“The Steel Shark”

Southland Times, Issue 23977, 18 November 1939, Page 11

“The Steel Shark”

EVERY time a German submarine fires a torpedo £3OOO is added to Hitler’s war budget. That’s one reason why U-boats have taken to sinking Allied tramp steamers by shell-fire now, instead of torpedoing them. It’s cheaper. Another reason is that the U-boats are running out of torpedoes. They can only carry a limited number, varying with the size of the submarines. Accurate torpedo firing from a submarine requires great skill, as the speed of a submerged submarine does not. exceed 10 knots. A submarine commander out to sink a ship has to calculate to the smallest fraction before giving the order, “Fire.” He peers through the periscope, works out the victim’s speed, the distance she is from the submarine, and her course. If the ship is zig-zagging,

she becomes all the more difficult to hit.

Having finally worked out all the details the £3OOO “steel shark” is set accordingly—speed, course, depth,— they are all regulated’ before firing—the torpedo-man squeezes a trigger and away goes the torpedo on its deadly mission. A torpedo is discharged by cordite firing or by compressed air. Once it contacts the water it is propelled by delicate internal compressed air engines; Each', torpedo has five compartments: (1) The explosive charge compartment situated in the nose; (2) Compressed air chamber; (3) Balance chamber; (4) Engine compartment; and (5) Buoyancy compartment. No. 1 compartment is usually about one-fifth the total length of the torpedo. In peace-time practice, dummy “noses” are substituted for the explosives. The speed of a torpedo is about 25 to 30 knots, and the' distance it runs varies with the speed at which the engines are set. A torpedo can travel for six miles at least. The most sensitive part of the “steel shark” is the balancing gear. It is vital that once set on its course, the torpedo must not rise or dive, and to keep it even a pendulum bears against a sensitive control which adjusts the setting of the rudders should they come unset.

Directional control is achieved by means of a gyroscope which applies pressure on the controls, should the torpedo turn right or left. —Noel Monks, in The Daily Mail.