Night reconnaissance flight reveals USN Chicago Sydney, May 30th 1942

A few nautical miles north-east of Sydney Heads on May 30th, 1942, a large Japanese submarine, the I21, surfaced onto a choppy sea. Within seconds, the glistening foredeck became a hive of activity while several crewmen busied themselves around a structure situated in front of the conning tower.

Water-tight doors facing the submarine’s bow were opened and behind them, a shadowy form appeared, like a huge chrysalis emerging from its dark cocoon, with its wings folded beside its body and standing high on spindly legs. It was no insect; it was a floatplane. A Yokosuka E14Y1 “Glen”, with its engine already running and warmed-up.

It was pushed out of its dark hangar onto the equally dark and pitching foredeck. There, the handlers grabbed the lifting points and struts on each wing and, with a well-practised routine, carefully manoeuvred each wing from its folded position, out and around to its flying position. Two shadowy figures, 27-year-old Warrant Flying Officer Susumu Ito and his observer Yuwasaki, clad in bulky flying suits and leather helmets, were already settled into the long, Perspex-covered cockpit. They completed their pre-flight checks, then, as Ito himself recalled “at precisely 2:45 am on the morning of 29th May when the mother submarine was at a suitable angle, my plane was catapulted out to begin the flight”. Thus began a crucial and portentous reconnaissance flight that would lead to an attack by three midget Japanese submarines on warships in Sydney Harbour the night of May 31st, 1942.

Flying aircraft from submarines was not a new idea. The British Royal Navy trialled a tiny Parnall ‘Peto’ biplane in the late 1920s. But nothing came of it. However, the Japanese navy planners developed the aircraft-carrying submarine concept into a highly efficient reconnaissance system. They constructed very large submarines that could carry up to three aircraft; these worked alongside other mother subs which carried several midget submarines. Ito’s Mother Submarine I31 displaced 2,530 tonnes, its length was 108 m, beam 9.2 m. Armament was 1 x 40 cm deck gun, 6 x 21 in torpedoes, one seaplane. Speed on the surface 23 knots, Underwater 8 knots. Crew 95.

After Ito was catapulted into the night, he was able to head for the loom of Sydney’s light. On arrival at the Heads, he was surprised to see that so many lights were not blacked out. At just under the cloud base of about 1,100ft he flew down the harbour towards Garden Island. He continued over the Bridge and, while circling over the brightly lit Cockatoo Island where night work was in progress, searchlights were suddenly turned on and he recalled pulling up into cloud for a few seconds to avoid them**.

He turned back towards the North Head having noted that two or three destroyers were in dock on the western side of Cockatoo Island and one light cruiser was moored in the Harbour. To make sure about the moored warship, Ito turned back just past Dobroyd Point for a second run at about 400ft.

On this second run, which did not take them over the Harbour Bridge they noted that there were two, warships moored, not one. As he wrote later, “One British warship of the “Warspite” type and another American warship.... I thanked my god that I had found two warships there”. What he had actually seen were the Australian Cruiser “Canberra” and the US cruiser “Chicago”, so the scene Marshall chose to reconstruct in his painting is of the little seaplane passing alongside the US “Chicago” while, in the distance, are the armed merchantman HMAS “Kanimbla” and the Australian Cruiser HMAS “Canberra”.

With success to buoy his spirits, he flew back up the harbour, exiting Sydney Heads and setting course for the I 21 which was about 35 minutes away in the gloom. Unfortunately, when he sighted it, he realised that the swell was worse than at take-off. This resulted in near disaster. On alighting, the “Glen” bounced off the top of a wave and crashed into the sea upside down. Both Ito and Yuwasaki were pitched out of the machine as they had deliberately undone their safety harnesses. Both were rescued quickly by the submarine crew, one of whom, Ito remembers, “Gripped my pilot’s uniform by the neck, as a mother cat would her kitten, and pulled me aboard”.

The seaplane eventually sank but the essential information was passed on, resulting in the decision being made to send in three midget submarines from the nearby submarine I 33 on the night of May 31st. The rest is well-documented history – history that would not have happened had it not been for this remarkable flight.

Artist's note: "Ever since May 1942 when Phillip Dulhunty, a young gunner stationed at an artillery base on Georges Heights overlooking Sydney Harbour, actually saw the “Glen” seaplane as it flew by him, he has been enthusiastic in gleaning details about Ito’s flight first-hand by going to Japan to meet him. It is mostly Phil, an ex-seaplane pilot himself, to whom I extend my thanks for important details included in his painting. Also, special thanks go to Capt. Chris George and Andrew Ahern who provided help and enthusiasm on the way." * Date quoted by Warrant Flying Officer Ito Susumu in his recall of the flight was May 29th, 1942. ** Official sources say that no searchlights were turned on at that time.