Page:Popular Science Monthly Volume 90.djvu/562

 The Terror of the Sea

How submarines are driven and submerged; the difficulty of building them very big; the folly of the one-man submarine

��A SUBMARINE is a maze of machin- ery. Unlike any other ship she has two sets of driving engines — one oil and the other electric — and she is built with the nicest regard for weight.

First let us say something about the engines. They are the most important part of the boat.

At first gasoline engines, like those used on automobiles and motor-boats, were in- stalled in submarines. The Germans had them in some of the submarines that they used in the beginning of the war. We, too, used them. But as the gasoline engine was made bigger to meet the demand for in- creased power and speed it literally broke down. The Diesel engine must be used. It was invented by Rudolf Diesel, a German engineer, while he was still a student.

In the Diesel engine air is sucked into the cylinder and subjected to such pressure by the piston that it becomes intensely hot. Then a little oil is squirted in. At once the oil-vapor ignites and the mixture of oil- vapor and highly compressed air expands with explosive suddenness. The Diesel is the most efificient type of engine ever in- vented, utilizing as it does about thirty per cent of the energy in the fuel as con- trasted with only thirteen per cent in the best steam-engines. But it also uses air. In other words it breathes. When a sub- marine is under water the crew must keep alive by breathing what air they can obtain from tanks. They have enough for not more than thirty-six hours.

So, it becomes necessary to equip a sub- marine with electric motors, fed by storage batteries. As soon as a submarine dives, the breathing Diesel engine is cut out and the electric motor switched in.

Down in a Submarine

Like the policeman's in Gilbert's song, the life of a submarine sailorman is not a happy one. The quarters are necessarily so cramped that it is difficult to provide ordinary ship comforts. The officers have cots and the crew hammocks for sleeping. In our new boats ice-boxes are provided, so that fresh meat and vegetables can be

��served. In addition there is a dry food supply sufficient for five days. At sea the crew is put on a daily fresh water allowance. To bathe, the men must jump over the side.

Even when the boat is running on the surface the ventilation is poor. The pro- prietor of a New York sweatshop who did not provide his workmen with any more air than the men in a submarine breathe would be arrested. When the boat is sub- merged, the' nauseating oil odor, the battery fumes, the vitiated air exhaled from a score of lungs make one wonder why everyone is not sick. As a matter of fact seasickness, produced by these conditions, is common enough.

What is the scene within a submarine when an attack is made? A German officer of the U-26 gave this account of an attack on an unnamed British warship:

"The boat Is cleared for action. The flagpole is taken down. Part of the bridge Is folded up and lashed. The periscope Is elevated. The hatch through the combined bridge and conning tower Is tightly closed. The motors cease their endless song. From now on electricity will drive us until we rise to the surface again.

"A young lieutenant Is posted at the periscope and looks for the enemy. The sailors take thei*' position near the torpedoes. The Interior of the boat is lighted with two small electric bulbs. They do not clear the gloom. Everywhere is the smell of stale oil. It is impossible to speak with the din of the machinery and of the inrushing water.

"From time to time the officer In command of the torpedoes looks at his watch, which he wears on his wrist, or at his compass. Intently the men all watch a signal board in front of them on the side of the boat. . . . Suddenly we start and forget the heat, the foul air, the discomfort. In small luminous letters the word 'Attention' flashes up on the board. The commanding officer grasps the lever which will release the first torpedo. The men prepare to launch the second as soon as the first Is discharged. Half a second later and the red letters on the board say 'Fire!' The lever is jerked, and the torpedo leaps out. There Is a short metallic click and the noise of the water rushing Into the empty tube. The second torpedo Is at once Inserted. A few seconds later and the Interior of the submarine looks as before the attack began.

"But what of the first torpedo? We hear only the noise of the motors. We wait. Nothing happens. Then suddenly we are all thrown In a heap by the shaking of the boat. Then the boat rolls as before. The regular purring of the motors is heard. We are on our way home. The attack succeeded."

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