by Attack on Pearl Harbor: Strategy, Combat, Myths, Deceptions
Had it not been for the one fortuitous hit, the level bombers would have given a very poor return on their investment.
The postwar Japanese Official History downgraded the claimed hits to eight: one on California (none actual), one on Maryland (two actual), two on Tennessee (two actual), and four on Arizona (two actual).19
Assessment:
Dive-Bombing Against Fleet Units BDA
Hits Claimed and Target Classification Accuracy
The individual reports from the carriers submitted to the flagship immediately after the attack complained that most of the second-wave dive-bomber attacks could not be properly assessed due to smoke obscuration. Akagi claimed an unspecified number of hits on a battleship and one hit on an Omaha-class cruiser. Kaga claimed that “most” bombs hit California and two other battleships. Soryu and Hiryu submitted a combined report20 claiming five hits on two light cruisers and one on a destroyer in drydock. The reports suggest a combined total of 20 to 30 hits.
The BDA Report claimed 49 hits for 63%. Almost a year later, Lessons changed this to 38 hits out of 65 bombs (59%). These percentages were in line with expectations from training: 60% hits from 78 bombers gave an expectation of 43 hits.
The air groups’ performances were very uneven: flagship Akagi was credited with one hit out of 15 or 18 bombs (6%), Kaga with 8 definite hits and 13 probables out of 27 (78%), Soryu 14 hits out of 17 (82%), and Hiryu a remarkable 15 hits out of 16 bombs (94%). This totaled 38 hits (49%) with 13 probables. In Fuchida’s BDA report to the Emperor, probables were not reported—11 probables were converted into hits, and two dropped.
Akagi was credited with a very low performance compared to the other carriers. Akagi was the flagship. This is extraordinary.
Flagships characteristically were the best performing ships in the fleet, the “Battle E” winners, the best of the best. While some of this elevated reputation can be attributed to flag staff members who give inflated grades in exercises to the ship in which they live and serve, it also can be attributed to the fact that flagships are “high profile” ships that get their pick of high-performing officers and men. Flagships were under constant scrutiny from the flag and his staff, and so were motivated to maintain top performance. This represents a cultural characteristic in all the major navies—flagships generally are the shiniest, and the best performers.
Assigning Akagi’s aviators a miserable hit percentage was a seismic turnabout. Experienced naval officers would note this with shock. The best dive-bomber aircrews were given the lowest scores. They were on the ship where the assessment was being formulated, and so were available for questioning. It would be hard to misrepresent their results. The huge gap between Akagi’s results and those attributed to the others is a huge anomaly.
In this context it should be noted that Akagi’s torpedo bombers were the ones that likely scored the majority of the 11 effective hits on Battleship Row, confirming that flagship aviators generally perform well.
The BDA Report claimed a target selection biased against battleships. No hits were claimed against priority 1 targets, carriers (granted, there were none in port, but at least Utah was not claimed to be a carrier). 14 hits were assessed against seven different cruisers (priority 2), 27 hits against five battleships (priority 3), and 8 hits against auxiliaries and smaller ships (priority 4 and lower). The chart shows how these hits were distributed, along with the number of aircraft reportedly attacking each target.21
The BDA Report has flaws in target identification. Dobbin, a 12,650-ton destroyer tender, was identified as a cruiser, as were destroyers Dale and Shaw. Shaw was correctly identified in the flyers’ report as a destroyer in drydock, but the BDA report promoted her to a cruiser.
Overall, only five of the claimed hits (10%) had their targets misclassified. While photographs were being taken by the attackers, they probably did not get 100% coverage of all the targets that were attacked, and had to rely to some extent on aviators’ reports.
(17) GP Bombs: Hits Claimed and Attacks Claimed
Actual Hits
US War Damage Reports (WDR) and ARs document 15 hits, 19% of 78 bombs, less than one-third of the hits claimed. Seven of the hits, against destroyers Shaw, Cassin, and Downes, and tender Curtiss, were on low priority targets that did not materially contribute to the objective of the attack.22
One hit on Pennsylvania resulted in minor damage that was put to rights in a few weeks, while a hit on California did not lengthen the time the ship would be out of commission to repair the damage from her two torpedo hits.
A hit on Raleigh added damage to a torpedo hit and nearly caused the ship to capsize, forestalled by excellent damage control. Five hits on Nevada started fires in the forward part of the ship that interfered with the crew’s attempts to contain the progressive flooding. Two of the hits broke the skin of the ship and added to the flooding.
Examined critically, none of the 250kg bomb hits hits contributed to mission success. The six hits on Nevada and Raleigh merely added damage to ships that were out of the fight from torpedo damage. The bomb hits did not extend their time out of service, only added to the manpower that would be needed for repairs. In Nevada’s case, the bombs mostly damaged parts of the superstructure that would eventually be removed anyway in the modernization effort.
The hit claims Fuchida showed on the report to the Emperor show a curious disconnect with reality. For example, 12 250kg hits were claimed on Maryland. Maryland was not hit by any 250kg GP bombs, only by two 800kg bombs from first wave level bombers at approximately 0810. Maryland did not record that she was attacked by dive-bombers for the duration of the second wave attacks.
Of the other ships along Battleship Row, five hits were claimed against California (actually hit by one 250kg bomb), and one against West Virginia (no 250kg hits). Three hits were assessed against Neosho which supposedly sank at the fuel transfer pier aft of California. Neosho had actually gotten underway at 0842 and moored near the submarine base at Merry Point at 0930. She was underway for the duration of the second wave attack, and was targeted by two dive-bombers while she was in the channel. The Japanese BDA report shows Neosho sunk at her Ford Island pier, her location at the beginning of the attack.
Matching Claims with Hits
The next chart shows the hits claimed by the Japanese and the hits and DNMs recorded in ships’ damage reports and ARs.
Hit Claims Away From Battleship Row
Five hits were claimed on three different cruisers at the shipyard piers. Only one bomb was an actual DNM. Six hits were claimed on Helena moored along 1010 dock, with no hits actually achieved. Two hits were claimed on Dobbin with no actual hits, two against Dale with no actual hits, and five against California with one hit actually scored. 14 hits were claimed vs. one hit and one DNM actually achieved.
(18) GP Bombs: Hits Claimed and Actual Hits
Hit Claims Along Battleship Row
Five hits were claimed on California, one on West Virginia, three on Neosho, and a rather remarkable 12 on Maryland, 21 hits at all. Applying the claimed overall hit percentage (63%) to these attacks would imply that 33 dive-bombers attacked Battleship Row targets, almost half of the total dive bombing effort. Such a significant level of effort ought to have merited entries in the American logs and accounts of the attack.
However, there are few references to second-wave dive-bomber attacks against Battleship Row, by either Japanese or Americans. In one veteran’s account:
Ofuchi swooped down on a battleship moored along the south end of Ford Island. “When we went into our attack dive, my feelings were numbed and, truthfully, I didn’t give a damn what happened. I just gave myself over to Fate,” Ofuchi said, “But when the bomb was dropped, and we pulled up to level off, I really got scared.”23
The “we” Ofuchi refers to apparently means himself and his rearseater. He does not relate how many other bombers accompanied his attack, but it was probably his shotai of three bombers. California was damaged by a 250kg GP bomb th
at hit her starboard side amidships and exploded on the second deck, blowing a hole in the main deck and starting a fire that engulfed three secondary battery casements.
In another account, Lieutenant (j.g.) Furuta claimed he attacked Maryland. He remembers that he “aimed at the enemy battleship’s mast using my scope…. I identified the ship as Maryland from its position in the battleship formation.” According to Hawaii Sakusen, Furuta’s target was the fleet oiler Neosho.”24 Neosho had nothing that looked like a battleship mast, and she was well away from the “battleship formation” before the arrival of the second wave. Maryland’s log and AR do not record anything corresponding to Furuta’s claimed attack.
Lieutenant Commander Abe reported he attacked Battleship Row:
I believe I attacked the Arizona, but at the time I didn’t know what ship I was attacking. All I was thinking about was the two paired-up ships on the east side of the island that I had heard about. I was looking at the ship from above and didn’t know that it was the Arizona, but I clearly remember seeing the shape of the Vestal, which was anchored near the outer side of the Arizona. However, when I attacked the ship was sinking, because it was attacked by the first wave. I confirmed an outline of a huge ship prior to dropping my bomb; however, I didn’t see any upper structures, flames, or smoke.25
Vestal had cut her mooring lines and was clear of Arizona ten minutes before the second wave arrived. Arizona at that time was totally obscured by smoke. There were no reports of bombs impacting at the northern end of Battleship Row to correlate with this claimed attack. Abe probably actually attacked Dobbin and her nested destroyers.
Assessment
Aviators during WWII generally overestimate the number of their hits, sometimes by as much as 100%. Overestimating by a factor of seven is unusually poor reporting. Considering that this was a “set piece” battle with targets at anchor, the aircrew had trained for months for this specific attack, and that the strike leader was flying over the area doing nothing but observing, it is unusually bad reporting. The 78 dive-bombers attacked over about a 36-minute period, an average of 2 per minute. From US witness reports, nearly all of these attacks were well clear of the smoke cloud rising from Arizona.
Claims Distribution
Twenty-seven of the 49 claimed GP bomb hits were against battleships—along Battleship Row, Pennsylvania in drydock, and Nevada underway. This was a poor weapon-target match, particularly considering there were four modern 10,000 ton cruisers tightly packed into the shipyard area, undamaged and clear of smoke, and four others at anchor. In the absence of the carriers, cruisers were the dive-bombers’ top priority. Only two cruisers sustained damage from 250kg bombs, rather than the seven claimed.
The GP bomb hits on battleships caused mostly superficial damage which would not have kept them out of the war for six months. The Japanese BDA report is an admission of poor weapon-target matching, poor target selection, and poor target identification—if it actually happened that way.
The Chronology estimated that 30 dive-bombers from the second wave attacked the Navy Yard area, which included the cruisers at the Naval Shipyard piers, Pennsylvania in drydock, and Shaw in the floating drydock. If that were true, then only two of these 30 bombers (7%) damaged targets on their priority list: a hit on Pennsylvania, and a DNM on Honolulu. If bombs that struck Cassin and Downes are included (bombs that missed their intended target, Pennsylvania), along with the hit on the Shaw, then six of the 30 bombs (20%) were useful.
Estimating the Japanese Attack Distribution from US Reports
The Japanese claims and US damage reports conflict. Ideally a combination of Japanese records of the debriefings of their aircrew combined with American ARs could be used to ferret out an accurate account. Detailed Japanese records did not survive the war, and the surviving dive-bomber aviators have left only a few anecdotal testimonies. The Japanese attack must be reconstructed largely from American records.
The most important records are the ARs submitted by the ships and the Chronology put together by the CinCPAC staff to support the Congressional Investigation of the attack. Care must be taken in using these sources. AR times were recorded inconsistently. They were mostly based on ships’ logs which, understandably, might not have been the Officer of the Deck’s first concern during the battle. Some entries record when an event started, some when it finished, and some might just indicate the time the Officer of the Deck glanced at his watch before writing the entry, which might be many minutes after an event. Some time shifts in the logs were as great as 20 minutes.
Many of the logs recorded “attacks” by dive-bombers. “Attacks” could have been bomb runs, strafing attacks, or even dummy bomb runs to draw fire away from other bombers, or just a bomber flying by as it recovered from its dive on a different target. The Japanese dive-bomber gunners sprayed machine gun rounds at whatever came into sight, making a log entry of an “attack” understandable.
The American logs are remarkably specific in recording bombs. They recorded how many were dropped, where they landed, and what they did. Cases were encountered where several ships in close proximity all would claim that a given bomb was actually aimed at them—a rather human propensity—but such entries could be correlated and helped reconstruct the Japanese expenditure of bombs. Consequently, this analysis relied on bomb counts to reconstruct the dive-bombers’ attack.
The next chart adds where 250kg GP bombs were dropped. The list of these attacks and sources are provided in Appendix A, with a summary provided in the table.
The analysis accounts for 76 of the 78 bombs. The “Possible” column adds up to 85 because the entries in that column represent the maximum number reported in each attack—when several maximums reported from different observers are combined there was some double counting, which was eliminated in the summary count.
(19) GP Bombs: Hits Claimed and US Records of Attacks
For instance, Egusa’s biographer states that the 18 bombers he led attacked Nevada. However, the ARs recorded that a portion of the group attacking Nevada broke off and instead attacked Shaw in the floating drydock. This could reflect either a shift of targets or bombs that were so inaccurate they landed closer to Shaw than Nevada. One ship’s log recorded that one-third of the attackers diverted. Another offered a count of 21 bombers that went after the Navy Yard area, some of which diverted to attack Nevada.
Fourteen D3A Val dive-bombers from the second wave were shot down. The missing two bombs could have been on aircraft that were shot down before they released their weapon.
Comparing Claims, Hits, and Attacks
Although the Japanese claimed 21 hits against Battleship Row targets, the Americans recorded only Ofuchi’s shotai attacking California. The Americans do not record any major dive-bombing attack against Battleship Row.26
Explaining the Mystery
There are several possible explanations for this mystery.
1) The Japanese dive-bombers did indeed make a major effort attacking Battleship Row that was not recorded in US logs.
This is very unlikely. First, there were many, many observers. The likelihood that all observers would have missed reporting an attack of 20 to 30 aircraft is diminishingly small.
Even if the dive-bombers did not score hits, the misses would have been sufficiently traumatic to be recorded. Between 0854 and 0930 there were men in the water all around Battleship Row, from the capsized Oklahoma, blown off Arizona, and driven off other ships by fires. Small boats and yard craft were picking up survivors. Firefighting craft were attacking the fires. One photograph (#24) shows over 20 boats and craft in the water.
“Tugs, lighters, gigs, and small craft of every kind rushed across the waters of Pearl Harbor rescuing swimmers.” Boatswain’s Mate First Class Thomas Miechurski, master of yard tug YT-129, approached Battleship Row but boats “were so thick around Arizona that YT-129 could not get close enough to help.”27 While standing by off Arizona Miechurski watched the dive-bombers’ attack Nevada in the channel. He does
not mention any attacks against Battleship Row.
A bomb thrown into that maelstrom would have killed people, sunk rescue boats and scattered flaming oil. It would have been recorded as part of the Battleship Row disaster. There are no such records.
In addition, the analysis of American records account for all but two of the bombs. There are no “missing” bombs that could have been dropped on Battleship Row and not recorded.
It appears that the major dive-bombing attack against Battleship Row claimed in the Japanese BDA report did not occur.
2) The US accounts of attacks are inaccurate.
Exact accuracy cannot be expected. However, the alignment between recorded attacks and physical damage is good. Reports of individual bomb detonations were recorded, sometimes by multiple independent sources which correlated well in the ARs. There are sufficient clues to allow a good recreation of the targets actually attacked.
3) The Japanese aircrews were mistaken regarding where they attacked and what they hit.
Aircrew ARs were notoriously inaccurate during the war, having a very bad record of claiming more damage than actually occurred. Sometimes the aircrews were overoptimistic, and sometimes the aviators saw what they wanted to see. Ensign Honma Hideo, flying a B5N Kate level bomber, relates how later in the war 18 level bombers attacked an airfield at Lae. He felt that only a few bombs actually hit the airfield, “But after the mission, our commander said that we had a 100% hit rate.”28
There were two witnesses in each dive-bomber (pilot and gunner/radioman). Doctrine had the dive-bombers attack as a shotai giving six aircrews to testify on the target location. In addition, the attack commander, Fuchida, observed the progress of the attack as the individual unit commanders selected their targets.