sailed from Truk for Sydney about the 20th. of May, whilst the seaplane from I-29 carried out a reconnaissance flight over Sydney on the same date, confirming " both Cruisers and a Battleshipo anchored here."

It would seem most likely that the US 8 inch gunned heavy Cruiser Chicago, with her heavy type of upper works had been mistakenly reported as a Battleship, but from the pilot's message the die was cast.

These Japanese Submarines were: I 21, (with an aircraft) I 22, (carrying Midget No 21) I 24, (carrying Midget A, it was given this designation, as this craft was not recovered, and her number is not known) I 27, (carrying Midget No 14) and finally, I 29, (probably carrying a damaged aircraft),

On the following day, about 0420 (4.20AM) a single float plane burning navigational lights flew over Man of War anchorage in Sydney, then circled Chicago at No 2 buoy, at this time I was serving as a watchkeeping Sub Lieutenant in HMAS Canberra, we were secured at No 1 buoy.

An air raid warning was issued in due course, but searches by Fighter aircraft found nothing, and this incident did not trigger any special defence measures. Post war it was learned that this float plane came from Japanese submarine I 21, and her pilot, Lieutenant Ito, flew up the harbour at 600 feet, sighted Chicago and four destroyers in the Man of War anchorage, and Canberra in Farm Cove, he flew back to his submarine, but on landing close by in rough water, his aircraft crashed and sank. 

Ito and his Observer reported " A Battleship and Cruisers in Harbour." It was decided to attack the following day, the 31st. of May.

Boom Protection
The boom safety net at Sydney was designed in January of 1942, and its construction began that month. It was located at the narrowest point of the inner harbour entrance, between George's Head, on Middle Head, and Green Point on Inner South Head, this protective net was not actually completed until July.

The single line steel Anti-Torpedo net, was supported between piles, the centre portion was complete, but there were large gaps at both the East and West ends, at the Western end, unnetted piles were in place.

Eight Magnetic Indicator Loops were in place across the sea floor of the Inner and Outer harbour entrances, the Loop produced a Signature when a vessel crossed over it.

Midget 14, commanded by Lieutenant Kenshi Chuman with Petty Officer Takeschi Ohmori, was the first inward crossing recorded by the Indicator Loop at 2000 (8PM). With ferry and other traffic passing over the Loops, its significance was not recognised.

About 15 minutes later, Mr J Cargill, a Maritime Services Board Watchman, reported a suspicious object trapped in the net, with his assistant he investigated this object from a skiff which they had rowed over to the scene, and he reported to Lieutenant Eyers, an RANVR officer in charge of a patrol boat HMAS Yarroma. Eyers did not close this mysterious object fearing it may be a Magnetic Mine, so he sent a Stoker in a skiff to investigate, and it was 2230 (10.30PM) an hour and a half after Cargill first reported his discovery before Eyers reported the object trapped in the Boom Net was, in fact, a Submarine, and he asked permission to open fire.


But Lieutenant Chuman, hopelessly entangled in the net, solved this dilemma by firing demolition charges which destroyed both the Submarine and it's crew of two.

Meanwhile, Midget A, with Sub Lieutenant Katsushisa Ban, and Petty Officer Marmoru Ashibe, and Midget 21, with Lieutenant Keiu Matsuo and Petty Officer Masao Tsuzuku on board, had been ordered to follow Midget 14 at 20 minute intervals. Ban had registered a Loop crossing at 2148  (9.48PM) and proceeded up the harbour with Chicago as his target.

At long last some action was forthcoming, the "General Alarm" was ordered at 2227 (10.27PM) by Rear Admiral Muirhead-Gould, Royal Navy, the Naval Officer in Charge at Sydney. 

Ban was having problems with the depth keeping behaviour of his Midget, it kept coming to the surface, and lookouts in Chicago sighted him, but Ban managed to submerge as this US cruiser opened fire with a 5 inch gun, but the Midget was too close to hit. The Corvettes Geelong and Whyalla alongside the Oil Wharf at Garden Island sighted Ban's conning tower, 20 mm fire from Geelong, and searchlight searches from both these ships proved abortive.

By now, the third Midget was approaching the Anti-Torpedo Net area, but Lieutenant Matsuo was having his problems with the trim of his boat, and he was sighted by the unarmed Patrol vessel Lauriana, then Yandra attacked with a pattern of 6 Depth Charges, after a series of explosions, Midget 21 was not seen again.

Flood lighting at the Graving Dock illuminated the scene very well, no one had thought to order them to be extinguished up to now, and they silhoutted Chicago nicely. Finally, these lights went out at 0025, (12.25AM) it was now June the 1st.

Ban was now in position to sink Chicago, only 800 meters from this juicy target, he should not miss as he set his torpedo to run at a depth of 2.4 meters- (Chicago was 170 meters long, with a draught of 7.6 meters) Ban fired, once the torpedo left it's tube, the Midget lost stability, it's bow breaking the surface, and it took Ban 2/3 minutes to regain trim.

His torpedo veered off course, passing well ahead of Chicago, under the Dutch Submarine K9, then under an old Sydney ferry HMAS Kuttabul, being used as a Naval accommodation vessel, berthed alongside Garden Island. 

The torpedo struck the retaining wall, and exploded, lifting Kuttabul high out of the water before coming to rest on the bottom, 19 Australian sailors and 2 British sailors died.

Ban now fired his second torpedo at Chicago, but it missed by some 4 meters, and ran aground on the east side of Garden Island without blowing up. By now the harbour was in absolute turmoil, I can recall ships and small boats rushing all about, searchlights seeking a target, guns being fired, and no one really knowing what was going on.

Captain Howard Bode of Chicago had been ashore dining with Rear Admiral Muirhead-Gould, hastily returned to his ship, decided he had enough of this chaos within Sydney Harbour, and took his Cruiser to sea, obviously not aware that there were five I Class Japanese submarines lurking off the Heads of Sydney, hopefully awaiting the return of their victorious Midgets.

Midget 21 had not been sunk by Yandra, and was discovered in Taylor Bay, she was then battered by attacks from Steady Hour and Sea Mist. Later on the 1st. of June, Navy Divers found this Midget on the Harbour floor, both torpedoes jammed in their tubes, and the propellors still turning slowly. One of the Divers used was Able Seaman Jack Greening, a cousin of mine.

A registered Loop crossing was recorded at 0158 (1.58AM) and the subsequent analysis determined this was an outwards crossing, and could well have been made by Midget A, with Ban making good his escape after his abortive attempts to sink Chicago. Ban and his crew member did not rendevous with their Mother Submarine, they were never found and their actual fate unknown.

Early in 1997 there was a report that a metallic object had been located in the ocean off Cronulla, there was speculation that it may be the remains of Ban's Submarine, but nothing came to pass in this regard.

The Royal Australian History records: "Luck was certainly on the side of the Defender, and was undeserved in the early stages, when inactivity and indecision were manifested."

On the 9th. of June 1942 at 1100 (11AM) the four bodies of the crewmen from the two Midgets sunk during their attack on Sydney, were cremated at Sydney's Eastern Suburbs Crematorium, and accorded full Naval Honours, their ashes were returned to Japan.

A memorial plaque for those who took part in this daring but unsuccessful raid on our shipping on the 31st of May/1st of June in 1942, was erected and unveiled at Garden Island. Sub Lieutenant Ban's Mother made the journey from Japan to be present at this ceremony.



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