Alan D. Zimm
Page 20
Of the 94 operational American fighters, only fourteen sorties got aloft, with two other aircraft shot down as they attempted to take off. Those fourteen sorties scored eight to eleven kills, some by interjecting themselves unnoticed into the holding patterns of Japanese aircraft waiting their turn to dive in on strafing runs against the airfields. None of the American fighters appeared over Pearl Harbor or contributed to the defense of the fleet, their primary mission.
The second wave attack began at 0854. The fleet’s defenders reckoned the attack was over around 0930.
Finally, over the harbor, the sky was clear of aircraft.
The attack left behind 2,403 people dead or dying and another 1,178 wounded. Of the dead, 1,177 were assigned to Arizona and 429 assigned to Oklahoma. Three battleships were sunk and two sinking. Two cruisers were torpedoed and three destroyers wrecked. The majority of the Army Air Force and Navy aircraft were either destroyed or damaged.
The Japanese left behind 29 aircraft with their crews, and five sunken midget submarines.
CHAPTER SEVEN
ASSESSMENT OF THE ATTACK
The Pre-Dawn Reconnaissance
Just prior to the day of the attack the Japanese had received accurate information that the fleet was in port and not off Maui, that no carriers were present, and there were no torpedo nets. This was important information, needed to allow the plan to be changed if necessary before the strike was launched. The submarine accomplished its mission without being detected.
Why, then, were additional floatplanes launched on the morning of the attack to repeat the reconnaissance? The chances that the fleet would move out of Pearl Harbor to Lahaina Roads on a Saturday night were miniscule—the Japanese had months of reports and knew the Americans’ operating patterns. Lahaina Roads had not been used as a fleet anchorage for almost a year due to its vulnerability to submarine attack.
The reconnaissance seaplanes might be spotted and identified. The most probable American reaction would be to launch additional fighters, in addition to the usual dawn patrol, to investigate. The air defenses might also be placed on alert, as the presence of a Japanese floatplane required the presence of warships. As it was, two radar stations on Oahu detected these aircraft at 0645.
Planning an aircraft reconnaissance of Lahaina was appropriate, in case the submarine did not accomplish its mission. However, after the submarine reported, this flight ought to have been cancelled. This is another example of the lack of flexibility demonstrated by Japanese decision makers, and another place where alert defenses could have changed the course of history.
A second floatplane was to overfly Pearl Harbor to report the number of ships and the weather conditions. Again, this was an unnecessary report. The first-wave strike would receive this information en route, about 40 minutes before the attack, with no real opportunity to act on it due to a lack of communications between leaders and the strike aircraft. At this point the information had no real tactical significance. It accurately reported that there were no carriers in the harbor, but the Japanese did not use the information, and the information did not prevent the mistaken attack on Utah. The weather report was not particularly useful, since the attacker would be able to see the weather for themselves in a few minutes, and the report was not needed for any decisions. Even then, a more accurate report was intercepted from a commercial Oahu radio broadcast. There simply wasn’t time (or communications paths or command and control) to react to any unique information the reconnaissance flight might discover.
Both of these sorties risked the success of the strike for very little return. Had the Army’s Air Information Center been active, a full alert could have been triggered. But the Japanese plan assumed that their scouts would not be detected, and that was the end of the matter.
Updating the Plan for the Updated Intelligence
Two different sources confirmed that the carriers were not in port. There were no changes made to the attack plan to reflect this intelligence—the planners clung to the hope that a carrier would arrive in time for the attack.
Hope is not strategy. This intolerance to dynamic circumstances was an early manifestation of the inflexibility that would dog Japanese planners throughout the war. Matsumura’s 16 torpedo bombers remained assigned to the carrier anchorages in spite of the knowledge that the carriers were absent, a stunning decision (or lack of one). Either the carriers were so important in Genda and Fuchida’s minds that they could not bear to re-allocate the aircraft, or alternately, after working on their plan for so many months they were psychologically wedded to it in all its details. Both, perhaps. Certainly the second factor was there, considering that when earlier they needed to provide a contingency plan for the case where surprise was not achieved, their response was to only make minimal changes to their established plan. This reflects a fundamental lack of flexibility in Japanese staff processes.
The meeting between Genda, Fuchida, and Murata, where they considered what to do if surprise was not achieved, was a very curious meeting. It only involved the three of them, the chief planner, the strike commander, and the commander of the torpedo bombers. Absent were the commander of the fighters and the commander of the dive-bombers, the commanders of the OCA strikes and, most significantly, any flag officers. One would think that such a momentous decision would need to be coordinated with all elements of the attack, and would warrant flag interest and review.
The torpedo bombers who were to attack the carrier anchorages were, if the carriers were missing, to seek out other targets. The attack routes available to Murata’s formations included routes against nests of destroyers and tenders, targets low on the priority list. Were these actually intended to be considered as targets, considering that only “crippling power” was allocated against the battleships? How could Murata’s aviators be expected to allocate their attacks down a priority list without information on the damage inflicted to higher priority targets by other torpedo bombers that they might not see?
The failure to react when circumstances were different from those assumed in the plan meant that 16 carrier attack planes were buzzing about Pearl Harbor looking for targets, an air traffic control horror story.
Fuchida’s Fumble with the Flares
The process of communicating using flares was not well thought out. Fuchida fired two flares, which was interpreted both as signaling the “surprise” and “no surprise” contingency plans by different elements of the force. The attack went into the attack with the same level of organization as the Kentucky Derby after the horses are turned loose. Everyone was racing for their target, the dive-bombers under the assumption that the defenders had been alerted, and the torpedo bombers realizing that surprise had been achieved and wanting to get their attack in before the defenders woke up. According to one of the observers on a torpedo-carrying Kate, “Due to miscommunication between our pilots the attack sequence was utter confusion. All of our aircraft were trying to attack at the same time.”1
The planners failed to provide a clear and reliable means of communicating which attack plan was to be used. They also failed to provide a plan that could be executed in an organized manner should the enemy defenses be alert. “Surprise,” and then “no surprise” was signaled, resulting in disarray. The communications problem could have been easily solved, either by designating different colored flares for each plan, or by specifying an interval between two flares as the signal, or by having the flares fired only to signal a change in plan away from a default plan.
Radio was not used, either as a primary or backup means of signaling. It is not known why the Japanese would signal the initiation of the attack (“To, to, to,” for “charge”) and not use that same means to signal which plan was to be employed. Tactically, apparently no attempt was made to use the radio by the leaders of the torpedo bombers to prevent the attack on Utah, or to sort out and allocate targets. Although as we have seen, the IJN’s radio equipment at the time was flawed, the Japanese had not yet come to terms with radio’s comman
d and coordination potential.
Fuchida’s attitude towards his error with the flares is remarkable. Rather than taking responsibility for the error, he disingenuously attempted to convince a historian that his blunder was of no import. This claim was accepted for 65 years, but more thorough analysis indicates that Fuchida’s blunder was significant. It cost lives and wasted weapons.
The mistimed wake-up call to Pearl Harbor came as bombs detonated on Ford Island a short distance from Battleship Row. A more effective reveille cannot be imagined. In exchange, the Japanese destroyed an aircraft and a hangar, targets that were not time-critical and could have no impact on the early part of the battle. If surprise had indeed been lost, the first bombs ought to have been targeted as SEAD to support the torpedo bombers’ attack—but the Japanese did not think in those terms.
Most of the ships in Pearl Harbor were in Condition Three, an alert status that required 25% of the anti-aircraft battery to be manned, with ammunition adjacent to the guns but locked in ready service lockers. These explosions triggered a frantic search for the keys, which in most cases were held by the senior duty officer, the duty gunnery officer, or the duty gunners mate. Many impatient gun crews smashed the locks off. The minutes required to get the “ready” guns firing were provided through Fuchida’s error.
The average time to get the ship’s anti-aircraft batteries into operation was five minutes for the battleships, four minutes for the cruisers, and seven minutes for the destroyers.2 The first bomb landed about two minutes before the first torpedo detonated against Utah, which in turn was several minutes before the attack developed against Battleship Row. The bomb explosions preceded the torpedo attack against Battleship Row by about four to five minutes, compared to the four to seven minutes needed to get AA batteries in operation.
The first torpedo planes to attack Battleship Row took fire, led by Murata and Lieutenant (junior grade) Goto Jinichi. Goto reported, “In spite of the surprise attack early on a Sunday morning Murata and I saw machine-gun bullets coming onto us before we launched our torpedoes!… We were under a curtain of machine-gun fire.”3
The premature warning allowed American machine gunners on Bagley critical seconds to get their weapons in operation. Bagley reported that she was able to engage the third torpedo bomber in the stream of attackers.
Fuchida’s blunder cost lives and aircraft.
A British study of low-level aircraft bombing attacks against merchant ships in the Mediterranean found that when ships fired back during an aircraft attack, 10% of the ships were sunk, while 25% were sunk when they did not. The AA only shot down 4% of the attacking aircraft, but reduced the rate of ships being sunk by two thirds. At Pearl Harbor, the defensive fire caused torpedoes to be launched outside the release envelope, disrupted their aim, and contributed to poor target selection as the torpedo bomber crews hurried to drop against the easiest available target. Of the 40 torpedoes brought to the battle, 35 were dropped, 19 hit a ship and perhaps 4 ran but missed their targets. Probably a total of 12 torpedoes (34% of those dropped) were delivered out-of-envelope or had technical failures and ended up stuck in the bottom mud of the harbor. Two of the 12 were dropped against Utah, three against Helena, and seven against Battleship Row.
The poor approach tactics handicapped the attackers. Most of those that attacked Battleship Row flew directly past the Navy Yard, one at a time, allowing the gunners on Bagley and other ships to practice, learn, adjust, and hit.
Fuchida’s fumble with the flares contributed to the loss of five torpedo bombers and precious torpedoes that were shot down or jettisoned before launch, and probably also contributed to the improper delivery of 12 others.
Assessment: Torpedo Attack
One of the ideas pounded home during the aviators’ briefings was that heavy damage on one battleship would be better than slight damage on many battleships. This was one of Genda’s initial planning principles. Yamamoto, too, wanted battleships crippled or sunk. How many torpedo hits are required to sink a battleship?
The US Naval War College assessed that the Treaty classes present at Pearl Harbor could take six to seven Japanese aerial torpedo hits before sinking. If the hits were scored within a fifteen minute period they could only take four to five, as the ships’ counterflooding capability would be overwhelmed and the ship would capsize.4 A postwar study conducted by the US Navy’s Operations Evaluation Group derived similar numbers.5
American battleships sacrificed speed in favor of sturdy construction, heavy armor and better torpedo protection. The damage-resistance capability of their hulls was demonstrated when the Colorado-class hull of the battleship Washington (BB-47) had to be expended under the terms of the Washington Naval Treaty, and so was used for damage-resistance tests.6 Two 400-pound torpedo warheads and three 1,000-pound bombs were detonated against the torpedo defense system. The hull remained afloat for three days, even without a crew to perform damage control.
The best condition to resist damage is where the ship is at sea, with General Quarters set, fuel levels and tank closures in combat condition, the firemain split and pressurized,7 dewatering systems manned and ready, and with the ship buttoned up with all watertight doors secured. This was known as “Material Condition Zed,” or, more familiarly, Zed.
Zed was not maintained in harbor. Maintenance, repairs, and resupply had to be performed, watertight doors were open for access and ventilation, and at times tanks and voids and other unmanned compartments were opened for corrosion inspections or maintenance. Open doors, hatches and access ports allowed progressive flooding, where water can spread far beyond the immediate vicinity of the hit.
The effects of reduced watertight integrity on ships in port were demonstrated earlier in the European war. The Japanese were aware of them via information from their Axis partners.8 On 14 October 1939, the British battleship Royal Oak was sunk by three German submarine torpedoes in Scapa Flow. At Taranto on 12 November 1940, the Italian battleships Conte di Cavour and Caio Duilio were each hit by one aerial torpedo and sunk, and Littorio (a modern ship completed in 1940) was intentionally grounded after three aerial torpedo hits. In November of 1941 the British battleship Barham was sunk by three German submarine torpedoes when she was underway, though not at Action Stations.
Royal Oak was an old ship, an “R” class laid down in 1914 under lesser standards for anti-torpedo protection. Italian Navy crews did not have a good reputation for damage control. From these examples the Japanese would have concluded that four hits on a battleship would be sufficient to achieve their objective. With potentially eight battleship targets, and assuming 80% hits, five aircraft should attack each battleship. This would require all 40 torpedo bombers.
The Japanese received specific reports on where the battleships were moored, and knew that only four battleships were positioned where they could be hit by torpedoes. There were four additional ships within their targeting instructions and accessible to torpedoes. Phoenix, a modern 10,000 ton cruiser, was anchored in the East Loch astern of Nevada; a sister ship, Helena, was moored at 1010 Dock; Raleigh and Detroit were at the carrier moorings. Four other cruisers were at the Navy Yard piers, but New Orleans, San Francisco, St. Louis, and Honolulu were inaccessible to torpedo attack.
Adding the accessible cruisers to the four outboard battleships gives eight valid torpedo targets within the Japanese prioritization instructions. An even distribution would have put five torpedo bombers against each target; a better distribution would be four against each cruiser and six against each battleship. A 50% hit rate would have likely sunk the four cruisers and sunk or crippled all the battleships. This would have more than doubled the returns for the torpedo bombers over what was actually achieved.
The original Japanese plan had 24 torpedo bombers directed against Battleship Row. Evenly distributed, this would allocate 6 bombers against each vulnerable battleship; an 82.5% hit rate (as achieved in the last practice session) would give five hits per battleship.
The second gr
oup of 16 bombers had 13 potential attack paths against ships at the carrier moorings northwest of Ford Island, cruisers anchored in the East Loch, and two potential paths of approach directed against ships pierside at 1010 dock at the Navy Yard.9 Had they gone for the cruisers, as would be logical under their prioritization scheme, there would have been four torpedo bombers per cruiser, enough to sink them all even with a 50% hit rate.
Mental Errors and Physical Errors
In sports such as football and baseball there are mental errors and physical errors. The same holds true in battle: there are bad decisions, mental errors, and physical errors, such as poor execution in aiming and firing. The torpedo bombers committed both types of errors.
The first significant mental error was committed by the torpedo bombers assigned to attack the carrier moorings. These moorings were occupied by Utah, an aged demilitarized battleship serving as a target ship, two early-’20s-era cruisers Raleigh and Detroit, and Tangier, a former cargo ship converted to an 11,760-ton seaplane tender. The obsolescent cruisers were legitimate targets on the priority list, although not very glamorous; Utah was a clear waste of ordnance.
John Toland relates the story of Lieutenant Matsumura, leading Hiryu’s torpedo group, as he approached Pearl Harbor:
“Look for carriers!” he called through the voice tube to his observer…. Half a dozen planes converged on a big ship that looked like a carrier on the northwest side of Ford Island. “Damn fools,” he repeated, “Who can they be?” Before takeoff he had warned his men to leave this one alone. It was merely the thirty-three-year-old target ship Utah, her stripped decks covered with planks.10
Mori, flying on Nagai’s wing, also observed this attack. “Can’t they see that two of the ships are nothing but cruisers? It would be a crime to waste torpedoes on them when the battleships are right there in sight a bit further on.” Mori was determined to use his torpedo on nothing less than a battleship,11 an attitude shared by all the Japanese aviators.