How Britannia Came to Rule the Waves Part 25

MODERN ENGINES OF WAR.

For many centuries after the invention of gunpowder, little change took place in the weapons used in naval warfare, the chief developments being in the way of better workmanship and material, and the production of guns of larger size.

About the end of the eighteenth century, however, the period from which so many of our modern improvements begin to date, inventors began to plan new and improved methods of disposing of the enemy. About the year 1770, the American Bushnell conceived the idea of what his fellow-countryman Fulton afterwards called the "torpedo." This weapon consisted of a case of powder which was to be attached to the bottom of the enemy's ship by the aid of a submarine boat, leaving it to explode later on by means of a clock inside.

The submarine boat was actually made in 1775; it was egg-shaped in form, and held one man. It was propelled through the water by means of a screw propeller, worked by manual power; a similar screw, arranged vertically, enabled the boat to rise or sink at will. With this boat, during the War of Independence, he, or some other operator, succeeded in getting under a British man-of-war lying at anchor near New York.

Without her crew having the slightest suspicion of his presence, he attempted to screw his torpedo to her bottom, but his auger encountered what appeared to be a bar of iron. When shifting to another position he lost the ship altogether, and being unable to find her again was forced to cast off the torpedo and make away, as the clock-work inside had been arranged to explode soon afterwards. And about an hour later the crew of the warship were first roused to their danger by the explosion of the torpedo at no great distance from them, and they were the more alarmed as they were wholly unable to account for it.

In the beginning of the nineteenth century another American, named Fulton, having borrowed Bushnell's ideas, came over to Europe and endeavoured to get the French government to take up his plans for submarine warfare. After long delay he was at length given the sum of 10,000 francs, with which he successfully constructed a submarine boat.

In this boat he remained under water for more than four hours, and having been required to blow up a small vessel had no difficulty in getting under her and in blowing her to pieces with his torpedo. The torpedo in a highly developed form is now one of the most important weapons in naval tactics.

In spite of the success of Fulton's experiments, his plans were not adopted, either by Napoleon or by the British Admiralty, to whom Fulton afterwards offered them. The great European wars having been brought to an end by the downfall of Napoleon, the torpedo for a while sunk into oblivion, although during the Crimean war the Russians used submarine mines to protect their harbours. But during the American Civil War the torpedo was again brought to the front, and the Southerners, or "Confederates," used vast numbers of them, to the great damage of the Northerners, or "Federals."

At first these torpedoes proved so harmless--so few exploding out of the hundreds laid--that the Federal officers paid little attention to them.

But as the war went on, better methods of exploding them were devised, and vessel after vessel was sunk in a few minutes, often with great loss of life. Some of these were sunk by submarine mines fired by electricity, others by floating torpedoes drifted down by the current or tide; others again by torpedoes at the end of a long spar carried in a small launch. In one instance, a submarine boat was employed, propelled by a screw worked by eight men. Instead of running just beneath the surface, however, her crew insisted on keeping the hatchway just above water, and open, with the result that the wave caused by the explosion of her torpedo rushed in and swamped her, so that she went to the bottom with all on board.

Another night a large frigate was blockading Charleston harbour when a _David_--as these torpedo boats were then called--was seen approaching.

The frigate, which carried a crew of 700 men, slipped her cable and made off at full speed, although she was only being attacked by a small launch, manned by four men, armed with a few pounds of powder extended on a spar in front of her! In spite of a fierce fusillade aimed at her, not a shot struck the _David_, which returned in safety to Charleston.

The Russo-Turkish War afforded several additional examples of the same kind, which, as already mentioned, had not a little to do with the alteration in naval design and tactics that took place during the last two decades of the nineteenth century.

Torpedoes were of three kinds: the first were really submarine mines, and were placed in a river channel, being fired by electricity when the vessel came over them. The second kind was the floating or Harvey's torpedo, consisting of a long narrow, but deep wooden case from 44 to 60 inches in length, which contained 30 to 80 pounds of gunpowder, inside a copper lining. It had two levers projecting on the outside, which, on striking an object, set off the explosive inside. This torpedo was used in two ways: the first by setting it adrift on a river, or where there was a well-marked current setting towards the enemy's ships, when the current carried it to its destination; the other way was by towing it at night, by means of a long line, across the bows of an enemy's ship; it exploded whenever it came in contact with the ship.

The third kind of torpedo was practically a Harvey's torpedo attached to a long boom, or pole, about 28 feet long. This was carried at the gunwale of a fast steam launch at night; on nearing the enemy's ship this boom was pushed forward so as to bring the torpedo ten feet below the surface and well in advance of the boat. The torpedo exploded when it struck the ship, and to prevent the torpedo-boat from being sunk by the huge wave raised by the explosion, it had to be covered in front by a shield.

The experiences of the two wars already mentioned showed the difficulty of dealing with torpedo boats at night, and "search lights" are now installed on all modern warships. These consist of an electric arc lamp of 25,000 candle-power, combined with a reflector, which concentrates the light so that it brilliantly lights up objects at a great distance.

Torpedo boats can be readily discovered when a mile or more distant and, at the same distance from the light, the rays are so powerful that a newspaper can be read with the greatest ease.

Torpedo attack, however, has been revolutionised by the invention of "Whitehead's torpedo," which can be used from a distance. In shape it is exactly like a huge cigar, 12 to 18 inches in diameter, and 6 to 10 feet long. At the head is the explosive; behind this is a reservoir containing air compressed to an enormous pressure, which drives engines contained in a third compartment, and which in their turn work a screw propeller at the back of the torpedo. There is also mechanism which automatically adjusts the depth at which the torpedo travels below the water, and other mechanism which ensures that it will keep going in the direction in which it was fired. Such a torpedo is now effective up to two miles, and it will traverse this distance in about six minutes.

Torpedoes are discharged from what are called "torpedo tubes" by means of compressed air. These tubes are to all intents and purposes, guns made of thin steel, the torpedo being put in at the breech. Those used on board torpedo boats or similar light fast craft are mounted on a swivel on the deck; in larger vessels they are usually placed below the waterline so as to be free from the serious consequences that would ensue if the tube were struck by the enemy's shot, while a torpedo was in it. Torpedoes have also been invented which are steered by electricity.

The problem of protecting ships against torpedoes is a difficult one, and no satisfactory solution has yet been arrived at. All large warships, however, are provided with "torpedo nets" of thick iron wire, which are hung round her at the end of long poles, which, when not in use, are tied up alongside. But mechanism has been invented by which the torpedo will cut through the netting, if it encounters it, so that at present the torpedo is master of the situation, within its range. In fairly shallow water a torpedo will throw a column of water nearly 200 feet into the air, by the impulse of the gases generated by the explosion, and no ship yet built would be able to withstand its enormous shock.

Reference has already been made to the huge guns of the _Inflexible_, and to the improvements in both powder and guns made later on. The modern gun is what is called a "wire gun," from its method of construction. Round a central tube of steel, several layers of immensely strong steel wire is tightly wound; a second steel tube is then slipped on above the wire, and as this tube is hot when first put on, when it cools it contracts and binds the layers of wire tightly together, forming a gun of very great strength--as, indeed, it would need to be, seeing that it has to withstand a pressure of over 16 tons to the square inch.

The projectiles fired from naval guns are of three kinds, solid shot for piercing the thickest armour,--as on the conning-tower, or barbettes; "armour piercing sh.e.l.l," with very thick walls and small bursting charge, which can only penetrate armour, two-thirds of that piercible by solid shot; lastly, "common sh.e.l.l," in which the sh.e.l.l walls are much thinner, and can thus only be used with effect against the lighter structures of the enemy. By placing a small "cap" of iron on the points of ordinary shot, "capped shot" are produced; and thus provided, they will pierce a much greater thickness of hard-faced armour than the ordinary ones. Against soft armour, however, they are not so efficient.

The armour of modern ships has also been greatly improved in resisting power. The _Inflexible_ of 1881 was protected by wrought-iron plates 24 inches thick, which weighed 2,400 tons, or a fifth of her total weight, yet only a third of her length was protected. Soon after her completion, "compound" armour plates,--with a hard steel face on a backing of wrought-iron--were introduced, which enabled a third of the weight of the armour to be saved, yet leaving the amount of penetrability unchanged. Later on, "Harvey" armour, made of steel alloyed with nickel, still further reduced the weight, and recent improvements now make the best armour equal in resisting power to three times its thickness of wrought-iron. It may be mentioned also that the coal bunkers are now arranged so as to further protect the engines, being reckoned equivalent to about three inches of wrought-iron.

Facing page 464 are two "sections" of warships, which will, no doubt, interest the reader. The first is of an old steam battleship, such as the _Marlborough_, the other, that of a modern second-cla.s.s cruiser, like the _Minerva_, which could blow the _Marlborough_ to pieces before the latter could get her within the range of her guns. Notice the enormous difference in the s.p.a.ce devoted to the engines and boilers.

The modern vessel gives a general idea of the arrangement in all cla.s.ses of modern warships. The conning-tower will be seen below the bridge, in front of the foremast. The magazines are at the bottom, right below the forward and aft guns, which in this type of vessel, are protected by a shield only, with armoured ammunition hoists going down from it; the barbettes of the more powerful vessels would simply be iron breast-works, extending all round these guns. The curved protective deck is also seen, about the waterline, and the projecting ram, while at the stern is the curiously shaped rudder, made in this form, because it takes less power to work, than that of the ordinary type.

CHAPTER TWENTY TWO.

THE BRITISH NAVY OF TO-DAY.

In giving a brief outline of the general features of the battleships and cruisers composing the present British navy, it must be remembered that the navy is made up of ships built during a period of fifteen or twenty years; the newest being a great advance upon the older ones, yet differing but little from those launched a few years before.

The indications at present are for fast ships of very large size, the battleships--intended to act in squadrons--possessing the maximum of offensive and defensive power; the cruisers--intended for scouting and similar purposes--possessing a high rate of speed, heavy armament, and a certain amount of protection; and, as the travelling speed of a fleet is limited to that of the slowest vessel in the group, the aim of British naval architects is to design all the battleships to go at approximately the same speed, and similarly for the cruisers. A special feature of all British warships is the large coal supply carried, in view of the fact that they may be required to operate in any part of the world. For this reason the armour in our ships is sometimes not so thick as in some foreign ships, which sacrifice coal supply and radius of action to obtain better protection. In other respects our ships are second to none.

The British battleship of to-day varies from 12,000 up to 15,000 tons in displacement, and has a maximum speed of fully 18 knots, or about twenty-one miles an hour. They are armoured from end to end, and are provided with two protective decks; the lower one, about the level of the water-line, being to protect the "vitals"; the upper one, to prevent the fragments of sh.e.l.ls from above penetrating to the batteries below.

Forward and aft are the two barbettes, each carrying a pair of long 12-inch 50-ton guns, firing 850-pound shot, capable of penetrating 28 inches of wrought iron at a range of two miles. The secondary armament of 6-inch or 7.5-inch guns is mounted in "casemates," or armoured chambers, so disposed that two of them can also fire straight ahead, and the other two straight astern. The most recent ships have these ahead or astern guns mounted in turrets, and in the largest ships of all, some of which are of 18,000 tons, these guns are 9.2-inch 380-pounders.

After the battleships come the cruisers, corresponding to the frigates of olden days,--ships whose functions correspond to that of the cavalry of land forces, having to act as scouts, carry messages, intercept the enemy's ships, and capture his mercantile ships, or protect their own merchant convoys. To perform these varied functions, one of the chief requirements is speed, rather than heavy armament, so that it can run, if need be, if it should happen to encounter a ship of greater power.

Accordingly the best cruisers are given the high maximum speed of 23 to 25 knots.

Cruisers are divided into two cla.s.ses: armoured and unarmoured. The former are really modified battleships, with thin armour and somewhat lighter armament, to enable the necessary engine power and coal supply to be provided. Armoured cruisers of this description could, at a pinch, take part in fleet actions--even against ironclads, as shown at the battle of the Yalu, between the Chinese and j.a.panese, when the latter, with protected cruisers and one or two armoured cruisers, defeated a fleet in which there were several ironclads much larger and better protected than themselves.

The most recent armoured cruisers are ships of 13,000 to 14,000 tons displacement, and are protected by a belt of 6-inch armour, in addition to protective decks. They are armed with two or four 9.2-inch 380-pounder guns, mounted in barbettes of thick armour, and with a number of 6-inch 100-pounders; a number of 12-pounders and 3-pounders are also carried. Some ships of this description can spurt up to 25 knots--not so long ago considered a high speed even for a torpedo boat destroyer.

The unarmoured cruisers are intended chiefly for scouting purposes, or for capturing or protecting commerce. As they are only intended to fight with ships similar to themselves, which may attempt to make havoc among our merchantmen, their only protection is a protective deck which covers the vitals. The first-cla.s.s unarmoured cruisers have an armament and speed similar to those of the armoured type, and may have cas.e.m.e.nts for their broadside guns, and barbettes for the heavy ones; the second-cla.s.s cruisers are armed with 6-inch and 4.7-inch guns, protected by simple shields only, and they have a speed of from 19 to 20 knots.

In a previous chapter, the torpedo boats used in the American Civil War were mentioned as being simply fast launches, and little progress was made in their construction, until the Russo-Turkish war taught that their value was much greater than had been supposed. From that time onwards, larger and faster boats began to be built, and even a certain amount of protection began to be given them, consisting of 1-inch iron plates round the boilers and engines, which was proof against small-arms, and even against the heavier Nordenfelt machine guns, except at the closest quarters. Boats of this type were from 130 to 170 feet long, and went at a speed of 22 knots. As speeds increased, there was less risk for the torpedo boat, and greater risk for her enemy, and it became plain, that some means of averting torpedo boat attack must be devised, else it would be absolutely impossible for a fleet to blockade an enemy's coast without grave risk to itself. Torpedo boats were essentially for coast defence, as they could only venture out in calm weather. It was therefore seen that a new type of boat was required, capable of keeping the sea in all weathers. Accordingly, the "torpedo boat destroyer" was designed with this object, and which, possessing superior speed, and an armament sufficiently powerful, could run down and destroy existing torpedo boats, would safeguard the fleet, and enable it to keep comparatively near the blockaded coast. These boats were also furnished with a torpedo equipment, so that they could be used as torpedo boats in connection with a fleet.

In these "destroyers," as they are called for short, everything must be sacrificed to save weight; the hull must be a mere sh.e.l.l, and the engines and boilers reduced to the very minimum of weight that can be expected to stand the strain of the power developed. When we know that the sides of a destroyer are only 0.3-inch thick, and that her engines and boilers only weigh 50 pounds for each horse-power they give out, while those of a mail steamer weigh 280 pounds, and those of a cargo steamer 440 pounds, per horse-power developed, we can hardly wonder that these boats have frequent breakdowns.

Present day destroyers are boats of 200 to 300 tons displacement, and are about 227 feet long. They attain a maximum speed of about 33 knots, or 37 miles an hour, which is produced by engines of 6,000 to 8,000 horse-power. They carry two swivel torpedo tubes on deck, and an armament of one 12-pounder gun and six 3-pounders. They are also fitted with search lights. To prevent the sea from breaking over the bows, it is raised somewhat higher than the rest of the deck, and is curved at the sides, so that waves breaking over it are diverted to the side, instead of sweeping aft over the deck. The bridge is placed at the rear of this hood, and carries the 12-pounder gun. These boats carry 80 tons of coal, and have a crew of 60 men. The accomodation for the crew, however, is very cramped, and those who work them have to put up with a good deal of discomfort.

Like the torpedo boats, destroyers are low in the water; with their short dumpy funnels, short mast, and inky hue, they have a peculiarly "wicked" appearance.

A new departure in these boats has been made by the introduction of "turbine" engines, which are much lighter and take up less room than engines of the ordinary type. These engines go at such a high rate of speed that four screw-propellers have to be provided to transmit the power efficiently. Turbine destroyers have attained a speed of 35 and a half knots, or nearly 41 miles per hour. One more type of vessel remains to be mentioned, which is receiving a good deal of attention at present. These are the "submarines," or boats designed to navigate under water. Their use, however, is largely discounted by the fact that it is impossible to see to any distance under water--in fact, a well-known submarine expert has said that the navigation of a submarine, even under the best conditions, presents exactly the same difficulties as that of an ordinary ship sailing in a fog. Hence a submarine must frequently rise to the surface to ascertain the distance traversed, and see that the proper course has been kept, and until some satisfactory means of avoiding this has been discovered, submarines will probably remain of comparatively little value for purposes of war.

The submarines made for the Navy are, 63 feet long, by 11 and 3 quarters feet broad. When running "awash"--that is, with a small part of their upper works above water, they are driven by a gasoline engine at a speed of over 10 miles an hour. Sufficient gasoline is carried to take them over 400 miles at this speed. When submerged, the speed is naturally glower; the gasoline engines are stopped, all openings are closed, and electric storage batteries are put in operation. These drive the boat at the rate of eight miles an hour, but for a run of four hours only, after which the batteries require recharging. For this reason submarines always require to act in concert with what has been called a "mother ship."

The most important types of vessels composing the British Navy have now been described. There are many others--sloops, gunboats, transports, despatch-boats, coal ships, hospital-ships, etcetera, which need not be more than mentioned. What warships will be like in the future it is impossible to forecast, as will be seen from what has been already said.

Improvements in armour and guns, as well in machinery, are ever being made, which may alter the present type of ship altogether. Sad it is to think of the enormous expenditure of money and ingenuity in providing means of destroying our fellow-men with the greatest facility, and what a relief it would be to everybody if only the nations could agree to disarm--and keep disarmed! But as this may not be, for the present at any rate, we must be content to bear the burden of our national insurance policy, and, however much we may grudge its necessity, see that our naval power is sufficient to keep the command of the sea, on which our very existence as a nation depends. Of one thing we may rest certain, that the same spirit, the same indomitable courage and readiness to sacrifice their lives in defence of their country, exists among our officers and men in not less proportion than it did before England was engaged in that glorious struggle, with the world in arms against her, for her liberties and independence, the successful termination of which secured for her that peace which has now endured, with few interruptions, for well-nigh a century. That peace it will be our wise policy to maintain while we can do so with honour; at the same time guarding ourselves by every means in our power against the a.s.saults of envious foes who may venture to attack us.