The Captain's Tale

The destruction of U-1051 by HMS Calder on 26th January, 1945, was a minor incident in the Battle of the Atlantic: a battle that raged unceasingly throughout sixty-eight months of the Second World War, with the loss of fourteen and a half million tons of shipping attributable to U-boat action, and the destruction of 781 German submarines, 632 being sunk at sea. Against such a vast canvas one small action has little significance excepting, perhaps, that it served as a classic example of the tactics employed by both sides during the final phase of that epic struggle. As the last weeks of the Battle took place British and American forces were vastly superior to the enemy in numerical terms. Boosted by the tremendous shipbuilding capacity of American yards, the Allies had not suffered serious losses in escorts for many months. On the other side the Germans had experienced a disastrous year during which the number of U-boats sunk had exceeded new construction for the first time. Technological advances were more evenly balanced, with the edge slightly in favour of the Allies. Only in terms of morale were the enemy still on equal terms - a remarkable example of fortitude when all the factors are considered.

Such was the scene that was set when HMS Calder sailed from Belfast as a unit of the Fourth Escort Group. Unattached to any convoy, the Group was to act as a 'striking force' to search out and destroy U-boats in the Irish Sea. The morning of 26th January dawned cold and clear with a calm sea, unusual in these waters at this season. All six ships were at 'cruising stations', a state of readiness that allowed a third of the armament to be manned, while the hands off watch were engaged in routine tasks about the ship. In fact, it started just like so many other days in a long, dreary war. Lookouts scanned the sea for the 'feather' created by a periscope, or the tell-tale line of bubbles marking the passage of a torpedo. In the charthouse the radar operator focussed his eyes on the scan, searching for the tiny 'blip' that would provide the sole warning of a snorkel protruding above the surface, while above him in a little cabinet forward of the bridge two asdic ratings listened to the incessant 'pinging' of their set, awaiting the returning 'echo' from a submerged submarine. In the W/T office earphones were manned to receive messages from base and other ships: even the U-boat frequencies were monitored in the hope that the interception of a rash transmission would enable the sender's position to be fixed by the direction-finding equipment. The whole ship reverberated to the steady rumble of the main engines, an almost soporific murmur required to maintain the speed of twelve knots. On the bridge the officer-of-the-watch propped himself up against the compass, occasionally checking that the ship was keeping station within the Group, formed up in line abreast, 2,000 yards apart.

It was the W/T office that raised the first alert: an 'enemy report' was received from HMS Manners, a sistership with another group, indicating that she had been hit by an acoustic torpedo, but remained in contact with the U-boat. Her position was plotted off the coast of Anglesey, some fifteen miles distant. The Senior Officer of the Group in HMS Bentinck decided to detach his own ship and the Calder to the scene at maximum speed, leaving the other ships to follow at the more leisurely 21 knots dictated by their diesel-electric engines. 'Action stations' alarms rang out through the Calder as she heeled over to take up her new course, and the two hundred men that made up the ship's company scurried to their allotted positions in a matter of seconds. Like the vast majority of British ships in the Western Approaches her crew were 90% 'hostilities only' - engaged solely for the duration of the War, and with an average age in the early twenties. Typical were her captain, Temporary Lieutenant-Commander 'Teddy' Playne, an architect in civil life, and her anti-submarine control officer, Temporary Sub-Lieutenant John Huckle, who had been at school when war was declared. Despite a distinctly 'amateur' attitude towards their duties, after eighteen months service almost continuously at sea this crew displayed a discipline and efficiency that would be the envy of any peacetime naval unit. An air of expectancy gripped all aboard as they enjoyed the rare luxury of tearing through the water at full speed.

The half-hour dash towards the stricken Manners was occupied preparing for the forthcoming action. In the charthouse the captain and navigator consulted a chart on which all known wrecks were plotted: they were not too pleased to discover that Manners' position coincided with a positive graveyard of sunken ships. The guns' crews swung their weapons around menacingly as they checked for full and free movement. In the asdic cabinet fresh rolls of paper were fitted in the recorders to ensure they did not run out at a critical moment. Below decks damage control parties readied the shores that would support the bulkheads if the ship was holed. While all this was taking place another message was received from Manners: she had been struck by another torpedo! Tragically, this too had hit the stern where many officers and men were gathered making good the damage caused by the first explosion, and in consequence she had now suffered heavy casualties. Nevertheless she continued to pass on vital information about the U-boat's movements, a fine example of courage and devotion to duty.

Shortly after, the lookout in the crow's nest reported Manners visible on the horizon. As the stricken vessel was closed she was seen to be still riding high in the water despite the hull being cut off at the quarterdeck, and many recalled the controversy that had raged when the all-welded hulls of these ships were first delivered to the Royal Navy. Welding had been adopted in the United States as the most convenient means of introducing mass-production into the wartime shipyards. In Britain most hulls were still riveted, the popular belief being that rivets provided an essential 'give' without which the hull would simply split asunder from the force of an explosion. Manners' survival completely vindicated her American builders: very few ships of barely 1,300 tons remained afloat after being struck by two torpedoes, and had she been riveted her condition must have been far more serious. She was even able to pass the range and bearing of the U-boat to the approaching assistance: invaluable information, for it removed the necessity to establish a time-consuming search pattern.

Within minutes both Calder and Bentinck were in contact with a target which appeared to have remained at periscope depth, either with the intention of delivering the coup de grace to Manners, or of picking off the newly-arrived support. To prevent the enemy adopting either option immediate depth-charge attacks were delivered by both ships, the only apparent result being that the U-boat decided that discretion might prove the better part of valour, and he retreated to the murky depths of the Irish Sea. If the U-boat commander possessed a chart of the wrecks he must have assessed that his chance of escaping was good, for the hunters would be easily misled by the echoes returning from these nearby obstructions. Even without this encouragement he would be aware that a submarine creeping along near the bottom would be difficult to attack accurately, for the Germans possessed a considerable knowledge of our equipment and its limitations. His subsequent manoeuvres plainly indicated that this particular captain had 'read his books'.

The arrival of the remainder of the Group enabled Calder and Bentinck to commence a series of deliberate attacks. While four ships circled around 'holding the ring', the two in the middle poured pattern after pattern of high explosive into the water. Before each run the attacking vessel would open out to about 1,500 yards from the target before turning to commence the run in, while her consort remained at a distance holding asdic contact. Half a mile from the target the attacker would increase speed to 18 knots to avoid damage from the explosion of her own charges when they were dropped. The captain would direct the attack on the information he was receiving continuously from the asdic cabinet, success depending upon three factors: the quality of that information: the ability of the captain to 'interpret' it and 'guess' his opponent's intentions: and finally, the drill of the depth-charge crew to ensure the pattern was dropped at precisely the correct time with proper spacing. Many believe that once a U-boat was located its destruction was a relatively simple matter. This was not true, and it is necessary to consider some of the limitations imposed by the anti-submarine equipment in use at that time. In ideal conditions asdic sets provided a good range and bearing of the enemy, but the type of set installed in Calder would not hold contact right up to the target. The deeper the U-boat, the greater the range at which contact was lost, so an enemy near the bed of the Irish Sea would disappear from the instruments at 200-300 yards. While this distance was being covered he would be free to turn or alter his speed undetected. Furthermore, depth-charges required several seconds to sink to the seabed, providing even longer for avoiding action. All this was known to the enemy who, by listening to the asdic transmissions, could gain a very good idea when contact was lost and time his evasion accordingly. So it was very much a 'guessing game': the attacking captain guessing' the U-boat's probable course of action, while the enemy would try to assess what the hunter might be expecting, and so take a different tack.

The commander of U-1051 soon showed that he knew all the tricks of his trade: a 'Wily Bird' or 'Artful Dodger' in fact. For nearly four hours he dexterously avoided the attacks by both ships, so far as can be judged without suffering substantial damage, although the conditions inside his boat must have been wellnigh intolerable under the constant barrage of exploding charges. His general policy was to move slowly in a slight curve, only using a sharper turn or burst of speed at the very last moment to avoid the descending charges. These tactics not only preserved his craft intact: they also served to shake the confidence of the hunters. After a considerable expenditure of depth-charges it was only natural that they should begin to doubt whether their quarry really was a U-boat, or some non-submarine target. The first to voice this concern was the Senior Officer when he tersely asked Calder to confirm that she was on the correct target.

What evidence was there enabling Teddy Playne to make a positive assertion? There was no doubt that a U-boat had been present at the start: "Manners'" stern was testimony enough! It was also fairly certain that the enemy had remained near the surface until after the first attacks, and had then gone down near the bottom. Differentiating between a U-boat near the bottom and a wreck was a far more delicate matter, relying on small, rather technical details, backed by experience and 'instinct'. Firstly the target's apparent movement conformed to the tactics U-boats were known to employ in these circumstances, and this was backed by confirmatory evidence: 'hydrophone' and 'doppler' effects had both been detected. 'Hydrophone' effect is easily explained: it is caused by the noise produced by a U-boat which may be picked up by the asdic set. However, by itself it cannot be regarded as conclusive since a strong tide running through a wreck can also produce it. 'Doppler' effect is more difficult to describe: basically the note of the returning asdic 'echo' changes pitch dependent upon whether the target is approaching or receding and, unlike hydrophone effect, this could not be produced by non-submarine targets. Finally there was one piece of almost bizarre evidence to take into account. Depth-charge attacks on wrecks usually resulted in large numbers of dead fish rising to the surface, and these had not been apparent. Convinced they had retained a firm contact with the U-boat throughout, Calder's asdic team supplied their captain with an emphatic reply with which to reassure Bentinck.

Absolute certainty about the movements of a wily enemy 200 feet below the surface is not easy to communicate, especially when it is based upon the use of out-moded equipment operated by a team of youngsters with minimal naval training. Doubts persist, and to settle these Teddy Playne decided to adopt a bold course of action. He would attempt to run directly over the U-boat whilst using the navigational echo-sounder, a machine that gave a picture of the seabed immediately below the keel. If he could con Calder sufficiently accurately, then the trace would show the U-boat as a faint mark a few feet above the bottom, putting the matter beyond all reasonable dispute. Success would also provide his asdic team with fresh hope and inspiration. Absolute accuracy was the vital ingredient in this ploy, yet he would be relying upon equipment that had not been designed for the purpose, and knew that he was bound to lose contact before the target was reached. If the U-boat was to be lulled into a false sense of security subterfuge would be required. If he crept up upon the target at a steady eight knots perhaps he could avoid provoking the enemy into a sudden alteration of course and speed. To assist him the asdic crew would not reduce the transmission interval during the approach, misleading the U-boat commander into believing they were still an appreciable distance away, even when right overhead. As this stealthy operation commenced, the Senior Officer, still doubtful whether the target justified further pursuit, withdrew Bentinck to the outer ring, inviting the Senior Officer of another group which had reached the scene to move to the centre of the stage to "take a sniff".

Slowly Calder slid across the calm sea towards its quarry, only the monotonous 'pinging' of the asdic set, the quiet reports of range and bearing, and the captain's occasional orders to the helmsman breaking the silence on the bridge. Across the horizon, not many miles distant, a hospital ship maintained her course towards Liverpool, clearly relying upon the sanctity of the red crosses prominently displayed on her hull and ignored by friend and foe alike. At 1,000 yards the asdic team stabilised the transmission interval: at 500 yards the navigator switched on the echo-sounder: at 200 yards contact was lost: at least the enemy remained deep and was not coming up to take a pot at his tormentor! At the precise moment that the asdic cabinet reported "Overhead target" a near-shout from the charthouse informed the captain "Echo twenty feet off the bottom, Sir!", followed in a lower tone as the young Sub-Lieutenant recalled his Dartmouth training, "Must be our sub, Sir!". It was remarkable how this news revived the spirits of all aboard. All doubts were now at rest. Their captain and the asdic team had demonstrated that they were capable of conducting the most difficult and skilful operation demanded of an anti-submarine vessel.

Jubilation was short-lived: despite this fresh and seemingly irrefutable evidence, the Senior Officer of the other group in HMS Aylmer decided that after taking a sniff the contact was probably not a U-boat, although he did agree to support a further attack by Calder. To add to their frustration at this moment, the very slow approach had enabled Calder's asdic team to calibrate the equipment with great precision and a defect had been detected! Ironically this could be attributed to their having tried too hard! During the time required to reach the Manners a small, but vital part had been replaced in the set by a brand-new component simply to ensure 100% efficiency when the action was joined. This had affected the alignment of the equipment which meant that all the attacks launched so far might have been slightly off target! It was an apologetic anti-submarine control officer and senior rating who reported to their captain as they hurried below to make an adjustment. Fortunately the rectification required only a few seconds during which contact wes not lost.

As Aylmer did not appear interested in making an attack, Teddy Playne turned Calder about once more with the intention of using the 'Hedgehog' for the first time, enabling him to deploy the same careful, slow approach that had proven so successful. Below them the U-boat continued its leisurely meanders across the floor of the sea, her captain unaware that Nemesis was stalking up upon him. This was as it should be, for the Hedgehog was a precision weapon relying upon a bomb actually striking the U-boat to achieve a kill. Eventually the moment arrived to press the firing button. Away went the bombs high into the air, seaming to hang at the peak of their trajectory for an interminable time before turning and plunging into the water in an elliptical pattern. As Calder crept up to the tiny swirls that marked the points of entry, seconds ticked away and hopes began to fade. Only the asdic officer, stopwatch in hand, knew that there was still time before the bombs reached the seabed. Suddenly one sharp explosion! Followed almost immediately by a muffled roar as the rest of the pattern exploded harmlessly on the bottom. A hit had been scored!

Calder increased to full speed to clear the spot and then turned to point towards the target. As she did so a dark shape erupted from the calm surface. Like a wounded whale the U-boat had come to the top, either to surrender, or to use her last gasping breath to avenge herself upon the hunters, for she may still have been capable of firing torpedoes or using her gun to inflict damage. Calder's guns swung round onto her port bow, the close-range weapons commencing an immediate bombardment of the submarine, tracer shells bursting on the hull and conning tower, or glancing off to explode harmlessly in the air. The 3-inch guns should have opened fire at the same time, but an altercation broke out between the gunlayers and the Control Officer, a fiery Scot, who had neglected to pass the target's range! As the distance between the Calder and her adversary could scarcely have been less, 'Guns' was not too pleased at having his drill questioned and responded in very naval language that the range was of no importance. Whereupon his crews opened fire, securing immediate hits. It was fortunate that at the height of the firing Teddy Playne noticed that his hitherto reluctant partner Aylmer was now dashing in at full speed, clearly intent on ramming. In the nick of time he pressed the 'cease-firing' gongs.

As the fearful racket of the gunfire stopped the ship was left wrapped in an awesome silence while the crew watched in horror as Aylmer's bow rode up over the U-boat and came to an abrupt halt. Escaping air arose in clouds like steam from the fractured hull. Then U-1051 slipped below the surface once more, leaving only a stream of bubbles marking the spot where she sank, and Aylmer there alone, with a badly crumpled stem. Although dramatic, this climax was also tragic in that Aylmer's precipitate action sealed the fate of a gallant U-boat crew who might otherwise have been spared to assist in reconstruction of their devastated homeland, destined to surrender in a few short weeks. There was little real excuse for this ramming, which was contrary to Admiralty orders at that time. Even under the most favourable circumstances it was always a risky undertaking which could easily result in severe damage to the ship necessitating a refit in the over-worked dockyards. Nor did it assist towards the capture of the enemy, which, apart from humanitarian considerations, was always a top priority if his latest equipment and tactics were to be studied. Perhaps the frustration of Calder's captain at being denied this opportunity to take a valuable prize prompted his curt reply to Aylmer's congratulatory signal "Your bird I think?". Back flashed "Yes - and your refit!", which was as near insubordination as a junior captain dared to go when addressing a Senior Officer of a group. That evening Calder's asdic team speculated on what might have transpired had the equipment been at full efficiency throughout the day. Had one of the early depth charge attacks crippled the U-boat, they might now be returning to base towing a defeated enemy. As it was the Fourth Escort Group resumed its patrol: line abreast; 2,000 yards between ships; speed twelve knots.