In Europe there was a disposition to disregard the power of the American ships, but when public opinion in this country and in Europe turned in their favour it went to the other extreme, and turreted ships with low freeboards were advocated irrespective of the totally different conditions prevailing on this side of the Atlantic. It was claimed that no turreted ship with a low freeboard could possibly be a good sea-boat, or undertake an ocean voyage. The double-turreted monitor Miantonomoh, built at New York, in 1865, proved the contrary in the latter detail, when in 1866 she crossed the Atlantic under her own steam, in company with two other monitors, and visited some English and European ports. She was never tried in any engagement, but was considered by her designers to be superior to any vessel of the kind constructed for war both as a sea-going ship and for fighting purposes. Her armament made up in weight what it lacked in number. Each of her turrets contained two Dahlgren guns throwing projectiles weighing 480 lb., and she also had a 12 lb. howitzer. The turrets were 18 feet in diameter, and were protected by armour 11 inches thick. She did not, however, prove a good sea-boat, which is not to be wondered at when her low freeboard is remembered, and though she made the voyage in the summer months when the Atlantic is usually fairly calm, she proved very wet. However, her advent was quite sufficient to demonstrate to the European powers that she could make the voyage, and her novel appearance gave the impression that her fighting value was tremendous. When the American War was over the United States Government had no further need of a number of its vessels, and disposed of some of them, France buying two of the most powerful, and one or two other European powers were also purchasers.
Among the vessels France acquired was the Dunderberg, which was renamed Rochambeau by her new owners. It consisted of a long iron fortress mounted with guns to fire on the broadside and also ahead and astern. The hull, also of iron, was but little above the water, and the decks were iron-plated. The central portion had armour 7 inches thick with a heavy wooden backing, and the decks fore and aft of the fortress were plated 8½ inches thick. Her two engines, developing 5,000 h.p., gave her at a pinch a speed of between eleven and twelve knots, but when she crossed the ocean she made the voyage under her own steam at between eight and nine knots. The after part, containing the screw propeller and steering gear, was also shot-proof. She had an immense beak or ram. Her total length was 378 feet, her breadth 73 feet, and her depth 81 feet, and she drew 22 feet of water.
As purchased by the French she had an armament of five 15-inch Rodman guns, and twelve 11-inch Dahlgrens. Another vessel, the Onondaga, was also purchased from America by the French, and both were altered at Cherbourg to meet French views.
When the French decided to adopt ironclad ships carrying a very few guns of great power, they did not hesitate to make some extraordinary experiments. One of their vessels, built in 1866, was the Taureau. It was like nothing that had been afloat before or has been launched since. Viewed from the stern, it resembled a sphere with a deck-house, a couple of masts, and a chimney. Much the same aspect was presented by a front view, except that before the deck-house was a small turret in which was one large gun. The turret was carried very far forward and could be revolved so that the gun had almost an all-round fire, the only limitation being the funnel and deck erections. The bow was extended enormously from the deck level to some distance below the water, and projected no less than 40 feet under the surface. The turret was not built on the deck, but descended to the bottom of the hold, and was protected by nearly 5 inches of armour, and a similar thickness was placed over the bows. The sides were plated 3 feet above the water-line, this belt extending to the stern. The engines were of 250 h.p. The Taureau was about 48 feet maximum width, and 197 feet in length without the ram. The idea underlying the construction of this unwieldy ship was that she should be able to deliver a heavy shot at close range to an enemy’s ship, and follow this up by ramming it, thereby completing its destruction; while her convex bows and circular turret would present no plane surface to the enemy, so that any shot which might strike it could only give a glancing blow and bound away harmlessly.
In 1862 another remarkable vessel called the Magenta was added to the French fleet. She was iron-plated and carried eighty guns on two decks, and in addition had a raised forecastle with ports on either bow, through which guns could be fired. She also had an immense blunt ram which projected like a cone upon the bows of the vessel and extended from the forecastle almost to the fore-foot. She presented an attempt to combine some of the features of the Monitor with the broadside ironclad, one American invention copied being the provision of a shot-proof tower just abaft the funnel for the accommodation and shelter of the officers during an engagement. She was barquentine rigged, and under sail and steam could get up a speed of about eight or nine knots.
The Marengo, another wooden ship which was plated with 8-inch iron armour, was designed to carry twelve guns. She had a central battery extending to the upper deck, and above this at each corner of the battery was an open armour-plated turret. The turrets each carried a large pivot gun, mounted en barbette, this being one of the first vessels France possessed in which it was sought to combine the advantages of the turret system with those of the barbette. These guns could fire in line of keel, and there were also four heavy guns on each broadside. She was 280 feet long by 57 feet 6 inches beam, and 28 feet draught, and was intended to have a speed of twelve knots. Her rudder was on the balanced principle. The rigging was brought down inside the bulwarks, something after the fashion of some modern sailing ships, so as to present a clean side outside. All the French ships were broad for their length.
The first large armour-plated ship to enter the Pacific was the Spanish screw steam frigate Numancia, constructed at La Seyne by the Société des Forges et Chantiers de la Méditerranée. She was 317 feet in length by 57 feet 2 inches beam, and depth 37 feet, and her draught of water was 27 feet 6 inches, with a displacement of 7,303 tons, according to English measurement. She was built of iron throughout, and had 5 inches of armour-plate backed with 16 inches of teak from end to end of the ship, and from no less than 7 feet 9 inches below the water-line up to the level of the upper deck. Her armament was forty 68-pounders. She was built in less than two years, a piece of unusually quick work for a French yard, and was launched in 1864.
In 1868 the Dutch Government received from English builders two single turret ironclad monitors, intended for harbour defence, which were stated to be the first of the low freeboard type completed in this country, and carrying turrets on Captain Coles’s system. These vessels, the Krokodil and Heiligerlee, were about 180 feet in length, with a beam of 44 feet, and a depth of 11 feet 6 inches. From the gunwale to 8 feet below the water-line they had iron armour-plates of a total thickness of 5½ inches, tapering off to 4½ inches at the extreme ends. This armour rested against a teak backing 10 inches in thickness, behind which was an inner skin of 1-inch iron, and inside this again was a series of longitudinal iron girders. For their size they were exceedingly strongly constructed, but as they were designed to be able to meet any hostile vessel which might approach any of the harbours of the shallow Dutch coast where they might be stationed, the reason for such substantial construction is apparent. The turret armour was 11 inches thick at the gunports, and 8 inches thick elsewhere. The armament consisted of two 12½-ton rifled guns firing a 300 lb. projectile, which could be discharged from within four degrees of aft on either side to direct ahead. The turrets could be revolved by steam or hand power as desired. The twin-screw engines were of 140 h.p. nominal.
Another vessel of considerable interest, designed and built for the Dutch Government by Napier, was the turret gunboat De Tygre, which inaugurated a type which found much favour in Holland. This vessel, of 187 feet in length, 44 feet breadth, and moulded depth 11 feet 6 inches, and of 1,613 tons, builder’s measurement, was built in compartments and with watertight doors, and was like most of the turret ships of the monitor variety, as she had a double bottom which could be filled with water to sink her to her fighting level. Thus only about 2 feet of her topsides would be exposed to the enemy. As an improvement upon her came another vessel from the same builders, which was described as “of a build which has long seemed to us as one of those most likely to become employed for the ‘ship of the future,’ not because she is a ram, but because she is essentially a sea-going turret ship.” She was “the De Tygre over again, with the following exceptions: She has about 3 feet less beam, a rather greater draught of water, and light topsides are raised over the armour-plating and the deck, with which it terminates to the level of another deck; the vessel is thus in appearance an ordinary sea-going ship of war, for she is pierced for a few light guns on the lower deck; but her fighting strength consists in her turret, which is similar to that of the De Tygre, except that the ports are at a higher elevation. This vessel is, therefore, a cruiser, unarmoured, higher than a level of 2 feet from the water; but practically for a fight at close quarters she is a monitor exposing only a turret and a low topside as parts vulnerable to shot.”[45]
The Greek armour-clad King George, of 1,774 tons, built at Blackwall by the Thames Ironworks, was remarkable for the smallness of her dimensions in proportion to the strength and extent of her armour-plating. This was 6 inches thick, and had a 10-inch backing, and extended from the gunwale to 8 feet below the water-line, and from end to end of the vessel. She was 200 feet in length, and with engines of 2,105 h.p. indicated attained a speed of nearly fourteen knots on her trials. She was also notable for the peculiar arrangement of a central hexagonal box-battery on the Mackrow system for two 21-centimètre breech-loading Krupp guns (300-pounders), with the portholes so designed that the guns could be fired on both sides forward in line of keel, and nearly so aft; on the actual broadside the guns could be fired direct and parallel at the same time, or made to converge their fire at 70 yards distance from the ship’s side, the racers being so placed that the guns pivoted from the muzzle and could each be trained over on the broadside, through an angle of 93 degrees, the front gun in this way pointing three degrees abaft.