Appendix F. Geographical considerations and Navy and Army  
  installations ................................................... 489 
    Geographical considerations ................................... 489 
    Navy and Army installations ................................... 490 
      Navy ........................................................ 490 
      Army ........................................................ 491
    Illustrations ................................................. 499
(Illustrations will be uploaded at a later date.) 

Appendix F





Appendix F

GEOGRAPHICAL CONSIDERATIONS The Territory of Hawaii consists of a chain of eight principal islands. [1] The island of Oahu is to be regarded as of most importance by reason of the excellent enclosed fleet anchorage at Pearl Harbor and the commercial port of Honolulu. Pearl Harbor is located on the southern or lee side of Oahu, in a strategically and commercially important position in the North Pacific Ocean, 3,430 nautical miles southeast of Tokyo, approximately 2,000 nautical miles west to southwest of San Francisco, and 4,767 nautical miles east of Manila. [2] The islands have a mild subtropical climate with moderate seasonal changes of temperature. They lie in the path of the steady northeasterly trade winds; therefore, the northern portions of Oahu and the immediately adjacent waters are characterized by fresh winds from a northerly direction. The force of the trades is broken by the configuration of the land so that so the south of Oahu the seas are relatively smooth. Much of the moisture of the trade winds is deposited on the high peaks to the north, forming mist and clouds. Because of this, the visibility to the south of the islands is better than to the north. The northern fringe of the trade belt lies roughly about 300 miles to the north of Oahu, a belt which is characterized by low ceilings, poor visibility, squalls and rain. The sea area around the Hawaiian Islands was, on December 7, 1941, divided into certain restricted fleet training areas where units and aircraft of the Pacific Fleet might carry out exercises and target practice. Two defensive sea areas were mapped off Pearl Harbor and Kaneohe, these areas having been designated by the President of the United States. Entry of all merchant ships, both United States and foreign, and of all foreign men-of-war was prohibited unless specific permission for such entry had been granted by the Secretary of the Navy. [3] When the Japanese attacked Pearl Harbor at 7:55 on the morning of December 7, 1941, it was 1:25 in the afternoon of the same day in Washington, D. C., and 3:25 a. m., December 8, in Tokyo. In order to obtain the corresponding time in Washington and Hawaii, it is necessary to subtract 14 hours and 19 1/2 hours, respectively, from Tokyo time. The time of sunrise on the morning of December 7, [1] They are the islands of: Oahu, Hawaii, Maui, Kahoolawe, Lanai, Molokai, and Kauai, Niihau. See attachment No. 1. [2] A nautical mile is roughly 1 1/6 land miles. For a table of distances with respect to Pearl Harbor, see committee exhibit No. 6, item 2. [3] For maps of the Hawaiian Islands and descriptions of the defensive sea areas, see committee exhibit No. 6 490 PEARL HARBOR ATTACK 1941, was 6:26 a. m., and morning twilight was at 5:06 a. m., both Hawaiian time. [4] NAVY AND ARMY INSTALLATIONS [5] NAVY Pearl Harbor was the base of the United States Pacific Fleet at the time Japan struck on December 7, 1941, having been such since May of 1940. The island of Oahu was the headquarters of the Fourteenth Naval District which included the Hawaiian Islands, Midway, Wake, Johnston, Palmyra, and Canton Islands. Except for Pearl Harbor itself, other installations were characterized as "minor" naval installations and were naturally integrated in the over-all defense of the islands, of which Pearl Harbor was the focal point. On the island of Molokai there was the Homestead Field Naval Air Base, which consisted of a runway, a warming-up platform and supporting installations. On the island of Maui there was the Puunene Naval Air Base, which consisted of runways, a warming-up platform, and a CAA Territorial landing field. Also on Maui was the Maalaea naval emergency landing field, which consisted of two runways and other supporting installations. On the island of Hawaii, the largest island in the Hawaiian chain, was located the naval radio station at Hilo. On the most important island of the group, Oahu, there was a naval air station at Ewa, which consisted of a mooring mast, a landing mat, and supporting installations. At the naval air station Kaneohe, on the opposite side of the island, was a landing mat and warming-up platform and supporting installations and also a seaplane base. At Kahuku Point, up at the north end of the island, there was an emergency landing field. At Lualualei was located a naval radio station-a transmitting station. At Wahiawa, in the interior, was located a naval radio receiving station. At Heeia, a naval radio transmitting station was located and at Wailupe a naval radio receiving station. Referring to Pearl Harbor itself, it is to be noted that the only entrance is from the south by way of a channel which was blasted through the fringing coral reef that had formerly blocked entrance to the harbor. This channel extending to the harbor entrance proper was 375 yards wide and 3,500 yards long with a minimum depth of 45 feet. The entrance proper to Pearl Harbor is between Keahi Point and Holokahiki Point. From here the channel leads to the various lochs and Passages which form the harbor. The major channels or the main channels and water in the vicinity of the major ships' berths had a depth of 40 feet. From the sea buoys to the large dry-dock a portion of the channel had a minimum depth of 45 feet to provide for the entrance and docking of damaged vessels. The entrance to the harbor was closed by two protective nets where the channel through [4] See committee exhibit No. 6 item 4 for a table showing comparative times and dates for Greenwich, England; Washington D. C.; San Francisco; Hawaii; Tokyo; and Manila on December 6, 7, and 8, 1941. [5] See committee record pp. 50 et seq.; also committee exhibits Nos. 5 and 6. PEARL HARBOR ATTACK 491 the coral reefs was about 400 yards wide and the depth from 41 to 50 feet. The nets themselves consisted of a combined anti-torpedo net and anti-boat boom to seaward and an inner anti-torpedo net without the boat boom. The Pearl Harbor fleet base included every type of naval activity. Many of the installations operable at that time were new, having been built subsequent to August 1939. Major installations in operation were, at the Navy Yard, Pearl Harbor: one battleship dock, built in 1928; one battleship dock, under construction; one floating dry-dock, 18,000 tons; one large repair basin, supporting industrial establishments for repairs to anything afloat; one fuel depot with two tank farms above ground; [6] one submarine base with all services for war conditions; one section base, inshore patrol and harbor entrance control post; and, the administrative office of the Fourteenth Naval District which was inside the navy yard. At the Naval Air Station-Ford Island, which is the large island at the center of the harbor-there was a large flying field, warming-up platform, sea plane parking areas, and supporting installations. ARMY On December 6, 1941, the Hawaiian Department included approximately 43,000 troops under the over-all command of Lt. Gen. Walter C. Short. The principal elements of the department were two Infantry divisions and supporting ground troops composing the beach and land defense forces; the Coast Artillery command, consisting of the seacoast and antiaircraft defense forces; and the Hawaiian Air Force. In the Kauai district were located the Third Battalion, Two Hundred Ninety-ninth Infantry (less Companies K and L) and attached troops; Company C, Two Hundred Ninety-ninth Infantry; First Platoon, Signal Company Aircraft Warning; Air Corps detachment. In the Maui district were the First Battalion, Two Hundred Ninety-ninth Infantry, less Company C and attached troops; Company K, Two Hundred Ninety-ninth Infantry (Molokai); Fourth Platoon Signal Company, Aircraft Warning; Air Corps detachment. In the Hawaii district were the Second Battalion, Two Hundred Ninety- ninth Infantry and attached troops; camp detachment, Kilauea Military Camp; Fifth Platoon Signal Company, Aircraft Warning; Air Corps detachment. On the principal island, Oahu, were located: The Twenty-fourth Infantry Division (less Two Hundred and Ninety-ninth Infantry Regiment); Twenty-fifth Infantry Division; Hawaiian Coast Artillery Command; Hawaiian Air Force; Thirty-fourth Engineers; Eight Hundred and Fourth Engineer Battalion (Aviation); Eleventh Tank Company; Company A, First Separate Chemical Battalion; Hawaiian Pack Train. The Twenty-fourth Infantry Division was responsible for the ground defense of the northern half of Oahu, and the Twenty-fifth Division for that of the southern sector. Most of the components of these divisions were located at Schofield Barracks. [6] A tank farm is a collection of fuel oil storage tanks. 492 PEARL HARBOR ATTACK The Hawaiian Coast Artillery Command, under Maj. Gen. Henry T. Burgin, consisted of the following harbor defense units: Fifteenth Coast Artillery Regiment (Harbor Defense). Sixteenth Coast Artillery Regiment (Harbor Defense). Forty-first Coast Artillery Regiment (Railway). Fifty-fifth Coast Artillery Regiment (155 mm., tractor-drawn) and antiaircraft units. Sixty-fourth Coast Artillery Regiment, semi-mobile. Ninety-seventh Coast Artillery Regiment, semi-mobile. Ninety-eighth Coast Artillery Regiment, semi-mobile. Two Hundred and Fifty-first Coast Artillery Regiment, mobile. Other large-caliber guns available for defense but manned by field artillery were two 240-mm. howitzers and thirty-two 155-mm. howitzers. The seacoast guns were installed principally in permanent fortifications. The fixed antiaircraft guns were emplaced generally to defend the seacoast artillery, and the mobile antiaircraft units were normally stationed at Fort Shafter, Schofield Barracks, and Camp Malakole. The principal units of Maj. Gen. Frederick L. Martin's Hawaiian Air Force were the Fifth and Eleventh Bombardment Groups, the Fifteenth and Eighteenth Pursuit Groups, the Eighty-sixth Observation Squadron, and the Air Corps services. The Air Force was generally disposed on four fields-Hickam, Wheeler, Haleiwa, and Bellows. For reference purposes in orienting the locations of various Army and Navy installations (as of December 7, 1941), the following illustrations are attached hereto: 1. Map of the Hawaiian Islands showing the disposition of Army forces. 2. Map of the island of Oahu showing Army installations, including airfields. 3. Map of the Hawaiian Islands showing United States naval installations in the Hawaiian area.

Page maintained by Larry W. Jewell, Created: 12/5/96 Updated: 12/5/96