NAVAL CONSTRUCTOR ON SUBMARINE PROGRESS.

Oamaru Mail, Volume XL, Issue 12538, 8 May 1915, Page 3 (Supplement)

NAVAL CONSTRUCTOR ON SUBMARINE PROGRESS.

The submarine, whether it does or does 11.01 ultimately fulfil Sir Percy Scott's famous prophecy of last June and drive th:e battleship from the seas, lias certainly dispelled anw doubts that may have been entertained by naval experts, before the present war began as to the real -importance of such craft

in. modcr.li warfare. An addies- on "The Modern Submarine in Naval Wariarc," delivered before a section, of the Franklin Institue by -Mr H. H. M. Robinson, a wellknown ex-naval- constructor of the 'United States Navy, is published in the current Journal of the same Institute. The iiulh;ir had manv years' experience in d?sigiiing battleships and other surface warsh.ps, and has therefore given much- thought to the question -of protecting -s-uc.'i vessels from under-water attack. There are only two possible modes of defence, viz., the destruction of the host ; le submarine, and the protection cf the bottom of_siirfaec ships from torpedoes. This former task must be entrusted to vessels of the same order of size as the submarine, ami the means of destruction are still problematical. As to protecting the- bottom of ii ship from torpedoes,, the tor-pedo-net is a common, expedient, but can only, be used when the vessel is at anchor.' Moreover, a net-cutter, attached to the nose of th? torpedo is: I jike'iy to make th ; s device ineffective. As to the alternative proposal to make the shio herself invulnerable:

"Unfortunately, it is much easier to increase the power of the torpedo than t is to increase the defensive- protection built- into the hull of the Dreadnought, withi the . result that, if any given class- of surface ship has protection against the then existing torpedo, it is fairly easy to vitiate the value of this protection Jiy in-creasing the power of the torpedo." Structural features tending to seenr.' protection from under-water attacks are (1) under-water armor, (2) additional compartment-ins. and (.3) compressed- air installations for localising the inflow of water. - . "The best solution, of the problem is a combination of the three methods referred- to above: Proper compartmenting,—and by tlii; 1 mean something different from the time-honored system in, use in the older days,—under-water armor not located on the externa] hull of the ship, and a graduated- com-.prossod-.iir installation for ' checking the water after it gets into certain compartments.'' Toe author thus enumerates the essential features of the submarine from a military standpoint: Surface speed, surface radius, submerged speed, submerged radius, and armament. In considering the speed of submarines he devotes much space to the question of engines. Heavy-oil engines, in preference to gasoline engines, are now u-od lor surface propulsion, and electric engines, run by storage battery, for submarine propulsion. Possibly a type of the future will use electrical engines exclusively for propulsion, the electricity being generated by oil engines while the vessel is on the surface. Another plan contemplates storing air. at, high pressure, in the tanks winle the vessel is at the surface, and utilising it in connection with the in-ternal-combustion motor, which would thus work under water as well as above it.

"The tendency of the United States Navy Department's requirements is in ■the 'direction of multiplicity of safety devices and escape hatches, greater water-tight subdivision, etc. While this may increase -efficiency by giving the crew greater confidence,additional hatches are really a source of danger, and close subdivision interferes with economical arrangement of the interior. I believe the dare-devil type of man who would naturally choose submarine service would rather have more effective means for dealing with the enemy and take any reasonable chance on his own safety. 7 '

Submarines must be variously constructed, according as they are intended for (1) harbor defence, (2) coast defence, or (3) general offensive operations. Classes 1 and 2 are relatively small vessels, and have only a moderate radius of action.

"For tlie protection of the harbors on the east- and west coasts of the "United States it has been estimated by a naval authority that there should be a group of five coast defence submarines and one suitable tender stationed at. each of the harbors arid places which are considered worthy of protection for strategical reasons. It has been estimated that- for the proper protection of the east and west coasts of the United States there should be a total of-fifty-five coast defence submarines on the east coast, and ;i- total of forty-five on the west coast. It. is intended that- these submarines be based on mobile tenders located at various points -along the coast- .which the author enumerates. Additional submarines would he needed for the various outlving possessions ct tin; United States." The large sea-going type of submarine, capable of accompanying the fleet on distant cruises, is a logical development of the future. England and France are already building such vessels, with a surface speed of eighteen to twenty knots, and a submerged speed of thirteen or fourteen knots. The author deals in detail with the tactics and operations of the various types of submarines, but we have not space to summarise the novel and interesting facts set forth under this head. As illustrating the expedients employed to lure the enemy into the submarine danger zone, it may be noted that the. Germans are said to be using a fishing- boat or some other surface vessel, pretending that it is a minelayer, as a decoy; and that in fleet manoeuvres weighted poles, painted to look like submarine periscopes, and floating with, the tide, have also been used.