Secret weapons of world.., p.24
Secret Weapons of World War II, page 24
From camouflage of ships at sea D.M.W.D. turned to the concealment of warships and merchant ships in port. Pilots of aircraft raiding Brest reported that the Scharnhorst and Gneisenau were so cleverly hidden that even when they managed to pick out the vast mass of the upperworks it was difficult to tell which way the battleships were lying. The Germans had painted the bows and sterns of the two ships the same colour as the ground, and they had used vast quantities of netting. Our own chief need was to protect valuable merchantmen unloading in the docks, so Currie went off to Newport, in Monmouthshire, where a steamship called the Marwarrin was lying. Using nets and outriggers to break up the line of the hull, he produced an effective enough camouflage, but it had one fatal drawback. Ships like the Marwarrin had to get to sea again quickly; they were seldom in dock long enough to justify all the effort of swathing them in a vast cocoon of nets and booms. Once in place, too, it would obviously slow down the work of unloading to a dangerous extent.
The Wheezers and Dodgers provided a camouflage scheme for naval air stations — and at Worthy Down Currie operated on some Scorpions so successfully with paint and special netting that observers flying over the field were unable to find any of the dozen vehicles parked round the perimeter. He went to Lerwick, in the Shetlands, and rigged up a cunning contraption of dummy lighters and oil-drums to hide the submarines lying alongside the jetty there; he devised special coloured clothing for Commandos carrying out limpet attacks on shipping in enemy harbours; and he produced ingenious nets for the M.T.B.’s which crossed the North Sea to hide up in the fjords of Norway. These nets were large enough to drape right over the boats. On one side they suggested a typical background of rocks and vegetation; when reversed, they gave an impression of a similar surface after a heavy fall of snow.
For an artist like Donald Currie, who for years had studied the sea and the sky, the effects of light and shade, and contrasts in colouring, the creation of a camouflage scheme presented no imponderable problems once he had seen the setting for himself. But now the Admiralty asked for something infinitely more difficult. They showed him the plans of a secret craft designed for raiding purposes. It could carry a small crew, two canoes, and a load of explosive, and when its occupants paddled ashore for reconnaissance or sabotage work the parent craft sank to the sea-bed. Several days later an automatic timing device came into operation, and the submerged boat rose to the surface under cover of darkness, ready to receive the raiding party when they paddled back.
These submersible craft, which could vanish without trace and return just as unobtrusively without human aid, were called “Mobile Floating Units.”
“We can’t tell you exactly where they’re going to operate, but you can take it that it will be in waters controlled by the Jap. The main danger for the raiding party will come from air reconnaissance, for the sea in that area is very clear. We’ve somehow got to reduce the chances of these M.F.U.’s being spotted while they’re lying on the bottom during the day-time.”
That was all Currie was told.
He set to work systematically to learn all he could about a wide variety of tropical sea-beds in all weather and water conditions. In theory this seemed simple enough; many encyclopaedias and other reference books purported to give this information. As so often happens, however, Currie found that the experts were not always in accord. Some had special knowledge of the highly coloured coral formations encountered in tropical waters, and stressed this aspect. Others emphasized the prominent characteristics of different kinds of tropical weed, and to reconcile all their conflicting impressions meant days of tramping from museum to museum, from one authority to another.
The Hydrographer’s Department supplied facts about the turbidity of water. The staff of the Natural History Museum told him all they knew about various types of sea-bed. He talked to experts on seaweed, mineralogy, and sea-bottom deposits. And from the head geologist of a famous oil company he learnt about the geological formation of the coast in the operational area.
At the end of it all he knew a great deal about the appearance of coral sand and quartz sand, tropical weeds like Laminaria, and all kinds of rocks. He was also aware that the camouflage problem was even more difficult than he had imagined, for the M.F.U.’s might equally well come to rest against a background of dark, grey-green mud, light yellow sand, or glaring white coral.
Somehow he had to produce a scheme basically suitable for any of these conditions, and he began experimenting with small-scale models. As a start he mapped out the whole surface of the deck in irregular light and dark patches. He then took his small boats to the Vale Farm Swimming Baths at Wembley.
The water there was crystal-clear — as clear, in fact, as any sea water in the world. Off the Tonga Islands a 15-inch Sechi disc can be seen at 200 feet. Vale Farm might well have been in the Tonga Islands, and, musing on this incongruity as he towed his models up and down the baths, Currie only came out of his reverie when he saw the astonished look on the face of the Cockney swimming-bath attendant, who obviously thought his visitors were too old to be playing with toy boats.
With the help of a team of lighting experts from the research staff of the General Electric Company, whose laboratories were not far from the baths, a very successful colour plan was evolved for the topsides of the M.F.U. The decks were given a sandy background, and disruptions of light and dark shading broke up the slab-like appearance of the craft.
They then turned their attentions to the canoes, for it was equally vital that the approach of the raiding parties should not be seen by watchers ashore. Here full-scale tests were possible, and Currie and the G.E.C. team began spending their nights afloat on the cold waters of the reservoir at Staines, paddling slowly to and fro in their flimsy craft while chilled observers peered through the darkness. At dawn they would all gather in one of the pump-houses to compare notes, and Currie invariably produced a large bag of Spanish onions which, he claimed, would fortify and invigorate his exhausted companions.
Privately, G.E.C.’s research team considered that almost any hazard of war was preferable to a ration of raw onions at six o’clock in the morning, but since their resistance was lowered by lack of sleep and they liked Currie too much to hurt his feelings they suffered in silence!
Only one essay in camouflage developed into a combined operation involving a whole team of the Wheezers and Dodgers, and, oddly enough, Donald Currie — busy with other work at the time — took relatively little part in it.
Strictly speaking, the story of the attempt to obliterate the Thames belongs to the earlier phase of D.M.W.D.’s activities, but water camouflage had more far-reaching aims than the defence of the metropolis. The London Blitz was over by the spring of 1941, but there were other targets. It became vitally necessary to protect the great factories in the Midlands. Lakes, reservoirs, and canals all helped the air navigator to pinpoint industrial centres, and it was not until the advent of radar that such visual aids lost their significance.
At full moon, rivers and lakes can be seen from afar. R.A.F. crews bombing Kiel spoke of sighting the Elbe fifty miles away, and Currie, making an aerial reconnaissance himself on a night when haze had already cut down visibility, picked out the Mersey quite easily at a distance of thirty-five miles. It was the heavy raids on Merseyside which first focused attention on the need for water camouflage, for the German bombers attacking the docks at Liverpool were observed to check their final approach by a line of five reservoirs leading from the Trent Valley.
Admittedly, other objects such as wide roads, woodlands, and the dark ribbons of railway track showed up just as prominently in bright moonlight, but in certain quarters it was strongly urged that the task of the bomber crews would be made a great deal more difficult if some way could be found to mask the surface of water.
When the proposal first came to Goodeve, Professor Rideal had already conducted some interesting experiments at Cambridge, where he had camouflaged a stream with coal-dust. Goodeve foresaw greater difficulty in applying such a method to any tidal waterway, and for stretches of static water other types of camouflage were, of course, available. Nets, supported by cork floats, could be spread over the water, and if properly moored they would not be so vulnerable to the wind. Within certain limits, however, the coal-dust experiments had certainly proved promising, and D.M.W.D. could not reject the idea without giving it a fair trial.
A team, soon to be known as the Kentucky Minstrels, was therefore formed under the leadership of Duncan Bruce to study the whole project, and work began on the Thames in a craft inappropriately named H.M.S. Persil.
From the start there was keen competition, for rivals were in the field. On Ruislip Reservoir a party from a research station which specialized in such experiments were already testing an apparatus rather like a Hoover (except that it worked in reverse). Towed behind a launch, this discharged large quantities of oiled coal-dust just beneath the surface; but the system was not proving very satisfactory, for the dust was first injected into a stream of air inside the apparatus, and when it finally met the water it tended to clog instead of spreading out freely. If, on the other hand, they sprayed the dust from a point just above the surface it blew away.
Bruce tackled the problem from a slightly different angle. After discussions with Dr Lessing, a well-known fuel consultant, he first fed the dust into a high-pressure water-jet, and then expelled the mixture through an ordinary fire-fighting appliance. In this way he could lay his inky screen ahead of the boat, and the method of discharge was faster and cleaner — though cleanliness was only a comparative term for any part of the Kentucky Minstrels’ activities!
The trials began in quite a modest way, but soon the Ministry of Home Security began to take a close interest. So did the special committee set up by the Prime Minister to co-ordinate efforts in the Battle of the Atlantic. Any measures which promised to protect merchant ships during their time in port received high priority, and so more helpers — a petty officer and a party of ratings — were drafted to speed the experiments on the Thames. The competing sprayers were installed in four large launches, which plied up and down the river at night, smothering its murky waters in a thick mantle of coal-dust or soot, and more than once Mr Churchill himself came out on to Westminster Bridge to inspect the results.
The experiments became extremely unpopular with Thames-side housewives, who wrote to their M.P.’s complaining that their laundry was being mined. There were contretemps afloat, too, and when, as the result of a slight technical hitch, a passing tug was deluged in a hail of oily black particles Bruce was given some extremely lurid, if rather impracticable, advice by her crew!
Nobody, however, suffered more than the Wheezers and Dodgers themselves. The coal-dust settled on them in clouds, ruining their uniforms and covering them with a sooty grime which soap and water took long to dispel. After a while they scarcely noticed one another’s appearance, and Coulson, returning to the office one morning after a whole night on the river, was quite surprised when he was stopped in Piccadilly by an immaculate young Commander R.N., who regarded him with extreme distaste.
“All you R.N.V.R.’s are the same,” he said scathingly . . . “Look at you . . . absolutely filthy … a disgrace to the Service! And you didn’t even salute me. Why not?”
As it happened, Coulson was accompanied by Richardson, who had been promoted to Commander two days earlier, but had not had time to acquire his ‘brass hat,’ so he said somewhat smugly, “As this officer with me holds the same rank as yourself I did not think it was necessary.” A trifle disconcerted, his interrogator abandoned all further examination of Coulson’s shortcomings.
As the trials on the Thames progressed it became evident that the effort involved in blacking out large stretches of tidal water would far outweigh any possible tactical advantage.
To cover one acre demanded at least a hundredweight of specially prepared coal-dust, and as fast as they supplemented the initial discharge a strong tide would wash the dust away. If a wind was blowing the whole film piled up against the lee shore, and choppy water swamped and sank the drifting particles.
In the greater shelter of the Surrey Commercial Docks results were more encouraging, but the Wheezers and Dodgers had their greatest success at Coventry. H.M.S. Persil, which, after the early experiments on the Thames, had been used mainly for retrieving the dead cats and dogs which floated odorously round the dock area, was transported north for these trials, and, with no tide to hamper their experiments, Bruce and his team camouflaged Coventry Canal so effectively that both an old gentleman and a dog walked into it, under the impression that it was a newly made-up road!
By that time, however, it was realized that any success by the Kentucky Minstrels could have relatively little effect on the Luftwaffe. The enemy had switched to moonless nights for their mass raiding, and with the swift development of radar the most ardent advocates of water camouflage abandoned their faith in this expensive and somewhat unreliable form of protection.
Goodeve always spoke of his acquiescence in the strange experiments on the Thames as “one of my gross errors.” But when the trials began no one could have foreseen with any certainty the speed and direction of the march of science.
PART III
KEYS TO THE FORTRESS
17
INVASION AHEAD
THE start of the war’s fourth year brought a dramatic change in Allied fortunes. Alamein turned the tide in North Africa, and Operation Torch launched a new drive eastward along the Mediterranean. By January 1943 the German Army was in full retreat on the Don. Churchill and Roosevelt could now look far beyond the conquest of Europe’s “soft underbelly”; when they met at Casablanca the possibility of invading Northern France as early as the coming August was discussed at length.
Invasion plans burdened the Royal Navy with heavy responsibilities, and from this time onward all D.M.W.D.’s own efforts were directed to problems of amphibious assault. Weird projects began to take shape: floating roadways and airfields, harbours created by streams of bubbles, and rocket-propelled monsters to blast a way through coast defences. There were explosive amphibians, invisible boats, and cliff-scaling devices.
In the preliminary stages many of these raised abstruse questions of higher mathematics, and new faces began to appear in the department. Goodeve had a free hand to enlist the aid of distinguished consultants in any field, and men like Professor G. I. Taylor and the youthful Dr William Penney were called in to advise on the creation of artificial harbours. Guggenheim, the author of a standard work on thermo-dynamics, at last had opponents in argument worthy of his steel, and he would lure Penney into lively discussion on the subject, while his naval friends listened in awed and uncomprehending silence.
Another notable civilian recruit was George Kreisel, whose mathematical calculations were far above the heads of most members of D.M.W.D. Given a problem, he would retaliate with pages and pages of hieroglyphics which reduced even Richardson to stunned perplexity. And once, when in desperation Richardson asked an eminent professor of mathematics to interpret an explanation of Kreisel’s, the learned man confessed with some diffidence that it was altogether too advanced for him!
Kreisel was certainly a colourful addition to the department. He had his own decided views on the appropriate rig for Service occasions, and would turn up at official trials attired in an old pair of grey flannels and a sky-blue shirt, widely opened at the neck. This gave him the carefree appearance of a holiday hiker who had somehow strayed into the decorous gatherings of uniformed officers by sheer accident. But George Kreisel himself remained entirely oblivious to the critical stares of the admirals and generals, all of whom seemed to him uncomfortably overdressed.
On the naval side of D.M.W.D. there were several officers now firmly established on the staff who have not, nevertheless, been mentioned so far. Ron Eades, a tall, good-looking R.N.V.R. lieutenant with a brisk, energetic manner, was a close friend of Boswell. Both hailed from Portsmouth, and for years they had sailed and played rugger together. Eades was completely fearless, and his indifference to explosives roused no little apprehension at Birnbeck, where he experimented with a lethal device called “Bookrest.” This was a canvas tube filled with plastic explosive and designed to blow up enemy minefields. Plastic explosive was a highly temperamental substance, and quite liable to react to the slightest rough handling, but Eades treated it with a cavalier disdain. Whenever he wanted to empty it out of its hosepipe container he resorted to the simple expedient of banging the pipe against the wall of the magazine which housed all Birnbeck’s cordite, flares, rockets, and detonators!
The leader of D.M.W.D.’s research into artificial-harbour problems was Robert Lochner, a sturdy, bespectacled man with any amount of drive, who had joined the department after commanding an M.L. flotilla in Coastal Forces. He was an electrical engineer when war broke out, but, being also an ardent yachtsman, he naturally gravitated into the R.N.V.R. His first appointment was to one of the Q ships, with which the Admiralty hoped to emulate the success of Rear-Admiral Gordon Campbell, V.C., in the First World War, but in the end little came of this venture, and while he was kicking his beds at Plymouth he put up an idea for countering the magnetic mine.
This brought a posting to H.M.S. Vernon, and there he met Goodeve for the first time. When he moved on to Coastal Forces he must have surprised some of his brother-officers by his spare-time preoccupation. He had decided to read for the Bar, and returning from patrols off the Dutch coast he would often prop himself up in an angle of the upper deck and study Roman law!
Robert Lochner’s sea time came to an abrupt end in 1941, when a picture appeared in a London magazine. This showed him on the bridge of his M.L., coming back from some operation and all too clearly he was wearing spectacles. The Admiralty promptly inquired how it was that a commanding officer of an M.L. and senior officer of the First Flotilla came to be suffering, apparently, from defective eyesight, and even the considerate test which the local admiral applied — “Look out of that window, Lochner, and tell me the colour of that large advertisement for Gold Flake Cigarettes!” — failed to secure a reprieve for long. Goodeve brought him into D.M.W.D., and after a time Lochner took charge of several of the department’s engineering projects.
