The Fleet at Pearl Harbor
1. WHY WAS THE FLEET THERE?
Pearl Harbor had been a relatively minor naval base for many years, and did not become a major base until the early summer of 1940. The decision to base the fleet at Pearl Harbor was a diplomatic decision, and was taken in the hope that it would accentuate our concern over the situation in the Western Pacific, and serve as a restraining influence on Japan's aggression.
From a military viewpoint Pearl Harbor was not a satisfactory fleet base for many reasons, such as:
a. It was restricted in area and had only one access to the open sea. Due to limited area it was necessary for ships to be clustered rather than dispersed.
b. It was far removed from the source of essential supplies, such as oil, food, mechanical materials, technical installations, and industrial capacity.
c. Transportation from the West Coast was slow and inadequate.
d. Essential services for regular fleet activities and exercises were in short supply. These included tugs, target practice facilities, and a host of other things required by ships of the fleet.
e. Hawaii lacked adequate housing and recreational facilities for military personnel.
f. The great majority of fleet personnel were separated from their families and friends over long periods of time. This was an unsuitable morale situation in peacetime.
g. The defenses of Pearl Harbor were almost non-existent. This was an Army responsibility, but the Army lacked the wherewithal to provide much defense, especially in anti-aircraft batteries and pursuit aircraft.
For these reasons, and others, the Commander-in-Chief of the U.S. Fleet protested strenuously and repeatedly the decision to base the fleet at Pearl Harbor instead of Southern California. He doubted that the presence of the fleet at Pearl Harbor was a deterrent to the Japanese, and pointed out
that it might have the opposite effect. The final result was that he, Admiral Joseph O. Richardson, was relieved of command on 1 February 1941 and was succeeded by Admiral Husband E. Kimmel. At that time the fleet became the U.S. Pacific Fleet, and the separate Atlantic Fleet was established. It might be well to mention here that Admiral Richardson felt that the fleet was not prepared for war and was seriously lacking in logistic support, especially oil tankers.
Despite the inadequacies at Pearl Harbor it is correct to say that during the year or so before the Japanese attack many of the handicaps were partially overcome through persistent and hard work. In retrospect, it appears that even though Pearl Harbor was in many ways an unsatisfactory fleet base, the fact that the Fleet was there prevented the Japanese from initially occupying Hawaii and Midway, thereby using them later as bases to intercept our naval forces. Our Fleet in that case would have had to operate from the West Coast during at least the early part of World War II. Most importantly, after the war started Pearl Harbor became the largest and most efficient naval base in world history. Its value as a springboard for mounting our unparalleled offensive actions against the Japanese was incalculable.
2. ARMY-NAVY DEFENSE OF PEARL HARBOR
As has been indicated, the military defenses of Pearl Harbor were quite meager. The development of a great military base takes years of planning, coordination, copious funds, and continual construction, installation, and support. Such development required close coordination of the various military services. This, of course, can be quite difficult in the face of separate evaluations both in Washington and on the scene. However, it is noteworthy that, contrary to views expressed by much of the news media after the Japanese attack, there was a high degree of cooperation and coordination between the Army and the Navy in the years prior to the Pearl Harbor episode. This was a friendly and hard working joint effort. Here are some of the results of that effort:
a. Hawaii was defended by Army forces including heavy and light artillery, infantry, and air force. The Air Corps was part of the Army at that time.
b. The Army Air Corps operated largely from the three fields at Hickam, Bellows, and Wheeler. The first two were principally bomber fields, while Wheeler operated pursuit planes. All fields were in process of development and were training personnel to operate planes on a combat basis. Hickam Field was busy receiving new B-17's from the West Coast, outfitting and commissioning them, and flying them to bolster the defenses of Wake Island and the Philippines. It is estimated that only about ninety-four Army Air Force planes were ready for combat by 7 December. Many of the planes were under overhaul or having new equipment installed.
c. The Army had 26 fixed three-inch anti-aircraft guns and 60 mobile three-inch guns. None of the latter were emplaced as the assigned locations for wartime emplacements were on private property. Also 140 thirty-seven millimeter guns were assigned, but only 20 were delivered, and these were without ammunition. A large number of 50 caliber machine guns were on order but only 40 percent had been delivered.
d. The Navy and Marine Corps had three airfields: Ford Island in the center of Pearl Harbor, the Marine Corps fighter field at nearby Ewa, and the seaplane field at Kaneohe. The Ford Island field served primarily to receive aircraft carrier planes and to operate them while the carriers were in port. Like the Army airfields, the Navy was busy training men, installing improvements and new equipment, and overhauling worn-out parts. The total number of Navy and Marine Corps planes ready for combat was approximately fifty-two.
e. All of these forces were busy every weekday in flight operations, target practice, and training. Citizens of Hawaii were accustomed to hearing planes overhead continuously every day except Sunday. Gunfire incidental to target practice was commonplace.
f. Ships of the active Fleet when in Pearl Harbor were assigned certain sections of arc to defend against possible air attacks. Standing orders of the Commander-in-Chief of the Pacific Fleet required that one-quarter of the anti-aircraft batteries be in a ready state at all times, that gun crews be near at hand, and a supply of ammunition be in ready service boxes near the guns.
g. To defend against prowling submarines the channel entrance to Pearl Harbor was guarded by a double submarine net or gate. It was kept closed at night; it was opened and closed as required by traffic of ships entering or leaving. Patrol vessels were always on duty in the approaches to Pearl Harbor to detect any submarines which might be attempting to enter.
The need for air reconnaissance was clearly understood by the high command at Pearl Harbor, and strenuous steps were taken to make it effective. As early as January 1941 Rear Admiral P. N. L. Bellinger, Commander of Patrol Wing TWO of the Fleet, and also in command of the Ford Island facilities, reported to the Navy Department that because of deficiencies in
planes, equipment, material, personnel, and facilities "we are operating on a shoestring," and that all efforts to improve the situation had not been effective. 
Similar correspondence ensued later with but little results. The usual answer from Washington was that "we are doing the best we can."
The Army Air Corps and the Navy Patrol Force cooperated closely in developing a joint operation to insure the best possible reconnaissance with the means then available. Admiral Bellinger, together with Major General F. L. Martin of the Army Air Corps, got out a joint estimate of the situation under date of 31 March 1941 which set up a search and attack group to be used in case of hostilities or in time of emergency. In this document the following statement was made: "The aircraft at present available in Hawaii are inadequate to maintain, for an extended period, from bases on OAHU, a patrol extensive enough to insure that an air attack from an Orange [enemy] carrier cannot arrive over OAHU as a complete surprise." Thus the possibility of surprise air attack was envisioned long before the attack, and plans were developed to detect and defeat such an attack. A surprise attack without a declaration of war or of hostilities was envisioned at an early date, but the words "surprise attack" usually referred to a carrier raid after a proper declaration. Such a raid was in the minds of fleet officers, but as in Washington eyes were turned to Southeast Asia.
The shortage of planes and personnel to carry out a continuous daylight patrol was startling, especially when the need to modify and overhaul these planes is considered. It was estimated that one effective patrol through 360 degrees at a distance of 800 miles required not less than 84 planes on a 16 hour flight. To do this continually with necessary reliefs in planes and personnel would require at least 180 reconnaissance planes. Of course no such number of planes was available, nor was the manpower required to operate them.
With the air forces available, however, a considerable amount of air reconnaissance was conducted by both the Army and the Navy, at times as a joint operation. When aircraft carrier task forces of the Fleet were at sea there were simulated air strikes on Pearl Harbor to improve air reconnaissance and air raid defense. The last such drill was held on 12 November 1941; the next was scheduled for 29 November 1941 but had to be postponed until 13 December because of a task force sortie. As early as the spring of 1941 joint air raid drills were held weekly for a time to familiarize
personnel with requirements, but the frequency was gradually reduced because of interference with training as well as wear and tear on equipment. Communications of that time were not equal to the tasks put upon them. This was especially true of the communications with the Army and with outlying stations. Anti-submarine search by both aircraft and destroyers was a regular part of fleet movements. Carrier reconnaissance planes ranged out over wide areas of ocean whenever task forces were leaving or entering Pearl Harbor.
On the morning of 7 December there were a number of reconnaissance planes aloft, and others were in a standby ready status.
a. Three patrol planes were searching the fleet operating areas, and three others standing by on a thirty minute notice.
b. Four other planes from Ford Island were in the air operating with submarines in joint exercises.
c. At Midway five planes were on reconnaissance to a distance of 450 miles, two others were enroute to rendezvous with the USS Lexington task force 400 miles to the southeast. Four additional planes were on ready alert.
d. Three Marine Scout bombers at Ewa Field were on two hours notice, and fifteen bombers and fifteen utility planes on four hours notice.
e. Some forty Army planes could be called upon for reconnaissance duty by Patrol Wing TWO in emergency but were never called except in connection with air raid drills.
f. In addition, the three task forces at sea were conducting a regular wartime search by aircraft and destroyers, as required by fleet orders.
The advisability of continuous and complete air reconnaissance was always in mind, but this presented a dilemma of the utmost difficulty. First there were insufficient planes and personnel; next was the intensive schedules, for training, instruction, maintenance, and improvement. The same principle applied to other elements of our military forces. In the fleet the workday was long and intensive, and reasonable consideration had to be given toward preventing staleness and poor morale among the limited manpower available.
In the days just prior to 7 December we were at peace, although peace was overhung by ominous clouds. The various military forces were preparing for probable hostilities, and it was imprudent to divert our efforts unduly in directions which would wear out planes and pilots in advance of actual needs. When Admiral Richardson was still the Fleet Commander, he took up the question of justification for continuous long range reconnaissance.
He addressed the Navy Department as follows under date of 28 November 1940: "I feel that the Fleet must operate on either of two assumptions, that is that we are at peace and no security measures are required; or, that wartime measures of security must be carried out. Heretofore, we have carried out limited security measures largely as a basis for training and on
the assumption that no foreign power would choose to bring on a war by an attack on the Fleet, but that some misdirected or fanatical nationals might undertake individual and irresponsible attack on Fleet units." 
This was answered by the Navy Department under the date of 23 December 1940 as follows: "There will be an advantage in making occasional sweeps by aircraft and surface craft but it is not yet necessary to make these continuous. I agree with you that the wear and tear on equipment, and the detrimental effects on training, of full security measures should be given due weight." 
With these points in mind, and others too, it was a command decision based on calculated risks that reconnaissance as well as other defense matters should be on a moderate scale in peacetime. Thus there was a minimum of air reconnaissance on Sunday, 7 December. Of course the Japanese were fully aware that Sunday was a day of rest and relaxation among the defense forces at Hawaii, and they also knew no doubt that Americans accepted in good faith the Japanese legal commitment not to attack without an ultimatum or declaration of war. On top of this was the general feeling that the Japanese would not be so irrational as to make their initial attack on the stronghold of the Pacific.
The importance of radar for distant reconnaissance was recognized by the late 1930's. Scientists, engineers, and manufacturers were engaged in important programs of development. Military officials were expediting the purchase and installation of radar equipment to the extent that funds and qualified personnel would permit. The installations in Hawaii at the time of the Pearl Harbor attack were new and quite experimental. There were few military personnel who were trained to operate a radar installation in a reliable manner.
The Navy was installing production sets as fast as they could be obtained and made reliable; but in December 1941, only about a half-dozen ships of the Pacific Fleet had radar installed. The Army was then in the process of installing three large fixed radars on high ground in Hawaii,
and six mobile radars on trucks. The effective distance for detection would depend of course upon the height of the installation and the height or elevation of the target. Thus a large ship could be detected by another ship with the radar at a distance of about twenty miles, while an airplane at 10,000 feet could be detected by a fixed land radar at a distance up to 200 miles.
Arrangements had been made between the Army and Navy for joint utilization of radar installations. Since the Navy had more experience in the use of radar, it was agreed that Army personnel would go to sea on four or more of the Navy ships for training and practice in radar operation. This was done in June 1941.
The Army radars were installed by the Corps of Engineers and operated by the Signal Corps. A system was worked out whereby radar information could be forwarded to an "Aircraft Warning Service" for evaluation and action. This came under the Army Air Corps which passed the information to the "Interceptor Command" when defense action was indicated. This system of air raid defense was not fully operative by 7 December although some drills had been held. As will be observed, this was an all-Army set-up since Navy radars were secured in port because of their low elevation on the ships and the interference from the high surrounding land masses and buildings. However, some from the Navy were assigned on an unofficial basis to assist the Army's evaluation system.
The Army radar service was operative every day except Sunday from 0400 to 1600 hours, but on Sunday it was manned from 0400 to 0700 hours. General Short considered these hours the most dangerous time for an air attack. Except for the large installation where one enlisted man had volunteered to continue because of his interest and desire for experience, no radar was operating on the morning of 7 December. This turned out to be a well publicized circumstance, because this man detected on the radar screen a large flight of aircraft bearing north at a distance of about 130 miles.
He was perplexed by what he detected, but reported it by telephone to a Lieutenant on duty at the "Aircraft Warning Service." The Lieutenant discounted the information as not being of much moment for several reasons:
a. They could be planes from our two U.S. aircraft carriers which he knew were at sea.
b. They could be planes out of Hickam Field.
c. They could be the twelve B-17's arriving from the West Coast for
transfer to the Philippine Islands. Actually these planes did arrive shortly thereafter and were badly shot up by the Japanese.
d. At that time there was no proper identification system to determine whether planes on the screen were friend or foe, so there was no sure method by which the planes could be identified as other than American.
The important fact of course was that the planes were the Japanese raiding force which arrived an hour later. If the radar information had been fully utilized it is likely that Pearl Harbor and all airfields would have been fully alerted. If our forces had been ready, what would the results have been? No doubt a much greater number of Japanese planes would have been destroyed, and possibly some of their ships damaged or sunk. But our own losses would not have been materially lessened, and the general outcome might well have been about the same. This interesting viewpoint will be covered in later pages.
5. OPERATION OF THE FLEET
During the eighteen months following the basing of the Pacific Fleet at Pearl Harbor great progress was made in training the sea forces for possible hostilities and in improving the facilities of the new base of operations. There were generous appropriations for new ships, equipment, manpower, and for shore installations. The results were beginning to show, but there is always a great time lag between authorizing such things and their integration into the operating forces.
New ships and planes were being delivered but the bulk of these were assigned to the Atlantic where actual war conditions existed and prospect: were extremely grave. The new units required trained men, and therefore training had topmost priority. It became the duty of the Pacific Fleet to do a vast amount of on-the-job training of men to be transferred back to the mainland for later assignment by the Navy Department. Many of these, especially officers, were reserves called to active duty. It is worthy to note here that these reserves became a major part of the fleet and fought with great distinction in World War II.
A large proportion of the new air strength was diverted to the Philippines, Midway, and Wake. It was the policy to strengthen these islands. Such a policy originated in Washington, and was part of the war plan which would be followed in case of hostilities with Japan.
In shoreside activities great improvements were made to the shop facilities at the Pearl Harbor Navy Yard. A large new drydock, additional oil stowages, and general expansion of repair capacity were also included. Without these, the wartime performance of the Navy Yard in supporting a greatly enlarged fleet would have been impossible.
In the summer of 1941 the Pearl Harbor Navy Yard was entirely competent to handle a limited number of overhauls of all but the largest ships. The Yard was gradually built up in officers and civilian manpower so that it could do a very creditable job within the limits of its capacity. Although major overhauls of ships such as battleships and aircraft carriers were performed at the West Coast Navy Yards, the Pearl Harbor Navy Yard was able to handle many important items of work on all ships including the installation and testing out of new improvements such as radar, anti-aircraft guns, fire control gear, radios, and so forth. The regular overhauls about once every eighteen months for battleships, aircraft carriers, and most cruisers and submarines were handled at the West Coast Navy Yards. The ships were rotated in the fleet schedules so that a minimum was absent at any one time. The arrangement insured a program of maintenance and improvement, and at the same time gave the ship crews an opportunity to visit the mainland for several months and to be with their families and friends.
The active units of the fleet operated on a strenuous schedule of training. They were engaged in sea maneuvers about 60 percent of the time and were in port at Pearl Harbor the other 40 percent. The submarines based at Pearl Harbor operated on a special schedule, while all other ships were divided into three separate task forces which overlapped each other in their scheduled time at sea and in port. While at sea, major units of the fleet were screened by aircraft and destroyers to be sure that enemy submarines were not in the operating areas. It was assumed that the operating areas were infested with Japanese submarines, and that a surprise attack would be by submarines against major units of the fleet.
6. HOW POWERFUL WAS THE FLEET?
Among most Americans, and even most military personnel, Pearl Harbor was believed to be a mighty bastion of defense. Together with the power of the Pacific Fleet, Hawaii was considered by the public to be impregnable.
The fleet itself was assumed to be invincible as compared to that of any prospective enemy. Even some of the high ranking personnel of the State Department had faith in the supposition that if hostilities occurred, the sea forces of Japan could be vanquished in a few weeks. But as we well know that viewpoint was quite mythical.
Just prior to the Japanese attack the Pacific Fleet had a total of 159 vessels assigned, including some smaller craft such as mine layers, mine sweepers, and patrol vessels. This compared to 224 such vessels assigned to the Atlantic Fleet. If we exclude the smaller vessels, the Pacific Fleet had 111 ships and the Atlantic Fleet 188. The Pacific Fleet had nine of the fifteen battleships and most of the modern submarines, but the Atlantic Fleet excelled in other types. At the time of sending the United States Fleet to base in Hawaii, that fleet was relatively stronger than the fleet based in the Atlantic, but events in Europe and the Atlantic forced Washington to transfer some of the ships from the Pacific where peace still prevailed. In May 1941 the following were detached from the Pacific and sent to the Atlantic for duty: 
1 aircraft carrier
To show Washington's concern over the Atlantic and the Mediterranean, it was proposed in the summer of 1941 that a like force from the Pacific be transferred to the Atlantic, but this proposal was dropped. These transfers indicate that the Atlantic was deemed to be the scene of needed strength.
The three major task forces comprising the Fleet were organized as follows: 
Task Force I, Vice Admiral W. S. Pye, Commander Battle Force, in USS California
1 aircraft carrier
5 light cruisers
5 mine vessels
Task Force II, Vice Admiral William F. Halsey, Commander Aircraft Battle Force, in USS Enterprise
1 aircraft carrier
4 heavy cruisers
4 mine vessels
Task Force III, Vice Admiral Wilson Brown, Commander Scouting Force, in USS Indianapolis
1 aircraft carrier
8 heavy cruisers
13 mine vessels
6 attack transports
At least one of these three task forces was always at sea. Usually two of them were at sea for overlapping periods during tactical operations.
In addition the submarines were organized as a task force for independent operations to provide an efficient Submarine Observation and Attack Force and to conduct patrols as ordered by the Fleet Commander. The operating schedule called for about thirty submarines and their supporting vessels.
The above gives a good approximation of the strength of the Pacific Fleet. However, all the ships were not in Pearl Harbor or not in full operating status. Some were at West Coast Navy Yards for regular overhaul, some at the Pearl Harbor Navy Yard for required material improvement work, and many were operating at sea.
While the strength of the fleet seemed quite formidable, it was realized by "those in the know" that the Japanese fleet was considerably stronger. Definite information, of course, was unavailable, but it was known that Japan had been busy building and training for at least a half-dozen years. The extent of their superiority was demonstrated in the early days of the war, especially in the category of aircraft carriers and aircraft carrier planes.
7. WHERE WERE THE FLEET SHIPS ON 7 DECEMBER?
Contrary to popular belief, many ships of the fleet were not present at Pearl Harbor on 7 December. A rough estimate would show that about one-half of the total force was absent. Fortunately all three of the aircraft carriers assigned to the fleet were elsewhere, but eight of the nine battleships assigned were present and took the brunt of the attack.
Several of the ships were absent in connection with Navy Yard overhauls on the West Coast. But others were on special missions, such as:
a. A special task force under Vice Admiral Halsey in Enterprise was about 200 miles west of Hawaii enroute to Pearl Harbor after having delivered Marine Corps fighter planes to beef up the defense of Wake Island.. This task force consisted of 1 aircraft carrier, 3 heavy cruisers, and 9 destroyers.
b. Another special task force under Rear Admiral J. H. Newton with Lexington was about 400 miles southeast of Midway enroute to that island to deliver Marine Corps scout bombers. This force consisted of 1 aircraft carrier, 3 heavier cruisers, and 5 destroyers.
c. A special task force under Vice Admiral Wilson Brown consisting of 1 heavy cruiser and 5 destroyers together with minesweepers was off Johnston Island to test a new type of landing craft.
d. Two heavy cruisers were on convoy duty in the Samoa and Solomons areas in connection with protection of shipping to Australia.
e. One heavy cruiser and four destroyer minesweepers were about twenty-five miles south of Oahu conducting special exercises.
f. Two submarines were in the Midway area, and two others in the Wake Island area.
g. Other ships, such as oil tankers were enroute to Hawaii from the West Coast.
All of these ships at sea were in a status of wartime alert, fully armed, and ready for any emergency. Their absence from Pearl Harbor left the following ships present:
2 heavy cruisers
4 10,000 ton cruisers
2 7,000 ton cruisers
27 auxiliaries such as repair ships, tenders, store ships, and tugs.
All of the vessels at Pearl Harbor, except those undergoing overhaul at the Navy Yard, were, in accordance with fleet orders, in readiness condition three, which required about one-quarter of the anti-aircraft batteries and their control stations to be in a ready status with gun crews and ammunition at hand. All fleet vessels had ready for use their full supply of ammunition plus a reserve supply. Also, these vessels were required to be on twelve hours notice for getting underway. Actually, however, none of the ships required twelve hours steaming notice to get underway, as will shortly be seen; the requirement for twelve hours was for a fleet sortie.
1 Commander Patrol Wing TWO letter of 16 January 1941 to the Chief of Naval Operations.
2 Hearings before the joint Committee on the Investigation of the Pearl Harbor Attack, Part 14, p. 975. Hereafter cited as Hearings.
3 Ibid., p. 980.
4 Report of the joint Committee on the Investigation of the Pearl Harbor Attack, and Additional Views of Mr. Keefe Together with Minority Views of Mr. Ferguson and Mr. Brewster, United States Government Printing Office, Washington, D.C., 1946, p. 167. Hereafter cited as Report of the joint Committee.
5 Hearings, Part 17, p. 2535.