The Outside of the Conning Tower.—From out of the center of the deck rises the conning tower. This is a heavily armored, shell-proof, circular structure, from which the captain makes his observations and sends his orders down into the engine-room and controlling compartments. On the bridge or upper deck of the conning tower is a hatch by which the crew can get into and out of the boat.
A steering wheel and compass are fixed to the outside of the conning tower, and the submarine can be steered by these when it is running on the surface. A stanchion for carrying the signal lights is also secured to the conning tower; while the periscope, or eye of the submarine, passes through the bridge and to one side of the hatch. Of this wonderful instrument we shall have much to say a little further on.
Wires, or stays, as they are called, fore and aft are used to brace and hold the periscope and signal stanchion firm against the force of the water which presses on them when the craft is submerged and under way. The tops of the signal stanchion and the periscope are also braced by a signal halyard, which is simply a wire, or cable, stretched taut between them.
On all modern submarines a wireless aerial is attached to a mast which can be folded down flat on the deck when the submarine is getting ready to make a dive.
A Look Inside of the Hull.—Now let’s take a look inside of the submarine. The whole hull is divided up into a number of watertight compartments, any one of which can be shut off from the others and so lessen the danger of sinking by ramming or by shell-fire, should the boat be afloat. In these compartments are placed all the machinery and the controls for operating the submarine.
These various compartments are: (1) the conning tower; (2) the navigating compartment; (3) the engine and dynamo room; (4) the fore and aft storage battery rooms; (5) the fuel tanks; (6) the diving control compartment; (7) the fore and aft ballast tanks; (8) the water pumps; (9) the fore and aft high pressure air flasks; (10) the high pressure air compressor; (11) the torpedo compartment; (12) the mine compartment; (13) the trimming tanks; (14) the quarters of the crew; and (15) the quarters of the officers. All of these are clearly shown in [Fig. 25].
The watertight doors of these compartments are worked by worm gears, driven by electric motors, as shown in [Fig. 25], and any of the doors can be opened or shut by merely throwing a switch.
A Peep into the Conning Tower.—The free space inside of the conning tower is not more than 8 feet in height and 10 feet in diameter.
Sticking down through the deck for about 2½ feet is the periscope, or two of them, for all submarines now built are fitted with a pair of them so that should one of them be hit and put out of business the other will be available.
