Secret weapons of world.., p.20
Secret Weapons of World War II, page 20
He now returned to the charge. The weapon he had in mind was a very simple affair — a rocket-propelled spear with a cast-iron, fluted head which would rip a large hole in the pressure hull of a U-boat — but perhaps its very simplicity told against it. The minds of the committee seemed fixed on more refined and scientific devices, and even Goodeve, who was attracted to the idea, was not altogether satisfied that Norway’s theory could be translated into practice.
“Why on earth shouldn’t it work?” said Norway testily, after one particularly abortive meeting in the Admiralty. “You can spear a fish quite successfully, and the principle is exactly the same. There was nothing wrong with the trials we did in the tank at Teddington.”
“I know there wasn’t,” Goodeve admitted, “but I still don’t think it will keep straight after impact. It will turn over.”
They gave the Rocket Spear some more ambitious tests at Birnbeck. It emerged triumphantly, and after that Goodeve was no longer sceptical. But outside D.M.W.D. no one showed any interest in the weapon, and it was not until the Army asked for rockets to be tried as anti-tank missiles that Norway got a chance to justify his claims.
For the anti-tank trials the R.A.F. allocated a Hurricane, and somewhat reluctantly they agreed to test the Spear against submarine plating at the same time.
Among those who heard of the trials about to take place was Admiral Sir Max Horton, who as Commander-in-Chief, Western Approaches, was now directing the Battle of the Atlantic from his headquarters at Liverpool. Horton was “that rara avis among admirals, a technician who had completely mastered the scientific discoveries and devices brought in to aid ships and aircraft engaged in the battle against the U-boats.” And he immediately dispatched one of his staff, Commander Phillimore, to Boscombe Down to see if the Rocket Spear had possibilities. Phillimore was greatly impressed by the trials, and when he reported enthusiastically on the new weapon Horton at once urged the Admiralty to adopt it.
At first they were loath to hasten development, pointing out that no proper sight had yet been designed, but Max Horton was a determined and forceful man who generally got his own way. “It seems incredible,” wrote Phillimore later, “but it is true that only eight weeks elapsed to introduce the new weapon, get aircraft fitted with it, crews trained in its use, and get a kill with it in mid-Atlantic.”
It seemed incredible to Norway too. For months he had tried unsuccessfully to make people understand its potentialities. But even when his arguments were reinforced with evidence from the trials at Birnbeck few had listened. As soon as Admiral Horton’s interest was known, however, the Rocket Spear was given immediate priority.
Norway paid one or two visits to the Royal Aircraft Establishment at Farnborough, to see that the weapon took shape on the right lines. After that there was nothing more for him to do but await developments. They were not long in coming.
A flight of Swordfish embarked in H.M.S. Archer, an escort carrier supporting Atlantic convoys, was armed with the Rocket Spear. At the same time the missile was fitted to an R.A.F. Beaufort squadron based at Gibraltar. It then became a race between the two Services for the first kill.
The Archer sailed for the United States, and had an entirely uneventful passage; patrolling in the Mediterranean approaches, the Beaufort squadron also drew a blank. Then, returning from the North American coast with a convoy eastward bound, one of Archers Swordfish pilots sighted a U-boat. Before she could dive he got a hit with a rocket, which holed the pressure hull, and now there was no escape. “She tried to fight it out on the surface with her gun, but the Swordfish which had dealt the blow called up a Martlet fighter from the Archer. The submarine’s crew, overcome by machine-gun fire, sank their boat and leapt into the sea.” When they were picked up survivors asked in amazement what had hit them. All they knew of the first attack was a sudden, tremendous bang on the pressure hull, and the spear passed right through the boat.
From other survivors — the crew of an Italian submarine sunk in the Mediterranean — came a graphic description of the devastation caused by the Rocket Spear.
In this case the weapon was fired at such close range that the rocket was still burning when the spear smashed its way into the engine-room. Once inside the hull of the submarine it ricocheted off the engines, and thrashed wildly about before tearing a way out on the opposite side of the boat. On its passage back into the sea it ripped a second hole three feet wide.
Norway was away from London when the news of the Rocket Spear’s first kill reached the Admiralty. From Goodeve he received the following message:
“You will be pleased to hear, if you haven’t done so already, that the Anti-Submarine Rocket Projectiles from aircraft scored a success the first time they were used. I am particularly pleased as it fully substantiates the foresight you showed in pushing this in its early stages. My congratulations.”
It was, indeed, a happy sequel to the frustrating months when most of the Admiralty’s advisers on U-boat warfare had refused to consider the Spear as anything more than an eccentric reversion to methods of the Stone Age.
As measures against them were intensified the U-boats began to rely increasingly on the cover of darkness. Homed on to our convoys either by signals from the big Focke-Wulf aircraft which ranged far out into the Atlantic or by directions transmitted from Doenitz’s headquarters ashore at Kerneval, in Northern France, the German submarines would trail their victims at a discreet distance until night fell. Then they would close in on the surface.
During the final approach the U-boats were trimmed for diving, with decks awash, and only the conning tower was really visible. Even on a light night it was not easy to see them when they were much over half a mile away. On the other hand, the U-boat could sight its larger quarry at six times the distance.
What was urgently needed was a method of turning night into day — both immediately over a convoy, to reveal any U-boat which might have penetrated the screen of escorting ships, and farther out on the flanks to a distance of some 4000 yards, so that fire could be opened on any submarine approaching on the surface. For the first task the Navy already possessed a large and brilliant flare called the “Snowflake,” and to increase its effect D.M.W.D. were asked to find a way of projecting this to a greater height.
With the aid of the indefatigable Schermuly brothers Richardson solved this problem within a week, fitting the flare and its parachute into the head of a standard P.A.C. rocket, which carried the Snowflake to well over a thousand feet. But still the difficulty of illuminating the area outside the convoy screen remained. Searchlights could not be used, for they showed all too clearly the position of the searching ship, and the only alternative was the standard naval starshell fired from a 4-inch gun.
This latter method had two serious disadvantages. The 4-inch was the only gun which many of the escort vessels possessed for engaging a U-boat, and they were therefore in no position to strike at the enemy if their only effective weapon was occupied in another role. Secondly, the gun had a slow rate of fire one round every ten seconds — and using it to search through an arc of 60 degrees with starshell was a dangerously protracted business. Fast-moving targets could escape far into the outer darkness before even a small arc had been covered.
Hitherto D.M.W.D. had never concerned themselves with illuminants, and Goodeve’s team had only been brought into the Snowflake project because they were the Navy’s acknowledged experts on rockets. Now, however, Richardson found himself worrying about this weak link in the protection of the convoys. For a fortnight he spent every spare moment studying technical reports of starshell trials, and the behaviour of different types of illuminant. Then, armed with some rough drawings, he went to see Goodeve.
“I believe I’ve got the answer to this starshell business. Do you think D.N.O. would agree to our trying it out?”
Goodeve looked at the drawings. “It’s pretty revolutionary,” he said. “Still, we can put it up to them and see what they say.”
Then he stared at the notes in front of him again. Richardson’s design — the result of brilliantly resourceful and patient research work — was unlike any other starshell ever invented. Planned for use in quick-firing a-pounder guns, it had no parachute, and, falling fast through the air, it was to burn for less than five seconds. But the method of operation was ingenious, for Richardson was suggesting that five of these shells should be in the air at once, their paths of light joining up and reinforcing each other so that a continuous sweep could be made at the rate of three degrees every second.
“Currie has some useful reports on night-vision tests, and that’s the fastest speed you can scan for small targets,” he explained.
Goodeve nodded. “What about lighting the target once you’ve found it?” he asked.
“I think that will work perfectly well. If the gun is kept on the same bearing you will get a continuous light from a succession of shells.”
“Well,” said Goodeve, “I hope you’re right about all this. I’ll certainly put it up to D.N.O., but we shall probably be told it’s quite impracticable.”
As they had expected, the Director of Naval Ordnance’s staff were decidedly sceptical. And the Ordnance Board, with their characteristic mistrust of novelty, produced several emphatic reasons why Richardson’s starshell could not possibly function. But D.M.W.D. were allowed to go ahead, and Richardson roped in Swan, Boswell, Lane, and Dr Purcell to help with the development work.
As an initial target he aimed at producing a magnesium flare of some half a million candle-power which would burn for two seconds, but, to make certain that this would be powerful enough, teams armed with balloons and oxygen cylinders were sent to sea in the Bristol Channel. With the flares attached — they were actuated by a delay fuse — the balloons were then released, and cine-cameras on the pier at Birnbeck recorded the spreading path of light on the dark water. Prototypes of the flare were tested in wind tunnels, and, much to the alarm of Londoners, who feared that a new and dreadful form of air raid was imminent, Purcell even lit some on the roof of the Royal College of Science in Kensington.
In this preliminary stage no snags were apparent, but when the Ordnance Board made the first actual shells Richardson was puzzled to find that they gave nothing like the illumination he had estimated. Filming the trajectory, he discovered that the magnesium stars were jamming in the nose of the shell when it burst.
He explained this to the Ordnance Board, who claimed that if special tinplate cases were made for the flares this difficulty would not recur. The cases would instantly burn away when the shell exploded, and the stars would fall free.
The Wheezers and Dodgers had no facilities for making the shells themselves. They were entirely in the hands of the Ordnance Board. When the next batch came up for trial Richardson was dismayed to find that there was little improvement. Testing them exhaustively on his own, he saw that all this extra work had been wasted. As the shells burst large parts of the Ordnance Board’s tinplate casing remained intact and masked the burning flare.
Once again D.M.W.D. had to go to the Ordnance Board and ask them to revise their design, but before doing so experiments were carried out in the laboratories of Imperial College. Purcell and Swan tried packing the ‘stars’ in a paper cover instead of the tinplate case, and immediately they found a remarkable improvement in the performance of the flare.
This suggestion was therefore put to the Ordnance Board — but it was flatly vetoed. Their pyrotechnic experts condemned it as unsafe and entirely unpractical, and the Board declined to have anything to do with the proposal. They were, they said, quite satisfied with the tinplate casing (which gave the low candle-power of 30,000), and refused to produce D.M.W.D.’s paper-covered ‘star’ for firing trials.
The arguments with the Ordnance Board had now taken the, project well into 1942 without any real progress being made, and unless some way could be found to prove that the new type of cover for the flare was feasible there seemed no way out of the deadlock. Goodeve decided to bypass the Board, and he took the problem to Imperial Chemical Industries. Looking at Richardson’s specification, I.G.I. said they anticipated no particular difficulty over the production design, and in a very short time they presented D.M.W.D. with a star which burned, not at 30,000 candle-power, but at 400,000!
Before the powerful new starshell could be issued for action, however, an important new development occurred in anti-submarine warfare. A new type of radar set which enabled rapid and continuous search for surfaced U-boats was fitted to convoy vessels in 1943. This deprived Richardson’s starshell of the main role for which it had been designed. These advanced radar sets were, however, in short supply; there were none for frigates and light Coastal Forces engaged in the E-boat war, and since the M.T.B.’s and motor-gun boats had no form of illuminant at all the 2-pounder starshell was a godsend.
The earliest reports of its performance at sea surprised even Richardson. The captain of the M.G.B. which fired the first starshells in action ordered his gunlayer to aim directly at a German trawler. To his astonishment, the starshells caused instant and fierce fires. As they struck home a blazing white light illuminated the ship for several seconds, and immediately afterwards flames blazed out all over the superstructure.
Richardson had not suspected the starshells to have any special incendiary properties, and, much intrigued, he carried out some laboratory tests of his own. He found that the shells would, in fact, easily pierce wooden hulls and light plating; on emerging the star burst over a wide area with a bright glow which would undoubtedly cause fires in the presence of petrol or oil leaks.
It was therefore recommended that all Coastal Force craft should belt the starshell rounds alternately with their high-explosive ammunition, and on the night of October 24-25 they were thus used in a number of actions with E-boats. One commanding officer described the effect as devastating. Of three boats attacked in one particular sector that night one was rammed and sunk, and the remaining two were quickly transformed into blazing wrecks by the starshells.
Although the development of radar had limited the starshell’s scope, over a million of Richardson’s shells were used in the next two years, and with this experience behind them the Wheezers and Dodgers went on to tackle a number of similar tasks. The most important, perhaps, and certainly the most eventful of these projects was the “Water Snowflake.”
Aircraft searching the night seas with their A.S.V. apparatus found they needed a special type of flare which could be dropped into the water when they detected a U-boat, and to meet this need D.M.W.D. designed a novel apparatus.
In a buoyant container was a rocket, a parachute, and a Snowflake flare. When this was dropped into the sea the aircraft had time to fly in a circle in the darkness until the U-boat lay between the dormant Snowflake and the plane. The rocket was then ignited by a cell operated by the action of the sea-water, and the floating object suddenly came to life, the parachute flare being hurled a thousand feet into the air, where it burned for a minute, silhouetting the submarine for the attack.
Translating this theory into practice, however, proved far from simple, for when the first containers were dropped during trials the parachutes which carried the apparatus down into the water from the aircraft generally wrapped itself round its load like a shroud and prevented the rocket from escaping. They got out of this difficulty by dropping the parachute head-first, with a weighted keel attached to it to drag it out of the way of the container, but problem number two was much more obstinate. When the rocket ignited sufficient power had first to be built up before it could climb out of its floating container into the sky. The delay was only a matter of seconds, but in a rough sea the whole contraption might well be swamped before the rocket emerged.
To test the Water Snowflake’s behaviour afloat Boswell was lent an R.A.F. high-speed launch, and off Ramsgate they began preliminary trials, dropping the apparatus into the sea astern, attached to a line which was paid out while the boat moved slowly ahead. Boswell explained to the coxswain that the rocket was expected to fire after thirty seconds in the water, but the first Snowflake went off too close to the launch for the coxswain’s liking. When the next was lowered into the water he decided that discretion was the better part of valour, and, opening the throttle, he went full ahead, completely forgetting that the proximity of the Snowflake to his launch depended entirely on the speed at which the line could be paid out. In a few swift seconds he was towing the Snowflake container horizontally, with the rocket pointing straight at the helpless observers on board, and by the time Boswell had explained by frantic shouts and gesticulations what was about to happen the launch had so much way on that nothing could be done to retrieve the situation. So every one lay flat on the open deck and waited for the explosion. At point-blank range how it missed the launch was a miracle, but the effect on the coxswain was salutary. For the rest of the day he treated the Water Snowflake with the deepest respect!
To overcome the swamping danger the department designed special lids — known as “Bug-bafflers” — which fitted over the top of the containers and were only knocked off by the rocket itself as it shot out. Once these were ready the R.A.F. launch and its reluctant crew again went to sea. Their task this time was to retrieve any Water Snowflakes which failed to function when dropped from the air, so that Boswell and his team could examine the defects.
At first all went well. An elderly Fleet Air Arm plane flew up and down dropping the containers. Boswell timed them as they hit the water, and when any refused to go off the coxswain would bring the launch alongside and the gear would be hauled on board.
The pilot of the plane seemed unduly anxious to get rid of his load, and, flying in tight circles, he dropped the Water Snowflakes at such a pace that after a while Boswell could no longer keep track of them all. A dozen had been retrieved safely, however, when he saw, to his dismay, that an enthusiastic aircraftman had just pulled a perfectly good container out of the water. Lying on the deck, it was smoking furiously, and Boswell knew it was just about to detonate. He picked it up to hurl it over the side, but it was too late. The Snowflake climbed straight out of his arms into the sky, to the considerable alarm of the pilot, who had chosen that precise moment to fly low over the launch as he dropped the last of his containers.
