SECRETS OF SUBMARINE

Greymouth Evening Star, 19 February 1937, Page 12

SECRETS OF SUBMARINE

ITS WORK AND ITS CREW. , The modern submarine is a wonderful and complicated machine. It is the home of a race of men apart, says C. A. Lyon, in the "Sunday Express. There are forty-two submarines in the British Navy. In them live, roughly, 2000 men. Of these submarines, the majority are of the ocean-going type with a displacement of about 1700 tons, and. the rest of the coastal type of about SOO tons. A submarine is not useful in the. first place for its actual destructive power, though that is not small, it is useful because it is a threat. It is the only ship with a cloak ol‘ invisibility. You never know wheie it is going to turn up. 0 o protect against a submarine necessitates the employment by its opponents of a body of men dozens of times as large as that of the submarine’s own crew. A single submarine can tie up a very large number of men who have to be taken away from, the other navy’s strength. The submarine is the most expensive of all ships to build. A battleship costs £2OO a ton, a submarine costs £320 a. ton. The largest type has five officers and about fifty men. It is a young man’s ship. Most of the crew are young. The captain of a submarine himself is probably only twenty-sir; or twenty-seven. A submarine can travel enormous distances. It makes the journey trom Britain to China, easily. It travels on the surface at fourteen knots, using' diesel engines. I ndcr water it switches on. its electric motor, which is run by batteries.

Let us take the submarine from four aspects. First, there is the task of getting the submarine under water diving. To do this safely and properly is a work of art in itself, an art of which the fine points-are known to hardly ■my one outside the Navy. Second, there is the art of steering a, submarine. It. is the most, difficult of all ships to steer successfully, yet tho Navy accomplishes it. Third, there is the art of living in a submarine. Fourth, there is the art of fighting in a submarine. How it fights, what it, can accomplish, and what it cannot. What its work is. Who its enemies are, and how much they are to be dreaded. First, 1 will tell you about diving tho submarine, the aspect every one thinks of first. On the surface the captain of the submarine stands on the conning tower, a little narrow steel platform. In front of the captain is a button. This button sounds hooters all over the submarine. (The Germans employ, or used to employ, bells instead). In an emergency he presses this button, makes a. dive for the hatch and slams it above him. Almost before he has come inside—in about, a, minute, in fact—the submarine is under the water. Down goes the nose at an angle of about one in four with, the crew “strap-hanging.” That is what happens. But. how does it happen? Everything depends on what is known as “trimming” the submarine. Trimming means letting in exactly the right amount of water to make the submarine dive.

DIFFICULT TASK. The accomplishment of this is a study of years. If the captain does not let in enough water, he will just stay upon the surface, and even a few seconds too long on the surface would mean—disaster. On the other hand, he could quite conceivably let in too much. Once he takes in too much water he may have to dive a long, long way down, perhaps even down to a. sticky end at the bottom, before he is able to pump it out. Moreover, a.'submarine.under water is an object (>f unbelievably delicate balance. A mti.ii walking from one end of it to the other will upset the balance. The exact weight of water necessary to sink the ship at any given moment js calculated very finely in advance, and the predetermined amount of water let in op receipt of the captain’s diving order. The amount of fuel used, food eaten, the density of the sea water twhich varies from place to place) all have to enter into these vital calculations. Every fact which alters the submarine’s weight is noted down in a book called the “trim book.” Ro much oil gone out, and so much water taken in. So much food consumed. (Each submariner, it is found, consumes 31b. of food per day).

The depth which the subnmrine travels beneath the surface is regulated, not by the weight, but by two horizontal fins, one on each side of the submarine, its depth is controlled exactly as the height of an aeroplane is controlled. Of course, the fins can only keep the submarine at a given depth and on an even keel so long as it is moving. It. is not. gencr-ally known that a submarine can no more .stop ttndi r water than an aeroplane can stop in the air. otherwise control is lost. The only exception is when it. is “sitting on 1 he bottom.” In controlling a submarine, ihore are many, many things the captain must r.emember. lie must always dive parallel with the rollers and novo)- head-on to them, or else he will find the two ends of his ship sticking out from the sides of the wave, an embarrassing situation Io be in. He must lake care Io dive at a pretty fast speed, say, twelve miles an hour, so that his fins gel a bite on the wafer and really take him down. He must, take care not to hit the bottom at too sharp an angle, however hasty his dive, or he will si ick

ill the Bill.!. The wartime submarine could go down one hundred and fifty feel, but this depth has now been increased — increased probably more than any one outside the Navy realises. The pressure at tiic greatest depths is so great that the whole strongly made steel cigar is flattened by thewat er. It is flattem'd to such an extent ■ that :: steel ladder fixed at both ends i an bo seen bulging out in a curve. So much for the art of diving. Now, for ■ tecring. The submarine is a one-man bind. 'Mor l than any other ship, the lives , of ttio whole crew of the submarine :>!.• auli.-i;ly in tin. 1 hands of one . man—; It• • ca pt co a. i Only one person at a time can see iti a submarine when it is under water.

That one person is the man looking through the periscope. For much ot the time, and always in time ot danger, it is the captain himself. His position has been compared to a. man trying to find his way along ■the street with a pair of binoculars [glued to his eyes and with his eais stuffed up. He stands in a cramped position hanging on to two handles of the periscope, his eyes glued to tho eye--1”h-’alone’ alone can detect danger, make a decision, take a risk. Every one else is groping in the dark under his ciders. A submarine officer's life m wa time is a. very trying one. The officer at the periscope has nothing to do but gaze steadily into an eye-piece, and That under considerable nervous strain. No one can stand it lor moie than two hours at a time. Therefore, the watches have to barranged, as two hours “on” the periscope, and four hours “oft which means that officers do not get a night’s unbroken sleep. Vision, especially through the periscone, is especially defective at dawn and dusk. These hours of dusk and dawn, when a. surface shin can see far better than a submarine through its penscope, are the hours of danger for the submarine —the hours when t it may be trapped. The submarine can travel ten miles an hour under water with its electric motor, but it has only enough ■ current stored in its batteries to keep up this speed for an hour. In the ordinary way a submerged submarine creeps along at less than ’ one mile an houi;. Now consider the living problems of the submarine. Going at one mile an hour the submarine'’ can travel under water for twenty-four hours. After eighteen hours the air is so full of carbon dioxide that a match will go out when struck. Nevertheless, this occasions no pronounced discomfort to the occupants. Submarines can safely stay under water for thirty-six hours in an emergency. A submarine has stayed under water experimentally for seventy hours. The submarine’s wartime routine is to keep just under the water with her periscope sticking out all day—until she sees something. At night it comes to the surface to charge its batteries and give the men fresh air ami to throw the potato peelings overboard.

FOOD SUPPLIES. The biggest British submarines can carry two tons of food. That is enough for six weeks. The fresh food they can carry in their refrigerators is only enough for four or five days. They eke it out by having several “meatless” days a- week. It is a strange world the submarine captain ruiles over down below. It is very quiet, and calmer than it is on the surface. There is no shouting or undue talking. One avoids walking about, without cause. It is necessaiy to conserve tbe air. The submarine is a much more pleasant place than in the old days. In the, earlier submarines sailors were intoxicated by the petrol fumes and passed out, as drunk as lords. Now the (atmosphere .is pure for the first few hours at least. . f . They have ice machines, a icii iterator, and even a bath. Cooking is done by electricity. No (cooking is allowed below the surface ■ —with one exception. . . n -. The men cannot do without then cup of tea in the afternoon, and the boiling water for this is allowed. Becau'se of this lack of hot foods submarine crews have a special Admiralty allowance of delicacies like tinned and bottled fruits and cold sausages. . Much of the men’s spare time below' the surface is spent in the eneigj conserving game of ludo. How and where does the submarine fight in war? . It is a life of long, long waits ami sharp, short springs. The war task of the submarine is very largely pinning the enemy down, keeping him in one place with the threat of destruction if he conies out. At the outbreak of a war submarines would not stay near our own coasts. They would sail off with all speed and settle down outside the enemv harbours. A flotilla of submarines could lurk outside an enemy port for six weeks at. a. stretch, diving at dawn and coming up Wfith the darkness. The blockading commander from time to time sends messages back to his base of what he sees Happening in the enemy port. ’ Some wavelengths are less easily detected on the direction-finder than others, and these the submaiine would use for its intelligence service. But sooner or later this peaceful warfare will be broken by an encounter with the enemy. In front of the captain of the submarine there is a white switchboard with a row of black switches that one can move with a flick, of the thumb. They look like electric light switches. These fire the 'torpedoes. The submarine carries fourteen torpedoes and it can fire six of them from its bow lubes at one time. t Tim tubes cannot bo moved. The whole submarine has to be aimed at its objective. The captain sights it with his periscope and trains his ship at it. A man at the switchboard flicks the little switches down and the long “tin fish” go on their dreadful mission.

British submarines now have a very high standard of firing. They can claim Nt) per cent, hits with their torpedoes. Within a quarter of a mile they can practically guarantee a hit. Snbmarim ; al love the long winter nights. Then they can “shut nn shop" about four o’clock in the afternoon and having recharged theit batteries, dive, down to the bottom to get a secure night’s shop. They need not come up again until half-past five or six the following morning. The submarine has many enemies. Destroyers arc- one. Aeroplanes •ire another. The i xte.nl io which a submarine can be detected by an aeroplane depends on three things, its depth, the state of the sea. ami the part of the world where it is. \ submarine is always safe from a- roplanes when tin re are “white horses” on the surface of the sea. In the limpid waters of the Mediterranean. with their strangely high transparency. a submarine can bo sct-n by an aeropkim through great dept Its. There remains one liter dancer to the submarine, its gre nest. To-day surface ships have instruments which can detmt the presume

of an invisible submarine under the surface with astonishing accuracy. Since the war. it is safe to say that all navies, including our own. have been experimenting with devices for the detection of 'tibmarines. and one can undoubtedly assume that any suitilicii UP j> ioucli tou HuUr LU an enemy destroyer in the future is ■ have a vmy thin titim.