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Raising a Submarine Minelayer

An exciting chapter was added to the history of salvage when, in 1917, Commander Davis raised from the sea bed and beached on the Irish Coast a submarine that was loaded with live mines


DRAMAS OF SALVAGE - 6


THE MINE-LADEN WRECK of the German submarine UC 44




































THE MINE-LADEN WRECK of the German submarine UC 44 was brought ashore slung between the two lifting vessels shown in this photograph. During minelaying operations, this submarine was herself struck by a mine. Commander Davis, who was in charge of the dangerous feat of raising this wreck and bringing her ashore, is the nearest figure in the foreground of the lifting vessel on the right.




IN 1917, when the enemy submarines were taking such a toll of British shipping, the least bit of information concerning the movements of the U-boats, however trifling it seemed, was of vital importance to the Admiralty. To gain this information some wonderful salvage work was performed. One of the finest achievements of this nature was carried out by Commander G. Davis, R.N.R., D.S.C., who safely raised and beached the UC 44.


Not only were the stealthy U-boats sending ships to the bottom with torpedoes and shells, but the enemy had also brought to high perfection a type of submarine that was particularly designed for laying mines. Operating in the shipping channels that carried the heaviest traffic, these minelayers were a big menace, for they generally laid their batch of mines at night, coming and going unseen and in silence. The consequence was that channels along which ships may have passed safely in the evening would be fouled by the next morning. Many an unfortunate ship and crew paid the penalty next day.


Fleets of minesweepers went out regularly to sweep the channels and ensure that they were free of mines before any ships were allowed to pass along them. Submarine commanders, however, sometimes watched through their periscopes until they saw the sweepers complete their job, and then the submarines followed in their tracks to lay a batch of mines. As soon as the sweepers returned to harbour to report “all clear”, the steamers would venture out, with the result that more ships would go to the bottom.


Such mishaps were inclined to raise in the mind of the naval command a doubt whether the sweepers had done their job properly. As for the sweepers that had gone to the trouble of sweeping the channel, they spared no pains to get even with the enemy. From observation the patrols learned to know when a minelayer might be expected to lay a new batch of mines in a particular area, and occasionally the minesweepers pretended to sweep up the mines and deliberately refrained from doing so, with the result that some enemy submarines were blown up by striking against their own mines.


One of the main areas in which the submarine minelayers operated was on the route across the Irish Sea from Waterford to England. Hundreds of live cattle were being shipped regularly from the Irish port to feed the English people, and the enemy did their best to stop the shipments by surreptitious minelaying. A submarine usually came along about once a month to eject its deadly cargo. This sufficed to imprison all the steamers in the port until the naval command was satisfied the danger was removed. On Saturday, August 4, 1917, the sea off Waterford was as smooth as it could be. The local fishermen along the coast were keenly interested in the movements of the submarines. Just before midnight, when one or two fishermen were standing before the doors of their cabins, they heard a terrific explosion at sea. It reverberated along the coast for miles. The noise of the explosion had barely died away when faint cries were heard coming over the sea.


What it was, or what had happened, nobody knew, but several fishermen raced quickly to launch their boats and find out. In a short time three fishing boats were being pulled as fast as the fishermen could row in the direction whence the sound came. Spreading out in a line, they searched the seas. About four miles from the shore they heard a cry that drew their attention to something dark on the waters, and it was not long before the nearest boat hauled a man on board. Had it taken them much longer to find him he must have drowned, for he was exhausted. Heaping clothes over him to keep him warm, the fishermen pulled ashore. There the authorities took the man into their keeping for the rest of the war.


This man turned out to be Captain Tebbenjohanns of the UC 44. He had laid a batch of eight mines, when the ninth slid out of the launching chute and must have made contact with another mine. Whether this mine was one of his own, or whether it was one that had been laid previously, it is difficult to determine.


The greater part of the stern of the U-boat was blown to pieces. How Captain Tebbenjohanns managed to escape at all is still a mystery. In some extraordinary fashion, the explosion blew him to the surface, where the Irish fishermen found him and picked him up. His own miraculous escape seemed to concern him less than the scurvy trick that Fate had played him by making him bump one of his mines into another.


No sooner did the naval authorities at Waterford learn about the loss of the UC 44 than the order went forth to salve her. It was early on Sunday morning before they could gather what had really happened. On Monday, August 6, Commander G. Davis, whose work for the Salvage Section had already brought him to notice, was called upon to relinquish another job on which he was working and proceed without delay to Waterford to raise the U-boat. Commander Davis and his men toiled all through the night to load up the salvage vessel with the lifting wires and gear that would be needed. There was no limit to the hours they worked. Their tasks were all rush jobs. They spent their energy and skill in cheating the winds and tides, so they were forced to snatch a bite of food when they could and a wink of sleep now and again.


It was midnight on Tuesday when Commander Davis drew into Waterford harbour and made ready for the morning. At dawn the naval authority ordered the minesweepers to clear a passage so that Commander Davis could go out to investigate.


Although the minesweepers had been at work since the UC 44 blew up, the wisdom of this precaution was soon proved, for one of the unlucky sweepers herself hit a mine and sank.


The german submarine UC 44 beached near WaterfordCommander Davis went out with his salvage ship and trained men and quietly lifted the minesweeper and brought her back to shore.


This done, he dropped his grapnels and began to drag them over the area in which the submarine sank. After he had steamed back and forth for a time his grapnels caught. He buoyed the spot and a diver went down to see what was there. It was, as they expected and hoped, the UC 44. She was lying in ninety feet of water broadside on to the current that made it so hard for the divers to work. The difficulties of the task, however, made Commander Davis all the more determined to prove his skill.





BEACHED NEAR WATERFORD, in Ireland. After the salvage vessels had raised her. loaded with live mines, from a depth of ninety feet, the submarine UC 44 revealed to the British Admiralty many important features of German submarine design. The serrated teeth on her bows, for instance, were intended to cut through the anti-submarine nets that were laid in the English Channel and elsewhere.





The depredations of the submarines caused such serious alarm that the Admiralty was doubtful as to what the end would be. The naval authorities wanted this particular submarine, if they could get it, for several purposes. In the first place, they were anxious to see how the enemy were developing their minelaying submarines, so that the naval architects could study its weak and its strong points. They hoped that from it they might learn a method of countering its activities. There was also the chance that the papers had not been destroyed by the explosion. Thus the instructions given to the commander might prove of primary importance, for if the Admiralty learned what the submarines were instructed to do they might use this inside information to destroy the U-boats.


We know now what Commander Davis did not know then - that the UC 44 was a submarine of 500 tons displacement, and carried eighteen mines that could be launched through six chutes. In addition, she carried two torpedo tubes in the bow and one in the stern, as well as a gun on deck to enable her to take the offensive against any ship she met. The salvage officer was certain, however, that the submarine had a number of live mines in her, and there was always the risk that handling her might detonate one or more of the mines.


Commander Davis concluded that the best method of tackling the job was to work a number of cables under the U-boat until they formed a cradle in which she could be lifted from the bottom and gradually carried ashore. This ingenious method of lifting a vessel depends mainly on the rise and fall of the tide. Let us assume that the tide rises and falls 12 feet. At low tide a vessel floating on the surface is 12 feet nearer to a ship lying on the bottom than it is at high tide. It follows that if cables are swept under the wreck and attached to floating vessels capable of supporting the weight, the sunken ship will be lifted off the bottom when the tide rises, provided the cables have been tightened up to the last inch when the tide is at its lowest. Once the wreck is clear of the bottom it merely has to be towed towards the shore until it touches the bottom again. The process is then repeated at the next tide.


It was this simple and clever way of using the power of the sea to recover a sunken ship that Commander Davis employed. A cable was suspended between his ships and a loop of the cable was dropped to the seabed. This loop was dragged along until it worked under the submarine into the exact position desired. As soon as this was done, a buoy was fastened to either end of the cable. Another cable was then swept into place, and yet another, until a row of strong steel cables lay at intervals under the U-boat from bow to stern.


Lifted by the Tide


This task took the salvage crew just nine days. They turned in that night thinking that the back of the job was broken, but the weather ruled otherwise, for in its usual perverse way it began to blow a gale. The wind continued for twenty-four days. The minesweepers cleared the passage again on September 10. The salvage crew found that the seas had been playing ducks

and drakes with the buoys at the ends of the cables. They picked up the dropped ends and sorted out the cables that had become entangled, until their buoys once more lay in two neat parallel rows. Between these rows they towed and anchored one of the special lifting craft that came into existence during this war.


These lifting craft were originally huge flat-bottomed steel barges, capable of carrying a load of 1,200 tons. To equip them for salvage work they were decked in and fitted with a series of tanks that could be flooded and emptied at will. When these tanks were full of water the lifting craft floated 4 ft. 6 in. deeper than when they were empty. If, when the tanks were full, the lifting craft was attached to a wreck that did not weigh more than 1,200 tons, it was only necessary to empty the tanks to lift the wreck 4 ft. 6 in. clear of the bottom.


BETWEEN THESE LIFTING VESSELS the UC 44 was brought ashore



































BETWEEN THESE LIFTING VESSELS the UC 44 was brought ashore. Cables were slung beneath the wreck to form a cradle, and these cables were attached to the lifting vessels at low tide. The force of the rising tide lifted the vessels together with the wreck, which was carried inshore until it touched bottom again. This process was repeated until the wreck was finally beached.





Commander Davis fixed the buoyed ends of the cables to the special attachments down either side of his lifting vessel. As the tide touched the lowest point of the ebb, every cable was tightened to its limit. This left the lifting craft floating directly over the submarine as it lay in the cradle of cables under the salvage vessel. While the tide was rising the water in the tanks of the lifting vessel was driven out by compressed air, and after a time Commander Davis was gratified to find that the UC 44 was moving clear of the bottom. After an hour or two the salvage officer began to tow her toward the shore while the tide still flowed, so that, as she moved slowly along, the tide would raise her farther from the bottom and thus enable him to travel a greater distance. By the time they had moved her three-quarters of a mile she touched bottom again, and Commander Davis allowed her to rest until next day.


Once again they tightened the lifting cables as much as possible and began to tow the submarine shorewards as soon as the clearance was sufficient. At one time she bumped on the bottom and they held their breaths, expecting one of her mines to explode; but nothing happened, and they continued the work. They gained another three-quarters of a mile, and brought the submarine to rest about three miles from low-water mark. They toiled like galley slaves far into the night making many adjustments to prepare for the next day’s work.


The salvage workers knew all about the live mines on board and were aware that death might overtake them at any moment. They exercised all possible care to avoid calamity. One day as she was moved slowly along, the submarine slipped out of her cradle of cables and dropped on the seabed. The men braced themselves for the explosion for a few tense seconds; but luck was with them, and they breathed again. Then began the task of picking her up again.


Bight in their path lay a sandbank that sloped steeply upward for 14 feet. It was a most difficult obstacle to negotiate. If they had gone on towing the wreck without altering its trim the submarine would have bumped her nose into the bank. It was therefore essential, before they could lift her up this bank, to raise the nose of the submarine by shortening the slings until the angle at which she was being carried conformed to the slope of the bank. This entailed another risk, for she might slide out backwards through the cables.


Dangers of Unloading


Commander Davis placed one lifting-craft on either side of the wreck and readjusted the slings. Carefully, by exercising all their patience and ingenuity, they tilted and balanced the submarine in her cradle of cables and carried her to the top of the bank.

After that they had a clear run, and on September 25 she was beached high and dry. It took twenty lifting operations to carry her a distance of slightly over four miles.


Inside the submarine they found nine gigantic mines. These had to be handled with extreme care until they were rendered innocuous by the salvage officer. In addition there were several torpedoes and many shells for the gun mounted on her deck. The after portion of the vessel was blown right off, and a shattered mass of plates sagged at the broken end as if it had been so much matchboarding.


Commander Davis fully earned the Distinguished Service Cross that he won, for he brought ashore confidential papers of priceless value. These papers revealed the ruse that the enemy had adopted to deceive the British Admiralty into thinking that the submarine defences across the Straits of Dover were driving the submarines right round the north of Scotland.


The papers stated that it was best for the U-boats to pass the Dover nets on the surface, or if necessary to dive under the edge of the nets. If a submarine was compelled to go north round Scotland it was to show itself as much as possible in order to mislead the English.


This proof that the Dover submarine defences were not stopping the U-boats enabled the Admiralty to improve the defences.








































AN UNEXPLODED MINE being raised from the wreck of the salved submarine UC44. The submarine had nine live mines on board when she was wrecked in September 1917. Commander G. Davis - seen on the left of this photograph - successfully undertook the dangerous salvage work involved, and for this he was awarded the Distinguished Service Cross.



[From part 18 & part 19, published 9 & 16 June 1936]



You can read more on “Dramas of Salvage”, “A Trinity of Dramatic Exploits” and “The Unlucky K 13” on this website.