THE UNDER-WATER FOES.

Taranaki Daily News, Volume LVII, Issue 105, 26 September 1914, Page 3

THE UNDER-WATER FOES.

SUBMARINE FIGHTING SHIPS. RECENT PROGRESS REVIEWED.

The fact that German submarines have succeeded in accounting for three British ships in the North Sea will surprise no one who has followed the recent developments of under-water craft, for they have reached such a pitch of efficiency as to constitute a menace to every blockading fleet. The episode of the destruction of the submarine Ml 7 by the British cruiser Birmingham showed the limitations, in some respects, of this form of attack, but circumstances must arise at times from weather conditions and otherwise which confer the initial advantage of submarines operating against a blockading fleet. In the French naval manoeuvres of 1913 submarines operating with a defending force attacked the blockaders so successfully that they were compelled to retire to a distance which enabled the interned warships to escape. The available particulars of the successful attack upon tho British cruisers in the North Bea do not suggest that the circumstances were in any way remarkable. Old ships, of the type to which the three ships belonged, would naturally be entrusted with the dangerous task of keeping in comparatively close touch with the blockaded enemy, and assuming that the cruisers were so engaged, tlie attack which in this instance was driven home would be an enterprise well within the capabilites of submarine flotillas possessed by all the naval Powers.

All naval countries maintain strict reticence regarding the design and fighting power of the units of their submarine flotillas, but so far as is known Germany does not possess any superiority in this branch of her navy. On the contrary, she began the construction of submarines or submersibles, five or six years after France and Britain possessed craft of this type, and according to the latest available figures Britain possesses more than three times as many effective submersibles as Germany, anil France more than twice as many. The position appears to be at their present stage ot development submersibles are much more effective in coast defence work than in operations over a more extended range. It is in connection with the operations of her submarine and destroyer Hotillaß that the possession of the sea fortress of Heligoland is chiefly of importance to Germany. This stronghold affords the small craft a convenient base, and in the shelter of its fortified harbor several flotillas can lie safely in any weather.

GERMANY'S LATE START. According to the Berlin correspondent of The Navy, writing in April last, the first German submarine- boat was put afloat in August, 1900 (other authorities say 11KI5), and christened "Ul." At that date the fleets of several Powers, notably those of France and England, already included a large number of submarines; but Germany, traditionally conservative towards all naval innovations, hesitated long before committing herself. The most contradictory statements were made about the behaviour of

"Ul." One account spoke of the boat having behaved admirably on trial, but a subsequent report, which had authority behind it, declared it to be, dangerous in a rough sea. On the whole, naval opinion remained unfavorable, and for the next four or five years the submarine flotilla increased very slowly. Nevertheless, the Navy Department had obtained a yearly grant of some £250,000 for experiments in submarine navigation, and with this money built improved boats. They were all constructed, from designs prepared by Messrs Krupp at their Gorman yards on the Baltic, though later on the Imperial Dockyard at Danzig took a hand in the work. A great mystery is still made of the actual number built. The Nautical Almanac up to 1!)12 gave the number as 12, but in its 1013 edition speaks of 23 as being completed. Obviously, therefore, progress has been very rapid during the last two or three years. Tiie new Navy Act of 1012 provides for the annual construction of six boats, beginning with that year, so that before the end of 19U at least IS submarines will be in hand. Taking two years as the average period occupied in building, it would seem that bv 1920 the German submarine (loliila would have reached its legal establishment of 72 boats—a remarkable figure, considering that it is only six years since the launch of the first German boat.

SUBMARINE OR SUBMERSIBLE. "Strictly speaking, there are. no German submarines; they are all submersibles—that is to say, they aro vessels fitted with powerful engines for surface navigation, possessing asi extended range of action, and able to keep the sea for long periods, whereas the submarine proper is a boat in which radius and seaworthiness are subordinated to under-water manoeuvring. This dill'crjentiation of a type finds its counterpart jin surface'torpedo-craft, as witness the coastal and sea-going boats. In passing it may be mentioned that practically every navy in the world is now" building submersibles in preference to submarines, though 'submarine' is still retained as a convenient generic term for all under-water lighters. "Any authoritative comparison between German and British submarines of equal date is rendered impossible by reason of the reticence displayed in both countries in regard to this type of construction. It was reported by a Berlin paper last year that the boats building under the current programme were of 800 tons, with two Diesel motors, developing ISOO-li.p. in the aggregate and capable of giving a speed on the surface of 17 knots, the speed submerged being estimated at twelve knots. Each boat was to be armed with two 14-pounder guns, on high-angle mountings, Jt is dillieult to say. however, whether thtfse details are to be relied upon. Equally little is known in regard to the latest British types, but t'ne Admiralty are believed to favor a. policy of developing the submarine as well as the submersible, thus providing a certain number of boats designed mainly for local coastal defence, in addition to the bigger seagoing craft w'hich arc able to operate on the high seas.

FIGHTING YAU'K OF THE SUBMARINE. "Public opinion is inclined to place an exaggerated value on the submarine, thanks to the highly sensational stories of its prowess, which are printed in the newspapers. 'Wonderful progress has no doubt been made, and it is certain that the best brains in many countries are devoted to the perfection of submarine navigation. Yet there are certain inherent difficulties, to overcome which definitely limit the efficiency of the type at the present stage of science and engineering. By greatly increasing the size, it might he possible to give a submarine a surface speed equal to that of modern battleships, i.e., 2i to 23 knots, thus enabling it to accompany a fleet at sea. The existence of such boats

would lead to modification of, accepted principles of strategy "and tactics. Submarines of this type may—probably will—be in service a few years hence, for the steady improvement of the heavy oil motor, leading to higher power and reductd weight, is slowly but surely raising the speed at which submarine boats can travel on the surface. There has not, however, been corresponding progress in relation to the machinery for cruising below water. The enormous weight of the accumulators sets a limit to the power of the electrical plant, which, in spite of its uneconomical operation in proportion to the weight it preempts, still monopolises the field as the only thoroughly practicable plant for submerged travelling. It may be doubted whether any submarine boat has a speed below water of more than 13 knots, though several French and Italian craft have higher legendary speeds. In some of their new boats the French have reintroduced the steam engine for .surface and submerged running alike, but [its iise is certain to be attended with discomfort and perhaps danger to the crew when the boat is below the surface. Another solution of the problem of how to increase under-water speed has been proposed by an Italian engineer, Signor Del Proposto. His plan is to utilise a Diesel four-cylinder engine as a combined surface and submerged motor. The difficulty of creating an adequate supply of air for the engine when the boat is below the surface is to he met by providing an air pump, which, driven by the motor during the surface run, will store up a large rescue of compressed air for the use of the motor when the hoat dives. This arrangement requires a great number of flasks for containing the compressed air, and the weight and space occupied by them is a serious defect. Moreover, the exhaust gases of the motor, rising to the surface, would betray the presence of the submarine, just as the course of a torpedo can be marked by the line of air bubbles. Nevertheless, there is reason to believe that the Proposto system is receiving the attention of move than one navy. , HIGH SPEED BELOW WATER.

"Tliat some satisfactory method of propelling submarines at high speeds below water will eventually be discovered is almost certain. When that has been done, the power of the submarine as a weapon of destruction will be augmented to an incalculable extent. At present, even the slowest battleship is virtually safe from under-wator attack when steaming at its best speed. The submarine is too slow below the surface to pursue its prey, while if it rises it becomes exposed to gun-fire. So it has perforce to lie in wait for its victims, or to fall upon them unawares when they are at anchor or steaming very slowly. A fleet of ships maintaining a blockade would represent the ideal objective of submarine attack, and the writings of General von Bcrnhardi and other strategists show that Germany places great reliance on her submarines as an antidote to a close blockade of her coasts. A flotilla based on Heligoland would be admirably situated for this work, a fact which goes far to explain the successful efforts of Germany to convert the island into a naval stronghold of the first rank."