The principal means of at ching submarines under water by dropping overboard charges which exploded at a certain depth.
The shock of these explosions seriously jarred the submit and. if near enough, deranged her mechanism or opened her joints. These depth charges were our earliest antisubmarine device. Gradually the methods of dropping them improved and their size and number were multiplied many times.
The second anti-submarine weapon was the thin wire net hung in long strips across straits or narrow channels.
These nets, buoyed on the surface with glass balls, were intended to foul the propeller of the U-boat and ie cling about the hull A U-boat thus enveloped, even if her motive power was not affected, would unconsciously be trailing a fatal tell-tale plode." This was an exaggeration; but we were certainly at fault in the matter During 1917 the failure of the 1916 Barrage across the Dover Straits had n total. From February to Novem-oats continued to pass through e rate of about 24 a month. time, and partly in con-th this discussion, Sir John ice was replaced as First Sea Lord by Admiral Wemyss, and Ad-con w succeeded in the r Command by Admiral Keyes.
volutionized the situation. He redoubled the patrols and by night ihe barrage from end to end became as bright as Piccadilly.
The German destroyers from Ostend and Zeebrugge attempted to break down the patrols by sudden raids. They were repulsed in fierce night actions and the watch maintained with ever-increasing efficiency.
Nine U-boats perished in the Dover area between January and
Text read from the printed page and cleaned; old type leaves the occasional error.