Chapter 13; Blockade by Mine & Bomb

WITH A FANFARE of trumpets according to their custom the Germans have more than once announced the startling successes which they claim to be achieving in their efforts to blockade this country. Concerning our counter measures they show greater reticence. Counter measures is the wrong term. From the first hour of the war we have imposed a blockade on Germany which has been successively extended to all the countries which her armies have occupied, and that blockade is complete to the limit of our capacity.

it began in much the same way as that imposed during the war of 1914-1918. A system of contraband control was instituted and applied to all ships bringing cargoes to Europe. Contraband control centres at Falmouth, in the Downs and in the Shetlands were set up and were kept very busy in the early days of the war. To them all ships whose cargoes were not covered by Navicerts or which were suspect were brought in by the Royal Navy. Coastal Command gave all the aid it could. In addition to numbers of German merchants, certain neutral traders, lured by the high profits to be made, sought to run our blockade. Devices used to disguise the ships were many of them ingenious. Swedish, Danish, Norwegian, and other colours were, frequently used, and alterations in the superstructure of the ships were made with intent to deceive.

The pilots of Coastal Command have always received a rigorous training in ship recognition. Silhouettes, photographs and models of every kind of vessel are kept at all stations, and those showing the most likely type to be encountered on patrol are often carried in the aircraft itself. Pilots photographed, if they could, any ship they saw or made sketches of her main features on a pad held on their knees. If they were at all doubtful about a ship they sent a message in code. This was passed onto the Royal Navy, which brought in the suspect for examination.

Bombing-up is a skilled and delicate process.

As the war progressed, the nature of the blockade changed. Germany has overrun so many more countries, and is using their products to maintain and increase the efficiency of her war machine, that the problem has become more difficult. We have not only to prevent goods and raw materials from entering Europe, we must also deny the enemy, as far as possible, the use of his ill-gotten gains.

Sea-borne traffic in the distribution of goods between European countries was in peace time of very great importance. It is even more so in time of war. The seaports of North-Western Europe have always been the main gateway for the exports and imports to and from the industrial areas of Central Europe and their immediate hinterland. Moreover, for the purpose of internal distribution the coastal trade of Western and Northern Europe was of considerable importance. It supplemented the use -so marked a feature on the Continent- of internal waterways for the transport of heavy goods. Coal, building materials, timber, structural steel, fertilisers, cement and other heavy products commonly travel by internal waterways and by sea in coasting vessels up and down the Western coast of Europe. Both methods of transport must be used if the flow of such products is to be maintained.

Moreover, uninterrupted sea-borne traffic is essential if the Germans are to make the most of their conquest of Norway and their domination of the Baltic. Norway has few industries but much raw material, and it can be made available for the enemy's war machine only if it can be brought to Germany for manufacture. It must travel in ships, and those ships cannot make use only of the comparatively safe Baltic ports, for to do so would place a heavy and perhaps an intolerable burden on internal transport in Germany, which must distribute the imports to their final destination. The ships must continue to put into Rotterdam and the North-West German ports.

It is now very dangerous to do so. The economic urge to use them, however, is as great as the danger. There is no better evidence of the importance of the port of Rotterdam to Germany, and of the vital part played by the Rhine as a channel for the movement of all that is produced by the heavy industries of the Ruhr, than the assiduity with which the Germans continue to use that port in spite of their losses. Some of the exports of the Baltic countries -such as timber, pulp and paper- are essential for the German controlled industries of the Western occupied Countries and Italy. The enemy would undoubtedly like, as in peace time, to be able to carry these to the seaport nearest to the consuming centre. Now, they go as near as they dare and then have to resort to inland transport.

The Germans have also to grapple with another problem. Their forces garrisoning the conquered countries are spread over a wide area. These troops need not only supplies of food, clothing, ammunition and all the other materials required by a modern army, they are engaged in accumulating large stocks of material for the possible invasion of this country and they are at the same time building fortifications along the whole coast of the Continent against the possibility that we may one day invade. Huge quantities of material for the construction of aerodromes, gun emplacements, air-raid and submarine shelters must be obtained and brought to the places where they are to be erected. The consumption of cement alone must be enormous. If this were peace time there is no doubt that all these materials would be brought by sea.

The German railways form one of the most efficient administrative machines in the world, and their efforts in this war have been as remarkable in their way as those of the German Army. All the early traffic problems of the war were clearly foreseen and efficiently dealt with, the two most difficult being perhaps the transport of coal to Italy and of oil from Roumania.

But even while they were still dealing with problems they had been able to foresee, it was clear that they were working under strain. One example will suffice. The dispatch of one million tons of coal a month from the Ruhr, the Saar and Silesia to Northern Italy involves a railway traffic movement which would be equivalent to the dispatch of a "Flying Scotsman" from King's Cross to Edinburgh every seven and a half minutes throughout the twenty-four hours of the day.

With the later developments of the Russian campaign, huge problems have arisen that were never foreseen and for which plans were never made. The strain has been tremendously increased and the German railway authorities have redoubled their efforts to keep traffic off the rails.

If Germany held the same dominion over the seas as she does over the continent of Europe, the strain on the railways would be so much less severe and her supply problem so much smaller that it would scarcely trouble her at all. No one realizes this more than she does, and it is for this reason, and also because many of the garrisons which she must supply cannot be easily reached except by dangerous sea routes, that she is making very great efforts and taking very great risks to use ships with which to relieve the heavy and growing pressure on her railways and other forms of transport. In doing so she has laid herself open to attack, and that attack has been, and is being, carried out with all the vigour at our command.

The part played in this sustained and prolonged assault by aircraft of all three Commands is of very great importance. Coastal Command has concentrated on shipping. It must not be forgotten that, when a ship is sunk, not only are the goods which it carries destroyed, but also that particular means of transport is lost, whereas an attack on a railway may destroy only some of the goods it carries and some of the rolling-stock, which can, moreover, be more easily and quickly replaced than a lost freighter.

Coastal Command makes use of three chief weapons in its operations against enemy shipping-the mine, the bomb, and the torpedo. All three are dropped from the air. Let us take first the attacks by mine.

The task of laying mines in enemy waters is shared with Bomber Command. Each Command has been allotted certain areas along the coasts of the enemy and of the occupied countries off which mines are laid.

The aircraft used for the purpose were originally Swordfish, of which the open cockpit added considerably to the discomfort suffered by the crews in winter, though in other respects it was an advantage, for the pilot could see the surface more easily. As soon as Beauforts became available they were pressed into service.

The method used is as follows : The aircraft sets out flying at a height between 1,500 and 2,000 feet. When it approaches near to the place chosen-a shipping channel, the entrance to a port, the mouth of a fjord, or wherever it may be-it comes down low in order to pin point its position.

This is done by picking up some prominent landmark, such as a building, a headland, a lighthouse, a small island.

Arrived there, the navigator sights the landmark through the bomb-sight and, at the exact moment at which the Beaufort passes over it, presses a stop-watch, at the same time telling the pilot to fly a course at a certain speed at a certain height for a certain time.

Fast-moving targets are not easy to hit. A German E-boat takes avoiding action -a sharp turn to port at high speed- as a stick of bombs goes down.

During this, the run-up, the aircraft must be kept on an absolutely level keel. At the end of the period, calculated in seconds and fractions of seconds by means of the stop-watch, the observer releases the mine and the operation is over.

Very rarely do the crew even see the splash when the mine hits the water. The operation is dull, difficult and dangerous. "Creeping like a cat into a crypt" is how one pilot has described it. The Germans do their best to cover all likely landmarks with anti-aircraft fire.

More than once the crews of Coastal Command have seen little lights moving, like strange fireflies, along the edges of cliffs. They came from the pocket-torches held in the hands of German gunners as they ran to man their guns.

Little is heard of these mining operations. Only an occasional reference is made to them in official communiqu6s. But they go on night after night and the crews who carry them out run risks as great as those who achieve a result by the use of a more spectacular weapon -the bomb or the torpedo. Over a period of six months in 1941 seventy per cent. of the mines laid by Coastal Command were placed in the position chosen for them.

It is impossible to do more than estimate the damage they cause. Intelligence and other sources can never discover the whole truth and it is doubtful whether the enemy himself knows all of it. Certain successes are known to have been achieved. Here are some instances. In February 1941 a German vessel of about 3,000 tons was damaged near Haugesund and beached to prevent her sinking. A German trawler struck another mine on the same day and sank. The area was closed to traffic for some time.

High-level attack. Flying at 8,000 feet above its target, a Hudson, using the Sperry bombsight, scored this direct hit on the stern of a German supply ship in northern waters.

Later that month a German ship was mined off Lorient and many corpses were washed ashore on the Quiberon Peninsula. An aircraft of Coastal Command had dropped a mine in that area a night or two before. In September of that year two cargo vessels were mined and sunk in the roadsteads of La Pallice and La Rochelle. In October a 4,000-ton ship was mined and sunk in the channel leading to Haugesund and the entrance to the port was blocked for some time.

The more direct method of attack is to bomb the ships of the enemy wherever they may be found. Coastal Command began early. Th e first enemy ship to be bombed was a tanker attacked by a London flying boat on 10th April, 1940, some forty miles from the Faroe Islands. The limited resources of the Command did not permit it, in those early days, to make attacks on a large scale. Nevertheless, its achievements are not to be ignored.

Between 10th April and 31st December, 1940, 223 attacks were made on merchant vessels and supply ships and 81 on enemy ships of war. They took place along the Norwegian coast, the Dutch, Belgian and French coasts, and also in the Heligoland Bight and off the North West coasts of Germany. The sinking of a merchant vessel off Haugesund by a Hudson on 22nd June and the hitting and sinking of twelve merchant vessels, one of which was of 14,000 tons, and a tanker of 10,000 tons in July must be mentioned.

The attacks in August 1940 were not very successful, but in September two E-boats were sunk by a Blenheim 18 miles off Dieppe on the 10th and hits obtained on ten merchant vessels, one of which was certainly sunk. In October 1940 three merchant vessels were hit. The attacks fell off in November, but in December no less than 45 were made on merchant vessels and one on enemy destroyers. So ended the year 1940.

The attacks had been mostly carried out by single aircraft, a Blenheim, a Hudson, or a Beaufort, though sometimes the attackers flew in formation of two or three. They were in the nature of an experiment. The crews taking part in them were gaining experience of which they were to make good use in 1941. It was not a quick process. To attack and hit a ship, especially when it is protected by its own fire and that of flak-ships, is not only dangerous but difficult. The technique was worked out and improvements made through that winter and spring.

During this period much work was done to determine the correct fuse-setting of the bombs. It was very necessary to do so. On 30th March an enemy ship loaded with depth charges, probably an anti-submarine vessel, was found off La Rochelle and hit by a 250-1b. bomb dropped from 400 feet without a delay fuse. The bomb detonated all the depth charges and blew the ship to pieces. The aircraft returned "riddled with bits of its target." As a result of this and other attacks of the same kind it has become the general practice to use delayed action bombs.

When vessels carrying ammunition, however, are hit, the explosion is naturally so formidable that the aircraft runs a great risk of suffering damage. On one occasion a Hudson belonging to a Dutch Squadron dropped a salvo of bombs on a ship near the Norwegian coast. " Nothing happened at first," reported the Dutch pilot. " The rear gunner started swearing because he didn't see anything. Then he said he saw the crew frantically lowering a boat. Then came a tremendous explosion and we thought our bombs had hung up and gone off underneath our aircraft till we saw the ship in small pieces."

Bomber Command took a prominent part in the attacks on shipping. The work they did has been described in the Air Ministry's account of the activities of that Command. In March 1941 Coastal Command aircraft made nine attacks, and eight in the following month, on enemy ships of war at sea, in addition to a large number of attacks on the " Scharnhorst " and " Gneisenau " in harbour at Brest.

They also hit for certain fifteen merchant vessels during the same period, and probably many more. One attack on a convoy of eight merchant vessels off Stavanger on l8th April was pressed home with great determination. Two merchant vessels were hit and left sinking for the loss of two Blenheims ; a 'second attack made on the convoy encountered heavy opposition from Me.110s which shot down three Blenheims after one of them had scored a hit on another vessel.

The attacks continued on much the same scale throughout the summer. On 11th June Blenheims scored seven direct hits on a large tanker discovered between Ostend and Dunkirk. On 5th July Blenheims, again escorted by fighters, discovered an enemy convoy near Zuydcote. Some of the aircraft attacked from a high level and drew the fire of the convoy and its escorting vessels. The remainder went in low and scored two direct hits on one merchant vessel and another on a second. One of the Blenheims, hit by anti-aircraft fire, struck the water, bending both propellers, but got back to base.

By then the Blenheims and Beauforts operating over the English Channel had been so successful that it was practically denied to enemy shipping. After July attention became more concentrated on the Dutch and Norwegian coasts. By the end of that month Continental business men were complaining
of the heavy losses incurred by them in shipping goods from Dutch ports.

The attacks by bombs on enemy shipping reached a momentary climax in October and November 1941. Many of them took place by night during the moon periods, and the aircraft employed were Hudsons flown by British, Canadian and Dutch Naval Air Squadrons. The attack on the night of 29th/30th October is especially noteworthy. Reconnaissance on the morning of the 29th had disclosed a concentration of German shipping in the harbour at Aalesund and the neighbouring fjords.

Aalesund, a few hours before the successful raid of 29th /30th October, 1941. Four merchant vessels were sunk and three heavily damaged.

Hudsons set out from the North of Scotland and delivered the attack. The first to arrive saw the ships lying at anchor beneath a brilliant moon lighting the harbour in its frame ol~ mountains on which the first snows of winter had fallen. The attack can best be described in the words of one of those who took part in it :

" There was a lot of flak coming up as I came over the target. I could see one ship burning, with smoke pouring from it. The ground was covered with snow and I had the whole target in silhouette. I flew around pretty low for a bit, then climbed up to get a better view and choose my target, keeping out of range of the flak. I saw a second ship hit and it soon became an inferno of flames. We could actually see the plates red-hot. I saw four other aircraft attack shipping in the harbour. They were flying very low, and the flak was streaming down on them from batteries in the hills-green, white, red, yellow. A lot of it was going straight on to the enemy's ships.

" I had by then chosen my target-the biggest ship in the harbour, about 5,000/6,000 tons. I approached from the North, about five miles away, my engines throttled right back. I came down to about 5,000 feet, by which time I was nearly over the ship, and dived straight on to it. I dropped my bombs at about 2,000 feet. I did my own bomb-aiming. Directly the bombs were gone I pulled up over the town. I was then down to about 1,000 feet, still throttled back; then I opened up fully and went off. There was a lot of flak coming up at us. Some of it came pretty close, but we couldn't actually hear it. The gunner definitely silenced two flak positions.

Image 1 of 3. Delayed-action bombs are used in low-level attacks, so that the aircraft shall not be damaged by the explosion. 1. A stick of bombs has been dropped from mast height over the stern of this enemy ship.

" I flew right round the harbour and when I came back to the target I saw the ship was still there. I said to the crew : ' We must have missed it.' A moment later the gunner shouted: ' Think I can see a glow forward.' I turned round to have another look and saw she was dow n by the bows. I flew round again and this time I saw the bows were awash.

I kept on flying round, and next time I looked the water was about up to her funnel. She got lower and lower, then we saw the rudder come out of the water and about a third of her keel. Just before she went down we saw part of the stern with the flag-pole sticking up, and as we watched she sank. The ship took twelve minutes to sink from the time I released the bombs. It was a most satisfying sight to see it going down."

All the aircraft returned safely. One of them was carrying the Air Officer Commanding the Group to which the Squadron making the attack belonged. Its bombs sank one of the four ships destroyed that night. Three others were hit and very heavily damaged. In the five nights from 31st October to 5th November eighteen merchant vessels were hit, the majority, perhaps all, being sunk or burned out.

On 2nd November the attack switched to the Dutch coast and four ships were hit. In less than a month about 150,000 tons of enemy shipping had been sunk or severely damaged, and of this about 120,000 could be claimed by Hudson Squadrons. The denial to the enemy of these ships and the loss of their cargoes undoubtedly affected his military operations against Russia.

Image 2 of 3. Delayed-action bombs are used in low-level attacks, so that the aircraft shall not be damaged by the explosion. 2. The ship steams on, apparently unscathed.

To read the reports submitted by pilots immediately after their encounters with enemy ships is to receive the impression of men so eager to get to grips with the enemy that they disregard the risks involved. This, however, is not so. A more careful perusal of them shows that the captain of a Hudson, a Beaufort, or a Blenheim, while prepared to take great risks, and in fact accepting them as in the ordinary course of duty, is not at the same time heedlessly risking the lives of his crew or the safety of his aircraft.

" From mast height I laid a stick of bombs across the ship. I didn't see them drop, but the rear gunner reported : 'There's one on the deck.' " . . . "At that moment both my engines spluttered and stopped. That shook me, for we were flying right between the masts." . . . " The whole sky lit up as two of the bombs burst and the ship seemed to disappear into thin air."

Such phrases as these indicate how closely pressed home is the attack, but they are often followed by the statement that it was made from cloud cover, that evasive action followed immediately afterwards, and that the aircraft regained the shelter of the clouds as soon as possible. Such actions on the part of the

pilot in no way detract from the achievement. On the contrary, they enhance it. The enemy's merchant vessels, of which all are armed and most protected by flak-ships which put up a heavy barrage, are not attacked haphazard. The tactics of swift approach and swift " getaway " have been carefully worked out and studied, and though the hazard of the operation is never allowed to interfere with its execution. if the chances of a successful attack are nil it is not made. If there is even the smallest prospect of success, it is.

Single enemy vessels or vessels in convoy hug the coasts of conquered Europe. They are discovered, therefore, by visual and photographic reconnaissance or by means of patrols given a roving commission to attack any suitable shipping target which may present itself. Such patrols are called " Rovers." They are sent out very often at the discretion of the Officer Commanding the station, who acts under a general order from the Group, and they are flown both by day and night. They were welcomed from the start by the pilots and crews as an exciting change from convoy or anti-submarine patrols.

Image 3 of 3. Delayed-action bombs are used in low-level attacks, so that the aircraft shall not be damaged by the explosion. 3. A second or two later the bomb makes itself felt.

In daylight, weather is of supreme importance. Crews detailed for such patrols cannot take off unless there is a reasonable certainty that the area they are going to investigate will be covered with cloud.

" There is a feeling of unreality," says a Wing Commander, "in starting out on a bright, sunny day and presently flying into horrible grey weather and so finding the enemy coasts, and flying along low-lying, sandy shores or an island of the Frisian group and perhaps stumbling on a ship before either she or oneself has quite realised what has happened. The whole essence of a successful shipping ' strike is surprise. . . . The attacking aircraft has to come in very close and very low. . . .

It is in this position, however, for only a few seconds, and we rely on catching the gunner on board when he is lighting a surreptitious cigarette, talking to a pal, or perhaps blowing on cold fingers. . . . The moonlight Rover is quite different and in some ways more fascinating. . . . It can take place only on bright nights. There is something indescribably exhilarating about flying low over the water along a path of living flame. . . . Surprise is nearly always achieved because it is possible to see much more looking up-moon than it is looking the other way, and the marauding aircraft comes suddenly on the ship out of the ghostly murkiness of night."