THE BATTLESHIPS

Evening Post, Volume CXXIV, Issue 108, 3 November 1937, Page 10

THE BATTLESHIPS

WHERE THEY DIFFER

METHODS OF CONSTRUCTION

TURRETS AND MASTS

Don't you often wonder what all that junk on a battleship is for, and why it seems to be different on almost every warship—and" why some ships have vertical bows and some leaning bows —and some have masts that look like tall baskets and some scarcely any masts at all? asks a writer in the "Chicago Tribune."

Well, here is your answer—at least an answer to some of the more common questions about how and why fighting ships are put together so.

First take the actual hull of the ship, which is made of steel plates. Iri the case of a modern battleship, which is virtually unsinkable, the plates are about a foot thick along the sides of the vessel from just above the waterline downwards, but tapering to only an inch or two of thickness at the bow and stern (which are not vital points), and at the keel, which is in a wellprotected position. The thick sections of plate are strong enough to withstand torpedoes and shells exploding against them almost indefinitely and are further protected by a "blister," or outer compartment, consisting of an inch-thick wall of steel constructed outside the hull in such a way as to leave an empty space three feet thick between it and the main armour. Torpedoes exploding against the "blister" leave the real hull untouched and do little damage other than tearing a hole in the easily-re-paired "blister." Likewise a torpedo, mine, or shell exploding against the relatively thin plates near the bow and stem could produce only minor damage, for strong partitions . and water-tight doors strategically placed throughout the vessel make it a simple matter to. isolate any portion of the ship which may have sprung a large leak. THE DIFFERENT BOWS. As for the shapes of warships' bows, several kinds have been tried out with a view to increasing the speed and efficiency of the ships. The later types have been developed after exhaustive experiments in a testing tank, using ship models a few feet long and. carefully checking the effect of different shapes of bow and hull not only in calm water but in every type of wave formation found in the real ocean. The so-called clipper bow is the style now being generally adopted by the navy. The portion above water leans forward wedge-shaped, and the portion below water also extends' forward in "a rounded spheroidal shape, giving the whole somewhat the effect of a plough. The submerged spheroidal part has the virtue of being streamlined to the maximum degree, while the upper part has the virtue of diverting the spray in a heavy sea from descending in full force upon the deck. The old "rammer" type of bow, with its nearly vertical upper portion, allowed the seas to rain so heavily upon the deck that the seamen were often hampered in their work. Coming to the subject of masts, the oldest type of battleship mast still in use in the United States Navy is the cage mast, which .presents a sort, of wickerwork or basketlike appearance. This originated in the old days when ships fired solid shot, for it would withstand this kind of projectile remarkably well. In 1927, however, the tripod mast was introduced as having greater resistance to explosive shell fire. • • , SEPARATE SUPPORTS. In this type, i n/ .which the lookout and fire Control stations are supported by. three stout supports, any two of the upright supports may be shot away and the remaining one will continue toliold up everything' unassisted. Recently the idea of having no mast at all hi.s come into favour, with the result that the latest warships have a built-up bridge and fire control station, a. structure known as a conningtower, though they generally have a light mast aft merely for the purpose of supporting radio antennae and signal flags. The conning-tower, of course, does not extend as high as a mast, but height is becoming less important in these days of aeroplanes, for now the aeroplane is the lookout station for all large ships of war, and air observation of gunfire effect on the target is so superior that there is no need of building masts for the purpose. Warships still check on, each other's firing, as formerly, and that is the purpose of the large dial that looks like a clock and is placed in a high and prominent position, facing both fore and aft, on all battleships. The dial has ten numbers, each representing a thousand yards in range when pointed at by the short hand and 100 yards when pointed at by the long hand. Thus each ship can easily signal to ships ahead of it and behind it that it is l firing at a range of, say, 8300 yards, by turning the short hand to 8 and the long to 3. As to guns,, battleships have their larger ones arranged in turrets, generally two main turrets fore and two aft, one set, above and behind the other. In former years three big guns were usually placed side by side in a single turret and designed to fire simultaneously, but recently the number has been reduced to two in the case of 16-inch guns, with the result that some ships have three-gun turrets, some two, and some mixed combinations due to the guns being of different calibres. MORE ACCURATE FIRE. The reason for reducing the number of guns per turret is that the guns are found to fire more accurately if placed farther apart than is possible with three 16-inch guns in a turret. Two or more projectiles travelling through the air on parallel courses only a few feet apart affect each other considerably, the more so as the distance between them is decreased. When one gets a little ahead, its wake, being a partial vacuum, enables another to speed up until it passes it, whence the process is reversed, causing a seesawing motion as first one and then the other gets ahead. But this generally results in deflecting both shells from their proper course somewhat, and is avoided by removing the middlegun from the old three-gun turret.

Smaller guns on warships are used in firing at shorter range, and there are numerous anti-aircraft and machine-guns placed about the upper decks for defensive fire against attacking aircraft. The function of the seaplanes seen upon the decks, and which can be catapulted into the air on short notice, to be picked up from the sea later by special cranes, is too obvious for further mention.

The top cruising speed of most of the battleships mentioned in this article is around 20 knots, but new superdreadnoughts now being built will be able to go nearly 30 knots, which is the speed of the aircraft carrier Lexington. Speed is extremely important to an aircraft carrier, because the take-off and landing speed of its planes is reduced by exactly as many miles an hour as thei ship is moving. At the take-off andj at the landing ship and planes both always move directly into the wind. J