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U.S.S. NEVADA Torpedo and Bomb Damage December 7, 1941 Pearl Harbor
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There are 51 photographs and 12 plates appended to this report. The reader with limited time for study of the full report will find a comprehensive summary in Sections I, II and VIII, together with Plates I and II and Photos 1 to 6, which have been arranged for a quick review of the case.
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FOREWORD 1. U.S.S. NEVADA was struck by one torpedo and five bombs on December 7, 1941. There were two severe fires on board. The ship got underway and was beached. Nearly all compartments below the main deck flooded. Two months elapsed before she was floated and docked. She arrived at the Navy Yard, Puget Sound, three months later for final repairs and modernization. This report deals with the damage in detail, and with the salvage and temporary repairs in general, during this five-month period. 2. There are naturally numerous conflicts of evidence and some points must remain obscure. A representative of the Bureau of Ships visited the ship on arrival at the Navy Yard, Puget Sound, interviewed many of the personnel and carefully inspected the ship. This report is based upon the results of this investigation and the referenced correspondence. The plans are based on those submitted by the Navy Yard, Pearl Harbor, with reference (d). 3. Plates I and II and the first six photographs have been prepared to facilitate a preliminary survey of the principal events, together with the following narrative. NARRATIVE (Plates I and II; Photos 1to6) 4. U.S.S. NEVADA was moored starboard side to the interrupted quay F-8 at Pearl Harbor on the morning of December 7, 1941. The depth of water here is about 40 feet. The weather was clear, with scattered clouds. 5. The Japanese air raid commenced with dive-bombing of the Air Station on Ford Island just before 0800, and a torpedo plane attack on the battleships followed immediately. NEVADA was struck by a torpedo on the port side between the two forward turrets at about frame 41, approximately 14 feet above the keel. This occurred at about 0810. The innermost torpedo bulkhead was opened at seams and butts and compartments below the first platform deck between frames 30 and 43 (on the port side only) began to flood. The ship gradually listed four or five degrees to port. Counterflooding reduced the list to nearly zero. 6. Orders were issued for the battleships to sortie. NEVADA had already started warming up, and got underway at about 0840. The torpedo plane attack had lasted only ten to fifteen minutes. Dive and high-level bombing continued, however, and was in progress as NEVADA backed away from her berth and swung out to clear ARIZONA at berth F-7. The subsequent movements are shown on Plate I, and a diagram of the torpedo and bomb hits is given on Plate II. ARIZONA'S forward magazines blew up and VESTAL got clear before NEVADA left. 7. The ship had nearly reached the channel entrance and was about opposite CALIFORNIA at berth F-3 when signals were received not to leave the harbor. The engines were stopped and - 3 - |
preparations made to anchor. This was at approximately 0900. PENNSYLVANIA, from her position in No. 1 drydock; reports that a flight of about fifteen bombers approached from the southeast at an altitude of 10000 to 12000 feet. Roughly two-thirds of the flight apparently observed NEVADA and swerved off to attack her, while the remainder continued on to attack the ships in the dock.* The group which attacked NEVADA apparently did so with no preconceived plan, for the bombs came from various angles and at various degrees of steepness, many from dives, as shown by Plate II. 8. Five bombs struck the ship almost simultaneously. No one can give the sequence of these hits. Certainly all landed within two or three minutes. The Chief Engineer, returning to the ship by boat, saw a close cluster of three bombs falling toward NEVADA, followed by three smaller objects (which may have been parts of the release gear) about 100 feet behind the bombs. Two struck the forecastle over the wardroom country near frame 15, one of which went out through the side at the second deck level and caused near-miss damage to the starboard side, while the other penetrated to the gasoline tank and exploded within the ship between the tank and the shell on the port side. Another struck near the port waterway forward of No. 1 turret at frame 25, penetrated to and ricocheted from the second deck and blew large openings in the main and upper decks. A fourth struck the port director platform in the foremast and exploded at the base of the stack on the upper deck. The other bomb exploded on the superstructure deck directly over the crew's galley. For convenience in future reference, the hits are numbered from 1 to 5 in the above order, it being understood that the actual sequence is unknown. 9. Fires broke out immediately. Men standing by to anchor on the forecastle were blown overboard and the anchor gear was wrecked. It was imperative to get clear of the channel, as other ships were leaving the harbor. The ship was therefore beached near the floating drydock which contained the destroyer SHAW. 10. Pressure on the firemain was not enough to fight the fires, especially the intense one in the foremast structure, and two tugs were summoned to assist in firefighting. The wind was from the east, and the stern of NEVADA tended to swing out across the channel in the way of departing ships. Shortly after 0900, the magazines of SHAW exploded** and showered the decks of NEVADA with debris. These various circumstances resulted in a decision to move to the other side of the channel. 11. A tug pushed the stern farther around and the bow floated off. It appears that the tugs moved the ship most of the way across the channel, and that the engines were used only at the last, when they were backed until the stern was hard aground. This was at about 1030, or an hour and a half after the bomb hits. Flooding was progressing aft, though at this time the third deck was dry abaft No. 2 barbette (frame 48) and the central crew space between frames 30 and 48 on the third deck apparently had only a little oil in it. 12. The after magazines had been flooded while the ship was passing ARIZONA. This was done by mistake; there was no need to flood these magazines. Flooding of the forward magazines was commenced at 0920, while the ship was aground near - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
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18. Gasoline was forced up from the tank ruptured by bomb No. 2. It is believed that vapor collected forward of bulkhead 8-1/2 on the main deck. The fire already raging in the officers' country must have caused the vapor explosion which occurred on Sunday afternoon, and which resulted in more structural damage on the main and upper decks. There may have been intermittent minor vapor explosions. It was late Monday afternoon before this fire was extinguished. It was extremely stubborn, re-igniting when apparently out. The two forward bomb holes and a long split in the upper deck were stuffed with mattresses, and the fire was finally brought under control by smothering with steam supplied from the tugs. 19. Salvage work was undertaken at once. The three bomb holes in the hull (exit hole and near-miss hole caused by bomb No. 1, and the hole near the forefoot caused by bomb No. 2) were covered with external wooden patches. A large patch was made for the torpedo hole, but it did not fit properly and was removed before the ship was docked. 20. The decks were gradually unwatered by gasoline-driven salvage pumps. Stores, provisions, auxiliary machinery, motors and ammunition were removed as the various compartments were pumped out. Toxic gases were unfortunately encountered which killed two men. All surfaces were covered with fuel oil, and the task of cleaning the ship was a formidable one. 21. NEVADA again became waterborne on February 12, 1942 and was docked on the 18th. Photos 1to6 illustrate her history up until then. Temporary repairs were made to the hull and the machinery was put into limited operating condition. She steamed to the mainland at twelve knots, arriving at the Navy Yard, Puget Sound, on May 1, 1942. 22. A discussion of the types of bombs and of the torpedo used is given in paragraphs 130to133. The conclusions are that bombs 1, 2, 3, and 4 were of the 250-kilogram general-purpose type, carrying 133 pounds of explosive; that bomb No. 5 was a light fragmentation bomb weighing about 60 Kg. and using an impact firing pin; and that the torpedo charge was under 500 pounds and possibly as low as 337 pounds(The "Type 91 mod 2" torpedoes used during the attack on Pearl Harbor featured an explosive charge or 452 lbs., or 205 kg). 23. The damage which the enemy inflicted on this ship was comparatively superficial. The main machinery was not affected and most of the armament could continue in action. The ship sank because of deficiencies in watertight integrity, by virtue of the lack of watertight bulkheads on the second deck and failures of boundaries and fittings elsewhere which should have been watertight but were not. These converted a fairly simple repair job into a salvage and overhaul problem. STRUCTURAL DAMAGE A. Structural Damage Caused by Torpedoes (Plates III and IV, Photos 7to10) 24. The torpedo evidently exploded on impact at frame 41 on the port side, about 14 feet above the keel, which placed it between the first and second platform decks. There was a dull explosion accompanied by a noticeable but not a serious shock. No derangements of machinery or other equipment were observed. - 6 - |
25. The protective structure in this vicinity is shown on Plate IV. It consists first of a blister, containing upper and lower void compartments, which was added during the modernization in 1929; next the original shell and inner bottom, forming fuel tanks; and finally a row of fuel tanks bounded by a longitudinal torpedo bulkhead and having voids over them extending to the underside of the sloping third deck. The torpedo bulkhead was strengthened by 40-lb. nickel steel doubling plates when the ship was modernized. All of the fuel tanks were full when the damage occurred, and there were thus one void and two liquid layers, about 14 feet in thickness overall, opposed to the torpedo. 26. The blister, shell and inner bottom were blown open by the explosion. The holding bulkhead in the torpedo defense system deflected in a well-defined elliptical dish 24 feet long (frames 37 to 43) and 18 feet high (inner bottom to just above the first platform deck), the maximum depth of which was about two feet. Seams and butts in it opened from 2 to 4 inches, as shown on Plate IV, which also shows the distortion of the stiffeners and the local buckling of the decks. The buckle in the second platform deck was unusually deep (Photo 10), but extended only between bulkheads 37 and 43. Considering the relatively low standard of torpedo protection in this area the structural damage inboard of the holding bulkhead was gratifyingly small. 27. The hole in the blister is shown on Plate III and by photos 7to9. The edges of the hole were turned outwards, as is generally the case when the outboard compartment is void, and were trimmed off by divers before the photographs were taken. The hole was about 16 feet long and 27 feet high. Indentation of the blister extended roughly over an area 48 feet long by 25 feet high. Both the shell and inner bottom were carried away as shown in the plates and photographs. 28. As was to be expected, the welded connections of the upper blister framing to the face-hardened armor broke off with one exception; see Plate III. There was a long split in the seam between the lower two strakes of blister plating, which shows clearly in Photo 9. This tendency to blow out of the bottom is not unusual. A similar break occurred in the case of SARATOGA*. There was also a vertical tear in the blister plating about 10 feet forward of the main hole, which was probably caused by gas pressure in the void over the hard spot on the shell at bulkhead 37; see plates III and IV. 29. The transverse bulkheads bounding the inner tank, A-44-F, were crushed, as was the flat above it. The inner bottom was torn from its connection to the underside of the sloping third (splinter) deck. Floors were torn from the shell plating, where not completely demolished, through rivets in the bounding angles. Photo 7 in particular shows the extensive failure of riveted connections which all cases of damage from contact underwater explosions exhibit. 30. The sea chest of a damaged blister flood valve can be seen in Photos 7 and 8. The plating was pushed in around
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the hard spot formed by this sea chest, and Photo 8 shows a crack in the plating. This illustrates the danger of such installations. In this case no harm was done. In other cases, broken sea chests have caused serious flooding.* Blister flood valves will be removed from NEVADA when these spaces are converted to fuel tanks. 31. The extent of flooding directly attributable to this explosion is discussed in paragraph 79 and indicated on Plates XI and XII. The salvage patch and the temporary repairs made at the Navy Yard, Pearl Harbor, are described in paragraphs 115 and 124. B. Structural Damage, Bomb No. 1 (Plates V, VI, VII; Photos 11to15) 32. This bomb struck the upper deck at frame 14-1/2, seven feet to starboard of the centerline, making the 12-inch hole shown by Photo 11. It penetrated the main deck and went out through the side about two feet above the second deck at frame 14. The underwater explosion ruptured the shell and inner bottom plating as shown by Plate VII and Photos 12 and 13. Damage extended inboard on both sides of bulkhead 14, which separates the storerooms A-501-A and A-502-A on the second platform deck (Photos 14 and 15). 33. The dished area in the hull measured about 36 feet in length by 24 feet in height. The seam between *M' and 'N' strakes was torn open for about 20 feet, and a vertical tear at frame 15 extended across 'M' strake and nearly across 'L' strake. The corner formed by these two tears was blown in about 3 feet. Plating in the affected area was deeply dished between longitudinals. The forward edge of the blister was opened up as marked on Photo 13. 34. Details of the hull plating connections are shown on Plate VII. The tear in the seam apparently started just forward of frame 15 by countersunk rivets pulling out in the seam strap. The seam strap ends at frame 14, forward of which a 20-lb. doubling plate is installed on the inner side. But the seam in the doubler nearly coincides with the seam in the shell, so that the failure of riveting continued on forward. At frame 12, a 40-lb. chafing plate begins; but its seam connection also follows those in the shell and doubler plates. This line of weakness could have been avoided by a wider separation of seams in the two and three courses of plating. The poor holding of countersunk rivets was the primary cause of joint failure, aggravated by insufficient separation of seams in doubled and tripled plating. C. Structural Damage, Bomb No. 2 (Plates V, VI, VIII; Photos 16, 17, 18) 35. This bomb also struck the upper deck near frame 15, eight feet to port of the centerline. Its trajectory was approximately parallel to the fore-and-aft centerplane of the - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - * The HONOLULU is an example; see Bureau of Ships War Damage Report No. 1 (HONOLULU) dated Feb. 14, 1942. - 8 - |
ship, at right angles to that of bomb No. 1. The hole in the forecastle deck was also about 12 inches in diameter (Photo 16). A main deck stanchion on frame 14 was struck and sheared off about a foot above the deck, which apparently deflected the bomb slightly outboard. This stanchion is visible in Photo 38. It penetrated the main deck, making a hole of about 15 inches minimum diameter, and left holes of about the same size in the second deck at frame 12-1/2 and in the third deck at frame 11-1/2. Continuing, it passed through a lightening hole in frame 11 in the void space A-4-V, through longitudinal No. 11 between frames 10 and 11, and through bulkhead No. 9 into the gasoline stowage compartment A-2 GAS. There it penetrated two more longitudinals and detonated about two feet above the base line. 36. The explosion apparently occurred just as the bomb was penetrating the shell. The shell plating was blown inboard over about 14 feet (frames 5-1/2 to 9), but the edges of the hole were turned outward. Photo 18 shows the hole after the salvage patch seen in Photo 17 was removed, prior to the installation of which divers had enlarged the hole and trimmed away the jagged edges. The trimmed hole measured about 4 by 7 feet. 37. The lower part of the gasoline tank was torn open. Frame 7 was demolished around to the first longitudinal on the starboard side, while frames 6 and 8 were flattened against the shell. The vertical keel was blown against the starboard side throughout the length of the compartment (frames 5 to 9, sixteen feet). The first platform deck, over the compartment, bulged upwards. 38. Structural damage was relatively minor. This is not believed due to any deficiency in the bomb, but to the fact that it exploded in a narrow space between two liquid-backed boundaries - the shell and the gasoline tank. HMS SUSSEX experienced a bomb explosion between full double bottom tanks and full fuel oil tanks inboard. The result was interesting in that the oil backed boundaries were very lightly damaged in comparison with other structure in the vicinity. These experiences indicate that an explosion near a bulkhead which is liquid backed will do very little blast damage to that bulkhead. Similarly, war experience and model tests have shown that liquid-backed shell plating will show less damage from underwater explosions than air-backed shell plating. 39. The 3800 gallons of aviation gasoline were evidently not ignited by the bomb explosion. The source of the gasoline vapor explosion has been mentioned in paragraph 18 and will be further discussed in paragraph 66. 40. This bomb travelled a greater distance through ship structure than in any other case so far examined in the raid of December 7. The distance between the points of impact and detonation is about 60 feet. All of the structure in the path of the bomb was fairly light, as indicated on Plate VIII. D. Structural Damage, Bomb No. 3 41. Opinions expressed in the references differ with regard to the source of the extensive structural damage on the - 9 - |
upper, main and second decks forward of No. 1 turret. There was a bomb entrance hole in the upper deck at frame 25-1/2 about 3 feet from the port waterway, which was similar in appearance to the holes made by bombs 1 and 2. The main and upper decks, however, were blown up and fractured nearly all the way across at about frame 27 with extensive damage forward and aft on these levels; and there was also a long split in the port side of the upper deck. References (a) and (b) suggest that this widespread damage must have resulted from a second and larger bomb in the same area, traces of which vere obliterated by the damage itself. 42. A careful examination, however, reveals no evidence of more than one bomb explosion here, and furthermore indicates that the bomb was of the same type as bombs 1 and 2. It entered the upper deck as noted above (Photos 19 and 21). It penetrated to the second deck and ricocheted from the armor, leaving the mark shown by Photo 23. The explosion must have occurred just beneath the main deck, for only two fragments pierced the shell below the main deck (both on the starboard side) whereas the blown-up portion of the main deck was riddled with fragments (Photo 22). Reference (f) considers that bomb No. 3 was of the heavy armor-piercing variety used elsewhere at Pearl Harbor that morning, but this is improbable because there was little penetration into the armored deck, the blast damage was more than would be expected from the 66-lb. charge in an armor-piercing bomb, and fragmentation was apparently better. 43. The principal arguments advanced in supposing that the bomb was very large, or that two bombs fell in the same area, are (a) that a long split opened in the upper deck (Photo 21) and (b) upper deck plating abaft the fracture at frame 27 was bent dovnward instead of upward (Photo 22). Although the split in the deck can be ascribed to bomb blast, it more probably was caused by a gasoline vapor explosion as described in paragraph 66. The downward-bending of one part of the upper deck cannot be easily explained. But at least it is no indication of a second bomb explosion beneath the deck. The hypothesis of a second bomb leaves more to be explained than it clarifies, and is believed to be false. 44. Excluding the effects of the gasoline vapor explosion and of the two-day fire in this part of the ship, the structural damage produced by the bomb becomes much less impressive than at first glance. The damage to be expected from the 250-kilogram general-purpose bomb can be fairly well predicted and examples are given in other reports.* Considering the confined space in which the explosion occurred, and the weakness of the upper deck with two skylights and a hatch in approximately the same transverse line, it is concluded that one 250-kilogram bomb would account for the damage. Identification of the bombs is further discussed in paragraphs 132 and 133. 45. The second deckk consists of four courses: 80 lb. S.T.S., 50 lb. S.T.S., 50 lb. nickel steel and 50 lb. medium steel. It was dished downward a maximum of 4-1/2 inches at the point of bomb ricochet, a distortion due to impact but possibly increased by blast effect. This caused two stanchions beneath
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to buckle as indicated on Plate V, located at frames 27 and 28, 10 feet to port on the third deck. All staterbom joiner bulkheads in Junior Officer's country, A-224-L, were completely demolished (Plate VI); bulkhead 11-1/2 was bulged forward and so was bulkhead 9 to a lesser degree. All four sides of trunk A-80-T were dished inward, but this was probably caused by the vapor explosion (paragraph 67). Bulkhead 30 was blown out at each side boundary and buckled throughout. The first four port side staterooms in Warrant Officer's country A-240-L abaft bulkhead 30 were demolished, and many partitions in this space were distorted as indicated on Plate VI. Blast damage on the second deck stopped at bulkhead 50, which was only bulged aft slightly on the port side. 46. Not much trace of fragment damage remains on the second deck level. There were two holes in the shell plating to starboard as mentioned in paragraph 42. The deck was deeply scored for about 6 feet inboard from the ricochet mark (Photo 23). The chain pipes and capstan shafts were gouged by fragments. There must have been a good deal more fragment damage which was obliterated with the destruction of bulkheads in the vicinity. 47. The main deck was torn open along frame 27 for about 20 feet on each side of the centerline and the edges of this split were blown sharply upwards (Photo 22 and Plates V and VI). Many fragments pierced it from below, especially on the port side. Blast damage on the main deck was much less extensive than on the second deck. The after bulkhead of the wardroom was apparently ruptured on each side and a moderate amount of blast distortion shown on Plate VI was caused to staterooms in A-140-L. The forward bulkhead of the wardroom was bulged and wrinkled, but there appears to have been no bomb blast forward of it. 48. The upper deck fractured all the way across between the stringer plates (Plate V) with longitudinal tears along the stringer seams and in way of the wardroom skylights and the centerline hatch. The anchor windlass shafts pulled apart at the couplings between the main and upper decks. The capstans were blown upwards and struck the outboard guns of No. 1 turret with such violence that the elevating screw was slightly bent and the supports of the elevating screw tilting box were sheared. A portion of the deck to starboard was blown upwards at an angle of about 60 degrees, carrying with it the attached electric deck winch; this was partly pushed back into place and the winch removed (undamaged) when Photo 20 was taken. The corresponding portion of the deck on the port side was bent downwards. This seems odd, even considering the weight of the winch; but bomb blast often produces peculiar effects because of the multiple reflections of the blast wave which always occur. 49. A 32-foot split in the upper deck extended between frames 13 and 21 with the outer edge bulged up 2 feet as shown in Photos 19 and 21. While it is possible that bomb blast caused this, it is considered more likely the result of a gasoline vapor explosion. The question is further discussed in paragraphs 65to69. - 11 - |
E. Structural Damage, Bomb No. 4 50. This bomb struck the anti-aircraft director platform 16 feet to port at frame 62-1/2, leaving the 12-inch hole shown in Photo 24. It penetrated the navigating bridge, the signal bridge, the overhead of the Captain's office and the superstructure deck, exploding at the upper deck at about frame 65, just inboard of the longitudinal bulkhead of No. 6 casemate, about 36 feet from the point of entry. An intense fire followed which destroyed much of the brass plating in the foremast structures. The effects of the fire, and of the explosions of ready service ammunition in the vicinity, are more fully dealt with in Section IV, paragraphs 71to74. The disintegration and collapse of brass plating are shown by Photos 25, 26 and 27. Only the direct effects of the bomb explosion are considered in this section. 51. Holes were blown in the upper deck on each side of the top of the uptake armor cone between upper and second decks. These holes are shown by Photos 29 and 30. Blast entering between the smoke pipe and the stack casing crumpled the forward port side of the smoke pipe all the way to the top, and ruptured the stack near its base as shown on Plate IX. 52. Casemate bulkheads in the vicinity were damaged in general as shown by the plates and photographs. The bent stanchion seen in Photo 30 is striking evidence of the violence of the blast. The upper deck was deflected downwards in the area forward of the uptake armor. 53. Blast wrecked the officers' galley and the dry cleaning room on the main deck beneath the explosion and blew a hole three feet square in the deck. The uptakes of boiler No. 2 were ruptured between the main and upper deck levels. Plate IX shows the bulkhead distortions on the main deck, and it should be noted that the trunk of the ammunition hoist to 5-inch gun No. 6 was blown in about 6 inches. Ventilation ducts were wrecked in the forward part of the laundry. 54. The upward force of the explosion blew a hole about 8 feet square in the superstructure deck (Photo 28), deflecting the deck upward so that it pulled away from the stanchion heads beneath. How much damage was done by blast above the superstructure deck cannot be said, for much of the wreckage was caused by the subsequent fire. 55. Fragment damage was effectively limited by the 30-lb. S.T.S. bulkheads which form the casemate boundaries on the upper deck. Neither the bulkhead between casemates 4 and 3, nor the one between casemates 4 and 6, was pierced by fragments, though the explosion was quite close to each of them. Two holes were found in the after bulkhead of the incinerator room which probably were made by fragments. There were holes in the director platform deck in the foremast, but these and any other holes above the superstructure deck may have been made by exploding ready service ammunition instead of by bomb fragments. Some fragments were blown out through the stack casing. Reference (b) reports evidence of fragment travel up to 55 feet from the explosion. - 12 - |
E. Structural Damage, Bomb No. 5 56. Bomb No. 5 struck the starboard forward skylight of the crew's galley between frames 80 and 81 on the superstructure deck. Unlike the others, it detonated on impact. The port crane (Photo 32) was trained forward at the time, and it was said that the bomb may have struck the tip of the boom. The distance from the tip to the point of impact on the galley skylight is approximately the same as that which the other bombs travelled before detonating. The handrail was bent near the end of the crane, but an examination disclosed no other marks on the crane. It is reasonable to conclude that the bomb did brush the crane, but that fuse action was initiated by striking the deck and was instantaneous. Photo No. 31 shows very clearly the scores in wood decking, which indicate such a detonation. A bomb with instantaneous fuse which hit CHESTER on February 1, 1942 produced very similar damage (see Bureau of Ships War Damage Report No. 10 (CHESTER), dated April 10, 1942). 57. The skylight was demolished. A hole about 12 feet in the transverse and 6 feet in the fore-and-aft direction was blown in the superstructure deck (Photos 33 and 34). Ordinarily a hole would be blown in the deck beneath, but in this case the tile and concrete galley deck, 4 or 5 inches thick, prevented any such rupture. 58. The violent rebound of the superstructure deck pulled it clear of the stanchion heads in the galley beneath as marked on Photos 33 and 34. The galley deck was deflected downwards a maximum of about a foot. This buckled three stanchions beneath in C-180-L on the main deck and partially fractured three longitudinal girders as shown by Photo 35 and Plate IX. The main deck was pushed down about 6 inches under each stanchion. The centerline stanchion on frame 82, between the main and second decks, remained straight and the longitudinal main deck girder over it was bowed upward about 6 inches. 59. For some reason now obscure the starboard bulkhead of the galley is of 7.5-lb. medium steel whereas the port bulkhead is of 30-lb. special-treatment steel. The port bulkhead was practically undamaged. The starboard bulkhead was bulged outboard and pierced by fragments (Photo 34). The door in it was blown open, and flash or fragments entering No. 9 casemate ignited ready-service powder there as described in paragraph 75. This door could not have been tightly dogged, if at all. 60. There was a good deal of fragment damage. Photos 31 and 32 show some of it above the superstructure deck. There were holes in the stack to within a few feet of the top. One fragment penetrated the 30-lb. S.T.S. splinter shield of 5-inch anti-aircraft gun No. 7, about 30 feet from the explosion, and it was deeply gouged in a number of places. The gun itself was hit by many fragments which wrecked the instruments and fractured the rammer oil reservoir. The ammunition hoist between this gun and the scene of the explosion had 8 holes from one to 3 inches in diameter in its inboard side, but none came through the outboard side. Two pierced the starboard leg of the mainmast about six feet above the deck. A 1-1/2-inch rib in the casting - 13 - |
beneath the platform of the starboard crane had a 3-inch fragment hole in it; this was about 25 feet from the explosion. There were even penetrations of the searchlight platform, approximately 50 feet above. A large number of pits from very small fragments may be seen in Photo No. 32, but there were a great many more which are not visible in the photographs. 61. Fragments and blast also caused much damage in the galley beneath. Most of the equipment was damaged, much of it beyond repair (Photo 33). Fortunately the galley oil tanks, located on the port side, were left intact; otherwise fire would have quite likely broken out in the galley. FIRES AND EXPLOSIONS 62. Bombs 3, 4 and 5 started fires which have been briefly described in paragraphs 16to18. The fires added a great deal to the ship's misfortunes, not only through the nuisance of smoke (see the Engineering Narrative) and the extension of damage, but also by initiating gasoline vapor and ready-service ammunition explosions. Flooding saved the ship from more extensive fire damage forward, though there is not much choice between these two evils. 63. The fire in the forward part of the ship was evidently started by the explosion of Bomb No. 3 on the second deck. There are no traces of fire anywhere on the third deck or below it. The Junior Officer's country was completely burned out on the second deck and about half the Warrant Officer's country was burned (see Plate XII). Two fire main risers were broken off forward of No. 1 barbette, presumably those marked on Plate XII. Flooding soon commenced over this deck, however; and must have practically drowned the fire out by Sunday evening. 64. The fire zone on the main deck extended about as far aft as it did on the second deck: i.e., the wardroom and all wardroom country forward of it were burned out, and staterooms abaft it back to No. 1 barbette were burned. Fire plugs in this area were useless, as the risers had been shut off at the third deck because of broken piping on the second deck. Firemain pressure was low anyway, and the available CO2 extinguishers were soon exhausted. A supply of them was kept in A-314-A on the third deck. This compartment was flooded with oil and inaccessible. 65. At some time during Sunday afternoon there was an explosion forward. It apparently occurred on the main deck between bulkheads 5 and 8-1/2. An observer reports that the lid of the sand locker was blown into the air. A study of the damage in this area shows definitely that a good deal of structural damage resulted which cannot be ascribed to any of the bomb explosions. 66. This explosion is believed to have occurred in the following manner. A vent line runs from the gasoline storage compartment up to the main deck, whence it is exhausted overboard by a blower in the gasoline measuring room forward of - 14 - ig |
bulkhead 5. Gasoline would be forced up this vent all the way to the top by the head of sea water entering the storage compartment through the bomb hole. It gradually leaked out around the blower into the gasoline measuring room and collected on the deck. Vapors (and perhaps gasoline) escaped through bulkhead 5 into the W.C. and bath forward of wardroom country. There may have been a leak through the door, as Photo 37 indicates that it was not tightly dogged. The advancing fire in the wardroom country finally reached this vapor-filled compartment and a violent explosion resulted. 67. Bulkhead 8-1/2 was torn loose at the bottom and blown aft as shown by Photo 36. Note that the door in it followed the contour of the bulkhead and that the dogs appear to have remained tight. The door in bulkhead 5, which opens into the gasoline measuring room A-101-A, was blown forward and does not appear to have been tightly dogged (Photo 37). The trunk on the centerline between frames 13 and 14 was badly crushed and torn from the deck as shown by Photo 38. Adjacent partition bulkheads in A-108-L were blown forward and aft as shown on Plate VI, which locates the approximate center of the explosion. No doubt there was a good deal of damage to staterooms abaft bulkhead 8-1/2, but this area had been entirely cleared out by the Navy Yard, Pearl Harbor, when the ship was inspected at Puget Sound. 68. The explosion certainly caused the bulge in the upper deck seen in the foreground of Photo 19. It probably caused the long split in the deck shown by Photo 19 and 21. This has previously been discussed in paragraph 43. 69. Reference (c) mentions a paint and oil fire in this area. This is believed to be in error, as the paint and oil rooms on the third and first platform decks do not seem to have been affected; and it has since been learned that undamaged tins of paint thinner and lubricating oil were subsequently removed from them. 70. Tugs were summoned to help in fighting this fire and the one in the foremast structure because fire main pressure was low. It proved very difficult to extinguish. It broke out again several times after having been seemingly put out. This indicates the presence of gasoline vapor, which also accounts for the observation that minor explosions occurred intermittently in this part of the ship. The holes in the deck were stuffed with mattresses and steam from the tugs was used as a smothering agent. But the fire continued to burn until Tuesday morning, by which time ,the water was nearly up to the upper deck and little conbustible material could have remained. 71. The most intense fires followed the explosion of bomb No. 4 on the upper deck just forward of the stack. All levels up to and including the 5-inch anti-aircraft control station were completely burned out. A fire main riser on the upper deck at frame 66 was broken. It was finally discovered and shut off at the third deck when the fire was nearly out. The pressure at other plugs was insufficient for fighting the fire. Water was supplied by the tugs, and the spread of flames to other areas was thereby prevented; but the fire finally burned itself out. 72. On the upper deck, fires in casemates 4 and 6 were successfully extinguished, though not before the canteen was - 15 - |
burned out (see Plate IX). The furnishings and papers in the Captain's office and quarters on the superstructure deck, and acid, alcohol and pyrotechnics stored on the signal bridge, were principally responsible for the intensity of the fire. The overhead of the Captain's quarters and the decks and bulkheads of the signal bridge and chart house contain a good deal of brass plating vithin the limits of the magnetic circle of the standard compass. All of this collapsed and much of it disintegrated in the fire, as seen in Photos 25, 26 and 27. Reference (b) suggests that unburned gases from the ruptured smoke pipe vere blown up through the foremast structures and contributed to the destructiveness of the fire. Reference (g) mentions that oil lines in the officers' galley added to the fire, but there is no record in this or any other reference of a fire in the galley. 73. Fire also spread to the superstructure deck and caused ready service ammunition to explode (Plate X). Fragments from these explosions punctured the starboard side of the stack and penetrated to the signal bridge. The superstructure deck was deflected downward locally. Photo 3 shows some holes in the starboard anti-aircraft director, which may have been made by this exploding ammunition or by debris from the magazine explosions on SHAW or ARIZONA. 74. Smoke from this fire was drawn into the boiler rooms and caused them to be temporarily abandoned. This is discussed in the Engineering Narrative, paragraphs 105 and 106. 75. The third fire occurred when Bomb No. 5 blew the door open from the crew's galley into No. 9 casemate (upper deck) and either flash or hot fragments ignited exposed bags of 5-inch powder. The casemate was entirely burned out. Both water and C02 extinguishers were used on this fire with little apparent effect except to prevent it from spreading. Cork insulation in this area added to the blaze. Apparently there was little if any fire damage in the galley itself. 76. The following miscellaneous comments concerning the fires are taken from reference (c):
FLOODING AND DAMAGE CONTROL A. As a Result of the Torpedo Hit 77. The compartments which were flooded as a direct - 16 - |
result of the torpedo explosion are shown in red on Plates XI and XII, in the region between frames 30 and 50 on the port side. This is, of course, only an estimate, since no accurate exploration could be made and the subsequent complete flooding obliterated most traces of the initial flooding. 78. All wing oil tanks in this area were full and are marked in green on the plates. The tanks in the hold and inner bottom were partially filled as noted. Most of the spaces forward on and below the third deck were closed before the attack, and Condition Zed was set as quickly as possible afterwards. Reference (c) gives the opinion that all except a very few Zed fittings were closed, but that during and directly after the attacks many were opened for access of damage control and first aid parties. Some ventilation closures were opened to help clear smoke filled compartments, and Zed fittings were opened to facilitate flooding of the forward magazines. No particulars are available. 79. Such information as can be deduced from the evidence is summarized as follows and marked on Plates XI and XII:
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80. The sounding tubes to tanks A-12-F and A-42-F terminate on the third deck in A-315-L, as marked on Plate XII. Each tube is closed with a threaded cap seating against a leather gasket. Before the cap is fully unscrewed, two 1/8-inch holes in the cap are exposed, the object of which is to indicate whether or not the tube is flooded without removing the cap. Oil spurted from both caps mentioned above. Since they could not be tightened to stop this leakage, it is assumed that the leather gaskets were missing or damaged. Several inches of oil had collected in A-315-L by Sunday afternoon. This made it difficult to locate the reach rods which terminate in deck plates in this compartment. 81. A list of four or five degrees to port slowly developed. Four starboard after blister voids were counterflooded. Four additional blister voids were opened but closed just before the ship reached the upright position. A slight starboard list subsequently developed. 82. The after magazines were inadvertently flooded shortly after the ship got underway at 0840. Flooding of the forward magazines was started prior to 0920, when fires were spreading through the area forward of No. 1 turret and reports were being received that certain magazine bulkheads were getting hot. After magazines have flooding-from-sea connections; forward magazines are flooded from the sprinkling system. Flooding of the forward magazines was supplemented by fire hoses, and was stopped before the magazines were entirely flooded. 83. Magazines are marked in yellow on Plate XII. It is not known whether all yellow spaces, which include shell and handling rooms, were actually flooded at this time. 84. Bomb No. 1 caused the near-miss damage on the starboard side at about frame 14 which has been described in paragraphs 32to34 and is shown on Plate VII. The flooding which - 18 - |
resulted from the underwater explosion is marked on Plates XI and XII. 85. The only spaces certain to have been flooded by this explosion are the storerooms A-501-A and A-502-A on the second platform deck, and the void outboard of A-501-A. It is quite likely that the corresponding compartments on the first platform deck also flooded. Apparently those in the hold remained intact. The forward blister void was also opened up. 86. Bomb No. 2 penetrated the third deck as previously described (see Plates VI and VIII), which would have admitted water to A-302-A from the space beneath flooded from bomb No. 1. The explosion opened the gasoline tank compartment and the void A-4-V. The compartment A-401-A on the first platform directly above may also have been damaged enough to be flooded. The trimming tank was certainly ruptured, but whether or not it already contained water is not known. About 200 gallons of gasoline were found above it in A-300-A after the ship was docked. D. Effects of Flooding as in A, B and C 87. Rough calculations, based on the flooding effect diagrams in the Damage Control Book, have been made to determine what effects would have resulted had no leakage through undamaged decks and bulkheads occurred. Only the compartments colored on Plates XI and XII are considered in what follows. 88. The drafts before damage were reported in reference (b) to have been:
After the torpedo hit and the counterflooding measures described above in (A), the drafts would have been
if all eight voids used for counterflooding were filled. 89. The after magazines were next flooded, which reduced the draft forward by about 2 feet and increased the draft aft by over 5 feet. This was followed by flooding from bomb damage forward; and if the compartments marked on Plate XII were the only ones involved, the drafts would have been roughly:
which would have still left the second deck forward nearly three feet above water. If the trimming tank had been empty before and flooded by the damage, the bow would have gone down about 4 inches more. 90. Flooding the forward magazines was the next step, which resulted (under the preceding assumptions) in drafts of approximately:
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bringing the waterline forward to a level about midway between the second and main decks. This put the hole in the side made by bomb No. 1 under water, and from then on there was little hope of checking its spread over the second deck. 91. As matters turned out, flooding of magazines was not necessary for the safety of the ship. It might be inferred that the ship would hot have sunk if the magazines had not been flooded. Actually, the draft forward would have been nearly 37 feet with no magazine flooding at all. This would have put the second deck underwater forward, and the final result would probably have not been much different considering the progressive flooding which took place. 92. It is difficult to trace the spread of flooding after the damage occurred. Up until Monday evening, when the ship finally settled on the bottom, the story is one of a losing fight against water spreading through boundaries and fittings which should have been watertight but actually were not. The following account is based on interviews with a number of those on board at the time. Reference to the second and third deck plans on Plate XII will aid in reading it. 93. A damage control party worked most of the day on the third deck. Bulkhead 23 was held during the morning. Oil was slowly accumulating in A-315-L, and water was coming up through the centerline hatch at frame 40. This is a water-tight hatch and the cause of its leakage is not known, but it might have been distorted by bomb No. 3, which buckled two third deck stanchions (paragraph 45). Reference (c) states that the flooded magazines were leaking through undamaged bulkheads between frames 30 and 48, and this was no doubt the source of the water. 94. The forward part of the ship is served by a drainage system with a pump on the second platform deck in A-506-E, a compartment reached by a trunk from the second deck and hence inaccessible because of bomb damage in the Junior Officer's country. Portable submersible pumps of the old type were used until some burned out and the others could no longer get power. 95. Water was meanwhile spreading aft on the second deck. The watertight bulkhead at frame 30 had been blown out by bomb No. 3. The bulkhead at frame 50 had been slightly damaged, and in any case it was only of fume-tight construction. About mid-afternoon on Sunday water came into A-331-L and A-332-L with a rush through the ventilation systems. The cause of this was probably as follows: since about 1000, water had been pouring over the low coaming of the ventilation intake in the "bull ring" on the second deck which supplies the dynamo compartments; see paragraph 107 of the Engineering Narrative. By 1300 the dynamo room was abandoned. It would be about mid-afternoon, therefore that water rose in the vent trunk to the third deck, where the rising water would meet the inpouring stream from the "bull ring", and both A-331-L and A-332-L would start to flood rapidly. Portable submersible pumps in use here could no longer control the flooding. 96. This forced the party on the third deck back of bulkhead 60. There were numerous leaks in it through the boundary - 20 -
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