U. S. NAVAL INSTITUTE, ANNAPOLIS, MD.

ARMOR AND HEAVY ORDNANCE. RECENT
DEVELOPMENTS AND STANDARDS.
By W. H. JAques.

(Read before Section G of the British Association.)

When I picked up the last issue of Brassey's Naval Annual (1896) and upon the title-page read

"No system of conduct, however correct in principle, can protect neutral powers from injury from any party. A defenseless position and a distinguished love of peace are the surest invitations to war."

THOMAS JEFFERSON.

it occurred to me how little our legislators are influenced by the words of the eminent statesman which have been selected by the editor of a British annual of the record of the naval events of the year as a warning to Great Britain, the first naval power of the world, that its preparations for defense must be liberal and continuous.

The situation and policy of the United States could not be more accurately described than by these words of Jefferson, "A defenseless position and a distinguished love of peace," yet little heed is given to his warning that these conditions "are the surest invitations to war."

In fact, our engineers and manufacturers are the only ones. who have awakened to the situation, and this awakening will no doubt be attributed to the hope of pecuniary gain. They have, however, no matter what the incentive, attained the highest standards in the production of armor, heavy ordnance and projectiles. All we need in the United States are adequate budgets. and well planned shipbuilding programs. That we are gradu

lowing table of estimates for 1896-7, taken from Brassey's Annual

although in the table of effective fighting ships, built and building, the United States is left out, England, France, Russia, Italy and Germany only being included.

The progress in armor making referred to in my last public pamphlet (1894) has been continuous, and the United States (The Carnegie Steel Co., Ltd.) and Germany (Krupp) have produced armor fully 15 per cent., if not 20 per cent., better than the best plain steel Harveyed armor that Great Britain has placed upon her battle-ships; although one is handicapped in making thorough comparison so long as England continues to determine the value of her battle-ship armor by firing 6-inch soft Holtzer shells against 6-inch plates at velocities below 2000 ft. sec.

This comparison of superiority is based upon the Admiralty report of 1895-6, which states that

'During the year various experimental armor plates have been submitted by manufacturers for the purposes of test. None of these, however, have shown qualities equal to those possessed by the Harveyed steel armor mentioned in statement of last year.'

Competition in the production of armor has become so active, the number of establishments for its manufacture so numerous, and the methods of its production and treatment, and its test, so complex, that it is not surprising there should be marked differences of opinion as to what kind and thickness of plate should be employed, and its distribution, and what caliber of ordnance should be used against it.

The most important tests that have been made in the past two years have taken place in the United States and Germany, and the results in these two countries have been so nearly identical that it became necessary for me to study very carefully

parative trials of Wheeler-Sterling, Holtzer and Krupp projectiles have been made in three European countries, as well as in the United States. Although not so complete as I would wish, the results indicate that the Krupp projectiles employed in the tests of the German plates in question were somewhat inferior to those employed at the Indian Head (U. S.) trials. The German trials of 1894 and 1895 have been fully described in the British engineering journals, Brassey's Annual, and particularized by the pamphlets of Captain Castner, who reproduced, with comments, publications in Stahl und Eisen. French tests showing excellent results have been published in the French technical papers. With these you are all familiar.

In making a comparison of the tests I have cited we must not lose sight of the fact that the German and French plates were experimental and made to secure the greatest resistance possible, whereas those of the United States were service plates, representing hundreds of tons of armor, from which the inspectors had selected what they considered were the poorest of the lot.

A careful examination of the results of these trials leads us to conclude that to the products of the United States and Germany the first rank must be accorded, Great Britain and France. being content to accept second place on the plea that as plain steel, carbonized, is so good it is not wise to pay the increased cost which the use of nickel entails.

Another very important test was made in the United States at the naval proving ground against a battle-ship turret (or rather a reproduction of one), the plate attacked being of carbonized nicket-steel armor, while its supporting plates, to complete the turret, were made of iron. While the results demonstrated that the 15-inch armor would undoubtedly keep out 12-inch projectiles with attacking service velocities and no injury to the vitals would result, the backward movement of the turret itself upon its supports was somewhat of a surprise; but it was estimated if the usual holding-down clips and roller flanges were employed they would be sufficient to enable the turret to keep its place on shipboard, even if attacked under similar conditions.

Examination of the published tests made in the various coun

inferior to the best nickel-steel gas-hardened plates now being used by the United States and Germany. If this be true, in matter of weight alone the better plates will effect a great saving, as these saved weights can be given to other elements requiring so much attention-such as ammunition, coal and other supplies, which are so exacting in the modern war-ship.

In my discussion of Dr. Elgar's important paper on the "Cost of War-ships," read before the Paris Meeting of the British Naval Architects, in June, 1895, I estimated there would be a saving of £64,000 in the item of armor alone for each of the first-class British battle-ships then under discussion if nickelsteel, carbonized, armor were substituted for the plain steel, Harveyized, which was to be used in their construction, even at the then comparatively high price of nickel. That this economy is not restricted to armor is endorsed by one of England's highest authorities, Mr. James Riley, who, at the April Meeting of the West of Scotland Iron and Steel Institute, in referring to nickel-steel, assured the shipbuilders and engineers present, that, by its use, " without any extra expenditure in construction, they could obtain 30 per cent. more efficiency out of their engines and boilers, effecting at the same time very considerable economy in the cost of fuel."

A summary of recent advances in the production of armor will include the cheapening and more extensive use of nickel; the substitution of the hydraulic forging-press for hammers and rolls; better means of removing scale; simplification of the methods, and more uniform results, of super-carburization; utilization of the valuable sub-forging process (now required for all United States armor); improved facilities for hardening; and improvements in the machines and tools for shaping and finishing.

Mr. Schneider's success in making nickel-steel so generally a commercial product is perhaps the most valuable of these; and when we recall its already extensive employment for armor, guns, shafting, hammer and piston rods, torpedoes, axles, beams, building and bridge structures, and even ship and boiler plates, if this development goes on in proportion to the strides of the past few years, nickel-steel must be given as important a place in metallurgy as the Bessemer process, notwithstanding the fact

799

armor protection, employing it, uncarbonized, only for difficult shapes.

Public notices of the placing of five British battle-ships, to be known as the Canopus type, contain information that the most significant modification to secure a less displacement than that of the Majestic type will be a reduction of thickness of the Harveyized armor which protects the broadside. It is stated that the new ships will have 6-inch plating instead of 9-inch as on the Majestic. It will be interesting to know whether nickel is to be employed, or some new method of treatment other than that now used in England, to secure the increased resistance which this great reduction in thickness would indicate; for no one will believe that the Admiralty will be satisfied with less ballistic resistance than that of the armor of the Majestic.

All the best examples of the plates that have been tested, whether experimental or service, are those that contain nickel. This is equally true of the trials of Germany, France, Austria, Russia and the United States. The latest United States specifications require that all armor shall be of nickel-steel, supercarbonized previous to finished forging, after which it shall be reduced to final thickness by sub-forging.. This reworking and compression toughen the plate, decrease the tendency to brittleness and restore the fine grain of the metal, which becomes crystallized during the long period the plate is undergoing the carburization treatment and by reason of the high temperature employed. The sub-forging further has the effect of closing pipes, blow-holes and fissures that may have originally existed as minor defects and have developed into injurious ones during the process of carburization. In other words, the molecular structure, impaired or damaged by the cementation, is restored or repaired, the density is increased, crystallization broken. up, elastic strength increased, and the product made tenacious, tough and hard.

The employment of chromium and tungsten in armor production has made some advance, principally in thin plates, and have been more used in France and Germany than elsewhere. There appears to have been very little done recently in the direction of manganese armor.

While in the United States the increased resistance of armor has determined the authorities to retain the higher calibers of