8-1 Preparations for the invasion operation
8.1.1 The preparations by Allied Forces
The Allied Forces saw little tactical value in the western Aleutian Islands. However, the occupation of the US territory by the Japanese forces moved the United States from a political standpoint. In December 1942, the Allied Forces planned a combined army and navy operation to retake both islands. The original plan had been to invade on Kiska Island after May 1, but in early February it was found that there were fewer military ships available than planned, and the Kiska invasion had to be rethought.
On March 3, Major General Kinkaid, Commander-in-Chief of the North Pacific Command, learned that the garrison on the island of Attu was estimated at about 500 men, and he planned to occupy Attu and Shemya Islands and build airfields there. The operation was to employ three battleships, three heavy cruisers, three light cruisers, one escort carrier, nineteen destroyers, four attack transports, one transport ship, other tankers, minesweepers, and seaplane tenders [8, p59]. The operation was approved by the Joint Chiefs of Staff on March 22 [2, p65]. The objective was to build airfields on Attu Island and Shemya Island to cut off the Japanese supply lines to the western Aleutian Islands, and to use these islands as bases for future invasion on Kiska Island [4, p559].
The planned invasion date on Attu Island was set to be 15 minutes before dawn on May 8 [8, p61]. This day was chosen as the time before foggy season [3, p306]. The foggy season actually began earlier this year, but it was impossible to advance the time any further. Subsequent reconnaissances estimated that the Japanese troops on Attu Island had 1587 men [2, p65]. The following two fleets were formed for the operation for invasion [8, p62-72].
Task Force King, Rear Admiral Thomas C. Kinkaid.
(a) Alaska Sector Escort and Supply Group, Rear Admiral John W. Reeves, Jr.: 1 Destroyer, 1 Light minelayer, 1 Minesweeper, 2 Destroyer escort(Canadian), 1 Gunboat, 3 Large minesweeper, 1 Tugboat, 4 Landing ships(Tank), 8 Landing crafts(tank, Mk. V.), miscellaneous small craft.
(b) Motor Torpedo Boat Group: 11 Motorboats.
(c) Submarine Group.
(d) Southern Covering Group, Rear Admiral Charles H. McMorris: 3 light cruisers, 5 Destroyers.
(e) Northern Covering Group, Rear Admiral Robert C. Giffen: 3 heavy cruisers, 4 Destroyers.
(f) Tanker and Service Group: 6 Oilers, 2 Destroyer tender.
Task Force Rodger (Attack Force), Rear Admiral Francis W. Rockwell.
(j) Support Group Capt. Pat Buchanan: 3 Battle ships, 1 Escort carrier, 7 Destroyers.
(k) Transport Group, Capt. Pat Buchanan: 4 Transport attack, 1 Cargo ship, 1 Troop transport, 4 Destroyers, 2 Light minelayers.
(l) Minesweeper Group, Lt. Comdr. Bernhart A. Fuetsch: 2 Light minelayers.
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The main force of the Army's ground force was the 7th Division of the US Army, led by Maj. Gen. Albert Brown, commander of the landing party. They had been training in their hometown of California in anticipation of a desert war in North Africa, but about three months before they were suddenly decided to be put into an operation to recapture Attu Island. Therefore, from February 21 to March 9, the landing training using attack transport ships was conducted in California [8, p59]. After the training, they set sail with their destinations kept secret. On April 25, as they approached off San Francisco, they were informed that they were heading to Cold Bay, Alaska, for the invasion on Attu Island [2, p61]. It was found that there was a lack of protection against the cold, but there was not enough time to improve [3, p306]. Besides the weather would be severe than they expected. The fact that troops for North Africa were used as they were without fully considering the climate of the Aleutian Islands was one of the causes of the increased sacrifice later.
The invasion on Attu Island was named Operation Landcrab. It was supposed to land 11,000 US and Canadian troops, mainly the 7th Division, in Massacre and Holtz Bays in the southern and northeastern parts of Attu Island, respectively. (Other than that, it was supposed to make a small landing in the Blind Cove and Sarana Bay). The invasion operation was planned for the main 8,000 soldiers lainding on Massacre Bay and another 3,000 soldiers on Holtz Bay. Then they would push Japanese troops from south and north into Chichagof Bay in the easternmost of the island, where the Japanese military was based. [8, p72]
Against the Japanese ground troops, estimated at only 1,350, the Allied Forces prepared more than 10,000 soldiers, more than 60 naval vessels, and 200 aircraft. About one brigade was placed on Adak Island as a reserve force. Moreover, it was planned that Attu Island would be bombed from air and be bombarded by naval artillery in advance. During the landing, repeated bombings were planned, not only by land-based aircraft, but also by ship-borne aircraft from an escort carrier. Supports for fire from the ship's artillery using helping from seaplane reconnaissance aircraft was also planned. So a naval fire control unit was included in the landing force for communication for pinpoint bombardments by ship's artillery [8, p72]. It was estimated to take three days for the occupation [16, p19]. At this time, Allied Forces were on the offensive in the Solomon Islands in the South Pacific, and two months later, the Sicily landings were planned in the Mediterranean Sea. The Allied Forces had mobilized almost all of their forces in the North Pacific for the invasion on Attu Island.
8.1.2 The preparations by Japanese troops
Before the Allied invasion, the Japanese force on Attu Island was actually 2,500 men of the Second District Unit (Attu Garrison) of North Sea Garrison led by Colonel Yasuyo Yamazaki. They were consisted of one and a half infantry battalions, and one engineering corps. They held their food until mid-July [18, p427]. Except the garrison command and navy, the Second District Unit was consisted of the local district unit of Chichagof Bay led by Battalion Commander Major Watanabe, the Massacre Guard unit led by 1st Company Commander Lieutenant Hayashi, the local district unit of Holtz Bay led by the North Kuril Island Fortress Infantry Commander Lieutenant Colonel Hiroshi Yonekawa, the anti-aircraft artillery corps, and the units under the direct control of the command (engineer units, communication units, field hospitals), and reserve units [3, p295]. They were equipped with twelve 75mm anti-aircraft guns, six each of 20mm and 13mm anti-aircraft guns, and four 75mm howitzers [2, p67].
On Attu Island, the construction of defensive facilities considerably delayed, since the island had once removed after destroying the materials in last September and the construction of an airfield was prioritized after the re-occupation of the island in November. In the end, the airfield construction only weakened the defenses of Attu Island. While the Chichagof Bay local district unit almost completed the defense except the mountain positions, those of the Massacre Bay Guard unit was 70% of completion. Most of the guns were exposed or only partially disguised because materials had not arrived. The construction of air-raid shelters and other facilities were also delayed due to the hard bedrock and the non-arrival of construction materials [3, p299].
The North Sea Garrison on Kiska Island was aware of the Allied Forces' movements through intercepted communications and other means. The "Detailed Report on the Battle of Attu Island" by the headquarters of the North Sea Garrison on Kiska Island recorded the followings. "The enemy was persistently bombing Kiska Island, and conducting vigorous searches of the area around Attu by their fleets. Also, they are persistently conducting reconnaissance of the coastal areas by airplanes and submarines. These are showing strong indications of a counteroffensive to the Japanese. In particular, the intelligence reports indicate that, on April 26, the enemy fleet launches a sortie from the base of the Crook [in Adak Island] ... and there is a strong suspicion that a powerful fleet is in action. Therefore, the garrison is on high alert, and is diligently promoting airfield constructions" [3, p266].
Since there was a high possibility of the enemy invasion on Attu, the Second Disctict Unit on Attu was being placed in combat positions from May 3 and it remained for nearly a week. However, as mentioned below, the Allied landing schedule was delayed due to the bad weather. Therefore, the Second Disctict Unit Command thought that the Allied fleet had gone elsewhere, and relieved their combat deployment on the May 9 [3, p320]. The Second Disctict Unit Command seemed to believe that even if the Allied Forces had come, it would have been difficult to land on the island in this deep fog.
8-2 Allied invasion on Attu
It was decided that the US fleet for Attu invasion would leave Cold Bay on May 4 and the invasion operation would be conducted on May 9. However, due to bad weather on the day, the departure was postponed to May 5, and the invasion date was also postponed to May 10. Moreover, due to the continued bad weather after the departure, the invasion date was further postponed to May 12 that the weather was predicted to recover [8, p72].
On May 8, the Allied Forces dispatched the supporting group of Task Force Rodger and the southern supporting group of Task Force King to the west of Attu Island, assuming an attack by the Japanese fleet, but could not find any fleet. They backed and joined the invasion fleet 200 km north of Attu Island on May 11, but the destroyer "McDonough" and the minesweeper "Cicard" collided in the fog. The two ships returned to Adak [2, p66]. It was also a foggy day on May 12 unlike the forecast, but the invasion operation was carried out, which was a three days delay from the initial plan.
8.2.1 Landing on the north area (north of Holtz Bay)
Attu Island was covered in fog on May 12. The reconnaissance units of 105 and 109 men, transported by the US Navy's largest submarines "Narwhal" and "Nautilus", respectively, landed safely by inflatable rafts in Blind Cove in the northern Attu at 0010 in the middle of the night [8, p73]. However, another 165 reconnaissance soldiers, aboard the subsequent transport destroyer "Kane", landed after seeing the beach at dawn because they could not find the beach they were to land on [8, p74]. There was no Japanese resistance during the landing in Blind Cove [8, p76]. Their role was to go south and to cross the snow-capped mountains to the west of the West Arm. Then, it was planned that they were to restrain the Japanese artillery position there from the west to ensure the safety of the main force coming from the Holtz Bay in the east [3, p326]. However, lacking sufficient protection against the cold, the reconnaissance units had difficulty advancing due to the rugged snow-capped terrain, cold weather and hunger. About 230 of them were barely able to join the main invasion troops from Holtz Bay at the West Arm on May 16 [2, p76]. However, this operation was not very successful.
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| Map of the Attu invasion by Allied Forces |
At Holtz Bay, one of the main landing points, nothing was visible at dawn because of fog. Nevertheless, the Allied Forces began landing on the narrow sandy beach north of Holtz Bay using SG radar. There was no information on the geography of the area. To investigate whether the geography was suitable for landing, a scouting party first landed at 0427. However, as no further contact from them could be made after their landing (it might be due to malfunctions by wet fog for electronic equipment), the transport commander started a full-scale invasion at 0910 by his own decision using 29 landing craft (LCVP) [2, p69]. The landing crafts were often lost their ways in the fog, and the commander had to search them [8, p74]. Nevertheless, by 1500, 1100 men of the 1st Battalion, 17th Regiment, led by Colonel Culin, commander of the Northern Landing Force, succeeded in landing [8, p76].
USS Heywood (APA-6) hoists out LCVPs, off Attu on the first day of the invasion, 11 May 1943. Note binnacle mounted in front of the ship's open bridge, in the lower left.
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The Japanese army was bombed by the American military aircraft from early this morning as usual. The visibility was very low due to fog. Returning a Daihatsu (Japanese landing craft) for reconnaissance, the Japanese firstly noticed the Allied Forces was invading at Massacre Bay around 1000-1030 [3, p324]. The Navy troops on Attu Island sent the first report of "Enemy landing on Massacre Bay" to the Imperial General Headquarters at 1300 [3, p335]. At 1320, it was reported that Allied Forces was also invading on Holtz Bay. These landings were surprise attacks for the Second District Unit. They immediately strengthened their defensive positions [3, p325] and dispatched officers to various places to confirm the invasion by the Allied Forces.
There was no Japanese resistance in Holtz Bay, but at 1015 the battleships "Pennsylvania" and "Idaho" made covering fire for about an hour using SG radar in the fog [8, p74]. Capt. Corn, commanding officer of the Pennsylvania, said "The SG radar is essential for combatant ships operating in the Aleutian area. The SG radar repeater (PPI) installed on the navigation bridge was invaluable." [8, p73]
The Allied Forces began advancing toward West Arm, deep in Holtz Bay, at about 1300 and had advanced nearly 3.2 km by the end of the day. They encamped there with fog obscuring their surroundings at about 1700. The location was about 500 m before a Japanese high ground base (Shibadai Highland) near the halfway point between the landing point and West Arm [3, p329]. At this rate, it was expected to secure the airfield at East Arm in the deep of Holtz Bay the next day [8, p76]. However, the Japanese forces, who had withdrawn from the position, deployed troops to the Shibadai Highland base during the night [3, p329].
West Arm and East Arm in the deep of Holtz Bay had sandy beaches suitable for landing, but the surrounding area of Holtz Bay was mostly reefs and rocks. It is believed that the Japanese forces expected the Allied Forces to invade directly on a sandy beach of West Arm or East Arm. If the Allied Forces had invaded there, they would have been met with strong Japanese counterattacks. However, they invaded on the north of Holtz Bay, which was only a narrow sandy beach. The Japanese did not expect the Allied Forces to land there at all, as it was not large enough for landing and accumulating supplies. However, if they were to land near the entrance to Holtz Bay and press the Japanese forces from the north, it would be the only possible landing point. That shows the circumspection of the Allied forces' operation.
Soldiers climb down cargo netting to board landing craft alongside USS Heywood (APA-6), off Attu on 11 May 1943. Note the M1 carbines carried by some of these men.
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8.2.2 Landing on the south area (Massacre Bay)
In Massacre Bay, the fog was even deeper than in Holtz Bay. On top of that, the landing was difficult due to the discovery of numerous shoals and reefs that were not shown on old nautical charts. To avoid collisions due to the deep fog, th fire support from the bay planned by two destroyers was suspended [8, p74].
Destroyer USS "Pruitt" and landi
ng crafts from USS Heywood moving toward Massacre Bay, Attu, Aleutian Islands, US Territory of Alaska, 11 May 1943.
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The transport vessels began unloading landing crafts at the planned location in the bay at 0315, but some crafts were missing due to fog, so it was decided that the landing was put off and would begin at 1030. The minesweeper "Pruitt", commanding the landing crafts, was guided into the launching position by the destroyer "Dewey", which had SG radar, but could not see any beach by fog [8, p75]. At 1020, the "Pruitt" departed for the shore with 12 LCPs of the first landing wave; at 1030, she departed with 13 LCPs of the second wave. However, the first wave was swept away by the current in the fog and its course was blocked by a cliff. The first wave arrived at the beach around 1120 at about the same time as the second wave since the first wave was correcting its course. Upon landing, the ship encountered no resistance from the Japanese [8, p75]. The "Pruitt" changed her plan and approached the beach until it was in sight. The rest of the landing party scheduled at 1140 also landed. One landing craft hit a reef, at which point the ramp (landing door) opened and sank, and four soldiers drowned. That was the only casualty during the landing [8, p75].
The abrupt invasion by Allied Forces on the Bay in a fog surprised the Japanese platoon guarding the beach and the Japanese platoon retreated [3, p341]. The 20 mm anti-aircraft machine gun positioned at a highlands near the beach, which was in an good attack position overlooking the shore of Massacre Bay, was left with a large quantity of ammunition [3, p331]. By 1630, totally 2000 men of the 2nd and 3rd Battalions of the 17th Infantry Regiment, and part of the 2nd Battalion of the 32nd Regiment, led by Colonel Earle, commander of the Southern Landing Force, had successfully landed without resistance. A command post was established on the beach at 1830 [8, p76]. The head of the landing party advanced about 2.5 km north through a steep inland ravine where it came under Japanese fire from a ridge. They were stopped 600 m before Jarmin Pass by heavy fire from the front and flank. They could advance no further [3, p332].
American troops at Massacre Bay, Attu, Aleutian Islands, US Territory of Alaska, 12 May 1943
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In Massacre Bay, LCPs loaded with troops and supplies were shuttled between the shore and the transports, and the narrow beach was crowded with landing craft. Moreover, trucks and tractors landed on the beach could not move from the shore due to the muddy ground [10, p79]. The supplies were mainly unloaded by human power.
8.2.3 Situation on May 13 (the second day after landing)
The next day, May 13, the visibility was poor as thick fog covered the mountains all day. The battleship "Pennsylvania" fired radar-based gunfire at 0658 in the fog against anti-aircraft gun positions in Holtz Bay for ground support. Aircraft from the escort carrier "Nassau" also bombed and shot. However, considering the changeable condition of clouds and fog, the numbers of available aircraft were normally limited to four and a maximum of eight [8, p83]. In addition, large bombers from Amchitka Island also bombed. These aircraft came under heavy flak from two Japanese positions in the East Arm [8, p76], so the battleship "Idaho" opened fire on them at 0900. The "Idaho" also opened fire at 1037 against the West Arm, where the ground troops encountered heavy resistances [8, p76-77].
Fierce battles ensued at Shibadai Highland, where the Japanese had deployed the troops during the night. The advancing landing unit was exposed to Japanese fire and became pinned down. The Allied troops requested air supports from ship-borne aircraft and supporting fire from destroyers, and the 105 mm howitzers recently installed on the shores of Holtz Bay provided supporting fire [2, p71]. With these supporting attacks and hand‐to‐hand fights, the Shibadai Highland was finally occupied by the Allied Forces by the evening [3, p344]. However, no further advance could be made that day. On this day, the battleship "Pennsylvania" was struck by torpedoes from the Japanese submarine "I-31". The Japanese judged her to be hits [3, p343]. By the US Navy document, though their wakes were confirmed, the torpedoes were avoided [8, p77]. The "I-31" was never heard from again after May 14 [4, p556].
On this day, visibility improved slightly in Massacre Bay, and the landing crafts engaged in transporting supplies managed to see each other. As the minesweepers finished their sweep, the attack transports (APAs) were anchored 500 meters closer to shore. This increased the efficiency of transport by landing craft [8, p76]. The Japanese took up their positions on highlands 3 to 4 km inland from Massacre Bay [8, p76]. As the Allied Force moved north up the valley toward Jamin Pass, they were pinned down by heavy machine gun fire from the Japanese positions on the highlands. The Japanese held several positions in the highlands, and fog obscured them [3, p345].
US Army soldiers unloading LCPR and LCM type landing craft on the beach at Massacre Bay, Attu, Aleutian islands, 12 May 1943.
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The battleship "Nevada" succeeded in destroying some of the positions on the highland facing Massacre Bay by firing guns under instructions from the fire control unit. The Japanese War History Series "Army Operations in the Northeastern <1>" stated that the fire was particularly intense [3, p342]. The US document also reported the weapons dismembered by the bombardment and the bodies of Japanese soldiers around there [2, p71]. Even so, the landing force was unable to advance any further north due to the heavy Japanese machine gun fire [8, p77]. At this time, Colonel Earle, commander of the 17th Infantry Regiment and commander of the Southern Landing Force, was killed in action during reconnaissance, and Colonel Zimmerman took over command of the Southern Landing Force [2, p74].
On this day, Massacre Bay was in a state of chaos. The trucks, tractors, and other vehicles that had landed could not be used on the beach because of the muddy conditions, and many soldiers had to be assigned to the task of unloading supplies [8, p77]. Many soldiers were mobilized to unload anti-aircraft weapons that were not needed for the time being, and they had to stand in line to hand-deliver supplies. Ammunition shipments were prioritized over winter supplies for the freezing soldiers on the front lines [2, p74]. The landing force commander, Major General Brown, was faced with the dilemma that even if he wanted to increase the number of soldiers needed for unloading, he could not land the soldiers without first completing unloading tasks on the beach.
On this day, the Fifth Fleet of the Imperial Navy received a report about the US fleets that were sighted from the Attu Garrison. According to the report, the US fleets consisted of one aircraft carrier (without a bridge), one heavy cruiser, one light cruiser, and two destroyers at Holtz Bay, and one battleship, six cruisers and destroyers, and ten transports at Massacre Bay [4, p531]. On the same day, the Combined Fleet sent 21 twin-engine attack airplanes of the 752 Air Force to Paramushir [4, p547]. The large flying boats of the 801 Air Force were also ordered to advance to Paramushir, but they did not actually advance until the May 20 in order to prepare the condition to receive the aircraft in Paramushir. The commander of the 752 Air Force arrived in Paramushir on May 23 with 24 attack airplanes and 4 transport airplanes [4, p547]. The attacks by these airplanes are described later.
8.2.4 Situation on May 14 (the third day after landing)
On May 14, the visibility remained poor due to fog [8, p78]. At 0815, 19 attack airplanes of the Japanese 752 Air Force launched from Paramushir equipped with torpedoes, but they abandoned the attack and turned back due to dense clouds and fog [3, p354]. The US Forces continued to unload supplies, and by 1900 the supplies unloaded was 55% for attack transports (APA) and 14% for transports [8, p79].
Soldiers unload landing craft on the beach at Massacre Bay, Attu, on 13 May 1943. LCVPs in the foreground are from USS Zeilin (APA-3) and USS Heywood (APA-6).
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On this day, at Holtz Bay, the Allied Forces advanced further from Shibadai Highland, but stopped because of mortar and machine gun fire from the West Arm jetty. However, the artillery fire from newly established artillery positions near Shibadai Highland and shootings from the "Nassau"'s shipboard airplanes stopped the Japanese fire from West Arm. The landing troops set up an artillery position near West Arm, but even the artillery fire from there failed to destroy the three Japanese artillery positions consisting of six 75 mm guns in West Arm [8, p79]. On the other hand, the Japanese were beginning to feel difficult to hold West Arm due to Allied Forces' heavy fire [3, p352].
On the Massacre Bay side, the naval gunfire was directed toward the Jamin Pass area. However, the Japanese positions were skillfully constructed on steep ridges and deep mountain sides, making them extremely difficult to destroy in poor visibility [3, p354]. The Allied troops had to climb up the valley floor toward Jamin Pass, which was surrounded on three mountain sides with the Japanese positions. The Japanese positions on highlands were hidden by fog, by contrast, the Allied movements on the valley floor were in full view from above when the fog had lifted. In the afternoon, when the fog lifted, the Allied Forces began their attack on Jamin Pass. They temporarily closed to within 200 m from the pass even under the fire by the Japanese mortars and heavy machine guns, but returned to their starting point by sunset [3, p355].
Soldiers advance across a hill near the Attu coast, as the fog rolls in, 13 May 1943.
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8.2.5 Situation on May 15 (the fourth day after landing)
The fog did not also recover this day, and the Japanese air attack from Paramushir was cancelled. After covering fire to the Holtz Bay area from the artillery positions and the battleship "Pennsylvania", the Allied troops newly landed attacked West Arm from 1100. The supporting fires in close coordination with the fire control unit destroyed the well shielded Japanese positions [8, p79]. The battle at Holtz Bay was culminated. As the battleship's ammunition was running low, the destroyer "Phelps" raced into Holtz Bay to provide support bombardment according to the instructions from observation planes. The ship succeeded in inflicting heavy damage on the Japanese positions [8, p79]. The Japanese reported that "the West Arm area was almost completely destroyed ... by shelling and bombing" [3, p. 362]. This put the East Arm across the hillside in jeopardy as well. The Japanese food and ammunition were stockpiled in West Arm and East Arm, but all boats were destroyed even if they attempted to transport them. The Japanese had no other option but to retreat to their headquarters at Chichagof Bay without food and ammunition. They thought that it would be difficult to hold out there without supplies from Paramushir [4, p538].
In the Massacre Bay area, the Allied attack on Jamin Pass was fierce from early morning. With support gunfire of naval vesselos and fires from artillery positions, the Allied Forces approached again within 200 meters from Jamin Pass. However, the Japanese counterattacks drove them back to 900 m [3, p362]. At the request of the landing force headed for Jamin Pass, US F4F fighters launched from the escort carrier "Nassau" provided the ground support on two occasions. However, a total of four fighters under cloud were brought down by localized strong winds [8, p80]. The Japanese reported that the anti-aircraft fire shot down three planes [3, p364]. However, the Japanese garrison found it difficult to hold Jamin Pass as one platoon was wiped out, and in light of the situation at Holtz Bay in their rear, they were forced to decide to retreat to the Chichagof Bay area as well [4, p538].
Photo of USS Nassau, underway in December of 1942. This photograph has been retouched by wartime censors to hide radar and other antennas on the ship's mast.
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Rear Admiral Kinkaid, Commander-in-Chief of the North Pacific Fleet, wanted to finish the attack on Attu Island as early as possible, fearing a Japanese fleet attack. He asked Rear Admiral Brown, commander of the landing force, to report on the progress of the battles. He reported that the Japanese had established a strong position on the steep ridge (Jamin Pass) between Massacre Bay and Holtz Bay and that there was not much progress on the battle line because there were more Japanese soldiers than expected [8, p79]. Kinkade was not happy with this report.
In Massacre Bay, the landing of supplies went smoothly, and by the May 15, more than half of the supplies were completed unloading from the attack transports. On the other hand, the transports finished unloading supplies only 30% of their plan [8, p.80]. In Holz Bay, only a narrow channel could be used due to reefs, which made difficult for the landing crafts to make their round trip. Also, when the fog lifted, the unloading of supplies was often disturbed by bombardments from the Japanese base at the Chichagof Bay area [8, p80].
8.2.6 Situation on May 16 (the fifth day after landing)
Landing force Commander Rear Admiral Brown requested a meeting with Landing fleet Commander Rear Admiral Rockwell, North Pacific Fleet Commander Rear Admiral Kinkaid, and Western Area Defense Force Commander Lieutenant General DeWitt [8, p80] to share with the command situation requiring the introduction of reserve forces. At this meeting, General Brown revealed from the seized documents that there were between 2,000 and 2,500 Japanese soldiers, which was more than initially expected. Rockwell agreed to mobilize reserve forces. He also proposed use of small boats, such as tugboats and barges, which could easily maneuver around the bay for the landing of supplies. He also proposed that the landing phase be completed and that the escort fleet including battleships be pulled up although air power continue to support [8, p80].
Later, Brown visited Rockwell on the battleship "Pennsylvania" and again suggested to him that all available forces had been committed and he could not secure Attu Island without the introduction of reserve forces. Rockwell reported the Brown's suggestion to Kinkaid, and also proposed that two attack transports could be turned around to Adak for the transport of the reserve force [8, p80].
Although there was fog at Attu on this day, the Japanese garrison judged that flight was possible because the visibility was 10 to 15 km. However, no attack airplanes launced from Paramushir [3, p372]. The submarine I-35 torpedoed a light cruiser off Holtz Bay and detected two sound hits. The torpedoes actually attacked was the battleship "Pennsylvania", but the torpedoes did not hit her [4, p557]. The submarine "I-35" was damaged by the destroyer's attack but returned to Paramushir on May 19.
USS battleship Pennsylvania. She was preparing for the bombardment of Attu Island in the Aleutians, 11 May 1943.
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The fog was thick until May 15, but from May 16 the fog faded, and the visibility became 10 to 15 km. As the weather improved, the Japanese positions were exposed and were destroyed by artillery fire and bombing. In the Holtz Bay area, the Allied Forces moved into West Arm, while the Japanese withdrew into the East Arm in Holtz Bay, abandoning their stockpiles of food and ammunition [3, p372-373]. This meant that the Japanese forces at Jamin Pass, which had been holding off the Allied Forces advancing to north from Massacre Bay, were now threatened from the rear. In addition, the Japanese forces at Jamin Pass were almost wiped out by the naval gunfire [3, p370] as the weather cleared. Although East Arm also had food, ammunition, and an airfield under construction, Col. Yamazaki, the commander of the Second District Unit, decided to abandon Jamin Pass and East Arm as well and to redeploy his forces to the Chichagof Bay area during the night [3, p370, 374]. The Attu Garrison requested emergency transport of ammunition and food to the Northern Army [3, p370]. However, Imperial General Headquarters could not find any transport measure (described later).
8.2.7 Situation on May 17 (the Sixth day after landing)
The Allied Forces attacked Holtz Bay intensively on this day. Shipboard aircraft from the escort carrier "Nassau" bombed targets in Holtz Bay, but two aircraft were lost. The destroyer "Abner Reid" supported the attack in Holtz Bay. Two P-38 fighters from Amchitka Island opened fire from under low clouds, but three large bombers could not throw their bombs due to the clouds [8, p81].
On this day, Rockwell was informed that one reserve regiment was scheduled to depart from Adak Island and arrive the next morning. The ships of the task force Roger, including the battleships, completed their support and pulled north [2, p77]. However, the gunboat "Charleston", the destroyer "Phelps", and the seaplane tender "Casco" were left behind to provide support. The ships of Task Force King remained behind to support the landing forces and continue the blockade of Attu Island [2, p77]. Later in the evening, Rockwell was informed that the landing force commander had been replaced by Rear Admiral Landrum on Kinkaid's orders, and Brown was removed [8, p81]. Several troubles of the 7th Division might not be Brown's responsibility, such as its inadequate equipment and underestimation of the number of Japanese soldiers. However, the sheer number of casualties and the delay in the progress of the operation seemed to lead Kinkaid to question Brown's ability to command.
8.2.8 Situation on May 18 (the Seventh day after landing)
On the 18th, the Japanese forces withdrew from the Holtz Bay area, including the East Arm where they had been building an airfield. At 1600, the landing force commander, Major General Landrum, reported to Kinkaid that he had cleared the Japanese forces from the East Arm of Holtz Bay [8, p81]. The Japanese also withdrew from Jamin Pass on the night of May 18 where their rear defenses of Holtz Bay were emptied. The Japanese casualties by May 18 were reported to be about 400 [3, p. 388]. Before noon on May 19, the Allied troops moving south from Holtz Bay were joined by the troops moving north from Massacre Bay near Jamin Pass [8, p. 81]. The Japanese took an endurance measure by retreating to a line around Chichagof Bay, where their headquarters were located. This clarified the result of the landing operation, and the Allied Forces renamed the landing force Army of the Occupation of Att's Island [8, p81]. The Japanese War History Series "Army Operations of the Northeastern <1>" gives the date of the Japanese withdrawal from Jamin Pass and the joining of American forces as the night of May 17 [3, p390].
On May 18, the 3,000 men of the reserve regiment requested by Major General Brown arrived at Massare Bay [8, p81]. On May 18 and 19, both Allied and Japanese forces took a break to organize the front. However, the Japanese forces that withdrew from East Arm, where they had stockpiled food and ammunition, were plagued by shortages of ammunition and food from then on. Around May 20, even soldiers on the front line had only 10 or 20 bullets. It is noted that the Japanese troops could be supplied with only one meal a day, and some soldiers went mad from cold and hunger, while others committed suicide [3, p380-381].
United States troops hauling supplies on Attu in May 1943.
https://commons.wikimedia.org/wiki/Aleutian_Islands_campaign#/media/File:Hauling_supplies_on_Attu.jpg
References are listed in "Reference" in the upper right-hand side.
8-3 Response of Japanese upper management to the Allied invasion on Attu Island
8.3.1 Response of the Imperial General Headquaters
On the morning of May 12, the day the Allied Forces invaded on Attu Island, as it happened, the Imperial Navy Staff gathered officials from the First Department (Operations), the Third Department (information), and the Special Affairs Group (Communications Intelligence) to study future vigilance ways of the northern area. On that occasion, the Fifth Section Chief of the Third Department said, "The US Department of the Navy has announced the Aleutian offensive, and the Intelligence Bureau is publicizing it to corroborate this. They are planning to invade within this month or next month. It is important to note that they make even clear about the (invasion) time.” He thought that there is a big possibility that "Attu Island" would be invaded first [19, p. 243]. However, when they received the report in the afternoon that the Allied Forces actually invaded on Attu Island, the Imperial General Headquarters and others were caught by surprise. At that time, the Chief Staff of the Northern Army stated, "The Allied invasion on Attu Island was a surprise to all of us. The invasion of the US forces was truly sudden for the local forces, ・・・and the fact that they landed from the southern coast, where the defenses were not yet completed, was surprising in the sophistication of the intelligence and operational guidance by the US forces." [3, p 334].
On May 13, the Imperial Army Staff and Imperial Navy Staff held a joint meeting to draft the guideline for defense operation. The guideline drafted was to attack enemy ships with naval aircraft on the assumption that the garrison would continue to hold Attu Island, in the meantime, the reinforcements of forces would be sent to Attu Island to attack the Allied invasion forces [3, p346-347]. The question was how and when to deliver the reinforcements, since preparations would take time. The Imperial Army considered creating an infantry regiment of about 4,000 men as an emergency deployment, but it was estimated that these men would leave Otaru on May 20 and arrive at Paramushir on May 25 at the earliest [19, p. 250]. Moreover, there was no prospect of transportation beyond Paramushir. It would take another month to mobilize the division's main force. The first question was how long the Attu Garrison would be able to hold the island [18, p436].
As previously mentioned, the US fleet reported from Attu Island on the May 14 was not so big, and consisted of one battleship, one special carrier, two heavy cruisers, three light cruisers, seven destroyers, several submarines, and four transports each being unloaded in Holtz Bay and Massacre Bay [4, p531].
When the Allied Forces invaded on Attu, the Chief of Imperial Army Staff Hajime Sugiyama was on a business trip to China, accompanied by Chief of the 2nd Section (Operations) Joichiro Sanada. They hurried back to Tokyo on May 14 upon hearing that the Allied Forces had invaded on Attu Island. The official joint study of the Imperial Army Staff and the Imperial Navy Staff was conducted at the Imperial General Headquarters on May 15. This study was generally concluded after three days of discussion. The concluding policy was as follows: The Attu Garrison holds the island until at least the end of May. In the meantime, by means of shipping supported by strong sea forces, the imperial army reinforces troops on Attu Island, occupies Semichi (Shemya) Island nearby Attu, and deploys forces to the Kuril Islands to defend northern Japan. The Combined Fleet then prepares for a fleet decisive battle that would most likely result from these transport operations [19, p263].
The first issue, then, was how long it would take to prepare the troops to repel the Allied Forces and how they would be transported. In the study on May 16, it seemed possible to send 6,000 men from the 26th Infantry Regiment from Paramushir until May 27 and another 7,000 men from the 27th Infantry Regiment until June 3 by total ships of 100,000 tons [3, p377]. For the time being, ammunition, food, and other supplies in order to hold Attu Island were planned to be transported by underwater barges called 'Unkato' towed by submarines, which had just been developed at that time, and by parachute drops from aircraft. Even so, the arrival of ammunition and food on Attu Island was considered to be around May 28.
As for ship transports, a cover by fighter planes to Attu Island was impossible due to their range, and if fog lifted, there was no way to guard transport ships. Considering that taking for one day before and after the entry into the Attu Island and two days for unloading, at least two-thirds of transport ships were expected to be sunk by enemy air attack [3, p377].
Thus, Operation "Te-Gou" was planned to thwart enemy air attacks. Operation "Te-Gou" consisted of a surprise invasion on Amchitka Island by forces of 700 paratroopers, 300 troops transported by submarine, 360 troops transported from Kiska Island by large motor boats, and 800 troops transported by destroyers (a total of 2010 men). This force would hopefully occupy the island, but if not, the plan was to use it as a throwaway to temporarily disable the airfield [19, p268]. There was also debate over whether the objective was to destroy air bases or to lure out the enemy fleet [19, p268]. However, given that the "Te" in Operation "Te-Gou" was from “Ten-yu (the Providence of God)” in Japanese, many questioned the success of this operation. The consideration of Operation "Te-Gou" was inconclusive, and the issue was continued [3, p378].
In the end, what was planned by May 16 was as follows. A transfer of troops from Kiska Island by three submarines (50 men per submarine), transports of supplies from the mainland by submarines (arriving around May 27 or 28), and parachuting of supplies from aircraft (carried out around May 24) [3, p379].
By May 17, however, the situation on Attu had changed. As mentioned above, on May 16, the Attu Garrison decided to withdraw from East Arm and Jamin Pass. This meant that the airfield construction site in East Arm would be occupied by the Allied Forces, and it was assumed that the airfield would then be developed and used by them. Both the Imperial Navy and the Imperial Army were forced to consider operations based on the assumption that the Allied Forces would use the airbase on Attu Island [3, p386]. Then, the only thing that could be done by the Japanese was abrupt assaults using destroyers. The idea of directing the destroyers for Operation "Te-Gou" to the relief of Attu was considered, but it was also argued that the destroyers should rather attack enemy transports or naval vessels [19, p272]. In the end, the official joint study on May 17 was inconclusive, with the only conclusion that the previous day's decisions should not be implemented.
After the official joint study, the Imperial Navy conducted its own study of the attack on Amchitka Island. It was to transport 3,350 soldiers using the battleships "Fuso" and "Yamashiro" and two light cruisers, and the invasion on Amchitka Island was expected to be around May 27 at the earliest [19, p275]. By contrast, the Imperial Army concluded by their independent study that "the possibility of holding Attu Island was small, and fog was unlikely to be relied upon very much. The Navy's chances of a naval fleet decisive battle were also small. The only thing that could be done was Operation "Te-Gou", but the probability of success was estimated to be 20%. Operation "Te-Gou" would be unfeasible until the end of May due to weather difficulties, delays in assembling troops, and delays in battle preparations [19, p278].
Based on the individual Army and Navy studies, the official joint study was held again on the following May 18. As a result of the study there, the conclusion would be reached to abandon Attu Island, as described in below. The major factor to the conclusion at the official joint study was the loss of the airfield construction site on Attu Island. However, the Allied Forces ignored that occupied site and built new airfields on the coast of Massacre Bay and on nearby Shemya Island. These were probably because the US forces questioned the Japanese military's ability to construct airfields, and chose new sites with better conditions if they were going to rebuild them almost from scratch.
8.3.2 Response of the Combined Fleet
Upon receiving reports of the Allied invasion on Attu Island, the Imperial General Headquarters speculated that a powerful task force consisting of three or four aircraft carriers was in the waters north of Midway, planning to support the invasion and to launch an air assault on the Japanese mainland [19, p244]. Following the official joint study of the Imperial Army and Imperial Navy, on May 13, the Imperial General Headquarters notified the Combined Fleet of its "policy to gather as large forces as possible in the northern area and secure the northern front" [4, p535]. The Combined Fleet had just completed Operation "I-Gou" in South Pacific in April, with half of its ships in the vicinity of Truk Island. On May 14, the command of the Combined Fleet issued an order that the major naval vessels assemble at Yokosuka by around May 22, and advance to the eastern sea of the Kuril Islands in late May to defeat the enemy Task Forces and support the Northern Army [3, p359].
Based on this operation order, naval vessels gathered in Yokosuka one after another. On May 21, the aircraft carriers "Shokaku", "Zuikaku", and "Zuiho", the 7th Squadron, the light cruisers "Agano" and "Oyodo", the destroyers "Hamakaze", "Arashi", and "Yukikaze", and the 10th Destroyer Group arrived in Yokosuka. On May 22, the battleship "Musashi", the aircraft carrier "Hiyou", the 3rd Squadron, the 8th Squadron, the 61st Destroyer Group, the 27th Destroyer Group, and the destroyer "Umikaze" arrived from Truk Island [4, p551]. At that time, the remains of General Isoroku Yamamoto were brought aboard the battleship "Musashi", and his death in battle was announced.
The Japanese Task Force's sortie from Yokosuka was tentatively scheduled for May 29, and the final decision was to be made according to the situation in the northern area by that date [19, p299]. However, as described below, the operation order would be cancelled on May 29 due to the annihilation of the Attu Garrison [4, p552]. On the other hand, the departure of the leading warships from Truk Island would afford for the US military to invade on Rendova Island in the Solomon Islands at the end of June. The response of the Combined Fleet Command is discussed again in 8.5
8.3.3 Response of Fifth Fleet and Northern Army
When the Allied Forces invaded on May 12, the light cruiser "Kiso" and destroyer "Wakaba" of the Fifth Fleet were escorting the seaplane carrier "Kimikawa Maru" to Attu Island. The attack on the invasion fleet was planned using seaplanes aboard this "Kimikawa Maru" on May 12 and 13, but was cancelled due to bad weather [4, p536]. The Commander-in-Chief of the Fifth Fleet immediately led the available heavy cruiser "Maya" and destroyer "Shirakumo" to depart from Paramushir on May 12. Then, he planned a joint attack with the above fleet. However, due to thick fog, the heavy cruiser “Maya” and the destroyer “Shirakumo” were unable to join the fleet, so the joint attack was also cancelled, and they returned to Paramushir on May 14 [4, p537].
The Japanese submarines "I-31", "I-24", and "I-35" also began combat actions toward Attu Island. As mentioned above, the submarine "I-31" struck the battleship "Pennsylvania" by torpedoes on May 13, but the torpedoes were evaded. On the same day, two US destroyers attacked a submarine in the water, and the submarine surfaced and went underwater again under fire. This is believed to have been the last of the submarine "I-31" [4, p557]. The submarine "I-35", as also mentioned above, struck the battleship "Pennsylvania" by torpedoes on May 16, but failed to hit her and returned to Paramushir after being damaged [4, p557]. Other than these, several submarines were engaged in transports and patrols in the western Aleutians, but these attacks by two submarines were the only attacks by Japanese naval vessels.
The Northern Army assembled 4,700 men at Otaru in Hokkaido on May 14 and began preparations to transport them by northern shipping convoys [3, p357]. The preparations for their departure from Otaru to Paramushir were almost finished on May 21. However, the decision of cancelling the dispatch of Attu reinforcements was communicated on the same day, as described below [3, p412].
8.3.4 Decision to abandon Attu Island
As noted above, the Attu Garrison became unable to defend Jamin Pass on May 16 due to exhaustion of soldiers and lack of supplies in Holtz Bay, back of Jamin Pass. Colonel Yamazaki, commander of the Second District Unit (Attu Garrison), decided to abandon Jamin Pass and the East Arm. Upon hearing of this decision, the joint meeting at the Imperial General Headquarters on May 17 was governed by the atmosphere that reinforcements to Attu Island would be unlikely to success. On May 18, the Imperial Army Staff presented the conclusion to the Imperial Navy Staff that the chances of retaking Attu Island were low [3, p393].
In the Japanese War History Series "Navy Operations in the Northeastern", the Chief of the Imperial Army Staff visited the Imperial Navy Staff to make this proposal, and the Chief of the First Department of the Imperial Navy Staff, Shigeru Fukudome, expressed his agreement to it [4, p542]. However, the Japanese War History Series "Army Operations in the North" states that at the meeting at the Imperial General Headquarters, "the Imperial Navy Staff did not make its position clear to the Army, and the Army's proposal to abandon the relief of Attu became the straight decision of the Imperial General Headquarters [3, p395]. The Navy seems to have somehow avoided making an own decision in the official meeting.
The decision was made to the cancellation of the recapture of Attu Island and the evacuation from Kiska Island. The reason for this was showed as "the difference between the air and sea power of the his (Allied Forces) and ours in the Aleutian area was too great, and the weather conditions in the area, especially fog, were not promising, making it unlikely that the fleet transports to reinforce the troops would be successful. In addition, the war situation on Attu Island is becoming more and more unfavorable, so even if reinforcements are transported, it is doubtful that the key positions in the island will be able to hold." From this description, it can be seen that the reason for giving up Attu relief is that the success of the transport was not expected and that it was unlikely that the island could be held until the reinforcements were ready [4, p542]. This was only seven days after the Allied invasion.
On May 20, by the Central Agreement of the Army and Navy, the Imperial General Headquarters decided on operations in the western Aleutians, including the temporal securing of Attu Island and the supply for this, the evacuation of the garrison from Kiska Island (Operation "Ke-Gou"), and strengthening the defense of the Kuril Islands [4, p543]. The operational guideline in this agreement stated, "(3) The Attu Garrison will endeavor to be evacuated by submarines at opportunities," but the words "opportunities" and "endeavor" in the guideline meant that there was practically no prospect on evacuation from Attu Island. This was an unusual order, and the Northern Army were gloomy.
Earlier, the Commander of the Northern Army Kiichiro Higuchi, who had received a visit for the explanation of situation by the Deputy Chief of Imperial Army Staff Hata on May 20, recalled as follows. "The Deputy Chief of Imperial Army, Lieutenant General Hata, said, 'As the Army Department of the Imperial General Headquarters, we have requested the cooperation of the Navy, but the current situation of the Navy is such that it is not capable of cooperating in counterattacks in the northern areas due to the situation in the southeast Pacific region. Therefore, we would like to cancel our plans for reinforcements to Attu Island.' I offered a condition, 'If the Navy will unconditionally cooperate in the evacuation from Kiska Island, I will agree to this.' The Deputy Chief of Imperial Army Staff discussed the matter with Tokyo by telephone, and the Navy agreed to this condition. I therefore accepted that I would dare to leave the Attu Garrison to die." [3, p411-412].
In response to the order, the Command of Northern Army sent the following farewell telegram to the commander of the Second District Unit (Attu Garrison) on May 23 [3, p421]. "Your unit has held the strategic point in the North Pacific for a long period of time while the troops were isolated, and checked the superior enemy .... You fought well with a small number of troops and made a great contribution to the whole battle fields by demonstrating the prestige of the Japanese Army.... I am deeply satisfied and cannot contain my emotion. The Army cooperated with the Navy ... in an effort to rescue the soldiers, but (since this was not possible) I hope that everyone, including the Commander of the Second District Unit, will eventually be bravely annihilated and will demonstrate all your determination as the true value of the Japanese soldiers." At the strong request of the Imperial Army, the Imperial General Headquaters added to the Central Agreement of the Army and Navy that a submarine would be dispatched to accommodate a few reporters from Attu Island [4, p545].
8-4 Until the annihilation of Attu Garrison
8.4.1 Situations after May 20
The Fifth Fleet planned a surprise attack and emergency transport by two destroyers on May 20, but it was canceled on May 22. The 752 Naval Air Corp, which had advanced to Paramushir had been unable to launch sorties due to the bad weather, and forced to stand by at the airbase. When the weather finally improved on May 23, 19 twin-engined Japanese bombers led by Captain Goro Nonaka launched the sortie with torpedoes (In March 21, 1945, he led 18 bombers equipped with Ohka manned bombs on a sortie to Okinawa as the commander of 721 Naval Air Corp, but all of them including him did not return. He had opposed using Ohka.), but the main US fleet had already pulled out. They reported the sinking of one destroyer and the destruction of one cruiser, but one plane was not returned [4, p549]. According to the US military material, four torpedoes passed near the gunboat "Charleston" but failed to hit her, and the destroyer "Phelps" was strafed from the bombers [8, p82]. The next day, May 24, 17 bombers sortied to bomb the landing forces. They were intercepted by five P-38 fighters while searching for targets in the fog over Attu Island, so they abandoned their bombs and engaged them. This fight resulted in two Japanese bombers being shot down and one crash landing [4, p549], while the Americans lost two [8, p83]. These were the only air attacks by Japanese aircraft during the invasion. On May 25 and 26, the weather on Attu Island became more favorable, but no air attacks were made. On May 27 and 28, the attack by 27 Japanese bombers were again planned, but was cancelled due to fog. Long-range air attacks were difficult unless the weather conditions at both the launch and destination sites were stable and good.
On May 21, the Japanese forces were breached at a hill (Suzume-gaoka), a strategic point from Massacre Bay to Chichagof Bay, and on May 22, they set up a defensive line to the west of the mountains surrounding Chichagof Bay [3, p413]. As of the morning of May 21, 2,150 men, including wounded and sick, remained in the Attu Garrison [3, p408]. Meanwhile, the Allied Forces were able to carry heavy weapons closer to the front line as the Engineers Corps built a road from the beach [2, p97]. The Japanese troops, squeezed into a small area without adequate defensive facilities, suffered increasing losses from shelling and bombing.
By May 23, the Japanese positions and the remaining heavy weapons had been destroyed, and the inability to build new positions due to solid bedrock led that the number of Japanese troops on the front line was rapidly dwindling [3, p416]. A section of Fishhook, southeast of Chichagof Bay, was breached by the Allied Forces with artillery support, forcing the Japanese to retreat further. This allowed the Allied Forces to launch a direct assault on Jimfish Valley, which could provide a direct way to Chichagof Bay via Lake Ohnuma [3, p417]. The Allied Forces first attempted to seize the high ground overlooking the valley on May 24, but were unable to advance because of concentrated machine gun fire from the Japanese positions along the high ground [3, p. 425].
On May 25, instead of advancing along the Jimfish Valley to the vicinity of Lake Ohnuma, the Allied Forces attempted to advance northwest over the mountains leading to Chichagof Bay [2, p79]. They then attempted to break through Prendergast Ridge, the western foot of that mountain [2, p79]. Although they were temporarily repulsed, they broke through Prendergast Ridge in the afternoon of May 26 by hand to hand fight [3, p433]. On May 27, the Allied Forces launched an attack on the mountains leading to Chichagof Bay, and succeeded in establishing the positions on Fishfook Ridge, the ridge of the mountain [3, p436].
The Northern Army and the Fifth Fleet cooperatively planned the transport, which was scheduled to arrive at Attu on May 27. On May 25 they launched two destroyers as the transport unit and two light cruisers and eight destroyers as the escort unit. As they approached Attu Island, the weather cleared and visibility improved. The date of arrival was postponed to May 28 because of the possibility of air attacks. However, on May 27, a low pressure system approached and the weather conditions became sea scale 4 with wind speeds of 15 to 20 m/s. This made navigation difficult, and the transport unit was ordered to return on May 28. The escort unit also ceased operations on the night of May 28 and returned on May 31 [4, p556]. Ironically, the weather was neither too good nor too bad for advancing to Attu Island. This meant that both the air attack and the transport planned for May 28 did not take place.
8.4.2 Final charge by Attu Garrison
On May 28, the Allied Forces attacked with artillery support, advancing to the front of mountain and Lake Ohnuma. The Japanese were pushed into the narrow plain around Chichagof Bay as a result of the seizure of the surrounding highlands, which made it difficult to push back [3, p442]. Besides, they were already running out of food. By the evening of May 29, the Allied Forces had advanced to the positions overlooking Chichagof Bay, and it was only a matter of time that they could advance to the Chichagof Bay coast [2, p. 80]. In the desperate situation, the command of the Second District Unit (Attu Garrison) made the following final telegram at 1435 on May 29: "Our remaining strength is about 150 men.... We will make a final attack from the direction of the Ohnuma Valley toward the enemy assembly point at Suzume-gaoka and destroy them.... We will destroy the wireless telegraphs and burn the cipher books.... We will give up our resistance here, as there is already no prospect of supplies and no hope of prolonged resistance in this small area.... We are deeply indebted to the commander for all you have done for us and wish your good health." [19, p303].
At 2230 on May 29, the remaining Japanese soldiers taking advantage of the darkness in the fog began the assault from Lake Ohnuma to Engineering Hill, where the enemy defense was weak. It is not known whether 150 soldiers that the command headquarters reported was the number of remaining forces or not. A diary by Nobuo Horiguchi, Field Hospital Chief Sergeant in North Sea Garrison, who died in the battle, listed more than 1,000 men [3, p441]. An Imperial Navy document listed about 300 [3, p448], and an US military document listed a force of about 1,000 [3, p450], or 800 able-bodied soldiers and 600 seriously wounded [2, p80]. According to a survivor account, three companies were formed with about 300 men [3, p448].
Since the Allied Forces had gathered their main forces near the highlands behind Chichagof Bay in preparation for the general attack the next day [2, p. 84], the forces in the vicinity of Jim Fish Valley were reduced and were only engineer corps. The sudden Japanese assault from Lake Ohnuma confused the Allied Company B of the 32nd Regiment, which was near Jim Fish Valley. Experiencing the banzai charge by Japanese soldiers for the first time, the Allied soldiers panicked and some of them ran away screaming. The charging Japanese soldiers broke through two Allied battle command posts and bayoneted the wounded at the field hospital they reached [2, p81]. Some US materials noted that the Japanese tried to occupy the Allied 105 mm howitzer positions, took supplies and artillery, and used them to burn the supply depots at Massacre Bay and wait in the mountains for reinforcements to arrive [3, p451] [2, p80]. However, many of the Japanese soldiers had not eaten or drank for several days, and many of them could barely stand. Those who were lucky enough to reach Allied food depots stopped there and threw canned food into their mouths [3, p452].
On the Japanese mainland, intercepts of emergency communications issued by the Allied Forces revealed that the assault by Attu Garrison had reached the line of the ridge overlooking Massacre Bay [3, p447]. The climax of the battle was near Engineering Hill around the time the date changed from May 29 to 30. Brigadier General Arnold, deputy commander of the landing force, rallied the soldiers of the 50th Combat Engineer Battalion and others around him and hastily established a line of defense. As many of the men in the vicinity were unarmed, they hurriedly searched for weapons. They returned fire with the only heavy weapon at hand, 37mm anti-tank guns [2, p84]. This barely stopped the Japanese charge.
The Japanese attack here was not a single assault; they withdrew, regrouped, and charged again, repeating the process for several hours. It is believed that it was here that Yasuyo Yamazaki, the commander of the Second District Unit, was killed in action [2, p84]. The Japanese soldiers, wounded and limping, rushed forward slowly with shouting. They gradually became easy targets for Allied fires that came in to support the 50th Combat Engineer Battalion, and the Japanese forces were annihilated [3, p. 454]. Some soldiers still managed to close in on the 105 mm howitzer positions, but organized fighting ended just before them [2, p. 85]. The 50th Combat Engineer Battalion put the number of Japanese dead at Engineering Hill at about 350, and it is believed that the rest of the Japanese soldiers who charged committed suicide later [2, p84].
One memoir by an Allied soldier noted that the surviving Japanese soldiers were so excited by their final emotions that they blew themselves up with hand grenades, ending their assault. Another noted that there was a group that reached near the shore of Massacre Bay and resisted for nearly a whole day [3, p453]. The US military record states, "The Japanese forces were successful in breaking through the front lines by the deadly but well-designed operation. Their attacks were never purposed for suicide" [8, p82].
However, at this time in Japan, it seems to have been thought that every soldier on Attu Island was manfully annihilated at once in the final assault, and it was announced, for the first time, in Japan using the term "Gyokusai" (the shattering of a jewel into pieces. The origin of the word is found in the Book of Northern Qi.). The Japanese in the mainland probably had no means of knowing at the time that the Attu Garrison was not wiped out in a single assault, but rather repeatedly assaulted. Moreover, there might be quite a few soldiers who survived after the organized assaults were over. This seems to differ greatly from the pattern of the final banzai charges of the Japanese forces that subsequently took place in various locations during WWII. If so, the announcement of "Gyokusai" in Attu Island might have had a significant impact on the way the Japanese forces were subsequently annihilated.
8.4.3 Afte the annihilation
By the afternoon of May 30, when the Japanese assault was over, the Allied Forces had eliminated the slightest organized resistance and occupied Chichagof Bay. Thus the fighting on Attu Island was over [2, p85]. However, the sweep continued for several days. Still some snipers remained in hiding until September [3, p456]. The Japanese lost 2,638 men killed and 27 taken prisoner [3, p457]. On May 30, the Imperial General Headquarters announced the annihilation of Attu Garrison: "The garrison of Attu Island ... decided to demonstrate the true value of the Imperial Guardsmen by delivering the final hammer blow against the main enemy forces on the night of May 29. They carried out a heroic attack with all their might. There was no communication at all afterwards, and we certify all of them as Gyokusai" [3, p. 446]. This was the beginning of the Gyokusai that would be repeated in many places throughout the rest of the war. Meanwhile, 552 of the approximately 11,000 Allied troops who landed were killed in action and 1,140 were wounded [8, p. 82]. Outside of combat, about 1,200 were wounded by frostbite or trench foot, and 932 were taken out of combat by disease or accident [2, p85]. In World War II Pacific Theater, the Allied casualty rate for the number of Japanese troops on Attu Island was consequently second only to Iwo Jima [16, p19].
According to the Army-Navy Central Agreement, Lieutenant Colonel Hiroshi Emoto, the Fifth Fleet's staff officer, and Captain Hiroyuki Numata of the Imperial Army were to be accommodated later by a submarine as reporters [4, p550]. The submarine "I-24", which was in charge of the accommodation mission, had difficulty penetrating the planned contact point due to bad weather and Allied patrols, and even when it did manage to penetrate, it was unable to make contact with the two men. The "I-24" gave up trying to accommodate them, but was sunk by an American patrol boat off Shemya Island on June 11 while returning home. The two men were found dead after the war in a cave on the east coast of Chichagof Bay by the Japanese Attu Island Mission in July 1953 [3, p457].
We do not know if they witnessed the Allies landings. However, if they had been able to be accommodated, they might have been the first high-ranking Japanese officers to actually witness the US landings (amphibious warfare). Although not all Japanese troops were wiped out at every US landing site in the Pacific (most of them were islands), few high-ranking officers returned to Japan after witnessing the US landings. Telegraphic reports from the landed fields only provided limited information, and there was little opportunity for the Imperial General Headquarters to learn specifically what the US landings were like.
After occupying Attu Island, the Allied Forces ignored the runway that the Japanese had almost completed in East Arm. They established a base for seaplane on Attu Island and began patrolling with flying boats immediately after the occupation. They also used their mechanical power to construct two new fighter airstrips at a site facing Massacre Bay, one of which was completed on June 9. They also built a 2800 m runway for bombers on Shemya Island, part of which became available on June 21 [8, p83]. After the completion of the runway, bombing raids were also carried out from Attu Island to Paramushir. Nine B-25 bombers bombed Paramushir on July 10, and six B-24 bombers bombed Paramushir from high altitude on July 18, but all bombs fell to the sea and caused no damage [4, p671]. On September 11, seven B-24 and 12 B-25 bombers bombed Paramushir, but three were shot down and seven were detained by the Soviets [2, p90]. Thus, bombing activities were temporarily halted. However, in 1944, not only bombings but also artillery fires by ships were occasionally conducted against the North Kuril Islands.
8-5 Consideration on annihilation of Attu Garrison
8.5.1 The circumstances which led to be annihilated
As had been feared by some in the Japanese military, Attu Island, which was less well defended than Kiska Island that was closer to the US mainland, was targeted first. Attu Island was once abandoned after the Japanese military changed their occupation policy, and after reoccupation, the priority was given to the construction of an airfield rather than the establishment of defensive positions. Furthermore, supplies were difficult to reach due to the Allied blockade. Most of reinforcements that were to be transported to Attu Island failed to arrive due to the appearace of US fleet for bombertment of Attu Island and the Battle of the Komandorski Islands. The subsequent small transports by submarine led completely shortage of supplies. Even after the change of the defense policy that the main defense shifted from Kiska Island to Attu Island in April 1943, reinforcements and supplies still could not reach Attu Island due to the tight blockade by the US forces. The only supply and troop reinforcements to Attu Island were planned to be transported through the fog from May onward. The early setback of the battle lines during the battles on Attu Island due to unfinished defensive positions and the lack of food and ammunition led to the questioning of local endurance by the Imperial General Headquarters. It contributed to the abandonment of any attempt to rescue or retake Attu Island. The Allied operation to cut off Japanese transportation shaped the success.
8.5.2 Considerations in Senshi Sosho (Japanese War History Series)
The annihilation of Attu Garrison was the first in the war in the Pacific, and its impact on the Japanese military was profound. Japanese War History Series (official), Senshi Sosho "Navy operations in the Northeastern", gives the following reasons for the destruction of Attu Island [4, p553-554].
- Throughout the occupation, there was a discrepancy between the objectives of the invasion and the enthusiasm of the various sections was insufficient.
- The idea of relying solely on ground forces for the defense of the islands was inappropriate.
- Decisions to build airfields and dispatch land-based aircraft were delayed.
- The Allied forces took the initiative and steadily advanced their bases to strengthen their counteroffensive. In contrast, the Japanese forces underestimated the Allied counterattack and were backward in their response, always thinking only after the Allied forces had moved.
- The judgment of the situation with regard to the potential of occupation of Amchitka Island by the Allied forces was poor, and no countermeasures were taken in response.
8.5.3 Considertations on the responses of Combined Fleet
As shown in 8.3.2, the Combined Fleet Command issued the operation order in order to support the Northern Unit on May 14. It was as follows [4, p551].
(i) Prepare for sorties while anchoring in the Tokyo Bay area, and launch and carry out operations when special orders are issued.
(ii) Observe enemy movements until the end of May. If there is a possibility that the main force of the enemy fleet has retreated, sorties will be cancelled. In addition, if Attu Island is lost, it is also likely that no sortie will be launched.
(iii) If the enemy fleet appears south of "Attu Island" and "Kiska Island", we will regard this as an opportunity to attack the enemy.
(iv) Reconnaissance method of the enemy's situation. We will make reconnaissance of the enemy's situation by submarines advancing northward.
(v) On day x, the Combined Fleet will advance to the vicinity of point A or B, and if there is a high probability of a preemptive attack against the enemy's task force, it will advance to attack the enemy.
(vi) Since it is difficult for the task force of the Combined Fleet to enter the range of enemy aircraft to meet enemy fleets, the Northern Unit will endeavor to guide the enemy fleet out of the range of enemy aircraft.
The day x is scheduled to be around June 2.
As you can see, the Combined Fleet's response was to wait and see for a while, and if they were to make a sortie, they would do by another instruction. Moreover, several conditions were placed on the case of sortie. They gathered their main ships at Yokosuka by May 22 and saw how things were going, but in the end they did not make the sortie.
One of the reasons that the Combined Fleet did not sail was tightness of fuel oil. At that time, the Japanese mainland had only 300,000 tons of fuel oil in reserve, and if the task force were to launch a sortie, it was expected to consume more than 200,000 tons. In addition to that, about 40,000 tons per month would be routinely consumed, so it was believed that if they made a sortie, the main fleet would not make any other operations until September [4, p552]. At that time, due to the smooth occupation of oil-producing areas and proper treatment of facilities in South Asia, the local oil production was growing steadily beyond initial expectations. But there was a shortage of oil tankers to bring them to Japan. Furthermore, due to the expansion of the war front, the consumption of fuel oil used exceeded initial expectations.
Although the above reasons were raised by the Combined Fleet, the transportation of oil produced in the oil-producing areas to Japan somehow managed to go smoothly in 1943. The planned oil shipment for 1943 was 2 million tons, but actually 2.322 million tons, more than planned, were transported to Japan (1.67 million tons in 1942) [23, p105]. Based on the above data, even if the Imperial Navy had used the 300,000 tons of fuel it had stockpiled, that would not have caused the ships to run out of fuel and be stuck for some time. Rather, it is not surprising that the Imperial Navy would want to conserve fuel in preparation for an anticipated fleet decisive battle to be discussed later. Or there might be some problems in the domestic distribution of fuel.
Another reason for not launching a sortie was the death of General Isoroku Yamamoto, Commander-in-Chief of the Combined Fleet, and many of his staff on April 18 [4, p520]. Although General Mineichi Koga was appointed as the new Commander-in-Chief on April 21, the new Combined Fleet Command had to deal with the imminent war situations in the Solomon Islands and New Guinea in the South Pacific as well as the western Aleutian Islands [4, p520]. Since General Yamamoto had been in office for a long time (three and half years) and was suddenly killed in action along with many of his staff members. Furthermore, the task force of the Combined Fleet was in the process of rebuilding after losing 17% of their fleet aircraft during Operation "I-Gou" in April 1943 in South Pacific [4, p521]. It is assumed that the new Combined Fleet Command had faced a variety of challenges.
In addition to the above factors, the factor of "a decisive fleet battle" may have had the greatest impact. At the time, as well known, the Imperial Navy's war plan was only to engage in a decisive fleet battle and to gradually weaken the enemy's forces for it. At the operation and defense meeting held on Truk Island on May 8, before the Allied invasion on Attu Island, Commander-in-Chief of the Combined Fleet Mineichi Koga expressed his determination as follows: "If necessary, we will sacrifice garrisons of islands for a fleet decisive battle." [19, p173].
The Combined Fleet had stipulated that operations with full force of the Combined Fleet conducted around the Kuril Islands area and in the waters east of Honshu as decisive battles would be only in special cases. Otherwise, they were to be conducted as operations of the northern units [19, p305]. From the above, it can be understood that the Combined Fleet did not intend to let their main forces enter the attack zone of enemy aircraft, so they limited the sorties of their main forces to the case where the US task force appeared in an advantageous sea area and a surprise attack could be expected [19, p299]. The above order was only in support of the Northern Unit, and this can be seen from the fact that the part regarding the sortie was accompanied by some conditions regarding the enemy task forces.
From this, for the Combined Fleet, it was critical whether they would be able to engage a decisive battle or not. In other words, it seemed that the Combined Fleet did not intend to sortie unless the US task force appeared in the Northwest Pacific. If the battle at Attu Island had dragged on and reinforcements had to be sent, some naval vessels might have been sent out to the Northern Unit to support them.
The war plan for Imperial Navy focused only on the US task forces. The Combined Fleet was expecting a fleet decisive battle with the US task forces that came on the eastern front of the Central Pacific, as had been their long stragic policy. To prepare for such a fleet decisive battle, it is thought that the fleet did not want to lose as few aircraft carriers and ship-borne planes as possible in the Aleutian area.
However, this would be a passive strategy that handed the battle initiative to the enemy. Even though it had been the stragic policy for long time, the Combined Fleet's decision to limit its response to the US fleet to fleet decisive battles in the Central Pacific seems to have made it less flexible in battles, not only in the Aleutian area, but in the war as a whole. What would have happened if they had made a sortie will be discussed in a later chapter.
8.5.4 Attu Invasion for Allied Forces
The US Army's 7th Division, which had been training in California, headed for Alaska by transport ship without being informed of their destination. Along the way, they were informed of the Attu Island invasion and realized that their equipment was inadequate for cold-resistance, but they had no time to prepare the eqipment for cold. The soldiers were sent to Attu Island without any cold-resistant or waterproof equipment, as they were not familiar with the island's climate in May. Even at this time of year, there was still snow on the island. The leather boots issued to the men of the 7th Division were deeply submerged in snowy mud and remained so throughout the day. Their feet quickly became wet and frostbitten. Their clothes also did not dry throughout the day due to snow and drizzle [10, p80]. Because of clothing and equipment unsuited to the May climate of the Aleutian Islands, about 2,100 soldiers were injured by frostbite and other injuries outside of combat [21, p23]. The same was true for machinery: communications equipment was often wet and inoperable due to fog and moisture. Thus, not only could troops not see each other through the fog, they often could not communicate with each other [10, p80]. Before fighting the Japanese, Allied soldiers also had to contend with these harsh climates. The reduced fighting strength caused by these factors was one of the reasons why the occupation of Attu Island took unexpectedly long.
One of the findings in this landing operation for the Allied Forces was the power of the cannon fire mounted on the ships. This had a great effect in destroying the Japanese defensive positions, but it also had a tremendous effect in inspiring the morale of the soldiers on their side and demoralizing the enemy. The Allied Forces learned that the diaries of Japanese soldiers seized on Attu Island contained numerous accounts of their fears, especially of the power of the battleship's cannon [8, p83]. The caliber of the battleship's main gun at this time was 36 cm, whereas the caliber of the cannon used in normal field battles are at most 15 cm. The power of the battleship's cannons must have been unimaginable, perhaps something the soldiers had never experienced before. The Allied Forces suffered fewer casualties in the battles when support was provided by covering fire from ships and bombing, but when support was halted by fog, casualties immediately increased and the advance stopped [8, p83]. Allied Forces found that the progress of their operations was greatly affected by the status of firepower support due to fog and other weather conditions.
8.5.5 A summary of the reasons why the garrison of Attu Island was wiped out
The United States had been broadcasting to the public since April 1 that operations would be conducted in the Aleutian area. As mentioned earlier, the Imperial Navy was aware of this broadcast. The Imperial Army was also aware that a invasion would soon take place, as the chief of the press department mentioned this broadcast at the section chiefs' meeting on May 7 [3, p267].
Japanese War History Series, Senshi Sosho "Army Section in the Imperial General Headquaters <6>" states, "If a central Army-Navy agreement had been prepared in advance for the case of an enemy invasion in the Aleutian area, it would have been possible to take countermeasures more promptly. In this regard, it was supposed that the Imperial General Headquarters may have a psychological tendency not to want the enemy to come." [18, p476]. If the Imperial General Headquaters had thought in early April about how to respond to invasions by the Allied Forces, they might have been able to prepare in advance how to supply supplies, mobilize soldiers and allowance of ships, and counterattack procedures more quickly as the Senshi Sosho states. If so, the withdrawal of the Attu garrison from East Arm and Jamin Pass on May 18 could have been delayed, and some support and counterattack operations could have been carried out from the Japanese mainland.
The eventual annihilation of the Attu Island garrison might not have been avoided in any way. However, the failure of the Imperial General Headquarters to consider a response to the Allied invasion in early April appears to have been a baseless postponement of the situation. If, as the Senshi Sosho is concerned, "there was a psychology of hoping that the enemy would not come," then it was the case that they did not think about what we did not want to happen. This may be a direct reflection of the psychology that humans are prone to have. Something analogous to this is sometimes called normality bias, which can also occur in modern society.
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References are listed in "Reference" in the upper right-hand side.