The Manawatu Herald. Saturday, July 31, 1915. SUBMARINES AND BASES.

Manawatu Herald, Volume XXXVII, Issue 1431, 31 July 1915, Page 2

The Manawatu Herald. Saturday, July 31, 1915. SUBMARINES AND BASES.

There is a suspicion that German submarines must have bases along the English coast, says Engineering ; but an examination of the endurance of such submarines as are utilised for operations far down the English Channel, in the Irish ►Sea, or on the Atlantic seaboard, shows that their radius of action is quite sufficient to enable them to do without such bases. Of these submarines, the latest built are said to be well over 20olt. in length, with surface displacements of from 650 to 675 tons. They are capable of steaming at from 16 to 18 knots, and have sufficient fuel to give them a radius of action of close upon 2000 miles at this speed. But the tactics of the submarine rarely demand this speed, because if danger besets them they have only to disappear to a sufficient depth’ in order to delude the enemy, at all events for the time being. Consequently their cruising is probably done at a low speed, and some of the vessels are quite capable of doing 4000 or 5000 miles at such low speeds. Moreover. the nominal radius of action can be greatly increased if, as is probable, the ships leave their base in the awash condition, showing only their conning towers. This is an advantage from the point of view of invisibility and safety, and is, further, conducive to rapid disappearance under the surface. In such condition their ballast tanks require to be partially filled, and when operations are to be carried out in waters distant from the German base, there is no reason why oil fuel should not be used in these ballast compartments instead of water, the fuel oil for the first part of a prolonged cruise being pumped from those tanks for use in the engine. When the oil in such tanks has been used vyater can be pumped in to ensure the required degree of immersion. The vessel, having reached her station, to await the passage of her prey, need use little fuel oil, as she may remain in any condition, with the decks above water, in the awash state, or submerged, in a stationary position, or with only a sufficient way on to ensure rapid submergence if on the surface.