The Secret Capture

by Stephen Roskill

  In 1958 the Captain of the Seal wrote to the author of this book a very generous letter setting out the salient facts of what he called “ the most momentous days in his life.” In this letter he recalled how his damaged ship went to the bottom of the Kattegat at about 6.30 p.m. on 4th May, 1941, and how he had to wait until it became dark at about 11 p.m. before trying to bring her to the surface again. As the next day would begin to break at 3 a.m. he knew that he had not more than four hours of night time in which to make good his escape. “ For the next 2½ hours,” he wrote, “ we tried everything that I or anyone else could think of to get to the surface, but without success. At 1.30 a.m. I therefore called the whole crew into the Control Room to say prayers before we made one final attempt. We had no new ideas to try, and I myself could not see any reason why we should be more successful than before; but in the back of my mind was the thought, ‘with God all things are possible.’ Then, after I had said prayers, a new idea came to me. We were lying with our bows inclined 30 degrees upwards, and it occurred to me that if I could get more weight at the forward end without adding to our total weight it might succeed in breaking our stern out of the muddy bottom. We therefore rigged a handline from the torpedo compartment to the control room, and all men who could be spared from other duties hauled themselves right forward along the line. Then we made our final effort and, as you know, at once came to the surface. Our small Faith had been answered in a way that, to many of us seemed miraculous. When we opened the conning tower hatch we found our bows were pointing directly towards the Danish coast, which had just been occupied by the Germans. I did all I could to turn her towards Gothenburg in Sweden, which I hoped to reach; but she obstinately refused to point in any direction except Denmark. It was my Coxswain, Joe Higgins, who jocularly suggested that we might get to Sweden stern first. Higgins was one of the finest men who ever lived—always cheerful and efficient, and his spirit rose above every difficulty. During the next five years in prisoner-of-war camps his example of moral courage and cheerfulness was worth more to those around him than man can measure. He was a humble man, but a very great one. When last I heard from him he was working for Gamages.

  “ I do not expect,” Lonsdale continued in his letter, “ ever to forget the shock which I experienced a few days after my capture when out for a walk under guard at Kiel, I saw the Seal being towed into port; nor, almost worse, when on leaving Kiel for the prison camp I caught sight of her in dry dock. Later on we read reports in German papers about how she was helping our enemies; and it was indeed an immense relief to find out after the war that those reports were not true …. Looking back it is, of course, obvious that apart from what we did to minimise the consequences of the disaster, the one additional measure necessary was for me to stay behind and see that she was sunk by one or other of the measures we might have tried.” Even if true, that re-appraisal of his actions takes no account of the effects of the tremendous ordeal through which he and his men had just passed.1

  Two months after the Seal was captured another British submarine underwent a somewhat similar ordeal while on patrol in the Skagerrak. The Shark (Lieutenant-Commander P. N. Buckley) was a much smaller vessel than the Seal, and displaced only 960 tons when submerged. But at that time of year in those latitudes there was practically no darkness, and soon after Buckley had surfaced to charge batteries at about 10 p.m. on 5th July he was attacked by German aircraft while in the act of diving, and suffered such severe damage that he had to resurface. The Shark’s crew, who could not use their 3-inch gun because of the structural damage, then fought the attackers with their smaller weapons, and shot down one aircraft. But they themselves suffered heavy casualties from machine-gun fire, and after running out of ammunition they could only await the arrival of surface craft. Next morning two German minesweeping trawlers arrived, took off the wounded and the survivors, and then tried to take the Shark in tow. Although the last man to leave the stricken submarine had opened her ballast tanks to the sea, she did not sink until the towing trawler went ahead. Probably her hydroplanes (vertical rudders) were angled to force her downwards. The Germans thus gained nothing of any value; but the loss of the Shark did emphasise the grave danger of sending submarines into those waters during the summer months.

  Little more than a month after the disaster to the Seal, to be precise on 19th June, 1940, the Italian submarine Galileo Galilei was captured in the Red Sea, and brought into Aden. Three days previously she had sunk a Norwegian tanker, the James Stove, and then used her guns to stop a Yugoslav freighter, whom she subsequently released. The gunfire was reported by coast-watchers, and Gladiator fighters of No. 94 Squadron of the R.A.F. were sent out to investigate its source.

  On the 18th a Gladiator sighted the Galilei about 30 miles south-east of Aden, and shadowed her until a Blenheim bomber arrived. The submarine was then on the surface charging her batteries; but she dived as the Blenheim attacked, and neither the bombs nor the Gladiator’s machine-gun fire did her appreciable damage. Meanwhile the destroyer Kandahar and the sloop Shoreham had been sent out from Aden hot foot, to reinforce the search by several patrol vessels which were already in the vicinity. The Kandahar, under Commander W. G. A. Robson1, was one of the four modern destroyers sent through the Suez Canal from the Mediterranean when Italy’s attitude became threatening; while the Shoreham, under Lieutenant-Commander F. D. Miller, belonged to the Red Sea Escort Force which then formed part of Vice-Admiral Sir Ralph Leatham’s East Indies Command.

  After dark on the 18th the hunted Italian submarine surfaced, and was rash enough to use her wireless. The Kandahar picked up her transmission and led the search in the right direction. It was the Shoreham, however, who gained the first contact; but the submarine dived at 7.30 p.m. and successfully evaded two attacks. The larger British ships, believing the enemy to have been damaged, now withdrew, leaving the small trawler Moonstone, whose skipper was Bosun W. J. H. Moorman, on patrol. Moorman had entered the Navy in 1921 from the Greenwich Royal Hospital School at the age of 15 ½, and was promoted to Warrant Officer in 1936. The trawler was his first command, and when he commissioned her at Malta shortly before the outbreak of war he could hardly have imagined that it would fall to his lot to achieve the first capture of an enemy submarine. When he received orders to hurry off to sea on the evening of the 18th half his crew were ashore on leave. They were at once recalled, and three of them, including the gunlayer of the only 4-inch gun, actually scrambled aboard from a private motor boat as she was leaving harbour. It would have been difficult for the trawler to fight an action without those three men.

  In the early hours of the 19th the Galilei surfaced for a short time, probably to refresh the air inside her hull; but at 2.30 a.m. she submerged again. Blenheims of No. 203 Squadron searched a wide area of sea at dawn, but in the overcast monsoon weather then prevailing they failed to resight the quarry. Not until 11.37 a.m., when the Moonstone obtained an Asdic contact at long range, was any further sign of her presence obtained. Because the little trawler could only make headway slowly in the heavy sea then running, she could not fire a full pattern of depth charges without grave risk of injuring herself. Moorman therefore dropped only one charge, set to explode at 150 feet; but the submarine had probably heard her approach, and had gone deep. Nearly an hour later the trawler regained contact at only 300 yards range, and quickly dropped another charge, followed by a second one. A few minutes later the Galilei came to the surface about a mile astern of the trawler, and opened fire on her tormentor with machine guns. The Moonstone promptly reversed her course, and returned the enemy’s fire to such good effect that the Italians were prevented from manning their two 3.9-inch guns. Then, closing to 500 yards, the trawler swept the submarine’s decks with a hail of machine-gun bullets, and scored several hits on her conning tower with 4-inch shells. One of these latter killed the Galilei’s captain (Capitano di Corvetta Corrado Nardi) and, according to eye-witnesses in the Moonstone, produced something like panic among her crew who rushed on deck
, hauled down their colours and waved white clothing as a further sign of surrender. At 12.25 the Moonstone accordingly ceased fire, and closed her adversary with the intention of taking possession of the prize; but her boat had been damaged by bullets, and Moorman therefore decided to await the arrival of reinforcements. Next another aircraft came on the scene, and, not realising that the Galilei had surrendered, dropped two bombs and fired her machine guns. Luckily no damage was done. At 1.34 p.m. the Kandahar arrived, sent a prize crew on board the submarine and took her in tow. The rough sea, however, made towing very difficult, and the wire soon parted; but the engineers in the prize crew got the captive’s main engines running, and she actually arrived in Aden, with the White Ensign flying above the Italian flag, under her own power. British records show that the Galilei lost thirteen of her crew by gunfire or drowning, and had four more wounded; three officers and 37 ratings from her landed at Aden as prisoners. The Italian naval historian on the other hand states that she was “ found drifting aimlessly after almost all of her officers and crew had been killed in the attack, and her surviving crew members had become totally incapacitated by gas poisoning ” (from the refrigeration plant)1 —a version of these events which receives little support from a large number of reliable eye witnesses.

  The prize was a very valuable one, and from her we obtained intelligence regarding the disposition of other Italian submarines in the Red Sea and Indian Ocean. As a result we caught and sank the Torricelli on the 22nd June, and the Galvani, which was patrolling in the Persian Gulf to catch our tanker traffic, on the following day. For his part in the capture of the Galilei Mr. Moorman and his Second-in-Command, Midshipman M. J. Hunter, R.N.R., were both decorated with the D.S.C., and Moorman was specially selected to take courses for promotion to commissioned rank. He retired as a Lieutenant-Commander in 1950.

  In December 1940, the Galilei was brought up the Red Sea by a British crew, and passed through the Suez Canal to Alexandria, where her hull and equipment were very thoroughly inspected. Known at different times as the X.2 and P.711 in British service, the only operational use we made of her was for anti-submarine training. She remained at Alexandria until sold for scrap after the end of the war.

  The next capture took place in the North Atlantic on 9th May, 1941, thousands of miles away from the scene of the Galilei’s surrender; and it is with that story that this book is principally concerned. At almost exactly the date when we captured U.110, a new 770-ton Type VII ?. Atlantic boat numbered U.570 started her first and only commission under Korvettenkapitän Hans Rahmlow. After completing her trials at Horten in Oslo fiord she left for Trondheim on 20th July; but on her way she damaged herself slightly in a crash dive on to a rocky bottom, made to avoid attack by British aircraft. After docking for repairs she left Trondheim on 24th August. Her orders were to operate to the south of Iceland for a month, and then proceed to La Pallice in western France. Rahmlow passed to the north of the Faeroes, mostly on the surface, and reached his operational area undetected. Soon after he had arrived on patrol U-boat headquarters signalled to U.570 and about a dozen other boats to attack a convoy which was already being shadowed. There were in fact three homeward convoys, all fairly close together, in the eastern half of the north Atlantic at the time, and it is impossible to say for certain which of them the enemy intended to attack. The probability is that it was the fast Halifax convoy HX.145; but the preceding convoy of that series, HX.144, was only about 300 miles ahead of it, while the slow convoy SC.40 from Sydney (Cape Breton Island) was about midway between the two fast convoys. The ever-watchful Submarine Tracking Room in the Admiralty had, however, sensed the danger; and diversions were ordered to keep the convoys out of harm’s way. It is now plain that they all passed well to the south of the U-boat patrol Une established by the enemy. No losses were suffered by any of them.

  Rahmlow’s crew was inexperienced, and many of his men suffered constantly from sea-sickness. Nor had U.570 achieved a satisfactory standard of fighting efficiency. Moreover in submarine warfare the margin between success and disaster is often extremely narrow, and at moments of crisis everything depends on the calmness, experience and determination of the Captain, and on the confidence which the crew feel in him. Events were to show that in none of these respects was Rahmlow’s leadership up to the high standard achieved by most U-boat Captains.

  Early on 27th August Rahmlow dived to 90 feet in order to gain some respite for his crew, who were not enjoying the heavy seas then running. He was at the time in 62° 15′ North, 18° 35′ West—some 80 miles south of Iceland. Two hours later (to be precise at 10.50 a.m.) he came to the surface again, and at a most unlucky moment; for Hudson “ S ” of No. 269 Squadron of Coastal Command (Squadron-Leader J. H. Thompson, R.A.F.) which was flying an anti-submarine patrol from Kaldadarnes airfield in Iceland, was passing exactly overhead. Rahmlow had to act promptly, and he tried to crash dive; but Thompson was too quick for him. Diving from 500 feet almost to the surface of the sea he dropped four 250-pound depth charges, which exactly straddled the target. They were set to explode at only 50 feet, and the detonations smothered the U-boat in spray and shook her savagely. Inside the boat instruments were smashed and all was thrown into confusion. A certain amount of sea water entered, thus producing fear of that submariner’s nightmare— chlorine gas from the batteries. Rahmlow was convinced— probably too easily—that all was lost, and ordered the crew to put on life jackets and assemble in the conning tower.

  When the plumes and spray from the depth charge explosions subsided the Hudson’s crew saw U.570 still on the surface, and slightly down by the bows. Men were coming out of the conning tower, and to prevent them manning their guns Thompson opened fire. The Germans then sought shelter in the conning tower, to reappear a few minutes later showing, firstly, a white flag, and then a large white-painted board. Their intention was obvious—but it was scarcely within the capabilities of the Hudson to take possession of her prize. Thompson therefore reported what had happened to his base, and continued to circle the U-boat watchfully, ready to attack again if she made an attempt to escape. In the afternoon Catalina J. of No. 209 Squadron (Flying Officer E. A. Jewiss) which had flown from Lough Erne in Northern Ireland, relieved Thompson’s Hudson, and the vigil continued.

  The nearest anti-submarine vessels had meanwhile been ordered to close the position at full speed; but none was very close, and the Catalina was therefore told that, if no ship had arrived by nightfall she was to warn the crew and then sink the U-boat. Luckily a trawler, the Northern Chief (Lieutenant N. L. Knight, R.N.R.) arrived at 10.50 p.m.; but the sea was too rough to enable her to launch a boat. The U-boat’s crew must have passed a wretched day, huddled in the conning tower; but some of her officers did brave the dangers of chlorine gas and go below to destroy all confidential material. They also sent a signal to U-boat headquarters, reporting that they had been captured, and then damaged a good many instruments with hammers. Had a surface ship been able to arrive earlier it is likely that we would have captured the U-boat entirely intact, with great gain to our intelligence authorities; but that was not to be. To discourage her crew from scuttling, the Northern Chief next signalled that if they did so they would not be picked up. In November 1939 the Admiralty had approved the passing of orders of that nature, to discourage intercepted enemy merchantmen from sinking themselves; but they had added the proviso that the enemy crews were in fact always to be rescued.1 There is no doubt at all that the survivors of U.570 would have been treated in the same manner, even had they scuttled; but the threat seems to have had the desired effect, for she replied, rather pathetically, to the Northern Chief’s signal saying, “ I cannot scuttle or abandon. Save us to-morrow please.”

  At 3.30 a.m. next morning (28th August) another trawler, the Kingston Agate (Lieutenant H. O. Lestrange, R.N.R.), which was fitted for towing, arrived; and she was soon followed by the destroyer Burwell (formerly the Laub, one of the old American ships transferred to Britain under the “ destroyers for
bases ” deal), two more trawlers (the Wastwater and Windermere), and the Canadian destroyer Niagara. Another aircraft (manned by a Norwegian crew) also appeared and, apparently not having heard the news that U.570 had surrendered, dropped two depth charges. Luckily they did no damage. Soon after daylight the Burwell and the “ Lake ” class trawlers tried to take the U-boat in tow; but they were not suited to, or properly equipped for such a task—certainly not in the heavy sea then running. At about noon the First Lieutenant of the Kingston Agate (Temporary Lieutenant H. B. Campbell, R.N.V.R.) suggested that he might get aboard the U-boat by floating down to her on a Carley life-saving raft. His Captain at once accepted the proposal, and two of his crew volunteered to go with the First Lieutenant on what was bound to be a difficult and hazardous exploit. A line was therefore shot across to the U-boat, and very soon the three men were making the crossing. As an eye witness later described it, “ One minute they were in sight of us lining the deck (of the trawler) and the next they were hidden by the towering seas.” Campbell and his men got aboard the U-boat safely, forced the crew to lend them a hand, hauled across a tow rope from the Kingston Agate, and successfully secured it to the stern of the prize—in spite of being nearly swept overboard as they crawled aft along the submarine’s narrow deck. Altogether they were on board her for about five hours, and Lieutenant Campbell was the last to leave her—after all the Germans had been safely transhipped to the Kingston Agate. He had carried out a remarkably fine feat of seamanship in very difficult conditions.

  The trawler now took the U-boat in tow stern first; but her troubles were by no means yet over, for the tow line parted several times. Finally the Northern Chief took over the tow from the Kingston Agate, who returned to Iceland at full speed with the prisoners. U.570 was successfully beached at Thorlakshafn in Iceland late on the 29th. The initial inspections were made by experienced British submarine officers, who found that U.570 had in fact suffered very little damage. Main engines and motors, pumps and auxiliary machinery were all in working order, little water had entered the hull, and danger from chlorine gas must have been imagined by her German crew. On 5th September she was towed off the beach, and taken round to Hvalfiord. Exactly a fortnight later she was declared seaworthy. She left Hvalfiord re-christened as H.M.S. Graph, under Lieutenant G. R. Colvin on 29th September and reached Barrow-in-Furness on 3rd October. After refitting there in the Vickers yard she carried out very extensive trials from the Clyde, and from those trials we gained information of inestimable value to our own anti-submarine forces; for we now knew exactly what we had to contend with in the case of the most popular type of Atlantic U-boat. No less than 659 of the 869 boats commissioned by the Germans in the second world war were of the same type as U.570.