That Time the British Navy Tried to Exchange Parachutes with Rockets

Of all main army conflicts of the Twentieth Century, the Second World Battle stands aside. Not solely was it the deadliest battle in fashionable historical past, claiming an estimated 85 million lives, or about 1 in each 25 individuals, but it surely was additionally arguably historical past’s first really technological struggle. Whereas many now-ubiquitous army applied sciences comparable to plane, tanks, and submarines noticed their fight debut within the First World Battle, it was in the course of the Second that they had been refined into really efficient weapons – together with different key improvements comparable to radar, guided missiles, and nuclear weapons. One of many much less glamorous however nonetheless vital developments of the struggle was using parachutes to quickly ship troops and gear behind enemy traces – a method that proved instrumental in dozens of operations, from the German invasion of the Low Nations in 1940 to the Allied D-Day landings in 1944. However the parachutes on the time had their limitations: they may not be steered, they usually delivered their payloads to the bottom slowly, making them weak to drifting off-target and being broken by anti-aircraft hearth. In an try to unravel this drawback and make airborne supply sooner and extra correct, in 1944 the British Admiralty carried out a collection of weird experiments to discover using retrorockets to sluggish the descent of falling payloads, eliminating the necessity for parachutes altogether. That is the story of Hajile, one of many Second World Battle’s most intriguing – and hilariously unsuccessful – ‘secret weapons.’

The Hajile mission was undertaken by the British Admiralty’s Directorate of Miscellaneous Weapons Improvement or DMWD, based in 1941 as an offshoot of the Inspectorate of Anti-Plane Weapons and Gadgets. In true cheeky British trend, this title was quickly corrupted to the “Instigator of Anti-Plane Wheezes and Dodges”, creating the DMWD’s enduring nickname of the “Wheezers and Dodgers.”

In any occasion, the DMWD was one in every of many related teams established by the British early within the struggle, leveraging the distinctive abilities of a ragtag group of scientists, engineers, and different eccentric misfits to develop artistic and infrequently weird options to tough wartime issues. Over its temporary 4-year historical past, the DMWD would make use of a lot of vibrant characters, together with motor racing photographer Louis Kemantaski; engineer Barnes Wallis, inventor of the “bouncing bomb” used within the well-known 1943 Dambusters raid; and engineer Nevil Shute Norway, later to turn into well-known because the writer of novels like On the Seaside and A City Like Alice. Headed by Canadian chemist Charles Goodeve and headquartered at HMS Birnbeck – a transformed pier at Weston-super-Mare in Somerset – DMWD tackled all types of unconventional tasks, together with radar countermeasures and ship camouflage, amphibious assault methods, anti-submarine weapons, and – after all – Hajile.

The idea behind Hajile was easy sufficient: as an alternative of a parachute, air-dropped payloads had been fitted with a set of downward-facing cordite solid-fuel rockets which had been fired simply earlier than affect, rapidly slowing the payload and delivering it safely to the bottom. This may permit the payload to free-fall for many of its descent, permitting it to be extra precisely dropped onto touchdown zones and defending it from enemy hearth. In follow, nevertheless, this scheme proved something however easy to tug off. One of many key technical difficulties of the Hajile idea was the right way to reliably set off the rockets on the precise proper second– too late and the payload would both plough into the bottom at terminal velocity or bounce again into the air, whereas too early and it could decide up sufficient extra pace after to be broken on affect. To resolve this drawback, the boffins on the DMWD developed a plumb-bob that hung a sure distance under the payload, and which might hearth the rockets as quickly because it touched the bottom.

Preliminary trials had been carried out by merely dropping a concrete block fitted with rockets from a tall crane. Sadly the mission received off to an inauspicious begin as the primary block, fitted with too few rockets, merely buried itself within the floor, whereas additionally being dramatically engulfed in a wreath of flame and smoke. Witnessing this spectacular spectacle, one of many observers, Captain G.O.C. Davies, exclaimed: “Have a look at it! It’s Elijah in reverse!” – referring to the biblical prophet who ascended to heaven in a chariot of fireside. The remark resulted within the mission being formally dubbed Hajile – actually Elijah in reverse.

Transferring on to the second drop, this ended very similar to the primary, whereas within the third the engineers fitted the block with too many rockets, inflicting it to launch itself a number of dozen toes into the air earlier than crashing again to the bottom.

These early assessments additionally revealed the difficulties inherent in designing a dependable triggering gadget, for the plumb-bob needed to be concurrently heavy sufficient to not be blown upwards by robust winds throughout descent and delicate sufficient to detect delicate terrain like lengthy grass.

Following these disappointing trials, the Hajile group determined to conduct all additional experiments over the ocean, which might not solely present a great flat floor to check triggering units, but additionally hopefully permit check rigs to be recovered intact. For these water based mostly assessments, rather than a crane, the check articles had been dropped from a Lancaster heavy bomber – a lot as they’d as soon as Hajile entered service. Sadly, the primary few drops landed too far-off to be efficiently recorded, so the engineers requested the Lancaster pilot to drop the following payload nearer to the pier…. What may go mistaken?!?

To their horror, the pilot took their request a bit too actually, as group member Gerald Pawle later recalled:

“As [Hajile] got here screaming by the air the watchers on the pier gazed open-mouthed. Then, out of the blue realizing that it was going to attain a direct hit, each one began operating for expensive life down the lengthy plank roadway. The concrete “bomb” landed squarely on the roof of D.M.W.D.’s engineering store. It sheared by an enormous metal joist after which demolished the coated approach resulting in the steamer jetty. Fortunately there have been no casualties, although the Wren [WRNS – Women’s Royal Naval Service] cooks getting ready lunch just a few toes from the wrecked shelter thought the tip of the world had come.”

Whoopsa-doodle!

Following this hair-raising incident, the Hajile group lastly started to make some progress once they elevated the variety of rockets from 4 to eight. On this configuration, the check blocks got here to a whole cease only a few toes above the water earlier than sinking slowly beneath the floor. Buoyed by this encouraging success, the Hajile group determined to maneuver on from concrete blocks to precise payloads, and attended to persuade the Royal Navy to supply them with a lot of jeeps for testing. Understandably, the Navy was skeptical about risking completely good autos on such an unproven and doubtlessly damaging gadget, and the DMWD was compelled to obtain its jeeps from america Navy as an alternative. Sadly, the Royal Navy’s fears proved well-founded as the primary check drop led to spectacular failure. Snowfall had dampened the rocket fuses, inflicting the rockets to fail and the jeep to hit the bottom at terminal velocity, fully destroying it. After two weeks of tinkering, the group was able to attempt once more. This time, the rockets fired proper on cue, however when the smoke cleared the group found the jeep mendacity upside-down.

Additional assessments had been no extra profitable, with the system proving maddeningly tough to get working reliably. As for the flipping problem, one main drawback was the problem of getting the primitive cordite rockets to ignite concurrently, a shortcoming that triggered many check articles to flip over or tumble end-over finish. Transferring on from there, matching the thrust of the rockets to the burden of the payload additionally proved tough, resulting in many payloads crashing to the bottom at excessive pace or being launched erratically again into the air.

Finally while the group finally got here tantalizingly near perfecting the system, the tip of Hajile lastly got here on June 6, 1944 – the day of the D-Day landings – when an electrician by accident triggered the rockets on a check rig whereas the engineering group was gathered round it. The ensuing blast injured a number of individuals, together with photographer Louis Kemantaski who was blinded for a number of days after receiving a blast of sand to the eyes. With the strategic want for Hajile rapidly fading, the mission was quickly shelved after which deserted fully because the struggle – and the DMWD – got here to an finish.

The hilarious failure of Hajile apart, the DMWD did make an ideal many helpful contributions to the struggle effort, creating such profitable units because the Hedgehog and Squid anti-submarine mortars, strategies for shielding ships towards magnetic mines, and the Mulberry floating harbours used in the course of the D-Day landings. Nevertheless, on the opposite finish of issues, the Hajile was not that solely of the DMWD’s weird misfires. Among the many group’s extra eccentric undertakings was a scheme known as “Kentucky Minstrels”, which sought to disguise reflective rivers and canals – utilized by German bombers as navigation aids at evening – as roads by coating them in a substance derived from coal mud. Whereas the actions of wind and tide finally made the scheme impractical, on at the least one event the impact proved remarkably convincing, when a person out strolling his canine at evening mistook a camouflaged canal for an asphalt street and ended up unexpectedly soaked.

However maybe the “Wheezers and Dodgers’s” most weird creation was the “Nice Panjandrum” – an enormous rocket-propelled explosive wheel designed to be launched from a touchdown craft, quickly roll up an invasion seaside, and destroy coastal defences with a bang. Like Hajile, Panjandrum was a spectacular failure – however that could be a topic for an additional video.

One other, associated wartime mission was the “Leaping Tank”, an try to make use of rockets to make mild armoured autos just like the Valentine tank and Common Provider leap over obstacles like canals or anti-tank ditches. For sure, this insane idea proved fully unworkable and the mission was rapidly scrapped.

Curiously, whereas Hajile proved an abject failure, the idea of slowing air-dropped payloads utilizing retro-rockets was later revived and efficiently carried out – albeit as an enhancement reasonably than a substitute for parachutes. For instance, ever because the first manned spaceflight by Yuri Gagarin in 1961, the Soviet Union and later the Russian Federation have opted to recuperate their house capsules on land reasonably than at sea just like the American house program. There are a number of causes for this; firstly, in contrast to the Individuals, the Russians don’t possess a big sufficient naval floor fleet to carry out environment friendly ocean recoveries. Secondly, in the course of the Chilly Battle, having spacecraft land inside Russia’s huge territory made them much less prone to be captured by the enemy.

Nevertheless, this restoration technique introduced with it a key security problem: attaining a floor touchdown delicate sufficient to stop the cosmonauts from being injured required a parachute far bigger than might be carried in the cramped capsule. The Vostok capsule flown by Gagarin solved this drawback by having the cosmonaut eject and land individually from the spacecraft. Nevertheless, the later Voskhod and Soyuz capsules landed with their crew nonetheless inside and used a system of solid-fuel retro-rockets to minimize the affect pace. On the Voskhod capsule, these rockets had been mounted on the parachute shroud traces, whereas on the Soyuz – which continues to be in use right this moment – they’re situated beneath the warmth protect which is jettisoned simply previous to touchdown. These six rockets are triggered by a gamma ray altimeter codenamed Kaktus-2V between 1.1 and 0.8 metres from the bottom, slowing the capsule from round 10 metres per second to round 2.5 – leading to a comparatively mild affect cosmonauts describe as a “mild thump.” Nevertheless, as it’s potential that the retro-rockets might fail, the crew couches are designed to face up to the affect of touchdown beneath solely a parachute – although it is a decidedly much less comfy expertise.

Within the Nineteen Seventies, the Soviets additionally developed a Hajile-like touchdown system for the BMD-1, a light-weight armoured combating automobile designed to be used by airborne troops. Weighing solely 7.5 tons, the BMD-1 will be carried by almost any Russian transport plane and a handful of heavy-lift helicopters, and airdropped utilizing a big multi-canopy cargo parachute. As this parachute lowered the automobile at a bone-crunching 15-20 metres per second (about 65 km/h or 40 mph), the unique operation doctrine known as for the BMD-1 and its crew to be dropped individually onto the battlefield. In follow, nevertheless, the 2 tended to float and land far aside, making it tough for the crew to seek out and attain their automobile. The Soviets thus started experimenting with dropping the BMD-1 with the motive force and gunner aboard, utilizing a system of retrorockets mounted on a drop pallet to sluggish the automobile’s affect pace to a extra cheap 7 metres per second. Different crew members, who dropped individually, got radio receivers tuned to a beacon on the automobile, permitting them to simply find their mount after touchdown. The system entered service in 1975 and its nonetheless in use right this moment – validating the Hajile precept some 30 years after the actual fact.

Increase for References