SUBMARINE SECRETS.

Poverty Bay Herald, Volume XLIV, Issue 14391, 1 September 1917, Page 3

SUBMARINE SECRETS.

HOW U-BOATS STALK THEIR PREY. — — ' I GIGANTIC TASK OF ALLIED NAVIe4.

(How many submarines has Germany at work? How do they operate? What Is the enemy's building capacity? '■ How are U-boats "mothered" and supplied? To these and several Allied questions the following answer is attempted by Harley lirooks m the New York. World.) There arrived recently m New , York from Havana an American importer who, because of .his German name and the intimate relations he enjoyed with certain important men m Berlin, had become a factor m. pro-German activities m Cuba. He knew the inner plans of the Tirpitz group, and admits frankly that he helped m their execution.' Like many others, he saw a light when the Zimmerma'nn note was published, decided his allegiance wag American, threw up his business, and returned home; I was talking to this man, whom I will call Johann Schmidt, and he gave me the information set forth here.

Germany's most successful and highly developed class of submarines has been, of course, the IT type submersible. These are the terrors of the undermurk which have succeeded m crossing the Atlantic (the Deutschland, for example, which turned the trick, twice) and those similar undersea demons which have sunk the Lusitania and other passenger craft.

"Yes." Herr Schmidt told me, "but the German naval men are not resting content with such successful types. At this very moment , "they are' building submarines 25 per- cent larger than, anything we have yet seen or heard of. Some ' will he at work before you get into print. If America has not been waked up before that she will then— this not m the form of a threat, but as a warning Mint Uncle Sam must not lay back, content with estimating the submarine menace on the U-boat basis. Alvearty .Germany is five years ahead of the i est of the world m submarlne\ development, and there is no telling how much further ahead this new type will take her. On May 15. they were turning out four submarines a week. 'After June m they will be building them at the rate 'of .eight every seven days.' This much I know.". : ilorr Schmidt :said that Germany now has building capacity m the shape of ways lor 19 submarines a week, should every available place be devoted fe this kind of shipbuilding. The 800-ton sub.marine requires about 25ft by 35ft working space. ;'. There are three G2sft dry docks at Wilhelinshaven, which permit the building, of six submersibles at the same time. Eight more underwater boats could be constructed at the same time m each of the larger dry docks, «22ft m length. Gei*niany also possesses many floating dry docks, which make excellent building , ways. Here are Just a few more facts he gave regarding the building of the typical Teutonic submarine: The U-boat is standardised— that i*, the parts are made m different places all from the same patterns, and the building of the finished boat is only a matter of assembling the finished parts and riveting them together. Germany is the- home >f "the Die*el of* engineer) submarines. . It. can be mado by ! the Krupps, and at the •.-great engine Works In Augsburg, Emden, and Nuremburg. as well as at v other places less weil known. The Deutschlaud took back with her under, the seas enough nickel and- tungsten 'to last two years, i The. conning towers (the German, dubs them ••commanding-' towers) are shielded with armour from 'iAln to 3in, m thickness. The false superstructure carries ■irom two to four lifeboats, life preservers, i-afts, etc. ■-; • In the larger and newer types they are planning to carry from two to eight folding hydro-aeropiahes, each with a spread of 30ft and a length of 22ft. These will be put m th« space provided for the lifeboats, and, will fold up into a. space 42ft by Gft. The Germans have about 200 submarines now at work, and perhaps as many as 500 on the ways. ;In another year they hope to have a lull thousand submersibles afloat. It takes ?ight weeks to finish a submarine once her keel is laid. Germany's submarine plans include, the training of reserve •rews. Her warships, -are idle, and from their personnel of more than 150,000 men they furnish plenty of first class seagoing material. Every submarine has an extra crew. They go on a cruise, shift, rest, and go at it again. . Then Herr Schmidt told me something that 1 have never seen m print— that all the submarines work m groups of four. \s he said: "Each group consists of four submarines, travelling along m a f dia-mond-shaped formation, one in* front, me on either flank, and one m rear. Eight miles separate the boats. The leading submarine carries the extra gasoline and supplies and acts as a scout ship. She sights a vessel, reports its speed and ilti-ection, and then submerges— her task Is done. The two torpedo carriers on either Hank immediately change their courses so. as to converge on the prey, and they ai - rive, one on> either side of uer— they get her m between them. The joat ill the rear keeps them informed as to the doomed, ship's pi-ogress and submerges at the last moment. She carries the extra crews for the fighting pair. Such a submarine squadron as this laughs at. an egg-shell submarine chaser, 85ft or. 100 ft long. Their decks are protected by close to 2ft of water, and the commanding tower by? -three iuches of the best steel armour plate. They could blow any motor boat off the face of the sea, no\ matter how hard . it pumped rapid fire guns at her tower." At the outset of the- U-boat menace England issued instructions to ram the submarine the moment it appeared on the surface. A council meeting had* an answer to England's order. Attacking -übmarines were, equipped with explosive mines containing 3001 b -or 4001 bof nitrogelatine, or some other equally devilish substance. On the top of each was fastened a fake periscope. The submarine towed this decoy 2000 ft behind her. c'loughing along, safely submerged herself, she trailed the decoy at a safe distance for some ship -to ram — which' tho ship usually did, guilelessly, with disastrous results and saving a torpedo to the German besides. ■

The German submarine loves white caps and rough weather. Then the wake of her periscope cannot be picked tip. It looks precisely like the crest of a wave. That is the reason the Deutschland went out from this side when it was kicking up a big pothoi' of a sea. la calm water the periscope makes a very apparent wave as soon as the submarine reaches a speed of four knots an hour. Fair weather Is the submarine's greatest danger. But even now the clever German has a device for making a periscope invisible.lt consists of two mirrors put together like a "V" lying on its side, the wide part m front. These skim tlmwgh the waves and converge the image upon the low periscope's lens, which shoots tlie light down tho tube to the receiving apparatus below. The mirrors reflect the surface of the sea. so that n lookout sees nothing but the waves as they appear m the mirrors and not the mirrors themselves. And microphones pick up the churning of a ship's propellers, thus giving warning of her distance and direction. This gives the submarine opportunity to approach very close without revealing herself even by her periscope. ■

"The English and French swfek submarine bases hidden on land," said HeiT Schmidt, "when they ought to seek them at the bottom of the sea. In fact, the Germans use . the bottom of the sea as the land, and when their submarines go to the surface it is precisely like an aeroplane mounting the air. The bottom is their normal habitat; that 1s where they belong. In ,the German submarine fleet arc submarine 'mother boats.' They lie on the bottom -m certain designated places where the water Is 50 or 60 feetf deep, and rise at .night to hand out their supplies of gasoline, oil, food, and the like. The crews are changed) and

the tired men go back to the bottom to rest up while their fresher comrades take their places. So, too. there are submarine mine layers. They lio on the' "bottom and work there, putting out their mines at their ease and convenienceDivers even walk out of these submarine resting- places and go about their business on the floor of the sea without ever seeing the surface. Even their air comes from the submarine."