SUBMARINE CAMPAIGN. When the World War broke out the submarine was a weapon of unknown capabilities. In its legitimate role as one of the essential arms of a modern navy, it was not a serious menace to Great Britain, but the "unrestricted" war on commerce was, in the words of Lord Jellicoe, "the greatest peril which ever threatened the population of this country." In Aug. 1914 the British navy had some 36 submarines of vary ing ages, of which the old "A" and "B" class boats were fit only for harbour defence. The "C" class could keep the sea for a few days and were used for defence of the Firth of Forth, mouth of the Thames, and Strait of Dover, while the "D" and "E" classes were based on Harwich and employed in keeping a close watch on the Heligoland Bight. Germany had 28 "U" boats, of which 18 were fit only for harbour defence. "U 19" to "U 28" were seagoing boats but their capabilities were then unknown either to Germany or England. It was the German custom, on the rare occasions on which their fleet ventured into the North sea, to station "U" boats off the British harbours beforehand to lie in wait for her ships as they came out, but these measures met with little success. Previous to the sortie of the High Sea Fleet which ended in Jut land (q.v.), "U" boats were lying in wait off Scapa, Moray Firth, the Firth of Forth and the Humber from May 23 to June 1, but Admiral Scheer says "Their reports gave no enlightenment," and in fact they were actually misleading. After the sortie of Aug. 18, however, "U" boats did sink the "Nottingham" and "Falmouth" on their way home. By the end of the war the Grand Fleet pos sessed a submarine flotilla designed to act with it as a tactical unit, but no opportunity occurred of testing its capabilities in battle.
In addition to their patrol work in the Bight and Strait of Dover, Allied submarines were employed in the Baltic, the Mar mora, the Adriatic, the Otranto barrage and the Dardanelles patrol. Owing to the mining of Danish territorial waters the Baltic was closed to the British fleet from the beginning of the war, and Germany was able to carry on her trade with Scandi navia unmolested. It was therefore decided to send British sub marines into it, and on Oct. 17, 1914, "E 1" passed through the Sound, followed two days later by "E 9." Though little time remained before ice compelled the boats to cease operations for the winter, the knowledge of their presence in those waters put an end to Germany's feeling of security. With the disappearance of the ice the submarines began to make their presence felt. More boats were sent during 1915. One of them, "E 13," ran ashore in Danish territory on entering, owing to a breakdown of her compass. The Danes correctly allowed her 24 hours to endeav our to refloat, but before this interval elapsed two German destroyers arrived and, in spite of her being in Danish territorial waters, opened fire on her, killing 15 men as they swam ashore.
In the autumn the boats were chiefly employed against the traffic in iron ore from Sweden to Germany, and produced a serious hold-up of that vitally important trade. They also succeeded in sinking the armoured cruiser "Prinz Adalbert," a light cruiser and a destroyer. After the Russian Revolution, when the Germans advanced on the submarine base at Helsingfors, the whole flotilla of eight boats was taken out to sea through the ice and blown up by their own crews.
The experiences of the Allied submarines during the Gallipoli campaign are among the most thrilling episodes of the war. The straits are 27 miles long and for 3.5 miles are only one mile wide. The current is swift and variable, and minefields were known to exist, but Lieut. Holbrook in "B II" successfully passed under the mines and torpedoed the Turkish cruiser "Messudieh." On the return journey his compass became unserviceable, but in spite of all perils he returned safely and was awarded the Victoria Cross. No further attempt was made until April 1915, by which time anti-submarine nets and obstructions had been added to the defences. The passage was then tried by "E 15," but unluckily she grounded some ten miles up. Being unable to get off again, she was destroyed after considerable difficulty with a torpedo dropped from a picket boat, one of two boats which crept up to the stranded submarine under cover of darkness. The next attempt, by "E 14," was successful. She sank three Turkish ships in the Marmora including a transport with 6,000 troops, but "A.E. 2" of the Australian navy was sunk by gunfire on the way up on April 30, and the French "Joule" struck a mine and was lost in May. "E 1," returning from a successful trip, found a mine sitting on her bows, but got rid of it by clever manoeuvring. She had penetrated as far as Constantinople itself where she tor pedoed a Turkish gunboat, sank transports and storeships off Rodosto and torpedoed the "Stamboul" in the Golden Horn. This was the first time an enemy warship had appeared in those waters since the Turkish conquest. Her exploits held up all sea communication between Constantinople and Gallipoli for a time. Many boats followed, most of them meeting with considerable success, all with thrilling adventures. They attacked troops and railway lines, fought with "Q" ships and "U" boats. "E 12," returning from a 40-days' cruise, carried off part of the Nagara obstruction in passing through the nets and was dragged down to a depth of 4o fathoms before the entanglement, whatever it was, was scraped off her by a chain stretched across the straits a little lower down. Though she broke surface in her struggles and came under fire from guns and torpedoes, she managed to reach Helles in safety. After the evacuation in 1915 there was no further object in sending submarines into the Marmora, and these hazard ous enterprises ceased.