“Climb Mount Niitaka:” a detailed description of the First Wave Attack on Pearl Harbor

Beginning at 0530 hours on the morning of Dec. 7, 1941 the first wave was spotted on the flight decks of the six Japanese carriers (Akagi, Kaga, Soryu, Hiryu, Shokaku and Zuikaku) and aircraft engines began warming up.

The Japanese planned a series of attacks at the beginning of the war. The Kido Butai [literally “Mobile Force” (but better translated as “Striking Force”) was the operational component of the First Air Fleet that comprised a combined carrier battle group comprising most of the aircraft carriers and carrier air groups of the Imperial Japanese Navy (IJN), during the first eight months of the Pacific War] was allocated to the attack against the main Pacific Fleet base at Pearl Harbor. Admiral Isoroku Yamamoto conceived the Pearl Harbor attack and Captain Minoru Genda planned it. The following article, featuring excerpts from Mark Stille’s book Pacific Carrier War, gives a detailed description of the First Wave Attack on Pearl Harbor.

The Kido Butai departed its anchorage at Hitokappu Bay at 0600 hours on Nov. 24, 1941. During the 13 day transit to the launch point 230nm north of Oahu, through the rough waters of the North Pacific Ocean, the Japanese encountered no ships. Diplomatic efforts having failed, the message “Climb Mount Niitaka 1208” was received on Dec. 2. This confirmed the attack would begin as scheduled on the morning of December 7. At 1130 on Dec. 6, the Kido Butai changed course to 180 degrees and headed straight for Hawaii.

A reconnaissance report from the Japanese consulate in Honolulu was received aboard Akagi aircraft carrier at 0150 on Dec. 7. The report indicated that nine battleships, three light cruisers, three seaplane tenders, and 17 destroyers were present in the harbor the day before. Four light cruisers and two destroyers were in drydock. The most important aspect of the report, which was generally accurate, was that all of the Pacific Fleet’s carriers and heavy cruisers were absent. A subsequent report indicated that no barrage balloons or torpedo nets were evident. On the morning of Dec. 7, there were a total of 82 warships at Pearl Harbor. None of the Pacific Fleet’s carriers were present when the first Japanese aircraft arrived over Pearl Harbor: Enterprise, escorted by three cruisers and nine destroyers, was delivering a Marine fighter squadron to Wake Island; Lexington had departed Pearl Harbor on Dec. 5 with three cruisers and five destroyers to deliver aircraft to Midway; and Saratoga was at Puget Sound, Washington, undergoing repairs. This left eight battleships, two heavy cruisers, six light cruisers, 30 destroyers, five submarines, and various auxiliaries in Pearl Harbor.

Beginning at 0530 hours on the morning of Dec. 7, the first wave was spotted on the flight decks of the six Japanese carriers (all six of Japan’s first-line aircraft carriers, Akagi, Kaga, Soryu, Hiryu, Shokaku and Zuikaku, were assigned to the mission) and aircraft engines began warming up. The seas that morning were some of the worst encountered on the entire transit. At 0550, the pilots manned their aircraft. The Kido Butai headed east at 24 knots to get sufficient wind across the deck for takeoff. The first wave began taking off at 0600. All aircraft were off the decks within an impressive 15 minutes. Following takeoff the 183 aircraft formed a single loose formation and headed south at 0620. Immediately after the launch of the first wave, preparations began for launching the second. The same procedure was repeated, with the aircraft quickly spotted on the flight decks and their engines warmed. The fleet again turned into the wind for a second launch at 0705 and ten minutes later the aircraft began to lift off. The second wave of 167 aircraft headed south to Oahu.

Despite being picked up by three of the five operational American radars on the island, the Japanese retained surprise when only one of these stations reported its contact: a report that was quickly dismissed by the Air Defense Center at Fort Shafter. There was some confusion at 0740 when attack leader Mitsuo Fuchida fired one flare to indicate that surprise had been achieved and called for the more vulnerable torpedo bombers to make their attacks first. Fearing that the fighters flying above had not seen his first signal, Fuchida fired another flare. Though not part of the same signal, two flares was the signal that surprise had not been achieved. Acting on this misunderstanding, the dive bombers and fighters rushed ahead to attack first in order to protect the torpedo planes.

The attack by the 40 Type 97s with torpedoes was the most important part of the Japanese plan. Of the eight battleships present, five were vulnerable to torpedo attack. At 0751, the torpedo planes split up into four groups. The 24 aircraft from Akagi and Kaga looped around Hickam Field to approach Battleship Row on the eastern side of Ford Island. The remaining 16 torpedo bombers from Soryu and Hiryu came in from the west to attack the ships anchored on the western side of Ford Island. This is where the American carriers were usually moored. Even though the latest pre attack intelligence indicated no carriers were present, no effort was made to change the basic attack plan.

The torpedo attack opened at 0755 hours with the 16 Type 97s from Soryu and Hiryu. In the absence of any carriers, the Japanese pilots were forced to make split decisions as to which target to attack. Chaos ensued, resulting in the expenditure of precious torpedoes against secondary targets. Six of the Soryu aircraft attacked the ships situated where the carriers should have been. None were worth a torpedo. Two torpedoes hit the training ship (and former battleship) Utah, which rolled over and sank. Another hit the old light cruiser Raleigh and caused severe flooding. Quick counterflooding saved the cruiser from capsizing. The other three torpedoes missed. The leader of Soryu’s torpedo group tried to find a more valuable target. He settled for a large target along the 1010 Pier in the Navy Yard. This was the ancient minelayer Oglala moored outboard of the modern light cruiser Helena. This torpedo ran under Oglala and hit Helena where it flooded one boiler room and one engine room. The explosion split open Oglala’s hull and she sank two hours later. The last Soryu aircraft continued toward Battleship Row. Hiryu’s torpedo group was less successful in handling the confusion when it became obvious no carriers were present. Four aircraft launched their torpedoes at the ships moored along the 1010 Pier but all missed. The other four joined the single remaining Soryu aircraft in attacking Battleship Row.

The 12 carrier attack planes from Akagi led the attack against Battleship Row. Genda’s plan had these aircraft approach in a line ahead formation from the same point. Battleships Oklahoma and West Virginia were directly in front of the approaching Type 97s; the first six Akagi torpedo planes targeted these ships beginning at 0757 and scored several hits in quick succession. The next two Akagi aircraft veered left to attack California, scoring one hit. Another aircraft attacked West Virginia and the final three targeted Oklahoma. The Japanese claimed that 11 Akagi carrier attack planes dropped torpedoes (one jettisoned its weapon as the result of a near air to air collision), and that all 11 hit one of the three battleships targeted. Interspersed among the Akagi torpedo bombers were the four remaining Hiryu aircraft. Two of these attacked West Virginia, and the final two targeted Oklahoma.

Kaga’s 12 torpedo aircraft were the last to attack. By this time the Americans had increased the volume of antiaircraft fire and the flawed Japanese approach exposed each aircraft in sequence to fire. As a result, five of the 12 Kaga Type 97s were shot down, making them the only torpedo aircraft to suffer this fate. Four aircraft attacked West Virginia, two targeted Oklahoma, and a single aircraft veered to the right to attack Nevada. The last aircraft’s torpedo hit Nevada forward. These aircraft were joined by the final Type 97 from Soryu, which selected California and scored a hit. This aircraft was heavily damaged by antiaircraft fire, but its skillful pilot made it back to the Japanese task force where he ditched in the ocean next to a destroyer. During this phase of the attack, the Japanese claimed that eight aircraft dropped their torpedoes against three different battleships and that all eight hit their targets.

Though the Japanese claims were excessive, the attack was still deadly. In only 11 minutes, and for a cost of only five aircraft (and a sixth later forced to ditch), the torpedo bombers sank two battleships and inflicted damage leading to the sinking of two more. Added to this was the sinking of a target ship and a minelayer and damage to two light cruisers. Of the 36 torpedoes launched, it is likely that 19 hit. The carnage could have been worse if the Japanese pilots had not concentrated on Oklahoma and West Virginia. A total of 12 torpedoes were launched at Oklahoma and at least five hit. The ship took three torpedoes in quick succession and immediately began to heel to port. No attempt was made to counterflood, so the ship capsized in 15 minutes, accounting for heavy personnel losses of 20 officers and 395 enlisted men killed. West Virginia was hit by a probable seven torpedoes. Orders from quick reacting junior officers to flood the voids on the starboard side allowed the ship to avoid capsizing. Personnel casualties were relatively light, with two officers and 103 enlisted personnel killed.

Nevada was moored at the end of Battleship Row. At 0803 hours the battleship was hit by a torpedo on her port bow which created a large hole. Burning oil from the shattered Arizona directly in front threatened to engulf Nevada, so the order was given to get underway. She began to move at 0840 and headed down the channel between the Navy Yard and Ford Island. When the second wave dive bombers made their appearance, they found the slow moving battleship too tempting a target to pass up.

California was positioned in the southeasternmost spot of Battleship Row. Two torpedoes hit the ship; one struck forward of the bridge below her armored belt, and the second struck under the belt in the area of Turret Number 3. Counterflooding corrected the resulting list, but a combination of poor watertight integrity and human error doomed the ship. California continued to slowly settle until she rested on the bottom of the harbor on December 10. Six officers and 92 enlisted men were killed.

The second fist of the Japanese double punch against Battleship Row was the level bombers carrying armor piercing 1,760lb bombs. The Japanese pilots were instructed to make as many passes as necessary to ensure accuracy. The 49 Type 97s approached Battleship Row from the south at 10,000 feet in groups of five. The primary targets were the battleships moored inboard, but these suffered widely differing levels of damage. Maryland was moored inboard from Oklahoma; of all the battleships on Battleship Row, she was the least damaged. Maryland was hit by a bomb on the forecastle below the waterline. A second hit the forecastle but caused little damage. Tennessee, moored inboard of West Virginia, suffered little damage during the attack. Two bombs hit the battleship; the first on the center gun of Turret Number 2, and the second penetrated the top armor of turret Number 3 but broke apart without detonating. Moored just aft of Tennessee was Arizona with repair ship Vestal alongside. Arizona took two hits. The first hit aft on the quarterdeck. At 0806, the second struck forward, penetrating the forward 14 inch gun magazine and resulting in a cataclysmic explosion. The explosion killed 1,177 crewmen and completely destroyed the forward part of the ship. Vestal also took two bomb hits which created flooding and a starboard list. She got underway at 0845 and was beached nearby to keep from sinking. The destruction of Arizona has become the iconic moment of the entire attack and has overshadowed the overall poor results from the level bombers. The best assessment is that ten hits were scored out of 49 bombs dropped; however, of the ten hits, six failed to explode or resulted in low order detonations.

Pacific Carrier War is published by Osprey Publishing and is available to order here.

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