On 14 February 1870 the Times newspaper carried a review of Chief constructor of the Royal Navy, Edward James Reed's recently published book 'Our Ironclad Ships; their qualities, performance, and cost, with chapters on Turret-ships, Ironclad Rams, &c.'.
|Extracts from the Times newspaper|
|Ma 14 February 1870|
OUR IRONCLAD SHIPS.*There are few subjects on which a popular book, written by a master hand, was more wanted than that of ironclad ships of war. Englishmen are justly proud of their ships, and are, perhaps, prepared to spend more money upon them than on any other national object that could be named; yet it is marvellous how little is really known about them, or even about their cost. Mr. Reed's book is doubly welcome — first, because it is full of interesting popular intelligence as to what our ironclads are actually and comparatively, and, secondly, because he shows plainly enough how small a proportion of the Naval Estimates is really devoted to the building of these new wonders of the world.
The Monarch, our latest launched great war-ship, when in fighting order burdens the ocean with a ponderous bulk weighing more than 8,500 tons. Her armour-plates are ten inches thick on the turrets, seven inches and six inches thick on her sides. Her guns weigh 25 tons each. They throw shot weighing 600lb., with an initial velocity of 1,212ft. per second, and any one of them strikes a blow the energy of which, at 1,000 yards from the muzzle, if otherwise employed, would be sufficient to raise a weight of 5,165 tons (considerably more than half the weight of the whole ship, armament and all) to the height of one foot. This tremendous structure has been driven through the sea at the rate of nearly 17½ English miles per hour. But as far as strength is concerned the Monarch will be left far behind by the ships now building in British dockyards, for the Devastation and Thunderer turret-ships are to carry 14, 12, and 10in. armourplates, in front of guns weighing 35 tons each, and the Rupert and Hotspur, specially designed as rams, are almost as strong. Nor is this at all the limit of possibility. Mr. Reed long ago designed a ship to carry 15in. armour-plates on her sides, 18in. on her turrets, and he speaks in his introduction of guns being superseded as a means of attack by ships capable of striking in various directions. The cost of ironclad shipbuilding in England during the past ten years has been, in round numbers, 10 millions, while the total Naval Estimates during the same period have amounted to nearly 117,000,000l. The number of ironclads built or being built amounts to 47.
Such is the actual state of our ironclad fleet, and such its cost to the nation. We will now attempt an estimate of its condition compared with that of other Maritime Powers, and try to ascertain what sort of progress has been made since the earliest British models were designed. Some of our facts will not be found in Mr. Reed's book, but they are all taken from authentic sources.
The two great rivals of England upon the sea are France and America. The French began with the Gloire class, with armour about 4½in. thick upon ordinary wooden hulls. The same thickness of armour as the Warrior is carried by the iron-built frigate Couronne. The Flandre, with her class, and the ram Taureau carry plates not quite 6in. thick on wooden hulls. The second-rates of the Alma class have 5 8-10in. armour at the water line, and 4 8-10in. and 4in. on other parts of the hull. Their best vessels are of the Marengo class. They have 5 8-10in. armour at the water line, and 6 1-5in. and 4in. on other parts. They carry their 14-ton guns in high towers lifted far above the sea, but not themselves movable. These towers are open at the top, and the gunners are exposed to shrapnel fire and to the effect of musketry from the rigging of an adversary. In strength of armour, in power of artillery fire, and in speed these frigates are much inferior to the Hercules. The Imperial Navy has further certain rams for coast defence only, carrying 8 2-10in. and 7in armour. We may grumble occasionally in England when some slight mischance tells us that our naval guns have not yet reached absolute perfection, but the French are very far behind us indeed. Their cast-iron breechloaders are weak and slow in firing. Secrets of this nature are usually well kept in France, but the effect of their secret system has only been to deceive their own junior officers, and postpone the day of final discovery. An English scientific artillerist knows without asking questions that the French naval guns must be, from their form and material, very much inferior to our own, nor can the facts of the case be always kept concealed. A well-informed writer in the Revue Moderne for December, 1868, shows that our 9in. 12-ton gun is better than all the artillery of France, and his conclusion is, — "It must then be confessed, whatever it may cost us, that in an engagement where the artillery would be called upon to play a decisive part, a French squadron would be almost powerless against an English squadron of similar force." Nothing more is necessary than to say that we entirely agree with the writer.
Still better information has lately crossed the Atlantic from America, in the shape of a Report from Mr. Robeson, Secretary of the United States' Navy. Not only has the Minister to regret a deterioration and a paucity of seamen, but his opinion regarding the state of the ironclad fleet is only equalled in its humility by that of a Select Committee of Congress upon American Ordnance. He states distinctly that, "in the event of a war our ships would be uselessly sacrificed, or obliged to find safety in neutral ports, or, abandoning the sea and leaving our commerce to its fate, to seek on our shores the protection of our Monitors and forts." He says that the Monitors are steam batteries, not sea-going cruisers. One or two successful experiments have been made showing the capacity of some Monitors for a sea voyage, "under favourable circumstances, but they could not be used with advantage as cruisers on foreign stations; they are valuable for auxiliary defence on our own shores, but should not be relied upon beyond them." He proposes to build ten ships impervious to the heaviest ordnance afloat, and carrying broadside batteries of heavy guns. But what guns?
The Report of a "Joint Committee on Ordnance," presented to the Senate of the United States in February, 1869, now lies before us.
It is entirely condemnatory both of the American system of large smooth bores, and of the material and manufacture of the guns. It has been our fortune to criticize the American system of ordnance on more than one occasion. The 15in. Rodman was shown to be a failure during the experiments against the Plymouth Breakwater target, but nothing that we have ever said has been so strong as the report from which we quote. When we read that "in the attack on Fort Fisher all the Parrott guns in the fleet burst, according to the report of Admiral Porter," and that "by the bursting of five of these guns at the first bombardment 45 persons were killed and wounded, while only 11 were killed or wounded by the projectiles from the enemy's guns during the attack," we cannot be surprised at the committee's recommendations that no more heavy guns should be purchased until the manufacturers have learnt how to make them, or at the chagrin with which they find themselves compelled to state that "the United States is in the position to-day of a nation having a vast coast line to defend, and a large navy, without a single rifled gun of large calibre, and a corps of ordnance officers who have thus far failed to discover a remedy for the failure of the guns, or to master the rudiments of the science m which they have been trained at the public expense." And that there may be no mistake as to their preference for rifled guns rather than for smooth bores, they remark a little further on: — "To return to smooth bores, throwing huge spherical masses of iron with low velocities, is to disregard all modern progress in the science of gunnery, and to go back to the arms in use two centuries ago."
Mr. Reed has given his readers an excellent opportunity for comparing the defensive powers of English and American ironclads by placing side by side drawings of them, which are so simple and suggestive as to need hardly any explanation. We are inclined to be cautious in accepting the rule of resistance varying as the squares of the thicknesses for all sizes of iron plates. It is probable that the 10in. and 12in. plates, now manufactured in large quantities, hardly come up to the strength arrived at by calculation according to the empirical rule; but, on the other hand, the action of large shells on laminated structures may be more destructive than is generally supposed. It is unfortunate that no experiments have been made to show the sort of effect produced by the new guns and projectiles upon American targets. A small amount of uncertainty upon these points still exists, but not enough to leave any doubt as to the enormous superiority of the belt round the Hercules, or the whole side of the Thunderer, over the strongest targets yet turned out of American dockyards — and the contrast is still more striking if we think of ships as not always set upon a "painted ocean," but as, more frequently than not, rolling lazily in a swelling and falling flood, and heaving up their glistening sides so as to expose some feet of the surface that is said to be under the water-line. The bottom of an ironclad, like the belly of a reptile, must always be weak to resist penetration, bat there is a vast difference between the depth to which the strong side armour is carried in different models. In the Kalamazoo class of Monitors — the strongest of all American ships — the lower edge of the lowest block of iron backing is but 18in. below the water, and at 2ft. 9in. below the water the plating is but 3in. thick. The case of the Dictator is still worse. A roll of only 2½ft. will expose a long strip protected by only two 1in. plates, and if she but lean over another six inches there is nothing stronger than 1in. iron between her interior at a vital part and the rushing attack of the projectile. The English ships, on the contrary, are strongly plated down to about 6ft. below the water line. The speed of the American Monitors is very small. Altogether, it is clear that the type of ships now being built in England to carry the heaviest guns in turrets are superior, and that to a vital extent, to the best and latest American Monitors in strength and speed, and so far superior in armament that comparison would be ridiculous. Let us not, however, rest content with what has been done. The Monitors first produced were eminently creditable to their authors, and the Americans are not a people to sit down contented with such a state of things when once they have discovered their position. We shall be much surprised if the broadside ships which they are about to build will not be stronger than anything now upon the ocean. They have all our experience to begin upon, and it must be the business of our naval designers to take care that the British fleet may never meet at sea a single ship so powerful as to be practically impregnable.
We have shown that the actual expenditure upon ironclads during the past ten years has been at the rate of 1,000,000l. per annum. We will now examine the cost of later vessels in comparison with those of the first models. It is well known that the great innovation of Mr. Reed was to reduce the length of the ships, and yet give them the same speed and buoyancy by improvements in their shape and structural design. A fine and narrow bow and stern hanging over the water cannot support their own weight. Mr. Reed has substituted what is called the U bow for that of the V form, thereby gaining buoyancy without loss of speed. The introduction of rifled guns of great power enabled him to concentrate the battery, even without using turrets, though in the later ships we find protected guns on deck both in the bow and stern. Step by step — adopting one scientific discovery after another — he has succeeded in lightening most materially the hulls of his vessels, even while adding greatly to their strength, and without decreasing the weights carried, — nay, sometimes increasing them.
In his chapter on the "Structure of the Ironclads," the author explains how he has added strength to the hulls of his ships by building them with double bottoms and bracket frames. The Bellerophon and her successors do not depend for their safety on one thin shell of iron or wood between the hungry sea and the life of the ship, with her precious burden of men and guns. For the thin and fragile iron belly skin of the Warrior has been substituted in Mr. Reed's ships a double cellular structure, light and strong as the Menai bridge. Even the Warrior has such an arrangement of iron under her heavy engines and boilers, but the new floating guardians of England have no place in their bodies so weak or faulty in construction but that they might be torn by sharp rocks or wounded by a glancing missile, and yet float securely and fight on. The Great Eastern actually experienced the value of the cellular construction, for she once struck on a rock, tore away enough of her outer skin to let death through, but was saved by the inner skin, and the damage was so localized by the cellular tissue that she continued her voyage without difficulty or danger. We should expect this elaborate structure to involve heavy and expensive hulls, and so it would, only that much thought and labour has enabled Mr. Reed to save unnecessary weight in other parts of the ship and distribute the metal to such good purpose that the proportion borne by the weight of the hull or carrying part of the vessel to that of the weights carried is continually diminishing as ship after ship is designed.
In the ironclad wooden ships the weight of the hull and the weights carried by it were about equal. In the first iron ships clad in armour the weight of the hull generally exceeded the weights carried, and that to a very considerable extent. In the Black Prince this excess was about 700 tons, in the Defence about 1,000 tons, in the Achilles more than 500 tons. In the Minotaur we find the first steps made towards improvement. Her hull carries weights exceeding its own by 190 tons. The Bellerophon — first of the "bracket frame" or cellular-built ships, with strong framing and plating and double skin, was yet capable of carrying 150 tons more than the weight of her hull, though she is a much smaller ship than the Minotaur. As we pass on to the later models we find the Sultan — a broadside ship — with a hull weighing 1,082 tons less than that of the Minotaur, yet carrying a weight of armour, artillery, men, rigging, and stores nearly 900 tons greater than that of her own hull. The Monarch's hull weighs still less, yet she carries an excess of more than 950 tons. The progress has been considerable, for the Monarch, with a hull of nearly the same weight as the Bellerophon's, carries 834 tons more than the Bellerophon carries. It is evident that there are here the elements of a vast economy. If the displacement of two ships be the same and several hundreds of tons are saved in the hull of one of them, the armour, armament, and equipment, or all three together, may be increased, and the ship become much more powerful than her rival; and on the other hand, if the armament, &c., is to remain the same, the weight, and therefore cost, of the hull will be much less in the newer model.
Let us see how this affects the cost of Mr. Reed's ships. Take the cases of the Black Prince and Bellerophon. The Black Prince has a hull weighing about 5,200 tons, and carries less than 1,000 tons of armour. The hull of the Bellerophon weighs less than 3,900 tons, but she carries nearly 1,100 tons of armour. Had no improvements been made in the Bellerophon, and the proportion between hull and armour remained as it is in the Black Prince, the Bellerophon's hull must have been about 1,970 tons or 50 per cent. heavier than it is. We will take the extra cost at the rate of 45l. per ton, a very moderate estimate, and we have the startling economy of more than 88,500l. We are not here concerned with questions of Royal Dockyards or Admiralty management, only with Mr. Reed's designs and his improvements, the proportions and structural arrangements of ships.
From similar calculations we find that, taking groups of ships together and comparing them, the Warrior, Black Prince, and Achilles carry 3,150 tons of armour on hulls weighing 15,800 tons, while the Hercules, Sultan, Penelope, and Monarch carry altogether nearly 4,900 tons of armour on hulls weighing about 14,600 tons — to say nothing of the extraordinary increase of artillery power in the latter ships. Calculating as before, the saving will be about 442,800l., or about 65 per cent. on the cost of the hulls. The four ships of the Invincible class carry about 3,700 tons of armour on hulls weighing a little more than 11,300 tons, while four older ships of about the same size — the Defence, Resistance, Hector, and Valiant — carry only about 3,000 tons of armour on hulls of 14,900 tons. The eonomy here is about 60 per cent. in weight of hulls, and the money saving more than 306,000l. If we were to take the last models — the Thunderer, &c. — and compare them with the strongest and finest of the old ironclads, the difference would be even greater and the saving something really enormous. Indeed, it would at first sight appear almost incredible, yet not more so than the possibility of building and arming the Thunderer, the Glatton, the Devastation, the Hotspur, and the Rupert would have appeared to the engineers and naval architects of but eight years ago. We refer our readers to a little book published in 1867, called European Armaments in 1867 (London: Chapman and Hall) for a sketch of the opinions held by the distinguished members of the Institute of Civil Engineers in 1862. At that time it appeared to be doubtful whether iron plate as thick as six inches could be made or carried by ships, and the idea of making armour to resist a 600lb. shot seemed absurd. In 1867 the Hercules was not launched, and in 1870 we are building ships to carry armour 14in. thick on the turrets, 12in. on the sides. In 1862, Admiral Halstead supposed that the 68-pounder smoothbore of less than five tons would be the gun of the future. In 1870 we are designing ships to carry 30-ton rifled guns. If the size of the vessels had increased in proportion to their armament and armour, who can say into what extravagancies the country might have been carried?
We find in the book just quoted a list of British and French ironclads, giving the most important details concerning them, and it seems worthwhile to complete the list to the present day for the benefit of those who may chance to possess copies. The backing of the Penelope as actually built is 10in. and 11in.; her speed attained is 12·76 knots. The Hercules should have been called partially armoured, and she has attained a speed of 14·7 knots. The Monarch also exceeded her estimated speed and arrived at 14·93 knots. She carries four 25-ton guns and three of 6½-tons. The following list includes all the new ironclads built or in process of building:—
"IRON-BUILT FRIGATES.“Sultan. — Same as Hercules, except in having an additional armoured battery on the upper deck, commanding all round fire.
“Audacious. — Partially armoured with deep belt. Two batteries amidships, one above the other, the upper commanding all round fire; 8-in. to 6-in. plates; 10-in. backing; 1¼-in. skin. Speed, 13½ knots (estimated). Bottom sheathed with zinc. Armament, ten 12-ton guns and four 64-pounders.
“Invincible, Iron Duke, and Vanguard. — Same as Audacious, but no sheathing on bottom.
"Swiftsure and Triumph. — Same as Audacious, but with wood sheathing and copper on bottom.
“IRON-BUILT TURRET-SHIPS."Glatton. — Low sided, with an armoured breastwork above for protecting the base of turret, engines, boilers, &c. One turret only. Upper-deck armoured; 14, 12, and 10-in. armour on turret and sides — 3-in. to 1½-in. on deck; 20-in. to 15-in. backing; 2-in. to 1¼-in. skin. Ram bow. Has a flying deck high out of the water for stowing boats, and for resort in rough weather. Speed, 9¾ knots (estimated). Armament, two 25-ton guns in one turret.
"Devastation. — Low sided, with an armoured breastwork above, as in Glatton. Forecastle forward, the guns firing over. Two turrets. Upper deck armoured. Can go to sea and carries sufficient coal, provisions, and stores for a voyage to the Mediterranean and back, or to America. Fourteen, 12, and 10-in, plates on turrets and sides; 3-in. to 1¾-in. plates on deck; 18-in. to 16-in. backing; 1½-in. skin. Flying deck like the Glatton. Ram bow, Port sill 13½ft, above the water, Speed, 12½ knots (estimated). Armament, four 35-ton guns in turrets.
"Thunderer, same as Devastation.
"IRON-BUILT ARMOUR-PLATED RAMS."Hotspur. — Bullt specially for ramming, and very strongly constructed. The bow is armour-plated for a considerable distance under water to prevent its being injured in striking. Has a fixed battery and breastwork amidships, the latter protecting the engines, boilers, wheel, &c. The side is protected by a belt, at the top of which is an armoured deck. The breastwork and upper deck extend above this; 11-in. and 8-in. plates on sides, breastwork, and battery; 3-in. to 2-in. plates on deck; 15-in. to 12-in. backing; 1¼-in, skin, Port sill 10ft. above the water. Carries a light rig, and is intended to accompany a fleet, Speed, 12 knots (estimated). Armament, one 25-ton gun in fixed battery, and one 64-pounder.
"Rupert. — Same in principle as Hotspur, except in having a movable turret instead of a fixed battery, and the addition of a flying deck high out of the water. The armour of the turret is 14in. and 12in.; that on the breastwork and sides 12in., 11in., and 9in. Armament — two 18-ton guns in turret, and one 64-pounder."
We regret that we cannot follow Mr. Reed through his interesting essays on the various disputed points regarding the sailing, steaming, and rolling of the ironclads, the conversion of wooden ships, and the qualities of turret-ships and rams. His book is written in a simple and interesting style. We can commend it heartily to all those who desire to study for themselves what has been done by England of late years to retain her supremacy on the seas.
*Our Ironclad Ships; their qualities, performance, and cost, with chapters on Turret-ships, Ironclad Rams, %amp;c. By E.J. Reed, C.B., Chief Constructor of the Navy. London, John Murray, Albemarle-street, 1869.