Perhaps the most effective weapon used by the Allies against the German submarines in the World War was the mine, accounting as it did for over 30 per cent of the losses. This showing is the more remarkable because of its extreme inefficiency at the beginning of the war. Functioning badly, coming to the surface at low tide, the early British mines customarily exploded one time in three. The Germans called them “caviar on toast.” The Russian mines in the Gulf of Finland, on the other hand, never failed to inspire a proper respect.
The value of mines, it is clear, is twofold. In the first place, there is the obvious material value; in no other way can a strait or harbor be blocked so efficiently (provided the mine itself is efficient) and submarines finding themselves in mine fields rarely escape. From this fact derives the second, the moral value. It is possible to escape a depth-charge attack; aim is not accurate, and pursuers may perhaps be thrown off. A strong mine barrage, on the other hand, offers a submarine very little opportunity of survival. Nine out of ten times, in the World War, the striking of a mine meant death for all on board. Small wonder, then, that by the time the Dover Barrage was completed the Flanders commanders were becoming prematurely aged; on the average they would be able to complete six cruises before going down in their wrecked boats. Some of them painted large eyes on their bows; it is not known whether this increased their safety.
The loss of the U-5 and U-11 off Zeebrugge in December, 1914, gave warning that there was danger of mines; but subsequent events showed that the English mines were not formidable. Submarines fleeing from British destroyers would sometimes hide in British mine fields; and for three years almost every loss from mines was due to the excessive efficiency of the submarine’s own mines, or to Russian mines in the Black Sea.
After an investigation by the Admiralty in 1917, it was discovered that both the firing and the mooring gear of the mines on hand were unreliable; and in September, 1917, the newly developed Mark H2 mines were tried out off Horns Reef. On the 7th, the U-88 was destroyed in such a terrific explosion that a sister-ship accompanying her was shaken violently and came to the surface in alarm.
At the end of September the Admiralty acquired information which led them to believe that several submarines would be returning home during the first ten days of October, passing southward between the longitudes of 00°-30’E. and 03°-00’E., west of the Dogger Bank. An operation with destroyers, submarines, and drifters with nets was therefore carried out to intercept them. On October 1 mine nets were laid just south of 56°-00'N. for about 10 miles, and 4 destroyers and 16 trawlers patrolled them. To the northward destroyers and submarines patrolled to force the enemy to submerge into the nets. To the southward there were more destroyers. On the morning of October 2 the first submarine was caught; the motors of the U-50 were heard on the hydrophones of the drifter William Tennant; then came a heavy explosion in the nets. The next day the U-66 met a similar fate. On the evening of the 9th two submarines were seen and attacked with depth charges by the trawlers; but these both got through without injury, and on the 10th the operations ceased. The U-106 also passed through this trap, but was proceeding through a usually swept channel in the Bight when she was destroyed in new mine nets on October 9.
More than a month later, on the morning of November 17, the French SS. Therese sighted a submarine which dived at 11:35. The armed trawler Lois received her wireless call and started out for the position, but when she had arrived close to 50°-08'-20"N., 03°-42'-30"W., there was a terrific explosion near by and a submarine was blown to the surface, turning over and sinking at once. A mine also came up in the vicinity. A great deal of oil appeared, and some pieces of wood and human entrails, as well as part of a sea boot with the name Meegzer on it. Meegzer was a member of the crew of the UB-18 under Georg Niemeyer. The UC-57 and UB-61 were also destroyed by mines during the month.
Reinhold Salzwedel, a young officer who in the UC-71 had been able to defeat Gordon Campbell in the decoy ship Dim- raven on August 8, was given command of the new UB-81 as his reward, and he took her out of Bruges at 10:10 p.m. on November 28, passing through the still incomplete Dover Barrage at 7:48 p.m. next day. Then after several unsuccessful attacks on shipping he headed towards a point to the west of Beachy Head on the 30th. On his way westward he attacked several convoys but was driven away each time. On December 2 at 5:30 p.m. the UB-81 headed for the coast and came to the surface to make observations. According to one of her officers, she then “dived because of the approach of patrols and probably of a convoy.”
Mr. Hector By water, in his book Their Secret Purposes, has described the loss of a large Flanders submarine in “peculiar circumstances” which closely resemble those attending the destruction of the UB-81. According to his account, this submarine was off her course and about to cross a newly laid German mine field when in the darkness she mistook the mine layer’s warning signal for the challenge of a patrol and dived into the field. The explosions which followed were observed by patrols, and the mines were swept up.
The explosions which sank the UB-81 were observed by two drifters in 50°-27,N., 00°-53,-30,,W., southeast of the Isle of Wight. The submarine’s ballast tanks aft had been destroyed by the mine, and water began to pour in through the stern. The electric motors continued to function, but the after tanks could not, of course, be blown, and her stern sank to the bottom in 15 fathoms. The after bulkhead began to leak, and the engine-room soon filled with water. The gauges showed the bows to be out of water to a height of about 12 feet, with the boat lying at an angle of 60 degrees. One torpedo was then lowered from its tube and the sea cap opened; seven men climbed out, but the cold was so bitter and the strain of hanging on so great that after sending up distress rockets five of them went back down and joined those below who were breathing oxygen from the flasks in order to lose consciousness. The drifters in the meantime had finally reported the explosions they had heard, and at 10:07 p.m. the P-32 was ordered to investigate. She came alongside the submarine, whose bows had gone down slightly, at 10:45, and because of the wind and rough sea struck her with considerable force. The water rushed in through the still open torpedo tube, and the submarine disappeared. Her two survivors were picked up.
German submarines coming out to raid along the East Coast were accustomed to fix their position by Flamborough Head; so on October 20 mine nets had been laid off the coast at this point. The UC-47 had been sunk by a patrol before she could test their efficiency, but on December 10, the UB-75 under Franz Walther was caught and destroyed.
The coastal barrage off Terchelling was successful three days later; the U-75 was sunk, although the commander, Schmolling, and presumably some of his crew, were able to escape.
Various mine and net barrages had been laid in the Straits of Dover ever since January, 1915, but the only submarine sunk was the U-8, which had successfully broken through the nets but was sighted by the destroyer patrol on March 4 of that year. The ineffectiveness of this barrage was not diminished until September, 1916, when mine nets with deep mines below were laid from the South Goodwins to the Snou Bank on the Belgian coast. By the spring of 1917 this barrage became more dangerous to the patrols than to the submarines, for the mines dragged and fouled the nets, and the nets sagged so that submarines and even destroyers could pass over.
In February, 1917, Vice Admiral Sir Reginald Bacon submitted a plan for a field of mines at varying depths from the Varne Shoal to Cape Gris Nez; later he proposed to extend it all the way to Folkestone with a shallow mine field and four lightships with searchlights. This plan was approved, and when in November the Mark H2 mine became available in large quantities (and after its successful use in the North Sea) the barrage was begun. The first section was laid on November 21, 1917.
Sir Reginald Bacon did not advocate the illumination of the barrage to such an extent as did some members of the Admiralty, and against his wishes on December 19 the barrage was brightly lighted and the UB-56, forced to dive to escape detection, struck a mine in 50°-58' N., -28 E. at 11:42 p.m. The destroyer Gypsy, patrolling near by, was shaken badly by the explosion and proceeded to investigate, hearing voices calling ahead at 12:10. Two minutes later some men were seen struggling in the water ahead, but before a boat could reach them they had all disappeared. To starboard some men were still shouting, and the searchlight made visible two of them. One of them sank before he could be reached; the other, a petty officer named Bleeck, regained consciousness on board the Gypsy for only a moment, and although everything possible was done to revive him he died at 1:15 in the morning. Hans Valentiner was the commander of the submarine.
A week after this sinking Sir Reginald Bacon was replaced at Dover by Sir Roger Keyes, who introduced magnesium flares and massed patrols. Three sinkings took place in January: the U-95 on the 19th, U-109 and UB-35 on the 26th. There were no survivors in any of these cases. Keyes says, in this regard, that “the Germans had become aware that some unpleasant new measures were being taken against them in the Straits, and after the U-109 failed to return, all submarines from the Helgoland Bight were ordered to go round the north of Scotland.”1 On the night of February 8 another submarine was lost—the UB-38.
1Keyes, Naval Memoirs, Vol. II, p. 173.
The situation for the German submarines was indeed critical, and an attempt to clear the Straits, as well as to facilitate the passage of certain submarines, was made on the night of February 14 by a destroyer flotilla from the High Seas Fleet. A trawler and seven drifters were sunk, but the deep mines were untouched, and the patrol was resumed the next night.
On March 10 some interesting wreckage was picked up after an explosion in the Barrage. A large pool of oil contained many small pieces of wood, loaves of bread (Keyes says “of very inferior quality”2) and papers which were found to include the battery log and details of the trials of the UB-58 at Bremen on August 1.
2Op cit., p. 186.
At six o’clock on the evening of April 11 the drifter Ocean Roamer observed a violent explosion to the southwest, in approximately 50°-55/ N., 01°-17' E.; and the entire division proceeded at once to the spot. Wreckage covered the surface, and oil came up until dark. Samples of the oil and wreckage were picked up, and on May 21 a diver discovered the wreck of the UB-33 under Fritz Gregor. As in the case of many submarines sunk in shallow waters, a steel chest with secret codes and signals was taken out of the wreck.
The UC-79 under A. Krameyer disappeared soon after the middle of April; probably she was the submarine which struck two mines in the barrage at midnight on April 19. Drifters near by proceeded to the spot and found oil and air bubbles coming to the surface in great quantities; this continued all the next day. The weather was so rough at the time that it was impossible for divers to go down, and the wreck was never found. French authorities also say that the UC-79 was lost in the barrage “near the UB-55,” but they give the date as April 27.
The UB-55 herself was destroyed early on the morning of April 22; she had left Zeebrugge the night before and was forced to dive by the drifter division. The mine blew her stern open, and she sank to the bottom. Two officers and four men escaped.
Two barrage sinkings took place on May 2, at 8:05 and at 8:10 in the morning. The submarines, from which there were no survivors, were the UB-31 and the UC-78. After this loss most of the Flanders boats confined their activities to the North Sea, although on May 11 the UB-119, on June 20 the UC-64, and on July 10 the UC-77 were sunk. The loss of the UB-108 in the first fortnight of July may have been the result of an explosion in the Barrage on the 14th (although no wreck was ever found), or else she may have been the submarine rammed and claimed sunk by the SS. Salient off the south of Ireland on the 7th.
Mine-laying destroyers of the Dover force during August laid mines in the Bight of Helgoland, on which the small UB-12 under E. Schoeller was destroyed about August 28. According to German records, she had left Zeebrugge on August 19 to lay mines in the Thames estuary.
A new type of magnetic mine was also laid in the approaches to Zeebrugge on the night of August 7, and the next morning a German destroyer was sunk in them, as well as some mine sweepers. The UB-57 under J. Losz, which had set out on her cruise on August 3, was returning to port on August 14 when she struck these mines. It is possible that, as Mr. Hector Bywater intimates, the leader-cable, an electric guiding device laid from Zeebrugge to the Thornton Ridge during August, ceased to function, and the UB-57 “lost [her] bearings at a critical moment.”3
3Bywater, Their Secret Purposes, p. 45.
In July the UB-109 under Ramien passed through the barrage on her way to the Azores; sighted by the patrol, she dived into a field of mines, none of which exploded. Her commander, however, was not eager to repeat the experience, and he decided to attempt a passage through the traffic-swept channel between Folkestone and Dover, just off the coast. At two o’clock on the morning of August 29 she was sighted by patrols and forced to dive, then she proceeded northeast under water. At 3:05 the Folkestone Observation Station heard the sound of a fast-running reciprocating engine. In December, 1917, the Channel Barrage Committee had made plans for detector loops such as these, along with a controlled mine field, and now for the first time they were tried out. At 3:22, when the galvanometer needle swung to indicate the submarine’s presence over a line of mines, a button was pressed and the line fired. A heavy explosion followed, and in a great bubble of air from the wrecked submarine two officers and six men were blown to the surface and picked up by the trawler St. Germain. On September 16 the UB-103 was driven into the mines to the southeast; and on October 1 the Flanders base was abandoned.
The last submarine of the disbanded Flanders Flotilla to be lost in the war was destroyed in an attack on the Grand Fleet at Scapa Flow; the German Intelligence Service evidently was not aware that the Fleet was in the Firth of Forth. H. J. Emsmann in the UB-116 set out on this audacious and superbly brave enterprise about October 26, when all over the world the U-boats were being recalled; and at 10:21 p.m., on October 28 his engines were heard as he approached Stanger Head at full speed. By 10:35 the listeners had decided it was a submarine, and traffic was stopped, the searchlights turned on—in their beams the UB-116 was seen for a moment at 11:30—and the mine field was made active. The submarine came to the surface momentarily to check her position, and then at moderate speed she made her way toward the*gate in the Hoxa Boom. She passed through the first gate and then turned and increased speed to pass through the second at 11:32; but she was indicated on the galvanometer to be over a field of mines, and the line was fired in 58°-50' N., 03°-04' W. Oil and air bubbles came up all the next morning; depth charges dropped at daybreak threw up air and wreckage. Divers found her wreck on the bottom with a great hole in her side. The crew were at their posts; Emsmann had died in the conning tower with his confidential log book in his hands.
We have previously discussed the Northern Barrage and its success (Naval Institute Proceedings, January, 1938). Suffice it to say that the lessons of Dover were applied to a wider field, and with more efficient equipment its mistakes were avoided. For the sake of completeness it should also be stated that the UC-11 was mined off Harwich, and the following submarines were blown up by their own mines: UC-9, UC-12, UC-32, and possibly the UC-42 and UC-44.
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A Tory Governor’s View of David Bushnell’s Submarine
One of the most interesting of the Naval History Society’s publications is a volume edited by Mr. R. W. Neeser, entitled, The Despatches of Molyneux Shuldam. Admiral Shuldam was a Vice Admiral of the Blue of the Royal Navy, and had command of the British naval force off the American coast from January-July 1776. In this book are the dispatches that Shuldham himself sent back to the Admiralty Board, together with reports and letters that he had received from Loyalist sympathizers in the revolting colonies, from spies, and from his own officers. Taken together they form a most interesting and valuable sidelight on the events of the times. One of the most interesting is the report from Governor William Tryon, Tory Governor of New York, on David Bushnell’s submarine. This report was sent to Shuldham, who forwarded it to the Admiralty Board. It was dated November 16, 1775, and reveals the worthy Governor as a man very much worried about this new weapon of warfare. He wrote:
The great news of the day with us is now to Destroy the Navy. A certain Mr. Bushnel has completed his Machine, and has been missing four weeks, returned this day week. It is conjectur’d that an attempt was made on the Asia, but proved unsuccessful—Return’d to New Haven in order to get a Pump of a new Construction which will soon be completed,—When you may expect to see the Ships in Smoke.