6-1 Arrival of winter
In November, low pressure systems often developed like typhoons near the Aleutian Islands, and there were many stormy days. The strong winds and water on the runway had restricted the activities of US military aircraft. Even if their aircraft took off, they often returned on the way or bombed from above clouds. The aircraft accidents due to the bad weather also occurred frequently, and the activities of US military aircraft declined until the end of December, except for the attack on the transport ship "Cheribon-Maru" on Attu Island on November 27. Meanwhile, the Japanese transportation using the light cruisers "Abukuma", "Kiso", and the destroyer "Wakaba" (K-Convoy) was carried out, and 525 independent infantry 302 battalions arrived at Kiska Island on December 3 [4, p380].
During the stormy weather, the US troops strengthened their bases preparing for the next spring offensive operation. The Navy Construction Engineers and Army Engineers built barracks, hangars, warehouses, radio communications stations, piers, and dry docks on Adak Island. A refueling pier, an oil tanks, and ammunition storage were also constructed on a nearby island. The US military not only reinforced their strength, but also carefully improved the facilities to support them.
In order to strengthen transportation to the Kuril Islands and Aleutian Islands, the Japanese military organized the 30th Harbor HQ in Paramushir in late December, and the HQ owned ship engineers, landing companies, maritime transport companies, and ship arsenals. On December 25, six Navy Type Two sea fighters were replenished on Kiska Island, and two army transport vessels, the "Kouan-Maru" and "Yamayuri-Maru", arrived at Attu Island on December 29 [4, p9]. At the time of landing of supplies, the measures were taken to avoid air raids and shorten the staying time in the bay, such as bags and drums filled with supplies are thrown into the sea and pulled up from the shore.
The activities of US military aircraft resumed around the New Year of 1943. The transport ship "Urajio-Maru" that had arrived at Kiska Island was bombed in the bay on December 31. On January 6, the following year, the transport ships "Montoriru-Maru" for Kiska Island and "Kotohira-Maru" for Attu Island were attacked before arriving at their destinations by US military aircraft. "Kotohira-Maru" was loaded with food, assembly barracks, and fuel [3, p196]. "Montoriru-Maru" carried 831 soldiers, some of the 302 independent infantry battalions [4, p391-392]. Due to the distress of these two ships, all supplies and soldiers were lost in the sea. The defense reinforcment plan for February had to be significantly delayed.
In the winter, the most of seaplanes of the Navy 452 air unit were unusable due to not only air raids but also storms and high waves caused by low pressure systems [7, p215]. The storm on January 4 was particularly fierce, and a high wave of 4 m on Kiska Island damaged all seaplanes moored in the bay. Therefore, after that, a hill near the coast was cut open and a dock for the salvage of seaplanes was built. At night and during storms, all of the seaplanes were to be lifted to land. Lifting light single-seater sea fighters were still easier, but heavy three-seater reconnaissance seaplanes were a hard work to pull into the bay and lift to land every day [7, p222]. On Attu Island, some of the food stockpiled was leaked due to the high waves caused by the storm that day. The scarce food could not be adequately replenished until the troops were wiped out in the end of May [3, p196].
6-2 Airfield construction
The airfield on Kiska Island was being built on a flat land north of Kiska Bay. The plan was to build a runway 800 m long and 120 m wide by the end of February, and another 1200 m long runway that intersects it by four months later. The construction began on December 1, 1942, but the progress was significantly delayed due to delays in the material transportation. The construction materials and the tools, such as pickaxes, rope baskets for carrying earth and shovels, arrived on February 4 [3, p201]. The priority was given to the construction of airfield, so the construction of defense facilities, barracks, and the road excavations between defensive positions was postponed. Also, at some opportunities, it seems that bulldozers were sent to Kiska Island [3, p398] and Attu Island [7, p423]. However, according to local records, the childish performance of Japanese bulldozers was not very effective against the hard rocks of the islands [3, p256]. This was not just a problem with construction machinery, but in Japan at that time there were no experienced operators. As a result, truck drivers who saw bulldozers for the first time were devoted to their operation [17, p199]. At that time, Japanese construction machines frequently failed due to poor manufacturing technology, poor materials, and immaturity of operating skills.
When the Allied forces discovered that the Japanese troop was constructing a runway on Kiska Island, they began bombing the construction site on January 20, Therefore, the Japanese had to build the air raid shelters and the fox holes for evacuation near the construction site [3, p202]. Not only the engineering corps but also soldiers were mobilized for the construction work. The average number of workers is almost 600 per day [3, p201]. However, when the weather was good, the work was interrupted by air raids, and when the weather was bad, the construction work did not proceed under the snowstorm [7, p148]. The disruption of supplies, especially the shortage of explosives for blowing up the bedrock, had a serious impact on the construction. In March, most soldiers returned to their original missions to strengthen their defenses, and airfield construction returned to work solely by the engineering corps.
The runway on Kiska Island was roughly completed at the end of April (there is another story that it was completed at the end of March. However, the Japanese War History Series, Senshi-sosho Vol. 21. "Army Operations in the Northeastern <1> has set the progress at the end of March to 55% [3, p278]). Kiska Island, which was frequently hit by air raids, needed bunkers to protect planes, so the fighter squadrons is scheduled to advance in mid-May after the bunker construction would be completed. At the end of May, not only the runway but also the taxiway and bunkers were completed, and the airfield on Kiska Island became available. However, the airfield was never used due to the collapse of Attu Island. Further expansion of the airfield was continued, but the work was discontinued on June 8 due to the start of evacuation operation "Ke-gou", which is described later [3, p279].
Initially, no suitable flat land for airfield was found on Attu Island, but it was found that there was a suitable site in Higashiura (West Arm) at the back of Holtz Bay by the survey after the re-occupation. A construction work on a runway with a width of 60 m and a length of 1000 m began on February 25, when personnel and materials were available. The soil of the airfield construction site was sandy, and it seems that the work was easier than that on Kiska Island [3, p297]. The constructing runway was compacted with human feet, and small rollers were pulled over it to further compact the surface. It was estimated to be completed at the end of May, but was not completed due to the landing of the Allied Forces in early May [3, p298] as described Chapter 8.
6-3 Invasion to Amchitka Island by Allied Forces
The Allied Forces significantly expanded the military facilities on Adak Island in preparation for the invasion, and as part of this, deployed torpedo boats on Adak Island. However, in winter, not only the top-heavy condition on hull by attaching ice made their operations impossible, but the high waves in winter also launched five boats to the shore [4, p399]. After all, the torpedo boats could not be used for any operations, but used only for patrols and transportation of supplies when the sea was calm [10, p47]. Amchitka Island, about 300 km west of Adak Island and only 130 km east of Kiska Island (about half-length between Kiska Island and Attu Island), was a flat island with a good port. If an air base was established by Allied Forces on Amchitka Island, they would be possible to make air raids increasingly during short gaps of fogs or clouds. If so, the Japanese troops on Kiska Island and Attu Island would be like chickens glared at by foxes. The occupation of the island became the next goal for the Allied Forces.
Kinkaid reading in his quarters on Adak, Aleutian Islands, 14 May 1943. https://ww2db.com/image.php?image_id=783
The Allied Forces landing day on Amchitka Island was scheduled for January 5, 1943, but was postponed to January 12 due to the bad weather. Although the day was far from ideal weather, the operation was carried out and 2100 troops landed on Amchitka Island. At that time, the destroyer "Warden" was swept away by strong winds and currents and struck a sunken rock, resulting in 14 people freezing to death in the cold sea [10, p59]. The bad weather continued, and one transport ship ran aground on the following day.
Immediately after the landing, the construction of an airfield on Amchitka Island began. The runway site had to be drained from the wetlands and covered with dry earth and sand, but the construction was time consuming because it was too muddy to use for vehicles [10, p60]. The Japanese seafighters which scouted Amchitka Island on January 24, 1943, discovered that Allied Forces had landed on the island and were constructing an air base [4, p384]. The occupation of Amchitka Island by Allied Forces gave a significant impact for Japanese on the defense of the western Aleutian Islands. Once the airbase on the Amchitka Island was completed, it was expected that heavy air raids would make transportation and supply to Kiska Island and Attu Island extremely difficult. The cost of leaving Amchitka Island unattended, knowing that it had a flat land suited for airfield, was expensive. After this, the Japanese military would make several plans to recapture Amchitka Island. However, landing operations on the island already occupied by the Allies could not have been possible given the possible damage. Again, the preparation for Allied invasion by the Japanese was too late.
Several Japanese seafighters and reconnaissance seaplanes bombed Amchitka Island five times from February 1 to 16 to disturb the airfield construction [7, p207]. However, the runway on Amchitka Island was completed on February 18, and P-40 and P-38 fighters advanced [8, p24]. The two Japanese seafighters that were scouted for the Amchitka Island on February 19 had not returned. Kiska Island radar had found that the two airplanes fought aerial battles with about 20 US fighters that took off from Amchitka Island to intercept them [7, p214]. One of the Japanese pilots was Air Sergeant Sasaki Hajime, known as the Ace, who shot down more than 20 enemy airplanes. They are believed to have reached a spectacular end during the engagement.
6-4 The fourth reinforcement
Major Iwakoshi Shinroku of the Imperial General Headquarters visited Kiska Island and Attu Island (without landing) on January 9 and 10. He found that only 40% of weapons, 60% of food, and 20% of building materials arrived due to the stormy weather and the obstructions by enemy submarines and aircraft. He reported on January 28 that, without an increase of one infantry battalion each by March, both islands would have the same fate as Guadalcanal Island [3, p537]. On February 1, Admiral Ichinomiya Nobuyuki, Chief of Staff of the Fifth Fleet, said at the Navy General Staff office that the enemy would invade after isolating Attu Island and Kiska Island by blocking the transportation, so the future policy should prioritize the transportation of the necessary supplies by the end of February. However, they estimated that the US naval forces for the invasion were about 10 ships including seaplane tenders [18, p138]. At that time, the Fifth Fleet command had insisted on the necessity to invade Amchitka Island [4, p416-417], but the result was that the Allied Forces had landed on Attu Island in May before the concrete plan for invading Amchitka Island was decided.
The Allied occupation of Amchitka Island had made the situation in the western Aleutian area imminent. The Imperial General Headquarters issued Continental Order No. 747 on February 5, and began strengthening the defenses of Attu Island and Kiska Island for the fourth time. The North Army Force, which had been tasked with defending Hokkaido and South Sakhalin and transporting supplements to Kiska Island and Attu Island, was suddenly changed to a new operational army (actual warfare army) called the "Northern Army Force" to take the charge for defending the Aleutian area [18, p140, 144]. Lieutenant General Kiichiro Higuchi, former commander of the Northern Army Force, was appointed as the new commander of the Northern Army Force.
Due to the central agreement at the Imperial General Headquarters on the same day, the North Sea Garrison left under the command of the Fifth Fleet and came under the command of newly formed Northern Army Force of the Imperial Army. The first district battalion (3 infantry battalions, 1 artillery battalion, 1 anti-aircraft battalion, 1 engineer battalion, 1 communication company) of the North Sea Garrison, headed by Colonel Masaji Sato, would defend Kisuka Island; The second district battalion (1 infantry battalion, 1 artillery battalion, 1 anti-aircraft battalion, 1 engineer company, 1 communication company), headed by Colonel Yasuyo Yamazaki, would be responsible for the defense of Attu Island [3, p245]. These became the turning point of their fates. In addition, the Navy decided to dispatch aircraft when the airfield would be completed, which was to be specified separately in the Central Agreement in the last November. However, because the airfield was built by the Army, the Navy was prudent about advancing aircraft until the airfield would be completed including the taxiways and the bunkers [19, p191]. The agreement was also to strengthen the defense of the entire Kuril Islands, and garrisons would be placed in the northern, central, and southern Kuril Islands. This defense plan also led to the construction of 15 new airfields in those areas, in addition to Sakhalin and Hokkaido, from late 1943 to early 1944 [3, p312].
Under this military central agreement, the Imperial General Headquarters decided to build defense base groups and air bases centered on Attu Island and Kiska Island by the end of March. The materials and troops for them would be transported by the end of February under the name of Operation "A-Gou" [4, p421]. And for escort of transport, four ships including the heavy cruiser "Maya" and the submarine "I-31" were incorporated into the Fifth Fleet. As a result, "Maya" would later participate in the Battle of the Komandorski Islands. This military central agreement presupposed the completion of the airfield as the condition for dispatching aircraft to Kiska Island. However, it was clear that if the US air base on Amchitka Island was completed, it would be deprived of air superiority over Kiska Island at all times. The commander of the North Sea Garrison was concerned that the air superiority would need to be secured first for the airfield construction [4, p242].
At the time of February 18, the six convoy transports planned for Operation "A-Gou" in mid-February were as follows [4, p436-438].
- The 14th Convoy for Kiska deported on February 13 (transport vessel "Sakito-Maru", "Shuko-Maru", light cruiser "Kiso", destroyer "Wakaba", "Hatsushimo")
- The 16th Convoy for Attu deported on February 14 (transport vessel "Akagane-Maru", coast defense ship "Hachijo")
- The 15th Convoy for Kiska deported on February 18 (transport vessel "Awata-Maru", light cruiser "Abukuma", destroyer "Ikadzuchi" )
- The first 18th Convoy for Attu would deport on February 19 (transport vessel "D?b?-Maru")
- The 17th Convoy for Kiska would deport on February 24 (transport vessel "Fujikage-Maru", light cruiser "Abukuma", "Kiso" )
- The second 18th Convoy for Attu would deport on February 24 (transport vessel "Yamayuri-Maru")
During this operation, on February 19, the US fleet made the naval gunfire on Attu Island as described below. As a result, the 16th Convoy "Akagane-Maru" was captured and sunk by the US fleet on the way to Attu Island on the February 20. The 14th Convoy turned back on the way and the remaining planned convoys (17th Convoy and the first and the second 18th Convoy) were canceled [4, p440]. Only the 15th Convoy, which loaded approximately 400 air defense troops, 8 25 mm machine guns, 8 13 mm machine guns, 20,000 bullets, 3 searchlights, 11 trucks, other landing crafts and protective materials, successfully transported to Kiska Island on February 22 [4, p440]. Totally, the successful transport operations were only the 15th Convoy above mentioned and the 13th Convoy (transport ship "Yamayurimaru") that had arrived at Attu Island on February 12. The remaining transports by 5 Convoys were ended unsuccessful.
6-5 The naval gunfire on Attu Island and sinking of Akagane-Maru
The Allied forces that occupied Amchitka Island feared counterattacks by the Japanese. It was believed that reinforcements would still be continued on Attu Island, which was far from Amchitka Island. Therefore, on February 19, the heavy cruiser "Indianapolis" led by General McMorris, the light cruiser "Richmond", the destroyers "Coghlan", "Gillespie", "Bankloft", and "Coldwell" [8, p24] fired the land facilities at Chichagof Harbor on Attu Island for 2 hours and 20 minutes [4, p439]. Despite the fact that the Japanese reconnaissance seaplanes in the 452 air unit had found the US fleet off Attu Island on February 16, 17, and 19 [4, p436], the naval gunfire on Attu Island was a surprise attack for the Japanese. After the bombardment, the US fleet pretended to retreat to the east and cleverly turned its course to the southwest of Attu Island [8, p25]. This was to prevent Japanese transport vessels from entering Attu Island after the US fleet would have left.
After being received the naval gunfire by the US fleet, the three Japanese reconnaissance seaplanes tried to chase the US fleet, but they could not find them due to bad weather. The commander of the Northern Army Force instructed the transport ship "Akagane-Maru", which had been waiting off the coast of Attu Island, to enter Attu Island [4, p439]. The US fleet discovered a Japanese transport ship south of Attu Island by radar around 1830 on the February 20. This was the "Akagane-Maru" that was about to enter Attu Island. This was just after the coast defense ship "Hachijo", which had been escorting her, had returned because they approached Attu Island. The US fleet fired the "Akagane-Maru" with artillery, but the ship did not sink, so the fleet launched six torpedoes. However, all the torpedoes came off or exploded before the ship. Inevitably, the US fleet fired again and finally sink it [8, p26]. The naval gunfire on Attu Island gave a small impact on the land force, but as mentioned above, it was effective in blocking the five transportations by the Japanese convoy. For the Japanese, this blocking was a major obstacle for the garrisons to strengthen their defenses to be completed by the end of March.
(to be continued)
References are listed in "Reference" in the upper right-hand side.