Country of origin:

Japan

Description:

Two-seat submarine-borne reconnaissance monoplane

Power Plant:

One 254 kw (340 hp) Hitachi Tempu 12 nine-cylinder air-cooled radial engine

Specifications:

Armament:

One 7.7 mm (0.303 in) Type 92 machine gun on rear flexible mount; provision for up to 60 kg (132 lb) of bombs

History:

The Yokosuka E14Y was designed by Mitsuo Yamada of the Dai-Ichi Kaigun Koku Gijitsusho (the First Naval Air Technical Arsenal) as a small submarine-borne two-seat reconnaissance seaplane to operate on twin floats.  Powered by a 254 kw (340 hp) Hitachi Tempu 12 (Heavenly Wind) radial engine, the prototype was completed in 1939 at Yokosuka and it was flown in comparative trials with the Watanabe E14W1, which was designed to the same specification.  The ‘Glen‘ was placed in production and 126 aircraft were built by K K Watanabe Tekkosho between 1941 and 1943.

The type operated from a number of the larger Japanese long-range submarines for reconnaissance duties, being stored dismantled in a watertight hangar forward of the conning tower on the deck, the twin floats, supporting struts, and wings being detached from the fuselage and placed in the hangar, the aircraft being quickly assembled on the deck when required.  The Yokosuka design was found to be superior to the competitor and it was placed in production as the Navy Type O Submarine-borne Reconnaissance Seaplane Model 1-1, later being re-designated Navy Type Small Reconnaissance Seaplane Model 11.  To the Allies it became known as the ‘Glen‘.

The type made its operational debut at Pearl Harbour on 7 December 1941 when one example, launched from the submarine I-7, made a reconnaissance to assess damage.  Probably the most famous operation of the type at that time was that of Warrant Officer Nobuo Fujita who, operating from the Imperial Japanese Navy submarine I-25, dropped four 76 kg (167 lb) phosphorus bombs in two attacks along the coast of Oregon, USA, the aircraft being flown solo in order to carry a larger bomb load.

The aircraft’s fuselage was of welded steel tube with an aluminium-alloy skin forward and wood and fabric-contoured cladding aft.  Fuel capacity was 170 litres (37.2 Imp gals).

In 1942-1943 a number of Japanese submarines, including I-11, I-21, I-25 and I-29, operated off the Australian and New Zealand coasts, sinking a number of ships with torpedoes.  Some 35 examples of this class of submarine were built.  The ‘Glen‘ on board each of these submarines was regularly used on reconnaissance duties, on each occasion being catapulted off a 20 metre (66 ft) catapult.  As noted above, one was used to make a reconnaissance of Pearl Harbour shortly before the devastating attacks on the United States Pacific fleet.

The I-class submarine was 108.7 m (356.6 ft) in length, 9.3 m (30.5 ft) in beam and 5.1 m (16 ft 7 in) in draught. It had a displacement of 2,344 tonnes (2,584 tons) when surfaced.  It was powered by two diesel engines providing 9,246 kw (12,400 hp) and electric motors providing 1,491 kw (2,000 hp).  It had a speed when surfaced of 43.5 km/h (27 mph) and 15 km/h (9 mph) when submerged.  Range was 25,928 km (16,111 miles) and it had a crew of 94 officers and men.  Armament comprised six torpedo tubes, a total of 17 torpedoes, and a 14 cm (5.5 in) naval gun on the deck.

The I-25 submarine which carried a ‘Glen‘ which flew over Sydney, NSW on 17 February 1942 was under the command of Lieutenant Commander Meiji Tagami and departed Yokosuka in Japan on 21 November 1941.  It made a number of patrols in the Pacific Ocean and sank a couple of ships off the American and Australian coasts.  It was eventually sunk by the US Navy destroyer USS Ellet off the New Hebrides on 3 September 1943.

The aircraft from the I-25 was flown over Sydney, Melbourne, Auckland and other cities.  Japanese records indicate it was flown over the Sydney Harbour Bridge and Garden Island, NSW on 17 February 1942, Melbourne and Port Phillip Bay, VIC on 26 February and Hobart, TAS on 1 March.  On 8 March it flew over Wellington, New Zealand, Auckland on 12 March, and Suva in Fiji on 18 March.  Pilots on these latter flights are known to have included Warrant Officers Susumu Ito and Nobuo Fujita, the latter being the pilot of the aircraft which dropped light bombs on the United States.  Flights were also made by the type over Africa, Madagascar, and the Aleutians.

Prior to the Japanese midget submarine attack on Sydney on 31 May 1942 five Japanese Class B-1 submarines (also known as the I-class) arrived off Sydney Heads.  These submarines were I-21, I-22, I-24, I-27 and I-29.  I-22, I-24 and I-27 carried the three midget submarines, each with a crew of two.  I-21 and I-29 carried Yokosuka ‘Glen‘ floatplanes for reconnaissance work.  The aircraft were carried in a hangar built on the forward deck of the submarine in front of the conning tower and the crew was able to assemble and get the aircraft ready for flight in about ten minutes, this involving the attachment of the wings, fins and floats, and the tailplane being unfolded, the aircraft being launched by a catapult on the submarine’s forward deck. Recovery was by landing on the sea near the submarine and the aircraft being lifted onto the deck, dismantled and placed in the cylindrical hangar.

On 29 May 1942 the ‘Glen‘ from I-21 carried out a reconnaissance of Sydney Harbour, being launched from 65 km (40 miles) out to sea, as a prelude to midget submarine attacks on Australian and American naval ships.  The flight identified the presence of a number of Naval units, including the USS Chicago, flying low near the American cruiser.

On 31 May four midget submarines were launched from the I-class vessels and attacked shipping in Sydney Harbour but little damage was caused, other than the sinking of a ferry, the HMAS Kuttabul, and the loss of a number of lives.  None of the midget submarines escaped from Sydney Harbour and three are known to have been sunk. One was missing for many years until located by divers in 2006.  Two of the midget submarines were recovered and one is on display at the Australian War Memorial in Canberra, ACT this being built from the wrecks of two of the submarines recovered from the bottom of Sydney Harbour.

In 1995 the engine of the ‘Glen‘ from I-21 [aircraft serial not known] which had flown over Sydney was located off Sydney.  After the reconnaissance at night the machine failed to locate the submarine, returned to North Head, took bearings from Macquarie Lighthouse, returning to its mother I-class submarine.  However, on landing in the open sea the aircraft capsized some 65 km (40 miles) off the coast. The crew of Flying Warrant Officer Susumo Ito and Officer Iwasaki as observer/navigator, recovered to the submarine. Efforts were made by the crews of the aircraft and the submarine to sink the aircraft but were unsuccessful because of buoyancy in the floats.  The crew of the submarine, assisting with tools and small arms fire, managed to sink the aircraft to avoid discovery.

It seems also the ‘Glen‘ which was on board I-29 had been seriously damaged in what has been said to be an earlier flight over Sydney Harbour on 23 May 1942. There has been some conjecture that at the time of the sinking of the I-21 aircraft this aircraft may also have been sunk.

Much effort has been undertaken to locate the wreckage of the aircraft flown over Sydney.  As mentioned, in 1950 a nine-cylinder radial engine and parts of an aeroplane were found at Pelican Point near Norah Head, NSW in a sand gutter and there has been conjecture since as to whether this is the wreck of the ‘Glen‘.  Divers located and photographed the wreck.

A flight by the ‘Glen‘ from I-25 flown by Nobuo Fujita and Shoji Okuda was made on 26 February 1942 after launch near Cape Wickham, flying via Cape Otway, Point Lonsdale, Portarlington and over RAAF Laverton, VIC where the aircraft was sighted. Two aircraft were scrambled but failed to locate the intruder.   The ‘Glen‘ flew on to Melbourne, Williamstown, St Kilda, Brighton and Sandringham, and back to Cape Wickham, where the aircraft was recovered to the submarine which then headed for Tasmania.

The submarine I-25 surfaced in Great Oyster Bay near Freycinet National Park, TAS where the aircraft was launched to gather intelligence in and about Hobart Harbour.  On this occasion Warrant Flying Officer Nobuo Fujita and Shoji Okuda launched via the submarine catapult and flew around the Tasman Peninsula and into Hobart Harbour noting cargo ships present but no warships.  The submarine later recovered the aircraft and proceeded to New Zealand where further reconnaissance flights were made of the harbours in Wellington and Auckland, then Fiji on 17 March, before proceeding on to its base at Kwajalein Atoll in the Marshall Islands.