Page 84 - NS-2 Textbook

WORLD WAR I 77

A British sailor on the stern of a torpedo boat destroyer prepares to drop depth charges on German U-boats in the North Atlantic.

convoy system was a key factor in saving Britain from hydropholle was invented. This device could pick up un-
defeat in World War I. derwater noises and indicate their bearing but not the
range. If two or tlU'ee ships, each with a hydrophone,
found a submarine, howevel; they could determine by
ANTISUBMARINE OPERATIONS
cross bearings almost exactly where the submarine was
No one single method of warfare, however, could defeat located, drop depth charges, and destroy their prey. TIle
the U-boats. In addition to the convoy, the following meth- subchasers were fitted with hydrophones in 1917 and
ods were used to finally bring the menace under control: proved to be even better equipped than the destroyers to
Swface Warfare. The destroyer came to be the main hlmt the U-boats. When three ships worked together in
smface vessel designed for combating the submarine. this manner, the system was called triallgulatioll. This
Along with its guns and torpedoes, the destroyers also was the beginning of what is nmv called sonar, tmderwa-
carried a new weapon called the depth charge. Designed ter sOlmd equipment.
by the British in the earlier part of the Wat; depth charges Milles. The blockade of German submarine bases
were canisters of TNT fitted with a device that would with surface ships did not prove to be very effective. So,
detonate at a preset depth. These could be rolled off the the Allies laid gigantic minefields to prevent U-boats
stern from racks or fired from simple launchers called "Y from getting into the Atlantic. One of these minefields
guns," so natned because of their shape. By 1918 de- was laid across the Dover Strait, from England to Bel-
stroyers carried from thirty to forty depth charges, each gillln. Because this field could be patrolled against Ger-
containing 300 pounds of TNT. The United States built man minesweepers, it proved to be the most effective.
273 destroyers dming and immediately after the Wat·. The Dover Strait Barrage destroyed at least twelve U-
Another ship designed by the U.S. Navy especially boats and completely closed the strait to German subma-
for antisubmarine warfare ,"vas the submarine chaser. This rine traffic.
was a wooden vessel 110 feet long. Subchaser patrols The largest minefield was the North Sea Mine Bar-
were established in the North Sea, and across the south- rage, which ran from Scotland almost to the Norwegian
ern end of the Adriatic Sea in the Mediterranean to bot- coast. The laying of this minefield presented great prob-
tle up Austriatl submarines. Nearly 400 of these little lems, all of which V\rere overcome with special equip-
ships were built, and they were very helpful in convoy- ment and hard work. When finished, the field had 70,200
ing and other antisubmarine nmctions. mines, 56,600 of them laid by the U.S. Navy. There is no
It was not enough just to escort and patrol against positive information available on how effective the field
lmking submarines, however. Locating the submarine was. It is believed that at least one submarine was sunk
under the water was the key to destroying it. In 1915 the and a nmnber of others damaged.