Secret Weapons (30 page)

During the month of October 1943 further trials were arranged in which heavy cables were attached to each end of the hub and secured to two winches which could, it was hoped, steer the contraption safely up the beach. Of course, when the test was run the clouds of smoke and flame from the combustion of the rocket fuel obscured the direction of travel from the controllers manning the winches, and the increased drag from the cables was itself an added disadvantage.

There was yet another practical problem in the design that began to emerge. The breaking-up of the rocket units was clearly very dangerous, yet it was obvious that the rockets might disintegrate. They were designed, as rockets always are, to produce a steady backwards thrust and by being fixed to the periphery of the Panjandrum wheels they were being submitted to centrifugal forces for which they were never intended. These acted laterally against the casings and the force would become considerable when we consider the dimensions involved. A 20lb (9kg) rocket whirling on the edge of a large wheel moving at speed is clearly subject to lateral forces of considerable magnitude and the break-up of some of the rockets was clearly probable. Yet this hazard was also ignored, and was omitted from the design calculations.

A further test took place over an uneven surface. The wet sand was specially cratered for this trial run. After a distance of only 140 yards (about 130m) the wheels of the Panjandrum buckled, the winches seized and the cables became entangled; its trajectory this time had been a wild zigzag pathway across the sand, ending up with the giant device lying pitifully on its side, spent rockets still smoking. If any further evidence of the impracticality of this absurd contraption were needed, this surely was it. But no – development work continued, in spite of all the accumulated evidence. Two new prototype Panjandrums were constructed. They were ready early in the New Year and an official demonstration was arranged in January 1944. A number of senior government officials came to witness this latest test run and several senior members of the Armed Forces were also in attendance. It was to be an auspicious occasion.

The rockets on the first Panjandrum were successfully ignited and the monster began to roll forward. But within a short distance, the first rocket exploded violently and disintegrated, soon to be followed by others. The great wheel, as it gathered speed, began to weave dangerously from side to side and then erratically to change direction. It was completely out of control, and began to head straight towards a group of terrified photographers. The VIPs leapt behind a sand-dune and fell into a tangle of barbed wire. The roaring device turned again, headed down the beach back towards the sea, then in a cloud of smoke and a series of explosions it crashed heavily on its side. Rockets broke away and screamed across the beach in all directions, at least one being vainly pursued by a holidaymaker’s dog. All that remained of the secret weapon was a scorched and twisted hunk of metal beneath a lingering cloud of black smoke.

So, at last, the project was terminated. All the scientific and engineering data should have shown that it could not work. Even a cursory examination of the elementary physics involved would have shown that it was doomed from the start. The cost of the project is unknown, but was clearly considerable, and the wastage of time was immense. At the time, a financial saving, or the release of a few thousand man-hours, would have been of the greatest value to the war effort. Householders were giving up their kitchen saucepans in order to supply light alloy to the aircraft industry and railings were being torn up and melted down to make steel sheet for weapons manufacture. To have these resources diverted to the Panjandrum project was unjustifiable.

This was not the last we heard of the wasteful Panjandrum fiasco, however. It has re-emerged in more recent times. A lightweight reconstruction featured in the BBC’s wartime comedy series
Dad’s Army
, first broadcast on 22 December 1972. This episode featured the many problems that befell the device, and paralleled the original trials in some ways. The only time a Panjandrum ran successfully was in 2009 when a 6ft (1.8m) diameter replica was constructed to mark the 65th anniversary of D-Day. Like their wartime predecessors, these designers also envisaged that it would speed along the beach, heedless of the problems caused by the question of torque and the backward pointing rockets. It was ignited in a ceremony for the Appledore Book Festival in Devon, and ran down a small ramp. Although it worked to a fashion, the model trundled for several yards, mostly moving at walking pace, before it slowed to a halt and its rockets burned out.

And so attention turned to designing an explosive landing craft. It was planned that this could deliver a load of explosives to breach a protective Atlantic Wall of concrete and allow the Allied troops through to the plains of France. It was being argued privately, that – even if the Panjandrum had delivered its load of explosives – they would not have exerted the desired effect. To give full benefit, an explosive charge would have to be clamped firmly against the wall. The blast would otherwise be dispersed and dissipated as it produced a huge crater in the sand. The proposed landing craft were designed with hydraulic rams which would provide the desired result – they would extend to force the explosive charge firmly against a concrete wall, maximizing its effect.

The vehicles chosen were Alligator landing craft made in the United States. They were based on the amphibious DUKWs vehicles but had caterpillar tracks instead of conventional wheels. Attached to the tracks were spoon-shaped paddles which propelled the craft through the choppy seas until it came to land, when it would rise from the water and proceed up the beach like a conventional tracked vehicle. The Directorate planned to fit each craft with a 1-ton bank of high explosive mounted on a mattress base; this – on contact with the concrete wall – would be firmly clamped in position by the hydraulic rams and automatically detonated.

The Alligator itself was a formidable device. Each was 26ft (10m) long overall and more than 10ft (3m) wide, weighing about 11 tons. But once in the water they were cumbersome and slow, and under sea trials they ran into repeated problems of instability that are reminiscent of the Panjandrum tests. On one occasion the hydraulic ram mechanism was actuated while the craft was still at sea. Its 1-ton mattress of explosive, ballasted with sand, tilted the whole contraption upwards at a crazy angle and a serious accident was narrowly averted. The Alligator took with it more casualties than its fiery predecessor had done as it spiralled up the beach.

As with the Panjandrum, eventually someone realized that they were unlikely so succeed with this project and the Alligator too was cancelled. It was just as well. Both devices were being specifically designed to blast through an impenetrable wall of concrete behind which the Germans would be hiding. But, as intelligence showed (and as the Allied landings would confirm), the concrete wall simply did not exist. The Germans had never thought to construct an impregnable wall, and the Allied strategists had been developing weapons against a target that had never even been built.

There was one final attempt to use rockets as a secret device for the Normandy landings that would aid the Allies, and intimidate the Germans. This was a novel idea: to drop containers of vehicles and equipment from low-flying bombers, using retro-rockets to slow the descent and cushion their landing on the beaches of Normandy. The Army proposed this novel idea to the Admiralty’s Directorate of Miscellaneous Weapon Development, who had been working on parachuting equipment during the invasion. Using parachutes to drop heavy equipment was no problem, but the relatively heavy impact was causing damage. Surely a retro-rocket assembly could cushion the landing. The preliminary designs seemed perfectly satisfactory, and the device was code named Hajile.

The idea was to set off a battery of rockets when the container was a few yards from the ground. Solid-fuel rockets could not be relied upon to ignite at exactly the same time, and early tests showed – when the smoke had cleared – that the container was often left crunched into the ground. It was decided that it would be safer to carry out some tests over the open sea, and the site chosen for the observers was the holiday pier at Weston-super-Mare, which was designated HMS
Birnbeck
during the war. It was decided to drop a large container, fitted with its retro-rockets, from a Lancaster bomber but the pilot’s aim was not accurate and the horrified technicians realized that it was heading straight towards the buildings. They ran back along the pier, just in time to avoid the container as it crashed through the roof and demolished the workshops.

There were plenty of other tests. One of them involved dropping containers from a tall crane. On the second attempt, the container hit the ground just as the rockets fired with a massive roar – this propelled the container back up into the air, where it smashed into the jib and demolished the crane that had dropped it. Several of these containers were built for the D-Day landings, but the device was never formally commissioned and remains a peculiar sideline to the war effort. The only remaining secret was the strange name given to the device: Hajile. Unlike Panjandrum, it seems to have no meaning at all, but its roots lie in the Old Testament. Elijah is said to have ascended unto heaven in a pillar of fire, remember?

Suddenly, all is clear: Hajile in simply Elijah in reverse.

Detecting the enemy at a distance has long been an aim of any warring nation. The first distant detection system relied upon the sound of the enemy, and methods of picking up and amplifying faint noise are more than a century old. In 1880, the pages of
Scientific American
featured the topophone, invented by Professor A. M. Mayer, which was intended to amplify a distant noise and make it possible for the user to detect the direction from where it originated. The use of sound reflectors to concentrate distant engine noise from enemy aircraft dates from World War I when Professor F. C. Mather dug a parabolic reflector into the cliff near Maidstone, Kent. This was in 1916 and the reflector was used to detect incoming aircraft or Zeppelin airships. An observer would be stationed at the focal point of the acoustic reflector, listening for distant sounds. The experiments worked well, and a similar reflector was then dug out in Baharic-Cahaq on the Mediterranean island state of Malta. Further examples were planned for Aden, Gibraltar, Hong Kong and Singapore.

A British parabolic concrete sound collector 20ft (6m) in diameter was erected near Dungeness, Kent, in 1928. A larger reflector 30ft (9m) across was built two years later, together with a large concave concrete reflector 200ft (60m) from end to end. During the 1930s, portable and steerable reflectors were designed. They could detect faint sounds over large distances, and the position of the sound source could be confirmed by the direction in which the reflectors were pointed to collect the loudest sound. By the beginning of World War II, as an alternative to the fixed parabolic reflectors, conical sound collectors had been built in Britain and were being successfully tested. Some were in the form of directional funnels that could be moved from place to place and could indicate the position of incoming planes. This was, though, a doomed technology. Detecting the sounds of aircraft engines was relegated to the sidelines when radar began to emerge.

It is hard to imagine contemporary transportation without radar. All the airliners in the world are tracked by operators using real-time images of where they are in the sky. Every liner and container ship is watched intently from the shore; and they see each other with an unblinking eye. Even little yachts can carry a radar device to survey the surrounding seas, and they have a radar reflector at the masthead to ensure they are seen by the rest of the community. Radar is taken for granted, and – were it to vanish overnight – global transportation would be finished. It is clear that the modern world relies on radar to a great degree, but this important technological development has a long and interesting history.

Many of the resonances between the secret weapons of World War II and today’s high-tech world will have come as a surprise. Radar, by contrast, is something with which we all feel more comfortable. It is widely believed that it was the urgency of World War II which led to the invention of radar, and that is was the brainchild of Robert Watson-Watt, the brilliant British electronics engineer and visionary. It may come as a surprise to many, then, to hear that radar was in existence prior even to World War I.

It arose from the grief of a radio engineer named Christian Hülsmeyer from Düsseldorf, Germany. One of his closest friends lost his mother at sea when two ships collided in fog. Hülsmeyer was greatly saddened by the death of someone so close, and began to speculate on a means of trying to prevent a recurrence. He had been studying radio waves, which had been examined since 1887 by Heinrich Hertz, who is now commemorated by the use of the term ‘Hertz’ to describe the frequency of a radio beam. Hertz made many observations that were of interest to science – and one of them was that radio waves could be reflected from a metallic object. This caught Hülsmeyer’s attention and he began to carry out experiments to see whether the metallic object might be a ship at sea, and whether the nature of the reflection could tell you where it was. In the 1890s Hülsmeyer was a school teacher and devoted his spare time to these experiments; he later joined the Siemens Company. In 1902 he met a successful businessman from Cologne who agreed to speculate on the invention and advanced funds for the work. They called it the
Telemobiloscope
and together they launched a company called Telemobiloscop-Gesellschaft Hülsmeyer und Mannheim. A public exhibition took place on 18 May 1904 in Cologne. Hülsmeyer set up his apparatus on the Hohenzollern Bridge, and as soon as a ship sailed into the forward-facing beam a warning bell sounded loudly. Then, as the ship sailed away from the beam, the ringing stopped. Hülsmeyer had demonstrated the remote detection of a ship – it could have saved the life of his friend’s mother. There were rounds of applause from the spectators, and positive reports in the press.