Alan D. Zimm

by Attack on Pearl Harbor: Strategy, Combat, Myths, Deceptions

  30. Willmott, et al, 2001, 83.

  31. Some historians have erroneously stated that the objective of the attack was the American aircraft carriers, such as the television program “Unsolved History: Myths of Pearl Harbor.” Carriers were indeed included in the Operations Order priority list, but as a second priority target: “The order of targets will be battleships and then aircraft carriers.” Carrier Striking Task Force Operations Order No. 3, 23 November 1941, in Goldstein and Dillon, 1993, 101.

  32. Werneth, 247.

  33. The reserve force of battleships, based out of the Inland Sea, was cruising south of the Bonins to “support” Kido Butai as it retired from the Pearl Harbor strike. These forces were over 2,000 miles apart, making support problematic. The battleships undoubtedly got underway as a morale measure, to avoid the shame of remaining in port while the rest of the fleet fought. After several submarine scares, the battleships cranked on knots for home, realizing that pride was not worth exposing the precious battleships to damage.

  34. Japanese battleships and battlecruisers were located as follows: off Indo China, 2: (BC Haruna, BC Kongo); Empire, 6: (BB Nagato, BB Mutsu, BB Fuso, BB Yamashiro, BB Hyuga, BB Ise); with the carrier striking force, 2: (BC Kirishima, BC Hiei). Under construction, Empire: 4: (BB Yamato, fitting out, in service 5/19/42; BB Musashi, to be commissioned 8/5/42; BB Shinano; BB Hull No. 111). American operational battleships totaled 14: Pearl Harbor, 7: (BB-36 Nevada, BB-37 Oklahoma, BB-39 Arizona, BB-43 Tennessee; BB-44 California; BB-46 Maryland, BB-48 West Virginia); East Coast US, 7: Casco Bay, 4 (BB-35 Texas, BB-33 Arkansas, BB-40 New Mexico, BB-41 Mississippi); Norfolk, 1 (BB-56 Washington); Iceland, 1 (BB-42 Idaho); Caribbean, 1 (BB-55 North Carolina,). There were 11 battleships in the pipeline: Bremerton, 1: overhaul, (BB-45 Colorado, completed 31 Mar 42); Norfolk, 1: overhaul (BB-34 New York, completed Dec 41); Pearl Harbor, 1: refit, 1 (BB-38 Pennsylvania, completed Dec 41). US East Coast, 8: under construction, 8 (BB-57 South Dakota, commissioned 3/20/42; BB-58 Indiana, commissioned 4/30/42; BB-59 Massachusetts, commissioned 5/15/42; BB-60 Alabama, commissioned 8/16/42; BB-61 Iowa, commissioned 2/22/43; BB-62 New Jersey, commissioned 5/23/43; BB-63 Missouri, commissioned 6/11/44; BB-64 Wisconsin, commissioned 4/16/44).

  35. Willmott, et al, 2001, 157.

  36. Prange, 1981, 374.

  37. Not included are the ships assigned to the Asiatic Fleet, one heavy cruiser, two light cruiser and 13 destroyers, which were in the immediate path of the Japanese advance and would likely not participate in any sorties of the Pacific Fleet from Pearl Harbor.

  38. Weinberg, 195–204.

  39. Agawa, 292.

  40. Willmott, 1982, 8.

  41. Asada, 108–9.

  42. Agawa, 196.

  43. Kinoaki, 208.

  44. SECRET letter, Chief of Naval Operations to Commander in Chief, United States Fleet, 10 December 1934.

  45. Asada, 181. Stephan, 80.

  46. Agawa, 196, 200, 202.

  47. Asada, 263.

  48. Agawa, 197.

  49. Miller, 286–7.

  50. Miller, 308.

  51. This practice also is a hint that the fuel tanks mentioned above were constructed during the war and not before.

  52. Agawa, 197.

  53. Stephan, 99. Agawa, 217.

  54. Stephan, 115.

  55. Aldrich, 64.

  56. OPNAV 16 V # A43, 2.

  57. This includes the Yamato class, whose bulk concealed a number of damage control flaws. According to Nathan Okun, “The anti-torpedo protection of Yamato was improperly designed. It used deep empty voids between the side and the innermost NVNC "holding" bulkhead (also the very thick—8" at the top and 3" at the bottom—anti-diving-shell lower belt). There was nothing to stop the concussion of the [torpedo] detonation shockwave, blast, and considerable number of high-speed fragments but a few thin bulkheads prior to hitting the innermost holding bulkhead. If even a few feet of water had been used to soak up part of the blast and almost all of the fragments, the protection would have worked better. A single torpedo hit snapped Yamato’s holding bulkhead off at the top where it joined the heavy waterline VH belt since it was not keyed to the belt. This led to very large amounts of flooding. This was never remedied, though somewhat reinforced later.”

  58. Agawa, 196.

  59. In the first six months of the war these ships served at the following locations: Akashi at Palau, Davao, Staring Bay, Ambon, and joined the Midway invasion force; Asahi at Camrahn Bay, Singapore, and then sunk by submarine on 25 May 1942; Yamabiko Maru at Takao, Balikpapan, Makassar, and Singapore; Matsue Maru at Truk, sunk by submarine on12 May 1942; Urakami Maru was evidently as much a coal transport ship as repair ship. She served a route between Truk, Kwajalein, and Ponape, delivering coal and making repairs as necessary.

  60. Agawa, 195–6.

  61. The Japanese would go to such extremes as to convert a musical instrument factory into aircraft propeller production. On the Japanese economy, see O’Neil, 2003, Cohen, Bisson, Barnhart.

  62. Prange, 1981, 298.

  63. There was another possible objective, an internal political goal within the context of war. Zenshiro Hoshima was the Secretary General of the Imperial Navy and Emperor Hirohito’s naval advisor. He argued strenuously against war with America. He “came to believe that Yamamoto, who also opposed war with America, staged the brilliant strike at Pearl Harbor not only to cripple the US Fleet, but to give the Imperial Navy parity with the Japanese Army.” Burlingame, 47.

  64. Willmott, et al, 2001, 39.

  65. Prange, 1981, 21.

  66. Agawa, 243–4.

  Chapter 2: Targets, Weapons, and Weapon-Target Pairings

  1. Prange, 1981, 19.

  2. Agawa, 221.

  3. At the time of Genda’s study carriers Shokaku and Zuikaku were still fitting out. The original dates of the attack would have been before they were operational.

  4. Prange, 1981, 27.

  5. Ships put into shipyard for underwater damage repair usually also undergo overhaul and modernization, which might add months to the total duration. For example, California and West Virginia were extensively rebuilt and modernized after their damage at Pearl Harbor, and would not emerge from the shipyards until January and September, 1944, 26 and 34 months after Pearl Harbor. They were delayed by low priorities and the crush of other work in West Coast shipyards. In contrast, when Saratoga was torpedoed in January 1942, BuShips estimated she could be placed back in action in four to six weeks if necessary. The decision was made to modernize her. She had her 8-inch and 5”/25 guns replaced with sixteen 5”/38s taken from new construction ships, a hull blister installed, her flight deck widened and lengthened forward, her light AA battery augmented, new radar and gun directors installed, and was still out of the shipyard in four months. The priority of work and state of modernization of the ship had a huge influence on repair times. Friedman, 1983, 51.

  6. German Fire Effect Tables, 15–16.

  7. Prange, 1981, 21–22, 99.

  8. Werneth, 199.

  9. Captain Baron Tomioka from the Operations Section of the First Bureau. Prange, 1981, 104–5.

  10. Sakai, 48. The only Allied fighter at that time with “strategic” range was the P-38 Lightning, just coming into service at the end of 1941. Similar range-extending fuel conservation techniques were developed for the P-38 Lightning but were not in place in the Pacific until 1943. Lindbergh, the famed pilot who first crossed the Atlantic in solo flight, made a tour of front-line squadrons to help train the pilots and “popularize” the techniques, which almost doubled the combat radius of the aircraft.

  11. Sakai states that the development of the strategic range capability in the A6M Zero freed up three light carriers. This probably is not exactly correct. In addition to the six fleet carriers, on 8 December 1941 the Japanese had six light and escort carriers available or in the latter stages of workups. The two escort carriers, Kasuga Maru and Chuyo, were engaged in aircraft ferry missions. Light carriers Ho
sho and Zuiho were attached as aviation support to the battleships of the First Fleet operating out of Hashirajima Anchorage. Light carrier Shoho was in the final stages of workups and not ready for active operations. Light carrier Ryujo was attached to the Southern Philippines Seizure Force operating off the east coast of the Philippines. From examining the dispositions of the fleet on 8 December, it would appear that CarDiv 5 (fleet carriers Shokaku and Zuikaku) was originally intended to provide air support for strikes against Clark Field, Cavite, and Manila, followed by the invasion of Davao, and possibly followed thereafter by a quick transit around north of Luzon to the west coast to support the Lingayen Gulf invasion. This support became unnecessary with the increase in range of the A6M Zero, allowing the Japanese to immediately strike the Philippine air bases from Formosa. In addition, fighter bases were established after the landing at Bataan Island (north of Luzon) on 8 December 1941, and on Philippine soil after the landings at Vigan and Aparri on Northern Luzon, 11–12 December 1941. MacArthur incorrectly evaluated those landings as a feint designed to draw his forces away from the main landing site at Lingayen Gulf, which was not invaded until the 21st of December. He allowed the 5th Air Army to become established on Luzon and elements of the 21st and 23rd Air Flotillas at Davao without opposition. MacArthur did not understanding the significance of allowing Japanese air power to become established on the Philippines.

  12. Prange, 1981, 158.

  13. Peattie, 2001, 102.

  14. Peattie, 2001, 108.

  15. Yoshimura, 27.

  16. Peattie, 2001, 113.

  17. Oberg.

  18. Francillon, 112–120.

  19. Watts and Gordon. Aircraft capacity numbers should not be considered fixed or standard. A carrier’s rated capacity would change as larger or smaller aircraft models were introduced, doctrine was changed, or the ships modified. In addition, most fleet carriers stowed additional disassembled spare aircraft that might be assembled before a battle in anticipation of losses.

  20. Operational were fleet carriers Kaga, Akagi, Hiryu and Soryu, light carriers Hosho and Ryujo, and escort carrier Kasuga Maru. Fleet carriers Shokaku, Zuikaku, Junyo, Hiyo, and Taiho were in the pipeline, along with light carriers Shoho and Ryuho and escort carriers Unyo and Kaiyo. The term “escort carrier” was not used until later in the war. The Japanese escort carriers listed here were considered as auxiliaries by the Japanese, and more often used as aircraft transports.

  21. The B5N Kate had the lifting capacity for three 250-kg bombs, and this capacity is listed in many references. However, only two were carried on the Pearl Harbor mission. The possibility exists that at this time the bomber had only the hard point attachments for two.

  22. This would include the carriers, considering that two of the potential target carriers, Lexington (CV-2) and Saratoga (CV-3), were built on battle cruiser hulls.

  23. Japanese Torpedoes and Tubes, Article 2—Aircraft Torpedoes.

  24. NavShips A (374), 7–9.

  25. Peattie, 2001, 36.

  26. Japanese Bombs.

  27. This shell has been variously identified as 15-inch, 40 cm, or 16-inch, even in official Navy documents. Initial estimates were taken from measuring the curvature of shell fragments recovered from the battleships, a process subject to some uncertainty. Most of the information cited on this weapon, correcting several errors in official documents, was provided by Nathan Okun, correspondence. Data Page on Type 99 No. 80 Mark 5 armor piercing bomb, from US Naval Technical Mission to Japan, Japanese Bombs. December 1945, 35. Note that it incorrectly identifies the original shell as “40 cm AP.”

  28. Striking Power of Air-borne Weapons, v.

  29. Japanese Bombs, 35. Also Richard Worth, correspondence with the author.

  30. Prange, 1981, 268.

  31. Brown, 208.

  32. Data Sheet 2-C5a. Perforation of Armor: Bombs. August, 1944.

  33. The US Naval War College Maneuver Rules (USNWCMR) and Fire Effect Tables represented the most advanced mathematical modeling of naval combat developed in the interwar years. It was a tremendous collaboration between the War College, BuOrd, and BuC&R to develop the most advanced training and analytical tool ever created. The rules and data tables were several inches thick of legal-sized paper. The rules and data were constantly updated with new releases nearly every year between 1922 and 1946. The calculations and values incorporated into the Maneuver Rules represent the official US Navy view of such things as gunnery effectiveness, armor penetration, and resistance of ships to damage, the effectiveness of bombers and fighters and submarines and torpedoes, and many other technical topics.

  34. Prange, 1981, 160.

  35. Striking Power of Air-borne Weapons, v.

  36. Prange, 1981, 259.

  37. Japanese Bombs, 19.

  38. Striking Power of Air-borne Weapons.

  39. Campbell, 1985, 172.

  40. Peattie, 2001, 143.

  41. USNWCMR, 12 March 1940, j-24, j-25.

  42. USNWRMR, 19 June 1944, j-24.

  43. Peattie, 2001, 146.

  44. Olson, 43.

  45. This was before the invention of NAPALM or other jellied gasoline weapons. NAPALM was first employed operationally in 1944 against ground targets. NAPALM was never used against warships underway during WW II.

  46. Downes AAR, Commander, Battleships, Battle Force AAR.

  47. Preliminary Report, USS Shaw (373) War Damage Report, and USS Shaw (373) Bomb Damage Report, 29 January 1942.

  48. Also reported at 500 rounds per gun

  Chapter 3: Wargames

  1. Prange, 1981, 113.

  2. Admiralty, Naval Staff, Tactical Section. Instruction for Tactical and Strategic Exercises Carried out on Tables or Boards. O.U. 5243, January 1921.

  3. Willmott, et al, 2001, 60.

  4. Prange, 1981, 30–39.

  5. Prange, 1981, 31.

  6. Prange, 1981, 381.

  7. Prange, 1981, 35–36.

  8. Fuchida and Okumiya, 92.

  9. Prange, 1981, 34.

  10. Prange, 1981, 404. In footnote 22 for Chapter 4 Prange cites Fuchida’s Midway book as his source, going on to say, “Similar cheating occurred during the war games for Pearl Harbor.”

  11. Prange, 1981. Toland, 161, states that one-third were shot down.

  12. The number of “130 aircraft” is from Prange. Agawa, 228, states that 180 aircraft were “shot down.”

  13. Prange, 1981, 229–230.

  14. Willmott, et al, 2001, 57.

  15. Prange, 1981, 161–3.

  16. Prange, 1981, 389.

  17. Prange, 1981, 234.

  18. Willmott, et al, 2001, 57.

  19. Willmott, et al, 2001, 57.

  20. Prange, 1981, 282.

  21. Prange, 1981, 229–230.

  22. Prange, 1981, 234.

  23. Burlingame, 50.

  24. Prange, 1981, 338.

  25. Agawa, 230.

  26. Prange, 1981, 263, 285.

  Chapter 4: Planning the Attack

  1. The Japanese solved the range problem by converting some voids in some of their carriers to carry fuel, by carrying fuel in drums on the hangar deck, and by underway replenishment from oilers. Another option that could have precluded the problem would have been for the carriers to refuel at the Marshall Islands from oilers at anchor after the strike. The destroyers would still require underway replenishment to make the trip. No satisfactory explanation has ever been offered why this option was not considered, although it is possible the Japanese were concerned that Pacific Fleet carriers might follow them to the islands and strike the carriers while at anchor, a remote possibility.

  2. Thomas Hone to the author.

  3. The A6M Zero was about 30 feet long, the D3A Val 33 feet, and the B5N Kate 45 feet, although they could be parked in overlapping configurations.

  4. Japanese aircraft carriers had closed hangars, so engines could not be warmed below decks. Applying full power for takeoff on a cold engine could crack the cylinde
r block or blow out engine gaskets. A proper warm-up would require about 15 minutes. The Japanese lost one A6M Zero in the water from engine failure after launch.

  5. Willmott, et al, 2001, 81. Werneth, 100.

  6. The American doctrine was different. When two carriers were operating together, one would be assigned as “duty carrier,” responsible for launching and recovering all the search aircraft, ASW patrols and CAP needed. The other carrier would spot all possible aircraft on the flight deck ready to launch a “full deck” strike. As aircraft got larger, not all the aircraft could fit on deck, so the full deckload would be launched and then orbit the carrier while the remaining aircraft were brought up from the hangar deck (where they had already been warmed, allowable in the Americans’ open hangar deck design). The process was awkward and cut down the range of the strike. Eventually the Americans adopted what they called a half-deck strike, which was similar to the Japanese doctrine but employed mixed groups of bombers.

  7. Chapter 12 contains a more detailed discussion of the experience level of the Japanese aircrew.

  8. Prange, 1981, 163, relates that Japanese naval fighters before 1941 never operated more than 100 miles from its base or carrier, which was also the maximum range of their radiotelephone. Since the Pearl Harbor raid would be at a range “250 to 300 miles from the carriers,” fighter pilots were trained in morse code. These statements appear to be erroneous, since fighters were not equipped with CW radios, and Japanese radiotelephones are reputed to have a much shorter range.

  9. Werneth, 35.

  10. Operational History of Naval Communications, December 1941—August 1945.

  11. Werneth, 214.

  12. The Roundtable Forum, the Official Newsletter of the Battle of Midway Roundtable. Issue 2010-07, 21 February 2010.