Engineering Wonders of the World
Volume I

416 ENGINEERING WONDERS OF THE WORLD. the destructive power of the 3-pounder Q., 6-pounder Q., 12-pounder Q., and even the 4-inch weapon, as much overrated; and the result of this discovery is seen in the influ- ence it has had upon the recently-launched warships of Germany, tho United States, and Japan. In the war between Russia and Japan the generally prevalent idea that a couple of 12-pounder shells would disable a destroyer or first-class torpedo boat, wherever burst, was disproved on many occasions. The most numerous engagements during the whole naval campaign were between the torpedo craft of the opposing nations, and the number of hits these small vessels could sustain without serious damage has been the subject of much wonderment ever since. Accepting this, the advent of such vessels as the Tribal and Swift classes will necessitate a return to secondary batteries in warships before their prophesied abandonment has fully taken effect. The Dreadnought carried 12-pounder Q. only ; the later ships have a 4-inch gun. The American Michigans carry the 12-pounder Q.; the Delawares and Wyo- mings will, as already stated, mount a 5-inch weapon. So by all the Powers is the truth being realized, and the 6-inch Q., or even larger gun, will return, not, however, as supporting the large guns of the main arma- ment, but purely for defence against torpedo- carrying craft. Before closing this article, an instructive word may perhaps be said as to the “ dis- position ” of guns. So many people think that the number of guns The . carried by a warship is con- Disposition troHed either by the length, Armament. an(^’ therefore, “ room of side ” displayed, or by the carrying capacity of the ship herself. Actually, the placing of the armament involves problems of the utmost intricacy. Thus there is first the mere length of the weapons to consider. Take a 12-inch 50 calibre gun. It is about 52 feet from muzzle to breech, and. from the breech to the barbette shield there is a clearance of another 6 feet. Thus each pair of 12-inch guns of the latest type requires a “ swinging ” space of, at the least, 62 feet, allowing a 3-foot passage behind the bar- bette shield and a foot clearance between the muzzle and the superstructure it faces as it swings round. The next prob- lem is that of “ blast ”—the vast disturbance of the air around the muzzle created by the discharge of a shot. So intense is this that many a time decks have been severely rup- tured. It is a fact both curious and not generally known that the blast does not cause a depression in the deck directly beneath the muzzle, but it tends rather to raise a “ bubble ” in it. Hence it is not support that the decks require, but holding down from below. The reason of this seeming anomaly is simply explained : • the gases composing the blast are at a super-terrific heat, and in their passage utilize all the combustible properties of the air, and form a momentary yet powerful vacuum directly above the deck. Where guns fire at all angles across decks, steel “ flash-plates ” are frequently sunk in t^e floor around a radius corresponding to the training arc of the guns. The last and governing difficulty, yet one which is dovetailed in with the first two, is the necessity for obtaining an all-round fire, and, at the same time, the ... r Difficult maximum concentration ot Problems. such, fire on the two broad- sides. Here constructors are at once faced by a hundred contending and hostile factors. Superstructure there must be, to support the boats, conning tower, fighting position, and masts, funnels, etc., though the natural ten- dency is to reduce all such “ top-hamper ” to the minimum dictated by necessity. Then the position of the magazines comes into conflict with the other considerations. The engines and boilers take up an immense