SMOKE SCREEN FOR SUBMARINES.

Manawatu Herald, Volume XXXIX, Issue 1695, 5 April 1917, Page 4

SMOKE SCREEN FOR SUBMARINES.

If merchant ships were to make use of the smoke-screen, they would find it to be a very effective defence against submarine attacks. If a merchant ship on sighting a submarine turns at once to windward and chokes off the draft of her tires, she can throw behind her a heavy cloud of smoke which would be very baffling to the enemy. If the ship were an oil-burner, the screen would be particularly effective, for oil smoke is dense, slow to dissipate, and settles low upon the water. The submarine would hesitate to use her superior speed to close in on a ship which she could not see, particularly if she knew that the merchantman, as soon as the submarine became visible through the smoke, would be prepared to open on her with a Gin. gun. Merchantmen should be armed with nothing less than a 4.7 or Gin. piece, since these in the hands of a gunner at all expert would be sure death to a submarine steaming at the surface. The armament should consist, of four of these guns, one forward, one aft, and one on each beam. The difficulty, of course, would be to provide quickly sufficient of these guns to arm the 4,000 ships of 2,000 tons and upward in the British merchant marine.