REPORT CONCERNING CERTAIN ALLEGED DEFECTS IN
VESSELS OF NAVY.

Mr. HALE presented the following

REPORT CONCERNING CERTAIN ALLEGED DEFECTS IN VESSELS
OF THE UNITED STATES NAVY, BY WASHINGTON LEE CAPPS,
CHIEF CONSTRUCTOR, U. S. NAVY, AND CHIEF OF BUREAU OF
CONSTRUCTION AND REPAIR.

FEBRUARY 19, 1908.-Referred to the Committee on Naval Affairs and ordered
to be printed with illustrations.

NAVY DEPARTMENT,

BUREAU OF CONSTRUCTION AND REPAIR,

Washington, D. C., February 14, 1908.

SIR: In conformity with the Department's instructions to prepare
data with respect to height of freeboard, gun height, water-line armor
distribution, and other features of the design of typical battle ships of
the United States and the most important foreign navies, so far as
such data might be available, with a view to definitely and con-
clusively refuting the many misstatements which have recently ap-
peared in the public press, and especially the misstatements contained
in a recent magazine article, I beg to submit the following report:

The preparation of data with respect to vessels of the United States
Navy is, of course, not difficult, although its presentation in a form
which would readily meet the needs of the Department required much
time and labor. The preparation of reasonably accurate data of a
similar character with respect to foreign battle ships involved much
greater difficulty; but the Chief Constructor has fully availed himself
of the resources of the Department in obtaining such data, and has
had examined all the most important special reports on such subjects,
including reports of naval officers who have recently made tours of
inspection in foreign countries, reports on file in the office of naval in-
telligence based upon the reports of naval attachés, official, Parlia-
mentary, and other documents which give statistics of foreign naval
vessels, and the principal British and French professional publica-
tions which deal with naval matters; he has also utilized the personal
knowledge and professional notes of various members of the corps of
naval constructors who have been educated at the Royal Naval Col-
lege, Greenwich, England; the École d'Application du Genie Mari-

time, Paris, France, and the University of Glasgow, Glasgow, Scotland, these officers having kept more or less in direct touch with professional developments in those countries. Although it can not be claimed that the data with respect to foreign battle ships is wholly accurate, it can be stated with entire assurance that it is the most accurate obtainable without having access to actual official drawings and specifications.

It is noteworthy, however, that in the case of several foreign ships unusually reliable official data was available; also that in the case of those battle ships of the Japanese fleet which took part in the battle of the Sea of Japan there was at hand accurate data which had previously been printed in English scientific publications, as well as very complete descriptions, with detailed data, prepared by the director of naval construction of the Japanese navy and published in the proceedings of a scientific society of Japan, and subsequently translated and republished in one of the most important English engineering publications. It is therefore evident that comparison between American battle ships and such Japanese battle ships as existed at the time of the Russo-Japanese war can be made accurately, and that comparison with certain other foreign battle ships can also be made with an unusual degree of accuracy.

In order that the Department might have complete information, in a convenient form, the following tabular statements and plans have been prepared and are made a part of this report:

I. Tabular statement giving principal characteristics of typical foreign battle ships.

II. Comparative table of gun heights, etc., of typical modern battle ships.

III. Tabular statement of heights of upper edge of main waterline belt armor above trial or designed load water line for typical foreign and United States battle ships.

IV. Length, width, and thickness of water-line armor and upper side belt armor for United States battle ships.

V. Tabular statement of principal characteristics of Russian and Japanese ships which took part in the battle of the Straits of Tsushima, otherwise called "Battle of Sea of Japan."

VI. Tabular statement of heights of turret and boardside gun axes above designed load water line for United States battle ships and armored cruisers.

VII. Cross sections of typical battle ships of the United States and foreign navies, showing breadth and thickness of main water-line belt; also depth of submersion of lower edge of main armor belt. below the designed load water line; also height of top of main armor belt above designed load water line; also designed load displacement and coal carried on designated load displacement; also height of free board and height of broadside gun axes.

VIII. Profiles and cross sections of typical battle ships of the United States Navy, giving distribution of armor, heights of gun axes, etc. (Sheets 1 to 14.)

IX. Profiles and cross-sections of typical foreign battle ships, giving distribution of armor, heights of gun axes, etc. (Sheets 1 to 15.) X. Booklet of profiles of United States battle ships, showing development of side-armor protection.

Among the various foreign publications, special reports, etc., consulted were the following:

Parliamentary papers and other published official documents relating to foreign ships.

Special reports.

Photographs of foreign ships.

Transactions of the Institution of Naval Architects.

Bulletin de L'Association Technique Maritime.

Other foreign technical society publications: Engineer (London), Engineering (London), Naval and Military Record (London), Nautical Gazette, Armée et Marine, Le Yacht, Brassey's Naval Annual, Naval Pocket Book (Clowes), Jane's All the World's Fighting Ships, Les Flottes de Combat.

After reading some of the sensational comments which have recently been made concerning certain features of battle-ship design one would be justified in believing that such features were novelties whose consideration had not heretofore been thought of, or else that the questions involved were so complex as to have confused and misled the responsible designers of the United States Navy as well as those of the principal foreign navies.

It would also appear that ill-informed representatives of a would-be new school of design deemed it necessary to invite special attention to professional subjects which, as a matter of fact, had already received most serious consideration by officers of thorough professional training and experience as subordinate officers and commanders of naval vessels or fleets. That the large majority of the alleged defects in our naval vessels do not exist in fact will be conclusively shown in the following pages. But before entering upon any argument which involves the use of the data contained in the previously enumerated plans and tabular statements, and before entering upon any categorical refutation of the many misstatements of fact contained in the magazine article already alluded to, it is deemed necessary to define with accuracy the conventional phrases used by naval designers in distinguishing between "light displacement." "load displacement," and "deep-load displacement," for it is doubtless the confusion of these terms by the nonexpert that has been responsible for so much of the silly and misleading criticism which has had such vogue in the secular and semitechnical press, and, I regret deeply to add, among some of the less well-informed officers of the United States Navy.

"Light displacement" in all navies is a term which describes the condition of the ship when complete in all respects, with armor, armament, machinery, equipment, etc., on board, but without coal, water, ammunition, or stores of any kind, or personnel.

"Designed load displacement" in the United States Navy, as well as in foreign navies, corresponds to our more familiar designation of "trial" or "normal" displacement, and indicates the condition of the vessel when it is complete in all respects, as in the "light" condition, and, in addition, has on board the personnel and all outfit, a certain proportion of ammunition and all consumable stores, and an arbitrarily determined quantity of coal in the bunkers; also, water in boilers at steaming level, and, in the case of battle ships, about 100 tons of fresh water in tanks and double bottoms. In the

United States Navy this condition provides for two-thirds of all ammunition and consumable stores being on board, and since the design of the Kearsarge class (more than twelve years ago) the quantity of coal in the bunkers on the designed load displacement has been from 800 to 1.000 tons, except in the case of the 17-knot battle ships. Idaho and Mississippi. An examination of the quantity of coal in the bunkers of typical foreign ships, under similar conditions, indicates that there were from 700 to 950 tons of coal in the bunkers on the designed load displacement. In this connection it is interesting to note that the "designed load displacement" of the Dreadnought provided for only 900 tons of coal in the bunkers, although the bunker capacity was 2,700 tons. The published accounts indicate that the actual load draft of that vessel was considerably more than 1 foot greater with the 900 tons of coal on board than was provided for in the design.

"Deep load displacement" in our own and foreign navies is a term which indicates the displacement of the vessel fully completed, ready for sea, with all stores, ammunition, coal, etc., on board, and is a condition which of course only obtains when the vessel has been freshly provisioned, coaled, etc. It also includes not only the full supply of potable water, but a substantial amount of reserve fresh water for the boilers, etc. It is obvious, therefore, that there are many weights on board at such a time which could be quickly disposed of and the ship lightened to that extent should the necessity there for arise, even though the enemy should be met with shortly after leaving port.

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Inasmuch as some arbitrary plane of reference is absolutely essential in determining such important features as water-line protection, height of freeboard, etc., the water line at designed load displacement is the arbitrary plane of reference naturally selected. It would be obviously improper to consider such important features as “freeboard," "water-line armor protection," etc., as being governed by the draft, of the vessel at "light" displacement. It would be almost equally improper to consider that such qualities should be governed by the draft of the vessel at "deep load" displacement. By common consent, therefore, all designers in all countries of which the Chief Constructor has knowledge base such essential requirements of the vessel as the "freeboard,"" water-line armor distribution," etc., upon the draft at the designed load displacement, this displacement being one which may reasonably be regarded as representing the minimum displacement at which battle ships will begin an engagement. The distribution of water-line armor, freeboard, height of gun axes, etc., are, however, such that even should a vessel be compelled to engage in battle shortly after being provisioned and coaled, the protection of the vital portions of the vessel and the ability to fight the guns under all ordinary conditions of weather would be as thoroughly assured as possible for the particular type of design in question.

The consideration of freeboard, gun height, water-line armor distribution, etc., is now and always has been a matter of the gravest concern to naval designers and naval officers who are in any responsible way connected with naval design. The transactions of scientific societies and reports of board of officers of the United States Navy and foreign navies afford ample evidence of the truth of the foregoing statement, and definite reference will be made to some of the more important of these documents later on in this report.