OFFICE OF THE COMMANDANT
FOURTEENTH NAVAL DISTRICT
AND NAVY YARD, PEARL HARBOR, HAWAII, U. S. A.
Confidential 30 DEC. 1940.
From: Commandant, Fourteenth Naval District.
To: The Chief of Naval Operations
Via: Commander-in-Chief, United States Fleet.
Subject: Situation Concerning the Security of the Fleet and the Present
Ability of the Local Defense Forces to Meet Surprise Attacks.
(a) Opnav dispatch 092135 of October 1940.
(b) Opnav dispatch 182128 of October 1940.
(c) Chief of Naval Operations' personal letter addressed to CINCUS
dated 22 November 1940 (copy sent to Com 14).
(d) Com 14 dispatch 150055 of October 1940.
(e) Com 14 dispatch 220230 of October 1940.
1. In view of the inquiries contained in references (a), (b) and (c), I consider it desirable to write this letter to set forth the present ability of the Fourteenth Naval District to meet surprise hostile attacks of an enemy with the equipment and forces at hand.
2. AIRCRAFT RAIDS.
Aircraft attacking the base at Pearl Harbor will undoubtedly be brought by carriers. Therefore, there are two ways of repelling attack. First, by locating and destroying the carrier prior to launching planes. Second, by driving off attacking bombers with antiaircraft guns and fighters. The Navy component of the local defense forces has no planes for distant reconnaissance with which to locate enemy carriers and the only planes belonging to the local defense forces to attack carriers when located would be the Army bombers. The Army has in the Hawaiian area fifty-nine B-18 bombers. All of these are classified as being obsolete. The model is six years old and the planes themselves are five years old. Therefore, it is my opinion that neither numbers nor types are satisfactory for the purposes intended. New bombing planes are expected sometime in the future. However, not before July 1941. For distant reconnaissance, requisition would have to be made on the forces afloat for such as could be spared by the Fleet.
To drive off bombing planes after they have been launched will require both fighting planes and anti-aircraft guns. The Army has in the Hawaiian area thirty-six pursuit planes, all of which are classified as obsolete. Some of them are six years old and some of them are four years old. In numbers and models there is a serious deficiency existing. New fighters are expected when the P-40 is in production to the extent that the 185 projected for Hawaii can be delivered. This does not appear to be probable before the end of 1941; this number does not appear adequate.
The Army is charged with the protection of the Pearl Harbor base by antiaircraft guns. There are in Hawaii twenty-six fixed 3-inch guns and forty-four mobile 3-inch guns. There are projected twenty-four more, to be delivered in 1941. There are no 37-millimeter and only 109 .50 caliber out of the projected 120 37-millimeter and 308 .50 caliber machine guns. The Army plans to place the greater part of the 3-inch guns around Pearl Harbor and only a few near other military objectives. In my opinion, it will be necessary to increase the numbers of guns around Pearl Harbor greatly to have any semblance of antiaircraft defense. Furthermore, I express my doubt as to the efficacy of a 3-inch gun with a 21-second fuse for driving off high altitude bombers. The Army has made no plans for the anti-aircraft defense of Lualualei or Kaneohe, furthermore, it will be necessary to have a considerable concentration of anti-aircraft guns to defend the shipping terminals and harbor of Honolulu in order that lines of communication may be kept open. With a limited knowledge of the density of anti-aircraft barrages abroad, I am of the opinion that at least 500 guns of adequate size and range will be required for the efficient defense of the Hawaiian area. This number is in addition to 37-millimeter and .50 caliber machine guns.
In addition to the above, the Army has planned an aircraft warning service which will consist of eight Radar stations. Three of these stations are fixed and five are mobile. When completed at an indefinite time in the future, this warning net should be adequate.
3. DEFENSE AGAINST SUBMARINES.
The ideal defense against submarines would be conducted by patrol vessels and aircraft working in conjunction. The district has no aircraft for this purpose. Recently, there have arrived here three vessels of Destroyer Division EIGHTY which is assigned to the local defense forces. These vessels have listening gear and, when repaired and ready for service, will be a valuable contribution for antisubmarine and escort work. A large number of patrol vessels will be required for anti-submarine work in the vicinity of Oahu and the other islands. At present, the district has none and request would have to be made on the Fleet for such vessels and planes as could be spared for this most important work. No anti-submarine nets are planned, nor are any considered desirable. Anti-torpedo nets are projected for the entrances of Honolulu and Pearl Harbor. They will probably be delivered about 1 March 1941. The net depot will be completed somewhat later.
4. DEFENSE AGAINST MINES.
The district has recently built and equipped one sweep barge and three tugs are being equipped for towing and energizing the coil. This barge can probably look out for Honolulu and Pearl Harbor until such time as it is seriously injured. The district has no vessels available for use as sweeps for anchored mines. A number of mine sweepers are being built or purchased, but their delivery dates here are uncertain. A large number of sweepers will be required in order to keep the harbors of Pearl Harbor, Honolulu and Kaneohe clear and, in addition, Hilo on Hawaii, Kahului and Lahaina on Maui, and Port Allen and Nawiliwili on Kauai. With the delivery of sweepers now being built or purchased, the general situation will be improved immeasurably.
5. DEFENSE AGAINST BOMBARDMENT.
The coast defenses of the Army are considered adequate except that Kaneohe receives very little protection from the batteries.
There are two tank farms, the upper and the lower. The lower is entirely contained in the government reservation and, by the use of roving patrols, is considered reasonably secure. The upper farm is adjacent to a public highway. The farm is surrounded by an unclimbable fence and each tank with an earth berm. Its chief exposure is along the highway. To counteract this, three elevated sentry stations have been erected, each equipped with searchlights. This enables sentries to keep a continuous lookout over the entire fence line day and night, the upper farm is considered fairly secure.
7. WATER AND ELECTRIC SUPPLY.
Recently, a guard house has been erected and an arrangement has been made, the Marines alternating with the Army, for constant guard on the water supply.
A constant guard is kept on the electric supply lines through which outside power is received.
8. An elaborate system of photographic passes, search and examination is in effect. There are over 5,000 Civil Service employees who come into the yard each day. In addition, there are about 5,000 employees of civilian contractors and several thousand enlisted men. In addition to the above, there is a constant stream of trucks and vehicles of all descriptions carrying supplies, stores, et cetera. It is impossible to maintain absolute security without disruption of the work of the yard. However, surprise searches and periodic stops, et cetera, are in effect in order that the alert may be emphasized. The main gate has been strengthened to prevent rushing; there have been two drills for the purpose of giving surprise training to the yard garrison in the event of a surprise riot in the yard. In addition to the above, a survey has been made not only of the yard but of all of the outlying stations, and every effort is being made to close holes and stop gaps. While the Commandant is not satiated, he feels that the precautions taken are reasonably effective but that they are susceptible to improvement, which will be made as occasion warrants.
9. It should be borne in mind that until comparatively recently none of us in this country had very much conception of what measures were necessary and what provisions were desirable in order to effect any measure of protection against aircraft, against submarines, against mines and against subversive elements. The officers and men of this command have been alert, zealous and vigilant in executing all measures under their control in order to properly prepare the district for any exigencies.
10. It should be assumed that the War Department is fully aware of the situation here and that they are proceeding vigorously with a view to overcoming deficiencies. It may be that they have failed to recognize the necessity for large
numbers of anti-aircraft guns and pursuit planes. I suggest that the Chief of Naval Operations make inquiry from the War Department as to what their plans are and on what dates they predict that they will be accomplished and then, if the numbers and dates are not satisfactory, these features may be discussed at length.
11. It is considered highly undesirable from my point of view that the War Department should in any way come to believe that there is lack of agreement between the Army authorities and Navy authorities here, or that the officials of the Fourteenth Naval District are pressing the Navy Department to do something in regard to Army matters.
C. C. Bloch.
C. C. BLOCH.