Part 9
In projectiles the tendency of the modern era has been towards simplification. Bar-shot, chain-shot, and grape have disappeared, while canister and solid shot are becoming obsolete. There remain shrapnel as the “man-killer” of this age, and explosive shell, differentiated into armor-piercing and that for attack on unarmored structures. Lieutenant Shrapnel, in 1796, invented the projectile which bears his name. In its modern form, it consists of a steel case containing lead or iron balls and a light bursting charge of powder, ignited by a time-fuse carried in the head. This projectile is most formidable against bodies of men, boats, and the embrasures of forts, since, when it is ruptured, the balls are dispersed, covering a wide area.
The use of explosive shell in high-angle discharge dates back to the fifteenth century. From Paixhans’ works, “La Nouvelle Arme,” published in 1821, came the stimulus to its development and to its deadly service, in our time, in horizontal fire. The “common shell” for the United States 13-inch rifle is made of forged steel, weighs 1100 pounds, and carries within it a bursting charge of 50 pounds of powder, ignited by a percussion fuse set in its base. It will penetrate 6 or 7 inches of armor and then explode within the ship. The United States “armor-piercing shell” is manufactured from crucible steel, alloyed with chromium; it is tempered to extreme hardness at the point, which carries a cap of soft metal. The function of the latter would appear to be that of a support to the shoulder of the projectile, or as a lubricant thereto, since, without the cap, the shell is broken or deformed in the attack on armor of surface hardened steel. To resist the crushing strain in its passage through massive plate, the walls of this shell must be so thick that no charge of gunpowder will burst it. Hence, as a rule, the shell is fired unloaded, although recently there have been adopted to some extent bursting charges of some high explosive, such as gun-cotton, joveite, or picric acid.
In closing this brief review of the progress of ordnance, but passing mention can be made of matters minor, but in themselves of much importance. Gun carriages, or mounts, are now intricate mechanisms, practically the whole service of large ordnance being performed by electric and hydraulic machinery. The rapid fire principle has been extended to pieces of 6-inch calibre, and bids fair to pass beyond that limit. Its success in increasing largely the number of shots within a given time lies in special breech-blocks, aiming devices, and prepared cartridges. Machine guns of rifle-calibre, partly or wholly automatic, have been so developed as to be capable of firing 1200 rounds per minute. The discharge of high explosives in large quantity was effected with success by the United States steamer Vesuvius off Santiago. The torpedo-gun afloat, however, would appear to be still in a tentative condition.
A brief lapse into technical terms may be permitted in summarizing the gun’s growth in power. The term “muzzle energy” is used to describe the work which the projectile is capable of performing when it leaves the bore. It is expressed in foot-tons, i. e., the number of tons which the energy stored in the shot would lift to a height of one foot. The figures as to this for the 32-pounder of the century’s beginning, for the United States 13-inch rifle and for the 111-ton English gun, are, respectively, 642, 33,627, and 54,690 foot-tons. Again, the round shot from the 32-pounder lost from the resistance of the air, in a range of 1200 yards, 76 per cent of its energy; while this loss, with the United States 13-inch, in a range of 1000 yards, is but 11 per cent. Finally, if the cast-iron shot of the 32-pounder were fired against armor-plate, it would lose, in breaking itself up, two thirds of its remaining energy, leaving at 1200 yards but 51 foot-tons for effective work; while with the modern armor-piercing shell the entire energy left at the end of the range is expended upon the armor-plate.
It will be seen then that the immeasurable superiority of modern guns is owing both to their great increase in energy and to their wiser disposition of that which has been attained. The gun has maintained fully during the century its primacy among naval weapons. It is true that, in theory and on paper, its supremacy has at times been questioned; but as to its two rivals, the ram would seem to be rather the weapon of accident than action, and the torpedo has yet to score in battle against ships in motion, while the precision, rapidity, and power of the gun grow more deadly with every passing year.
VI. THE DEVELOPMENT OF ARMOR.
Armor and the gun are natural and now hereditary foes. The function of the one is to resist, that of the other ever to attack. Since the beginning of the modern era in navies, there has been ceaseless strife for mastery between these two elements of warship design, the gun ever becoming more powerful, and the armor—at first through growing thickness and later through improved material—opposing a steadily more stubborn front. The official report of an English committee made in the year 1860 states that,—
“Vessels clothed in rolled-iron plates of four and a half inches’ thickness are to all practicable purposes invulnerable against any projectile that can be brought to bear against them at any range.”
The advance which forty years have seen may be shown by the single statement that the Krupp 15.7-inch gun develops sufficient energy to penetrate at the muzzle 47 inches of wrought iron. The battleship is at best but a series of compromises, each factor of the structure yielding or growing as the skill or whim of her designer may indicate. In the present stage of this unceasing change, the gun would appear to be the victor, and the power of this mighty 132-ton rifle seems scarcely needed on the sea. The distinguished chief of ordnance of the United States navy, in his annual report for 1898, says:—
“The development of the 12-inch gun has been so great and its power so much increased that the Bureau is of opinion that hereafter it will be the maximum calibre that it will be advisable to install on future battleships.”
With armor, as with the torpedo, the talent of Europe reaped where the genius of America had sown. John Stevens of New Jersey was the first inventor of modern times to suggest the application of armor to a floating battery, his plans being submitted to the United States government during the war of 1812. They received, however, no serious consideration, and to France, forty-two years later, fell the honor of attaining the first practical results in the building of ironclads. Members of the Stevens family, however, continued the experiments of its founder, until by the year 1841 they had determined the thickness of iron necessary to stop spherical projectiles at point blank range, and the comparative resisting powers of iron and oak. These results led to an appropriation by Congress, in 1854, of $500,000 to begin work upon an ironclad,—the Stevens battery,—which vessel, however, never left the ways and was eventually broken up.
[Illustration: PLATE VI. THE DISTRIBUTION OF ARMOR.]
[Illustration: PLATE VII. THE DISTRIBUTION OF ARMOR.]
General Paixhans, who revolutionized naval artillery by the invention of the modern shell, prophesied, in an official letter to the French government in 1824, that the new projectile would force the creation of armored ships. In 1841 he recommended officially the clothing of vessels with iron armor, as a protection against his own missiles; and in 1853 his words of warning met complete and terrible fulfillment in the annihilation by shell guns of the Turkish fleet at Sinope. This action was the immediate cause of the introduction of armor in modern navies.
The British admiralty, in 1843, had duplicated the Stevens experiments, using a target of 14 plates of boiler iron riveted together, which gave a total thickness of 6 inches; and experiments on laminated plating had been also at this time carried on at Gavres, in France. In 1845 Dupuy de Lôme, the famous naval architect, submitted to the French government the first European design for an armored frigate. His plans were, however, rejected; and only with the outbreak of the Crimean War was the construction of armored vessels begun. On October 17, 1855, the three French batteries which were the first results of this new departure went into action off Kinburn, in the Crimea, silencing in four hours forts which had held at bay the combined fleets of England and France. Armor had won its first victory, and had shown most signally its position as one of the main factors in the warship design of the years which were to come.
These vessels, with three similar batteries constructed immediately thereafter by the British government, were clad with solid iron plates 4½ inches thick, backed by 27¾ inches of oak, comparative experiments at Vincennes, France, having shown the marked superiority of solid over laminated plating. They were, however, in but a most limited sense sea-going ships, their low speed and other inferior qualities being radical defects as to this. France led in a further advance, beginning in 1857 and completing in 1859 the transformation of the wooden line-of-battle ship Napoleon into the armored vessel of 5000 tons, which, as La Gloire, is famous as the first sea-going ironclad. She carried a strake of 4¾-inch plating at the water line, and 4½-inch plates in wake of the battery. England answered the challenge of her hereditary foe with the Warrior, an iron vessel of 9210 tons, completed in 1861. While her rival had a fully armored side, but 212 of the Warrior’s 380 feet of length carried plating. Its thickness was 4½ inches.
[Illustration:
_“La Gloire” (France) 1857. Side Armor Iron 4½ in. Solid._
_“Warrior” (England) 1859. Side Armor Iron 4½ in. Solid._
_U.S. Monitor “Passaic” 1862. Side Armor Iron 3 to 5 in. Laminated. Turret Armor Iron 11 in. Laminated._
_“Inflexible” (England) 1876. Belt & Citadel Armor Iron Sandwiched._
_“Duilio” (Italy) 1876. Belt Armor Steel Solid._
_U.S. Battleship Oregon. Belt Armor Harveyed Nickel Steel Solid. 13 in. Turret Armor Harveyed Nickel Steel Solid._
PLATE VIII. THE GROWTH OF ARMOR. ]
At the outbreak of the Civil War in the United States, the government appointed a special naval committee to report upon types of ironclads. The conclusions of this board are of interest, in showing the state of armor development at that period. They required rolled armor of solid iron, whose minimum thickness was 4½ inches. Ericsson’s Monitor, however, carried laminated plating from 3 to 5 inches thick on her low sides, and 11 layers, each one inch thick, on her turret. This construction, which the difficulties in the manufacture of solid plate necessitated, made the record of endurance of this type far from good. The defect lay mainly with fastening bolts, which broke frequently, thus loosening or detaching the side armor, and the heads or nuts of which, flying off with violence when the armor was struck by shot, became sometimes fatal missiles against those within the turrets. In contrast with this, the behavior of the New Ironsides, clothed with solid armor, was most excellent. She was a casemated ironclad frigate with unarmored ends, her plating was 4½ inches thick, and inclined throughout the citadel, at an angle of 30° from the perpendicular. For two years she was subjected to the most severe test that a war-vessel must meet, the tossing and straining of blockade duty and the fiery ordeal of close action with fortifications. In one engagement, she sustained alone a fight against the combined fire of the forts in Charleston harbor, and, although struck on her side-armor sixty times, came out of the struggle unhurt. The record of this ship is one which does honor to the flag.
The achievement of the Confederacy during this war, in the matter of armor, was remarkable. With iron worth almost its weight in gold, and with most limited facilities for manufacturing, they yet succeeded in constructing some of the most formidable ironclads of their day. The Merrimac, for instance—with 3-inch armor, in two layers of narrow bars, at an angle of 30° with the horizontal—sustained no material damage to her plating from the fire of the Monitor; although had the full charge of 30 lbs. of powder been used in the 11-inch smooth-bores of the latter, the story would have been different. Every fair blow would have smashed a hole completely through the armor, and driven a shower of splinters about the battery-deck. Again, the armor of the Atlanta and the Tennessee—both casemated ships, with the sides of the citadel inclined at a sharp angle to the horizontal—was sufficiently strong, with the former vessel, to withstand, at 500 yards, the 11-inch projectile fired with a 20-lbs. charge, and, with the latter, the same shot practically at the muzzle, although the 15-inch projectile broke through completely in both cases.
It is unnecessary to follow in detail, through its many tests in peace, the advance of iron armor. Its growth in strength, as the power of the gun developed, came almost solely from increase in thickness, the latter reaching its maximum with the British Inflexible, completed in 1876, which carries from 16 to 24 inches of iron on her belt and citadel. This plating, however, is divided and “sandwiched” with wood, there being, exterior to the skin, 6 inches of teak, then 12 inches iron, 11 inches teak, and an outer 12-inch plate. As armor, iron received its death-blow in the famous tests at Spezia, Italy, during the autumn of 1876, when the 100-ton gun, with a full charge, at a range of 100 yards, attacked solid and “sandwich” targets of iron and solid targets of steel—the single or aggregate thickness of metal in each case being 22 inches. These trials were undertaken through Italy’s desire to build, in the Duilio and Dandolo, the most formidable vessels afloat. Steel won the day, and the roar of that mighty gun, thundering from the Spezia firing ground, sounded the knell of iron armor, deprived the as yet unlaunched Inflexible of her crown of invulnerability, and demanded, with success, a revolution in the armor manufacture of Europe.
As a compromise, compound armor, i.e., iron faced with steel, became popular for a time. As with steel, its beginnings were old, dating back at least to the year 1857. The first perfected compound plate, made by Cammel & Co., of England, was tested at Shoeburyness in 1877. It was composed of 5 inches of iron with a 4-inch face of steel; the iron being raised to a welding heat and the molten steel poured on its top. The great heat partially fused the contact face, the two metals were united, and the combination was assured by immediate rolling. Compound plates sprang in 1877 from obscurity to popularity; by 1879 iron armor had become obsolete with progressive naval powers, and, in 1880, both compound and steel plates had reached such development that they were close rivals, the leading competitors being Cammel in England and Schneider in France. Steel, however, slowly forged ahead during the next decade; and, at its close, compound armor was practically out of the race. In steel’s victory, its alloy with nickel, in minute proportions, has materially aided; the combination imparting hardness without decreasing the toughness of the plate. This material gave superior results from the beginning. Its first plate, tested in 1889, was 9⅓ inches thick; it was pierced by a Holtzer shell, whose body did not pass wholly through and whose energy was 1.6 times that just necessary to perforate a wrought-iron plate of the same thickness. To the increased strength given by nickel there has been added a further gain through the application of face-hardening processes—such as that of the American, Harvey—which produce superficial carbonization, transforming the surface into a high grade of very hard steel, without the pronounced plane of demarcation between the two qualities of metal, as in the weld of the compound plate. A 10¼-inch nickel steel Harveyized plate, tested at the Indian Head Proving Grounds in 1892, showed a strength which previously had never been equaled in the history of armor, and established beyond question the value of the face-hardening process, which, by various methods, is applied to the nickel-steel plating of to-day. The distribution of armor in the development of battleship construction is shown by the shaded sections on Plates VI and VII, and its relative thicknesses, on various vessels during this progress, by Plate VIII.
VII. THE RAM AND THE TORPEDO.
For two thousand years the ram—the razor-edged “beak” of the swift galley—was the chief naval weapon. With the advent of sail-power and the employment of gunpowder, it vanished from the seas; but to reappear when the coming of steam gave again controllable propulsion. In 1859 there was built into the French frigate Magenta a sharp spur,—the first modern ram. British construction of the modern era, from the Warrior down, has also recognized this weapon, and it is to-day a factor, although a minor one, in the design of all vessels of high speed.
The ram has, however, but a scant record of service in action, while in accidental collision it has wrought more than once appalling disaster. The ironclad Merrimac rammed and sank in Hampton Roads, in March, 1862, the United States sailing sloop-of-war Cumberland, which, under the gallant Morris, went down with guns thundering and ensign flying. On July 20, 1866, during the action off the island of Lissa, in the Adriatic, the Austrian flagship Ferdinand Maximilian rammed the Italian armorclad Re d’ Italia, which, with many of her 800 men, sank with a swiftness that chilled the blood of those who watched. Like this, in its sudden tragedy, was the destruction of the British battleship Victoria by her consort, the Camperdown, off Tripoli, Syria, in the summer sunlight of a June day in 1893. The ram of the latter vessel cut a deep and fatal gash in the Victoria, which within ten minutes turned bottom upward and went down, bow first, bearing with her 321 officers and men, whose unfaltering discipline gave a heroic splendor to their end. Despite these occasional instances of its deadly power, the ram holds a secondary place among naval weapons. To strike a modern vessel at high speed will require more than the skill of the swordsman.
The torpedo, like the ironclad, was an American invention, whose neglect by the United States government brought retribution when this deadly engine of war in 1861–65 destroyed not a few war-vessels flying our flag. Bushnell of Connecticut during the Revolution appears to have invented both the submarine boat and the marine torpedo, the latter being fired by clock-work. Fulton also met success in similar work during the period extending from 1801 to 1812. All of the elements of modern torpedo warfare, excepting the use of steam, compressed air, or electricity as a motive power, had been thus conceived by the early dawn of this century. The torpedoes of our day are practically of but two classes: the “mine,” or stationary (either “buoyant” or “ground,” as its position in the water determines), and the automobile, or “fish” torpedo. The former type is fired either by closing an electric circuit in a station on shore, or by the ship herself in contact, or in electric closure. During the Civil War nearly thirty vessels were sunk by mines, usually wooden barrels filled with gunpowder and fired by hauling lines or slow-burning fuses. It was a mine-field over which Farragut charged at Mobile Bay, when he uttered his famous oath and went “full speed ahead,” with the cases of the fortunately impotent torpedoes striking the Hartford’s bottom; it was a mine which, it is claimed, sunk the Maine; and it was a mine-field which kept Sampson’s battleships from entering the harbor of Santiago de Cuba. The stationary torpedo is now charged with gun cotton or other high explosive.
The origin of the most prominent of the automobile torpedoes is due to Captain Lupuis of the Austrian navy, and its development from 1864 onward to Whitehead, an Englishman. It is a cigar-shaped submarine vessel from 14 to 19 inches maximum diameter and from 14 to 19 feet long, which is blown from a torpedo-tube or gun within the ship by compressed air or an impulse charge of gunpowder. Twin-screw engines contained within its hull, and driven by compressed air stored in a reservoir therein, drive it at about thirty knots speed through an effective range of 600 yards. In its nose or “war-head” there is carried a large charge of gun cotton or other high explosive, which is fired by contact with the enemy’s hull. It is provided with both horizontal and vertical rudders, the depth of immersion being regulated by intricate machinery contained in the “balance-chamber.” The Whitehead has a somewhat formidable rival in the United States in the torpedo invented by Rear Admiral Howell, U. S. N. The automobile torpedo has never yet scored in battle against ships in motion. Its position in the naval warfare of the future is yet unfixed. The one certainty is, that its blow when struck home is almost surely fatal to ship and crew. The development of the submarine torpedo-boat, whose weapon is the Whitehead, has in recent years received much attention through the labors of the American Holland and others. France, in the Gustavus Zede, of 260 tons, has a diving boat of this character, for which much is claimed.
VIII. THE UNITED STATES FLEET.
Until the advent of the ironclad, the ships of the United States were equal, if not superior, in seaworthiness and fighting qualities to any in the world. The high standard set by the Constitution and her class of 1797 was maintained for sixty years; and, especially during the period from 1840 to 1860, the officers and men of the United States navy trod the decks of the finest ships afloat. They felt—as their successors feel—that, ton for ton and gun for gun, they had no foe to fear. The early steamers of the Powhatan class built in the late 40’s were a credit to the nation; the five screw frigates of the Merrimac type (1856–57) aroused the admiration and imitation of foreign experts, and the five corvettes which followed them in 1858–59–60, of which the noble Hartford was the chief, bore their full share in the war which was so soon to come. The gallant Kearsarge was the leader of a new class introduced in 1859.
During the Civil War two vessels, the Monitor and the New Ironsides, appeared which have left lasting traces on all battleship construction since their day. The great fleet of monitors, “tin-clads,” “90-day gunboats,” “double-enders,” and the like, which preceded and followed them during those dark years, served their country well. With the ending of that war, in the internal task of reconstruction and development, our maritime power was neglected and our fleet dwindled away. Its _renaissance_ dates from the appointment of the first Naval Advisory Board in June, 1881. The growth since then has been so much a matter of national interest and pride that it needs no detailed recounting here; its results have been summarized previously herein.
The sea-going personnel of the United States navy includes the line, medical, pay, and marine officers, the chaplains and warrant officers—a total on March 1, 1899, of 1589, with an enlisted force of 17,196 blue-jackets and 3166 marines. The officers who serve on shore are the naval constructors, civil engineers, and the professors of mathematics, a total of 69.