- Bogart, Charles H.
- Ship histories and stories, WWII operations
- RAN Ships
- HMAS Yarroma, HMAS Sea Mist, HMAS Kuttabul
- March 1985 edition of the Naval Historical Review (all rights reserved)
Mid April 1942 saw I27 with the other two boats of Sub Div 3 and 14 and cruiser Katori, flagship of 6th Fleet, sailing south for Truk which would serve as their base. I27 and the other boats’ southward journey was halted on 18 April, 400 miles south of Cape Shionomisaki, upon receipt or word that B25s were attacking the Home Islands and that an American carrier task force was operating in waters 700 miles east of Tokyo. The boats of Sub Div 3 and 14 were therefore ordered to head in a north-east direction to intercept TF16 built around carriers Enterprise CV6 and Hornet CV8. Due to the distance that had to be steamed and uncertainty of the carriers’ exact location I27 and the other boats made no contact with Admiral Halsey’s TF16. The boats were therefor ordered to give up the hunt and return to their original mission.
The Hei and Ostu detachment stay at Truk was short. Imperial Headquarters was putting into operation its plan to capture Port Moresby.
All of the submarines with the exception of I21 and I27 were assigned to support this operation which led to the Imperial Navy’s tactical victory at the Battle of the Coral Sea. Instead of being part of this fleet action I27 was ordered to reconnoitre New Caledonia while I21 performed the same type of mission off of Australia’s east coast. The strategic setback that Japan suffered as a result of the Coral Sea battle however caused 6th Fleet to recall I27 along with I21, I22, I24 and I28 to Truk on 11 May 1942.
The original operation plan prepared before I27 and the other boats of Sub Div 3 and 14 left Japan had called for an attack to be mounted in New Zealand and Australian waters by the Hei and Ostu detachments upon capture of Port Moresby. I27, I22, I24 and I28 were to have proceeded to Queen Carola Anchorage off the west coast of Buka Island and load type A midget submarines. These were to have been carried in the pressurized seaplane hanger.
The type ‘A’ midget submarine displaced 46 tons, was 78½ft in length, 6ft in beam and 6ft in draft. Surface speed was 23 knots while a submerged speed of 19 knots could be maintained for an hour. Armament consisted of two 18″ torpedos. They were crewed by two men.
This plan, for a raid by midget submarines in Australian waters, was now revised and modified. The midget submarines were now to be loaded on I27, I22, I24 and I28 at Truk during mid May. While this loading was taking place I21 and I29 were reconnoitering Suva and Sydney with their aircraft to determine which ports contained the most worthwhile targets. Before the operation could commence it had to be modified again as I28 was sunk while returning to Truk on 17 May by the US submarine Tautog (SS199) in the waters north of Rabaul.
With their midget submarines secured on board I27 and the other two submarines set sail for Australia on 20 May 1942. Commanding I27’s midget submarine was Lt. Kenshi Chuma. On the same day I21 and I29 launched their planes to scout the anchorages at Sydney and Suva. No naval vessels were found at Suva but two battleships and a cruiser were reported at Sydney.
Sub Ron 8 therefor directed I27, I22 and I24 to make for Sydney. They were to launch their midget submarines on 30 May as this was the same night Ko detachment would launch its midget submarines at Diego Suarez Harbor, Madagascar. As 129 plane had crashed on landing after its reconnaissance flight I21 was ordered to Sydney to reconnoiter the harbor immediately before the attack.
The afternoon of 30 May found I21′s plane circling over Sydney Harbor. Unchallenged it flew back to I21 reporting battleships and cruisers in the harbor. In reality the largest ship present was the American cruiser Chicago (CA29). 121’s plane on landing was severely damaged and was not recovered. The planned post attack flight had to be cancelled.
The next day at 1630 seven miles east of Sydney Harbor I27 launched HA14, its midget submarine, while at the same time I22 released HA21 and I24 turned lose her midget submarine ‘A’ (hull number unknown).