Chapter 4: British Countermeasures by Sea and Air
See Map 2, facing p. 50, and Map 1(b), facing p. 56
On 10th April the story of the initial German successes blends with that of the British counter thrusts by sea and air. These thrusts were delivered by sea more than by air because of the air supremacy which the Germans had already demonstrated in southern Norway over land and sea, and in the North more than in the south for the same reason. At Narvik the Germans, as they well knew, were running in any case a heavy risk by venturing ten of their relatively few modern destroyers on a voyage so far to the northward that the slightest hitch in the turn round would enable them to be bottled up by superior British forces. Ruthlessness, as we have seen, had achieved the rapid surrender of the port to the formidable German expedition in the early morning of the 9th. But for reasons which are not wholly clear the British Admiralty remained dependent upon press reports stating that one German ship had arrived at Narvik, no better information being obtained until 4 p.m., when an officer was sent ashore at the Vestfjord pilot station of Tranöy, some fifty miles to the west. His ship belonged to a force of four (later increased off Tranöy to five) destroyers of the ‘H’ class, about one-third lighter than the German destroyers, which had been despatched by Admiral Whitworth in the early morning to patrol the entrance to the Vestfjord, pending a rendezvous with the Renown (still chasing the Gneisenau and Scharnhorst) and the Repulse. But the Commander-in-Chief and the Admiralty had later given direct orders to the flotilla commander to proceed to Narvik, and they were actually on their way in when they learnt approximately what had happened there.
Captain B. A. W. Warburton-Lee, in the flotilla leader Hardy, was told by the Norwegian pilots that six ships larger than his and a submarine had been sighted making for Narvik, which the Germans held very strongly, and that the harbour entrance was mined. He reported this to the Admiralty, the Commander-in-Chief, and Vice-Admiral Whitworth, and at the same time announced his intention of attacking at dawn high water (dawn for surprise, high water for protection against mines) in accordance with the instructions which the Admiralty had sent him at midday on the strength of the misleading press reports referred to above. Admiral Whitworth had already been
considering the possibility of reinforcement, with the knowledge that the ships at his disposal would shortly include the Repulse, the Penelope, and four additional destroyers.1 But he maintained his decision that he could only reinforce at the cost of the postponement of the attack, for which the order had been issued direct to his subordinate officer. The final Admiralty telegram at 1:36 a.m. on the 10th,[1] which suggested that the two Norwegian men of war, in addition to the coastal batteries, might now be in the hands of the enemy, still left it to Captain Warburton-Lee to decide. ‘You alone can judge whether, in these circumstances, attack should then be made. We shall support whatever decision you take.’2 If the Admiralty had chosen to address either the Commander-in-Chief, Home Fleet, or Vice-Admiral Whitworth rather than their subordinate officer, then the decision would probably have been to send in a more powerful force even at the cost of some delay; this might have lost the advantage of surprise but would almost certainly have finished off the German naval forces in one engagement instead of two and might even have provided the opportunity for an immediate landing. But Captain Warburton-Lee for his part of the more heroic course.
By this time the five destroyers had passed Tranöy again on their way in, under weather conditions so appalling that they only sighted land once and that when they were about to run aground. The speed of approach along the Ofotfjord was therefore very slow, stern lights being in use to keep formation, but the poor visibility also contributed to the completeness of the surprise. Our ships were not spotted by the German submarines stationed in the outer fjord, which had been misled by sighting them the previous evening sailing in the opposite direction to fill in time; and the one destroyer on patrol had returned to harbour without replacement ten minutes before the British flotilla made its attack. Five destroyers then lay in the harbour itself, including two which were alongside the tanker Jan Wellem refuelling: the slowing up of this process (between seven and eight hours for each pair of ships) through the non-arrival of a second tanker was in fact the reason why the German flotilla had not already left for home. Two destroyers were at anchor in the Ballangen fjord on the south side of the main fjord, about twelve miles short of Narvik; and the other three lay at a lesser distance along the small Herjangsfjord beyond the town.
At 4:30 a.m. the Hardy entered the harbour followed by the Hunter and Havock, while the Hotspur and Hostile stayed outside with orders to watch the supposed coastal fortification, the sea approaches by which they had come, and the two fjords which open past Narvik to
the north-east (where three German ships lay) and to the east. The surprise was complete. As the three destroyers in turn made the circuit of the harbour up to the narrow channel (since bridged) which forms the entrance to the Beisfjord, firing fifteen torpedoes and also using their guns, the Germans were still under the impression that it was an air attack. The first torpedo caused a formidable explosion on board the German flotilla leader, which killed Commodore Bonte, the naval officer in charge of the expedition, and caused the ship to capsize twenty-four hours later; a second destroyer broke into and sank on the spot; the fire control equipment was smashed in a third; and the other two destroyers in the harbour were temporarily disabled. The Hotspur was then sent in separately to fire her torpedoes, which sank two merchant ships. No counteraction having been observed from outside the harbour, a second attack was made: all five British ships engaged with their guns at the harbour mouth, particularly against the merchantmen lying inside, which were reported to contain military stores. By this time an hour had passed, and although the German warships in the harbour had returned our fire and received some help from the rifles and machine guns of the soldiers on land, the British flotilla was still virtually unscathed.
A short consultation was then held off Skjomnes. Captain Warburton-Lee concluded that not more than two enemy destroyers were located outside the harbour (four out of six were computed to be inside the harbour, which actually contained five out of ten), and ordered one more attack. The Hardy lead the line, which was snaked so as to keep guns bearing continuously on the misty harbour entrance, where each ship fired as she turned; the Hostile, in the rear, discharged her torpedoes. The number of German merchantmen destroyed rose to six; as the seventh had been beached the previous day, there remained only the important tanker Jan Wellem from Murmansk, which was by the pier and somehow still escaped damage. In substance, Captain Warburton-Lee had now completed the task he had set himself, since the German force was clearly too large for there to be any hope of silencing opposition completely, so as to land at the ore quay. It was at this point that his luck changed.
Towards 6 a.m., as the British flotilla, having completed its third attack, was about to retire down the Ofotfjord, it sighted the three German destroyers which had been lying away to the North East at the head of the Herjangsfjord. They had received the alarm at 5:15 and were making their way to the scene of action as fast as their depleted oil supply would allow. The British flotilla increased its speed while engagingly enemy as a range of about four miles. But only a few minutes after the Hardy had made the signal for withdrawal two more ships appeared out of the mist, coming up the Ofotfjord and cutting the line of retreat. These, which for a brief moment were
taken for a supporting force of British cruisers, were in fact the last two of the German destroyers—those which the British had passed unseen in the Ballangen fjord on their way in. Our ships were thus caught between two fires, but poor visibility helped them to force their way past to the south of the enemy, making it once more a stern chase. The flotilla continued to act upon captain Warburton-Lee’s final signal, ‘Keep on engaging enemy,’3 but the heavier German guns now began to take their toll. A shell burst on the Hardy’s bridge with such effect that for a few critical minutes the Captain’s Secretary was the only officer left there to take command. The ship had now lost steam and was on fire forward, so he ordered her to be beached, and she made the south shore about three miles east of Ballangen, were her crew, including many wounded, struggled ashore through the icy water and found safe shelter in the village. Captain Warburton-Lee, when at last persuaded to leave his ship, died of his wounds on the beach; his Victoria Cross was the first to be awarded in the war. The Hunter and Hotspur were both hit, collided, and drew heavy fire while locked together. The Hunter as a result sank in mid fjord, but the Hotspur though struck by seven 5-inch shells[2] was saved by the two remaining ships, which turned back from their position two miles ahead to cover her retirement. But the German ships which had done the damage—the two from Ballangen—had now received hits affecting their gunfire and the others were short of fuel (as already noted), so after half an hour they broke off the running fight and allowed the three British destroyers to withdraw unhindered.
These then scored a further important success by the destruction of the German ammunition ship Rauenfels, which they met and blew up on their way out. The German ships in Narvik had used up half their ammunition. When the two which had completed their refuelling and were in a condition to sail reached Tranöy that evening, they could discern a patrolling cruiser on the horizon and knew their fate was sealed.
During the next few days, Admiral Whitworth was instructed to prevent both the escape of enemy forces from Narvik and the arrival of reinforcements there, while the Admiralty prepared for a further attack. This was complicated by uncertainty as to the strength of the German force remaining and by simultaneous preparations for escorting a military expedition into the area. At one stage the cruiser Penelope was designated by the Admiralty to carry out a new operation, but while this was still under consideration she went in search of a rumoured enemy supply ship for Narvik—which, as it turned out, had already been secured by the destroyer Icarus—and grounded on
a rock near Bödo. She had therefore to join the Hotspur at Skjelfjord,4 near the southern extremity of the Lofotens, where ships were stationed to cover the approach to the Vestfjord and a repair depot was organised.
One remarkable feat had meanwhile been achieved farther south, when the unrewarded RAF bomber attack on the German ships at Bergen was renewed by the Fleet Air Arm5 at extreme range from their land base at Hatston, Orkneys, in the early morning of the 10th. 15 Skuas scored three direct hits by dive bombing on the damaged cruiser Königsberg, which sank in the harbour within three hours. This was the first major warship of either side to be destroyed by attack from the air. But it was not until the early hours of 11th April that the generally northward movement of the Home Fleet enabled the carrier Furious, which the Admiral had diverted from her intended employment in the Bergen area,6 to launch her aircraft against Trondheim. In the meantime the Germans were busy there, as at Bergen, in landing their forces and turning their ships round as quickly as possible. Accordingly, late in the evening of the 10th, after the Royal Air Force had completed its reconnaissance on which the plans for the Fleet Air Arm attack were based, the main prize, namely the Hipper, went to sea down the long Trondheimsfjord. Shortage of fuel had reduced her escort to a single destroyer, and this was forced to put back on account of the heavy seas; but the Hipper broke through to the north westward, eluding the watch kept by destroyers close inshore and then all but running into the Fleet itself, which patrolled farther west of the approaches to the port. Her luck held, however, and at the time when our aircraft were over Trondheim she was already preparing to swing southwards towards Germany. The objects of attack were thus reduced to four destroyers, of which the one mentioned above was still making its return journey to Trondheim. Eighteen torpedo carrying Swordfish aircraft left the Furious at 4 a.m. in a position ninety miles from the town and attacked two of the destroyers, which were all they could see except one submarine and merchant ships. Several torpedoes grounded in shallow water and exploded before reaching their targets; no hits were registered. On the return of the airmen, for whom this was their first taste of action, to the Furious, the fleet continued northwards towards Narvik, though two destroyers, detached on reconnaissance, made an approach independently to the batteries at the mouth of the Trondheimsfjord, were fired on, and fired back.
It was becoming clear that the larger elements in the German fleet had on this occasion slipped through our hands, though at midnight the submarine Spearfish, lying in wait off the Skaw, had succeeded in torpedoing the pocket battleship Lützow (as previously mentioned)7 and put her out of commission for a year. The Home Fleet therefore continued north on the 11th, when a second of its destroyers was disabled (but not sunk) by German aircraft, and next day it became possible to launch an air attack on Narvik harbour from the carrier Furious. The leading squadron left the ship soon after 4 p.m. on the 12th on a round flight of about 300 miles. There had been no prior reconnaissance, and only Admiralty charts were available which lacked contours. No German destroyer was hit, but some damage was done to enemy positions on land and three small units of the Norwegian Navy, taken over for German use, were sunk. Two of the eight aircraft were lost through enemy fire, but the crews were saved. The second squadron, starting forty minutes later, ran into very heavy snow and turned back without reaching its objective to land on the carrier in the gathering darkness.
On the same day the Admiralty finally gave orders to the Commander-in-Chief to employ a battleship with strong destroyer escort for the destruction of enemy forces and batteries in Narvik. This attack, timed for the afternoon of the next day (13th April), was entrusted to Admiral Whitworth, who therefore transferred his flag to the Warspite overnight in a heavy sea. It is safe to say that no 30,000 ton battleship, even one whose history stretched back to Jutland, had ever seen action in inland waters like these before. She would be exposed to the threefold risk of a suspected minefield, possible submarines (we now know that four had been sent to the Vestfjord area), and the torpedoes of enemy destroyers concealed in the side fjords. Nine destroyers were made available for a screen and striking force. Aircraft of the Furious, cruising with the heavy units of the Home Fleet to seaward of the Lofoten Islands, were also to conduct supporting operations against Narvik and supposed enemy positions farther out.
The squadron passed the Tranöy light about 11 a.m. next morning. A bomber from the Furious met them an hour later but found nothing to attack in the outer reaches of the fjord. More important was the help receive from the scouting aircraft of the Warspite, serving as the eyes of the fleet. Not only did it sink a submarine at the head of the Herjangsfjord (the first such success in the war), but it was able to observe and report the manoeuvres of the first two German destroyers, found in and around the narrows off Hamnesholm. One German destroyer retired, exchanging fire with the British ships at a range of
about seven miles, which was the limit of visibility. The other could not retire as she had been damaged by running aground two days previously—she had in fact been brought out with a view to future employment as a floating battery. This vessel made for Djupvik Bay on the south side of the fjord, where her torpedoes might have been used with effect against the Warspite, had not the battleship’s aircraft enabled the British squadron to make ready to put the German ship out of action as they passed the mouth of the bay. Our destroyers engaged her with torpedoes and gunfire, so that her own torpedoes passed clear, and her destruction was then completed by the Warspite.
By this time the rest of the German squadron had received the alarm and were emerging from the harbour, whereupon a general action began about a dozen miles from Narvik. The leading destroyers went up the fjord as much as three miles in advance of the battleship, which was engaging the enemy with her main armament insofar as the smoke and manoeuvres of the destroyer battle permitted. Only three out of six German destroyers could raise steam in time to unite with the Künne, the vessel which had fallen back before the British after giving the alarm. These four, to which a fifth was added later, joined action with the British destroyers. Their torpedoes, however, were without effect; and although their gunfire was at first a serious threat to the leading British destroyer, which was acting as guide of the fleet and also had minesweeping duties to perform, they were gradually forced back towards the harbour. At 1:50 p.m. the Germans, still undamaged but running short of ammunition, received the order to retire up the Rombaksfjord lying north and east of Narvik, though the Künne made for the Herjangsfjord instead. There she beached herself and was almost immediately torpedoed by the pursuing British destroyer Eskimo.
At this stage in the action the British secured a further success, as another of the ships still left in the harbour had now raised enough steam to leave, but was almost immediately overwhelmed. The only casualty among our ships had been the Punjabi, which was forced to withdraw with her main steam pipe damaged but returned within an hour. Unfortunately, however, the ten aircraft from the Furious, arriving over Narvik in good weather conditions after flying there through snow squalls, apparently failed to score any direct hits: two aircraft were lost. Stubborn opposition was also offered by the last destroyer, which was lying in an unseaworthy condition alongside the quay and was engaged for a time by the Warspite under the impression that it was a shore battery. But after the retirement of the other Germans three British destroyers entered the harbour and sank the enemy with torpedoes, which are said to have broken the quay as well. In the course of this attack the Cossack was hit and went aground at the south side of the entrance, just east of Ankenes.
But the main problem was the pursuit into the Rombaksfjord. Five miles up, the fjord narrows at Straumen to a neck only a quarter of a mile across, with the fairway for the reduced by rocks and by the tidal current from which the name derives. It subsequently opens out again between its sombre mountain walls, but there is no view through. The Warspite therefore did not proceed farther in, but sent up her aircraft (which spotted two of the German vessels already at the far end of the fjord) and prepared for indirect bombardment if necessary. Four British destroyers led by the Eskimo passed through the narrows and engaged two German ships, which were lying in wait with torpedoes in a very strong position just beyond. The Eskimo’s bows were blown off, so that the progress of her three consorts was held up until she could make her way back stern first through the narrows, where the wreckage struck bottom. Meanwhile two of the three had almost exhausted their ammunition and one of them also had two of her forward guns put out of action. However when these and two other British destroyers finally made their way through, they found that their most determined opponent had now run herself onto the rocks three miles up the fjord and that the other three all lay at the very end deserted by their crews, who had made off up a track to the railway. There was nothing more to be done but to search and finally to torpedo one ship which, although aground, remained upright. But the situation might well have been critical, because the configuration of the fjord made it impossible for more than two ships under way to operate simultaneously against an enemy ensconced in its farther end, and we had no means of knowing that the German retreat was conditioned, in part at least, by the exhaustion of their ammunition supply. The three hulls, one of them marked with a huge swastika, are still to be seen in that remote wilderness of barren rock, bearing silent witness to the long arm of British naval power.
By 5:30 p.m. the Warspite had returned to a position off Narvik, where the grounded Cossack was exchanging a desultory fire with small guns across the harbour; but nothing was left afloat in it except thirteen merchantmen, which it was hoped in due course to investigate. Vice-Admiral Whitworth, having (at 5:42) signalled the sinking of all the German destroyers plus one submarine, then ‘considered the landing of a party to occupy the town as the opposition had apparently been silenced’.8 He decided, however, that the men available were too tired and too few to risk against 2000 German soldiers whose morale would speedily recover, at any rate unless Warspite remained off the town risking submarine and air attack. About a dozen German aircraft were in fact sighted within half an
Map 2: Narvik: Battles, 10th and 13th April
hour. The main force accordingly started down the fjord about 6:30, though the Warspite later turned back and remained through the night taking wounded on board. Our casualties were twenty eight killed and fifty five wounded, but one of two additional destroyers which had been sent up the Ofotfjord to Narvik at the close of the action picked up off Ballangen the survivors from the Hardy as well as some other British seamen from sunk merchant ships. The squadron did not actually withdraw into the Vestfjord until the following morning. Two destroyers were then left at Narvik to make a further investigation of the merchant ships, but this was abandoned the same day, apparently on account of a call for a submarine hunt.
An Admiralty telegram, timed at 9:15 p.m. on the 13th, had urged the Commander-in-Chief to occupy the town of Narvik so that there could be no opposition to a landing later. It is not clear whether Vice-Admiral Whitworth knew of this signal, wireless conditions inside the fjord being very poor, but he did later that evening report his ‘impression that enemy forces in Narvik were thoroughly frightened’ and recommended that the main landing force should occupy the town without delay; he also stated his intention of taking the Warspite in again.9 He followed this up next morning with an informational message which pointed out that Cossack was not seriously molested by the Germans although aground in Narvik Bay for twelve hours, and suggested that a small landing force could complete the task, given naval support of the strength of his own squadron.10 But by the 15th Vice-Admiral Whitworth in the Warspite was cruising farther west, under orders from the Commander-in-Chief to keep outside the Vestfjord unless required for an operation; the landing of the long projected Narvik expedition was then in progress fifty miles away at Harstad instead.11
Though the 1st Cruiser Squadron under Vice-Admiral Cunningham also stayed behind to examine the fjords northwards to Kirkenes, the naval operations arising directly out of the German naval thrust terminated on the departure of the Commander-in-Chief with the Rodney and Renown from his station off the Lofotens for Scapa on the evening of 15th April. The Gneisenau (with foretop and one turret damaged) and the Scharnhorst had passed far to the west of the Home Fleet and made their way back safely to Wilhelmshaven on the 12th. Our resounding successes at Narvik must be balanced against the fact that for six vital days the Germans had had a battlecruiser force at sea and largely unlocated, which necessitated the concentration of the Home Fleet and its exposure to air attack and distracted attention at
the critical moment from the coup directed against the Norwegian ports. The Germans had lost one heavy cruiser, to light cruisers, and ten modern destroyers. In relation to their total naval resources this was a big price to pay.12 But they had secured a big military advantage in return—a chance of overrunning the whole southern half of Norway, which the soldiers were quick to exploit. They had also obtained a compensatory advantage in terms of sea power, since a brief trial of strength had enabled the German air force to deny the British Home Fleet its control of the Skagerrak and eastern North Sea within range of Stavanger and the Danish airfield at Aalborg.13
Having failed to crush the German invasion of Norway by naval action, Britain turned to a counter-invasion instead. But logically a third alternative was possible—a sustained attack by air against the communications which were the enemy’s life-line.[3] It will be convenient to trace the history of our efforts to achieve this now, although they in fact continued pari passu with the landings in Norway over a period of almost exactly one month. Against the German Navy the Royal Air Force at this time had no success. In the early morning of 12th April the strenuous reconnaissance work on which it had been engage throughout the invasion period was indeed rewarded by the detection of the elusive German battlecruisers, when they had just being rejoined by the Hipper, south of Norway, on the last lap of their return journey. But a force of no less than ninety-two bombers scoured the misty North Sea for them in vain; and when part of it went on to attack another warship reported a Kristiansand, six Hampdens fell victim is to the German fighters. The attack on enemy supply ships and transports had then already begun with a night raid in the Oslo area, remote and difficult of access, in which twenty three Whitley bombers secured one direct hit. Such raids were continued from time to time by bomb of forces, by aircraft of Coastal Command making their regular reconnaissance patrols, and (to a small extent) by Skuas sent out from the Fleet Air Arm station at Hatston in the Orkneys. At this stage of the war, however, the bombing of ships at sea was not technically at all easy, and in the all-important Skagerrak-Kattegat area the RAF could not do more than supplement our submarine activities. But the Air Force also gave direct support to surface craft which revisited the area to help the submarines, when three French destroyers made a dash into the Skagerrak on the night of the 23rd/24th April; these sank two enemy motor torpedo boats and a trawler, but
their air escort on the return journey was heavily attack by German fighters from Kristiansand.
A more sustained effort was directed against the German held airfields. There was even a hope that the enemy might not be ‘able to develop ground aerodromes’, as a War Office appreciation puts it,[4] during the period before the thaw would deprive them of the use of frozen lakes. The Stavanger airfield, Sola, besides being the largest in Norway, was the nearest to our bases (325 miles from Lossiemouth) and approachable directly from the sea: this was the obvious target. Unfortunately, the niceties of Franco-British bombing policy, as it had been announced on 2nd September 1939, in response to an appeal by President Roosevelt, imposed a delay of two vital days, in which machine gun attacks were authorised but bombing was barred, until the Germans were known to have bombed some other landing ground that was still in Norwegian hands. Thereafter small raids, by an average of seven aircraft, were made at the rate of nearly one a day. The second objective in order of importance was the large Danish airfield at Aalborg in North Jutland, the third the partly developed civil airport of Oslo, Fornebu. We also tried to extend the attack to Kristiansand, Rye in Jutland, and even Trondheim. This last was at extreme distance for the bombers of those days, but a long-range Wellington—a type of which our total stock was two—counted twenty two enemy aircraft on the frozen surface of Lake Jonsvand, southeast of the city, as a result of which two raids were made, on the night of 22nd/23rd and 23rd/24th April, but neither found the target. The intensity of our efforts against the airfields was varied in accordance with their supposed usefulness to particular phases of the campaign, as we shall see in due course. But their general scale can be judged from the fact that they cost Bomber Command twenty seven aircraft in a month. This was at a time when the total number of aircraft available with crews, including those posted to the Striking Force in France, was only 216. Coastal Command, which had few aircraft to spare from other duties, lost five out of the twenty three made available for the purpose.
Distance was a severe handicap—only one of our raiding forces had even a small fighter escort (Blenheims) and the bombers, though their range was of course greater, were severely restricted in the time they could afford for locating targets.[5] The Germans were quick to organise the defence of the fields they had seized: heavy anti-aircraft fire was put up from Sola as early as the evening of the 10th and their fighters were in action when we attempted a daylight raid on the 11th. But, as modern navigational aids were then in their infancy, our most powerful enemy in the changeable North Sea area was the weather. Some operations failed (or were cancelled) because of fog over Britain, others because of storms over the water, others again because
of the lack of cloud over the target. The want of large-scale maps increased the uncertainty of the landfall among the intricate network a fjords and islands and hampered the search for the objective. It appears that our main resource was the town plans in Baedeker’s Scandinavia (revised 1912): to the pilot battling with snow and ice in the upper air it was small consolation to reflect that the absence of target maps and photographs at least argued our innocence.
But in any case the attack on the Norwegian and Danish airfields would have been at best a pis aller. The airfields of Germany lay nearest to us and were the real basis of the campaign, as we knew from both common sense and captured pilots; the official policy, however, was to take no action which might provoke, or at least help to touch off, retaliation against British or French soil. This means that the maximum result that we could have hoped to achieve was to limit the impact of the German air force in Norway to such activities as were practicable from bases situated at about the same distance from the theatre of operations as our own. It is therefore fortunate that we had an alternative way of employing our bombers in the struggle for Norway, which at least did not suffer from the same fundamental defect. This was the sowing of shallow waters with magnetic mines, for which urgent preparations had been in progress ever since the Germans began the practice in October 1939. By a coincidence the decision to make the first dropping in the next moon period had been taken for reasons unconnected with Operation Wilfred on 8th April: it was easy to extend the area of action from the North German estuaries northwards along their vital supply route to Norway.
Not all types of bombers were suitable for a task which involved dropping a weight of 1500 lb, including 750 lb of explosive, from a height of about 500 feet into some 30 feet of water, at a speed not exceeding 200 miles per hour, and with such unobtrusiveness and accuracy that the enemy would not notice the fall of the mine, much less recover it. Good weather as well as moonlight was essential. But operations began on the night of 13th/14th April and were continued until the 25th/26th, from which dates fog in the North Sea rendered them impracticable up to 1st May, and they were then resumed for a second fortnight. The main area covered from north to south was the mouth of the Oslofjord, the Sound, the Great and Little Belts, Kiel Bay, the approaches to Lübeck, and the estuaries of the Elbe and Weser. Two hundred mines were ready for use in each of the two lunar months with which we are concerned, and about two-thirds of these were duly dropped at a cost of eleven aircraft. The results were difficult to assess at the time, though the foreign press was combed for significant items, but we now know that the Germans lost twelve ships totalling 18,355 tons. Neutral losses were also considerable, including
at least two Danish train ferries. Minelaying aircraft therefore share with the submarines—which themselves accounted for at least 7000 tons of shipping by mines in addition to their other activities14—the credit for the fact that from 13th April until the end of the campaign German troop transportation was diverted to the railway through Jutland and the shorter Sea passage across the Skagerrak to south Norway.
The German invasion of the Low Countries put an end to all serious operations against German airbases and sea supply routes for the Norway campaign: our bombers were needed too urgently elsewhere. But even in the preceding month, the situation had been such that the Instructions to the Commander-in-Chief, Bomber Command, told him on the one hand not to hold back his heavy force for ‘operations on the Western Front which may not materialise’, and on the other hand to remain prepared to ‘switch...to Germany with the least possible delay should the situation develop’.[6] Coastal Command, planning on 14th April for a big raid on Stavanger, found the force reduced to six aircraft by a special Cabinet decision. The overriding consideration throughout was the smallness of our bomber force, computed to have been at the time not more than one-quarter the size of the German. In fine, the bombers of the RAF were not freely expendable, and could therefore play only and ancillary part in necessarily expensive projects for the recovery of Norway.
Map 1b: Naval Movements, 9th–13th April