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| Midway: Creation of the Artifact |
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| Having
identified the portion of Kaga from which the wreckage originated,
the question becomes how and when was the wreckage artifact created.
The appearance of the wreckage tends to support the conclusion that
it was created in a violent fashion, i.e. either by being blown off
the side of a carrier while the ship was in its death throes, or by
being detached during the sinking of the ship as the vessel disintegrated
in the water column due to hydrodynamic forces. Indeed, given the
size of the object (which comprises what used to be some 55 linear
feet of the ship’s side), it is difficult to conceive of a set
of circumstances wherein an object of this size could be blown off,
and the ship not being in a near-sinking condition. Nevertheless,
given that Kaga’s main wreck was not found in the immediate vicinity
of the wreckage, the supposition is that the artifact was created
while the ship was still on the surface. We now turn to a discussion
of the possible circumstances surrounding the creation of the wreckage. Circumstances of the Attack The general events of the dive-bomber attack on the Japanese Carrier Strike Force (Kido Butai) are well known. Only details pertinent to Kaga’s damage are reproduced here. At the time of the fatal attack (which began at 1020), Kaga was preparing to launch a second strike of aircraft. She and Akagi (comprising Carrier Division 1) had contributed the Type 99 (Val) dive-bomber component of the initial strike against Midway. As planned, their second strike was to comprise Type 97 (Kate) attack (i.e. torpedo) bomber aircraft and a contingent of Zero fighters. Thus, between 30-33 aircraft probably crowded her flight deck during the attack.[1] The aircraft from her first strike had been stowed below. It can be surmised (though not proven) that her Type 99 aircraft and first-wave fighters were concentrated mainly in the forward hanger spaces (both upper and lower), since they would have been struck below via the forward elevators. Since time was of the essence in preparing the second strike, it is likely that the first wave aircraft were moved the minimum distance from these elevators in order to concentrate available deck hand labor on the more important task of bringing the second wave up to the flight deck and spotting it for launch. As is well known, ordnance was strewn about the hanger spaces, and fuel lines were in use. Kaga was attacked by more than 20 American SBD dive-bombers beginning at 1020. During this attack she was hit at least four times. The first hit (the fourth bomb dropped) was located starboard aft, near the vicinity of the aft elevator. The second and third hits (bombs #7 and #8) struck near the forward elevator. The second hit apparently penetrated to the forward hanger spaces and detonated there, destroying the re-armed Type 99 aircraft there[2]. The third hit apparently either directly hit (or, as this author believes, caused fragments to hit) a fuel bowser parked in front of the island[3]. The detonation of the bomb and gasoline truck blew out the bridge windows and sprayed burning gasoline across the front of the island, killing everyone on the bridge, including Captain Okada. The fourth and final recorded hit (bomb #9) struck Kaga amidships to port. It should be noted that it is possible that Kaga received additional direct hits from American bombs that are not recorded. By the time of the fourth hit, Kaga’s flight deck was already burning strongly, and additional hits might not have been noticed in the confusion. The results of this attack were devastating. Power was apparently lost very shortly after the initial bomb hit. The planes topside were soon burning fiercely. Worse yet, the hanger spaces both fore and aft were wrecked by fire and internal explosions. Commander Amagai (Kaga’s Air Officer, who had taken command of the ship after the death of Capt. Okada) was faced with an insoluble damage control problem that would worsen progressively until he ordered the ship abandoned at 1640. She suffered two large-scale detonations at 1920 (apparently as the fires finally reached the lower magazines and avgas storage spaces), and sank at 1925. |
Creation
of the Wreckage The nature of the damage to the aft hanger spaces is the critical issue, since this space was adjacent to mounts S#8 and S#9. It is interesting to note that the initial bomb hit landed within 20 feet of S#9. However, it is unlikely that the detonation of a single bomb in this area would have caused the separation of such a large piece of wreckage from the ship. More likely, the wreckage was created by a combination of two factors: 1) heavy, sustained fires which weakened the ship’s structure, and 2) a powerful explosion or explosions, causing part of the gallery structure to be detached wholesale from Kaga. As was pointed out in the Preliminary Analysis, Japanese carriers were particularly vulnerable to explosive forces in their hanger decks. Unlike British fleet carriers (which carried a heavy armor deck over their enclosed hanger spaces) and American carriers (which had unarmored flight decks, but whose hangers were lightly screened on the sides, allowing easy ventilation), Japanese carrier hangers were fully enclosed by storage spaces and other hull structure, and were also unarmored above. The result was that when a bomb did hit the hanger, explosive overpressures had nowhere to vent themselves, often leading to catastrophic damage to the ship’s structure. This effect was also true for induced explosions caused by shipboard gasoline and ordnance. It seems somewhat unbelievable that a chunk of wreckage as large and heavy as that found on the seabed could be blown from Kaga’s starboard side without anybody noticing. On the other hand, the location of S#8 and S#9 were very near the initial point of damage, meaning that the men in the spaces nearby would have been killed or forced to flee almost immediately. It would be difficult to see this area of the ship from the bow, and survivors in the forward region of the ship might have noticed nothing more than another heavy explosion, and perhaps a large splash. They might simply have assumed that a plane had been blown overboard. It is probable that the only personnel in a position to witness the event would have been in the water nearby. Any men unfortunate enough to be in the area when such an event occurred stood chance of being killed by the wreckage falling atop them. It is notable, too, that most of the survivor’s accounts from Kaga tend to come from men who were well forward in the ship. These two reasons help explain the apparently incredible absence of any direct mention of Kaga losing two anti-aircraft mounts and a hundred or so tons of her superstructure over the side! Timing At some point in time, structural damage aboard Kaga’s upper hanger deck had advanced to the point where the ship began to literally fall apart. How soon, and where, this began to occur is largely a matter of guesswork. Commander Amagai’s testimony (as cited in Prange[4]) notes that “the heavy concussions [from exploding bombs and torpedoes in the hanger] blew men and even ship’s plates overboard like matchwood [my emphasis].” Unfortunately, Prange’s style of writing is sometimes less precise with temporal events than is desirable, and the timeframe of this event is difficult to know, beyond the fact that such events were occurring before the ship was abandoned at 1640. The position of this passage in Prange’s account suggests that these events were transpiring after U.S.S. Nautilus’ attack at 1359, but this is not certain. Walter Lord’s account is similar. In it, he cites Commander Amagai being forced by the flames to retreat to the lower boat deck.[5] “Huge explosions were ripping through the side of the ship, hurling men and chunks of planes like projectiles. Amagai couldn’t reach the hanger deck, where the fire was worst, but it looked like an inferno.”[6] Again, the timing of these events is uncertain. Surely Amagai must have been forced to abandon the island fairly soon after the 1020 attack, and Nautilus would not attack for another three and a half hours, indicating that heavy explosions were already present before the submarine attacked. |
On
the other hand, Lord also cites the plight of Kaga’s assistant
damage control officer, Lieutenant Commander Yoshio Kunisada, “…it
had been a losing fight against the fires all morning. For a while
[Kunisada] felt he was making some progress on the hanger deck; but
then the paint began to burn, spreading a thick oily smoke that nearly
suffocated his men. He had the portholes opened, but that was no answer.
The draft only fanned the flames. The ports were slammed shut again,
but soon Kunisda was back where he started—his men in more danger
than ever. There was nothing to do but leave. The exits were all blocked,
so once again the portholes were opened, and about seven of his men,
including Kunisada, squeezed through. They found themselves on a narrow
bulge[7] that ran along the side of the ship…” [8]
It was from this precarious position that Kunisada would shortly witness
the torpedo attack of the Nautilus. The timing and nature of Kunisada’s
account would seem to indicate that Kaga’s hanger deck was only
beginning to slide towards violent self-destruction by about the time
the American sub attacked. Up until shortly before the attack Kunisada
was still battling the fire with some limited degree of optimism.
This surely would not have been the case if Kaga were already self-destructing
to the degree necessary to create the wreckage artifact. In the opinion of this analyst, the nature of the damage control efforts aboard Kaga seem to indicate a gradual loss of the battle, rather than an outright rout. The men aboard Kaga fought her fires for more than eight hours. On Sôryû, by contrast, the ship was abandoned within twenty-five minutes of being bombed. The fact that Kaga’s men battled for as long as they did indicates that 1) the men must have felt that there was some remote hope of saving the ship, and 2) the bomb and avgas storage spaces were not being directly affected by the fires, which would have destroyed the ship outright. If those vital spaces had been directly threatened, Kaga would likely have been abandoned in the same fashion as Sôryû, which was abandoned shortly after fires reached her forward avgas storage spaces. In summary, given the evidence at hand, it seems highly unlikely that the initial American bomb hit caused the creation of the wreckage artifact (such a powerful initial hit would surely have been noted in the war log). Similarly, it seems unlikely that Kaga was falling apart instantaneously after the attack. Even in the face of the severe heat present in the aft hanger deck, it would have taken time, perhaps several hours, for the metal on the hanger deck sides to turn red hot and begin to lose their structural integrity. If Kunisada’s account is any indication, it may be that Kaga did not begin truly self-destructing until after Nautilus’ attack, in the 1400 range. At this point, the metal would have been weakened enough that a large internal explosion close by might have been able to separate the main portion of the wreckage from the remainder of the hull. At a guess, then, the creation of the wreckage artifact probably occurred after 1400, but before the powerful twin explosions at 1920. In other words, the wreckage may be as far as five and half hours (at whatever drifting speed was prevalent) from the main wreck itself. It is unfortunate that we cannot narrow the event down any further, but the gaps in the accounts of Kaga’s survivors are very large. Only the discovery of the main wreck, and its relative position to the wreckage artifact, are likely to solve the question of when the wreckage was actually created. |
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 Figure 23: Known bomb hit locations on Kaga. (Illustration by Parshall) |
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[1] Sources vary regarding both the actual number of Type 97 aircraft carried by Kaga during the Midway operation (either 18 or 27), and the number of Type 0 fighters slated for the second strike (either 3, 4 or 6). John Lundstrom, in an email to this author, states that 27 Type 97 attack bombers is the correct figure for Kaga, but ventured no opinion as to the number of Zero fighters to be launched, given the very chaotic nature of the Japanese CAP at the time of the attack. [2] The fuzing on the American bombs was such that they were supposed to penetrate a flight deck and detonate a short distance below it. The second hit on Kaga apparently did just that. [3] The presence of a fully loaded fuel bowser on the flight deck of a ship that had been recently undergoing American attacks illustrates just how desperate the Japanese must have been to refuel their CAP fighters and keep them aloft during the morning’s air battles. [4] Miracle at Midway, p. 310. [5] This was located on the starboard side of the ship, directly below the ship’s superstructure, at approximately the level of the upper hanger deck. [6] Incredible Victory, p. 181. [7] This can only be the Kaga’s anti-torpedo blister, which indicates that Kunisada was fighting fires on the lower of Kaga’s two hanger decks. [8] Ibid, p. 210. |
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