A 25,000-Tonne Bomb That Has Never Been Detonated Is Set Off | The Ultimates: Explosions | Spark

the truth about what's under this farmhouse has never been revealed until now buried here is the world's biggest unexploded bomb if detonated it would destroy the farm the road and anybody who happened to be nearby nobody knew the bomb was there least of all the farmer until researchers found old records proving exactly where the 25 tons of explosives are hidden at the end of a tunnel 70 feet below ground wyatt's there is an astonishing story a legacy of man's attempt to create the ultimate explosion [Music] [Music] for more than a thousand years in war and peace mankind has been refining the deadly and devastating science of explosives no technology ever moved so far so fast ramping up explosive power 100 000 times over 50 years leading ultimately to this it was without doubt the largest man-made detonation ever the only other larger detonations have been caused by asteroid and meteor impact the nuclear bomb harnessing particles too small to see too fast to imagine changed the course of history but conventional explosives from old-fashioned gunpowder to modern-day tnt are still a potent force how do they work we'll experiment to see which are sensitive to impact which are sensitive to heat and will make an extraordinary journey deep underground finding vivid proof that though explosives may lie buried forgotten for decades the danger doesn't diminish [Music] the small belgian town of messin has a violent history it was here during the first world war that the awesome power of explosives was demonstrated for the first time this is the evidence these are giant craters now filled by rainwater left by a single quite extraordinary act of war a million pounds of explosives buried deep underground was detonated killing 10 000 unsuspecting soldiers it was the bloodiest 30 seconds in the whole history of armed combat it was quite unique that never been so much explosive in a small area before in history the plan was born out of desperation by 1916 world war one had reached stalemate a killing contest waged from static positions machine was a key objective for the british because of one unique feature the ridge which dominates the belgian flat lands the british marked blue were on the lower slope of messin ridge they looked up at an enemy in an impregnable position thousands of young men had been slaughtered trying to capture the commanding heights was there nothing they could do to break through the german defenses the british were being pounded into defeat at macine [Applause] until one of the oldest of military stratagems promised a way out of their dilemma you had trench lines that many cases were very close together and you have a situation that's closely akin to in effect siege operations it didn't take very long for the old-fashioned siege techniques of digging underneath and attacking them from below by trying to blow the enemy defenses to take hold suddenly a new kind of warrior began to appear on or at least under the western front their weapons weren't rifles but picks and shovels and though the idea was borrowed from ancient history this plan would be on a scale so large it's hard to imagine the british aimed to secretly dig a whole network of tunnels to where the german trenches lay at the end of each tunnel they would build a chamber into these chambers they plan to pile huge quantities of a brand new powerful explosive called ammonal 40 000 sacks of it each weighing 25 pounds would be dragged into place the plan would take a year to complete but after that time one million pounds of explosives would be in position the largest quantity ever in one place directly below the german army ready to erupt the british commanders who devised the planet messine demanded the new explosive amino soon the first shipments began to arrive amino has special characteristics ideally suited to mine warfare it has a powerful lifting effect it's a slow burning explosive and therefore it moves things rather than cuts into them with heat [Music] ammonia was designed for just this task though the principle behind all chemical explosives is exactly the same this is black powder also known as gunpowder the old is known explosive originally invented by the chinese well over a thousand years ago and i'm laying it out here in a nice loose heap with no confinement whatsoever the powder is just heaped in a pile with nothing to contain it we need a way to set off the black powder what i'm going to do is put this delay fuse into the charge set fire to it and it will give me time to walk to a safe distance before the charge goes off the powder simply burns releasing smoke and hot gases harmlessly burning like this is called deflagration as opposed to detonation [Music] what would happen if those gasses couldn't escape here's the same amount of gunpowder in a cardboard tube this time a powerful explosion the gases had nowhere to go pressure built up and the same would happen but on a giant scale at machine the amino would be tightly confined in the mine chambers and its ingredients make it three times more powerful than gun powder ammonia is basically about two thirds ammonium nitrate the remaining third consisting of a mix of tnt aluminium and a certain amount of charcoal so just how powerful is it we'll detonate four and a half kilos about nine pounds at machine each individual mine was as large as ninety thousand pounds once the charge is primed only the expert and a remote camera are allowed to be this close the minimum safe distance for this explosion 1 000 feet away the firing circuit must be checked and then [Music] firing now debris is thrown a hundred feet into the air and takes a little while to come down so how much damage will our own miniature mine have caused this is the effect of just four and a half kilos the charges during this first world war were 10 000 times bigger than this the british hoped that this magnified thousands of times would wipe out an entire german army the british wanted to cause the biggest explosion the world has known up till that moment not just to blow the germans into the air but to cause an artificial earthquake a psychological shock to the defenders the british were counting on the element of surprise but how could they keep such a vast undertaking secret fifty thousand men engaged in mining and the logistic effort was enormous so the timber needed the explosives the special equipment etc existence of the tunnels was kept secret even from the british troops in case they were captured and questioned but the greatest security threat wasn't from german interrogators but from the local geology deep down the tunnels were cutting through what's called blue clay and tens of thousands of tons of it had to be brought up to the surface blue clay was very different from the brown surface soil the german aerial observation went over every day and i could see the places where actually the blue clay was concentrated and then they know these are the places where they were digging to protect the secret every last shovelful of blue clay had to be loaded into sandbags then carried away from the front line under cover of darkness they would put it into shell holes cover over the top with topsoil or use it to fill up old dugouts that weren't needed but they had to hide it finally with the germans very close to discovering the secret the warren of mine shafts was complete all the mines would be detonated at the same instant then the troops would charge forward to the top of messin ridge nothing was left to chance like 21st century battle commanders british generals even ordered a full-scale model of machine for the troops to study they ordered 100 000 soldiers up to the front line and a massive artillery barrage to pound the german trenches right into the night before the attack as dawn approached firing cables were laid detonators connected troops prepared to go over the top the mines will be detonated at exactly ten minutes past three charges [Music] just before zero hour the barrage ceased in the deadly routine of the western front the germans thought they knew what was coming next troops rushed their trenches from dugouts where they've been sheltering to repel the expected infantry charge this time the pause was a trick their trenches were directly on top of the mines as silence descended the eerie calm seemed more terrifying than the cacophony of battle as the last seconds ticked away there rose a sound never heard before on the front line a dawn chorus of birdsong [Music] uh it must have been something incredible the whole ridge was one huge flame like a big mushroom which went open and then which exploded the military authorities really didn't know what the effect of blowing so much explosive at the same time might be registered as an earthquake in switzerland there were genuine fears that it might cause some kind of rift it had completely shattered the german ability to resist the attacking troops within the first couple of hours had gained the main german defenses it was a striking success where the german trenches had been now there were just craters and 10 000 bodies [Music] for the british though now the masters of machine ridge it was time to celebrate but in that moment of triumph there was one thing they failed to consider had all the mines that were planted gone off several decades would pass before that question was answered [Music] it was a sultry summer's evening in 1955 when the storm finally broke over messine village it awakened memories of days gone by when the roar of giant guns rocked the town it also awakened something more sinister what could have caused an explosion on this scale what had been a cornfield was now a massive hole 60 feet deep 200 feet wide we're actually at a spot here where on the 17th of july 1955 one of the four forgotten minds of the scenes have exploded it caused a huge crater between here and these houses in the distance for the whole village it must have been an enormous shock the crater has since been filled but it's easy to see how close it came to wiping out these houses the lightning had struck one of these poles which flashed the charge underground to the buried explosives amazingly no one was hurt villagers thought this was a one in a million freak occurrence but now experts have discovered long forgotten battle plans and there's bad news there are three others there's one behind us in the field one in that direction and one here in front of us it was an immense crater in 1955 if the three others would come to a simultaneous explosion i think it would be a real catastrophe the british attack at messin heralded a new kind of warfare killing on an industrial scale only made possible by new and more powerful explosives as well as aminal tnt first appeared during this war invented in germany but quickly adopted as a standard explosive for shells by all armies the generals demanded tnt in vast quantities it was more powerful yet safer to handle than earlier generations of explosives even so just six months after the battle of messine feeding that appetite for tnt led to the biggest unplanned explosion of all time the sea in this part of the world is everything for halifax nova scotia a deep water harbour on canada's eastern seaboard ships are the city's livelihood but one ship in particular nearly spelled the death of halifax proving that whether explosives danger is never far away the halifax explosion is the largest prior to the atomic bombs there's no explosion prior to 1945 that matches it during the first world war halifax played a vital role in sending explosives and other war materials from north america to the western front many of the explosives used at machine passed through here halifax harbour approaches were always crowded with shipping on december the 6th 1917 on the french steamer moore blanc a huge shipment of raw tnt and other explosives had been crammed aboard her skipper expected another routine atlantic crossing but then another steamer the emo was approaching fast on a collision course was coming from the open ocean proceeding up the harbor emo had been in the bedford basin at anchor ready to go out to sea a collision would be bad enough but the mont blanc on the right was a giant floating bomb mont blanc was loaded with 2.9 kilotons that's 2 900 tons of explosives everything from picric acid used for making munitions to gun cotton to the new explosive 200 tons of tnt even loaded stem to stern with explosives moonblood had survived the impact how the cocktail of explosives that were on board the mont blanc may seem quite horrendous to the layman however explosives need to be insensitive otherwise you can't transport them around and if you can't transport them around you can't use them what does happen when high explosive tnt exactly the same as almond blanc is subjected to massive impact in this experiment we'll find out this is half a kilogram of tnt enough to demolish a house the mont blanc was specially designed as an explosives carrier her hold was lined with wood to prevent sparks we'll also avoid direct contact with the metal weight the weight is more than 400 pounds it'll be released by a small explosive charge cutting the rope dropped from a height of 10 meters the weight will strike with a crushing force of 6 000 tons a tiny remote camera will capture the moment of impact if it survives firing now the weight crashes down but the tnt is just turned to dust it's reacted exactly as it was designed to do you have primary high explosives which are very easy to set off and secondaries which are difficult tnt is a secondary high explosive you can drop a considerable weight onto it and it still won't go off the reason you want to have secondary high explosives is that you don't want an explosive that goes off by accident when you don't want it to just like on that morning at halifax moor bloor survived the impact but a tragic chain of events had begun the moon blonde unfortunately did not go up she drifted above the tnt 30 tons of benzoil similar to petrol sparks had showered from the grinding metal of maul blanc's torn hull fire raged in the benzall and eventually the heat got down into the cargo the crew of moore blunt knew what was coming the only question when [Music] they race to abandon the blazing ship leaving her to drift across the harbour towards halifax city that 15-minute delay made it particularly tragic for the population in halifax you can imagine with the ship burning in the harbor everyone in halifax lined the hill stood there stopped and watched the blazing vessel was drifting to precisely where she'd do the most damage but with a fire on board now an inferno why didn't she explode another experiment will provide the answer we'll create a fierce blaze using kerosene as the fuel and here's another half kilo of raw tnt like the 200 tonnes on board more blonde this time the tnt is about to be cooked for safety reasons a remote detonator will ignite the fire but will the heat of the fire set off the explosive after three minutes it's an inferno but you can see the tnt one of the most powerful of modern explosives simply burning tnt like other secondary explosives requires a very heavy shock wave in order to set it off you need a detonator which gives it a really hard smack when it's put in a fire there's no shock wave produced so it will not go off the thousands of tons of raw explosives on mold might just have burnt out harmlessly like this there might have been no disaster but for a final and fatal piece of the jigsaw the moon ball had been blazing for 15 minutes she was now right alongside the crowded shoreline of halifax harbour and her cargo included the quantity of artillery shells the detonators inside the shells were exactly what was needed to trigger the raw tnt it's easy to imagine the excitement in the crowds there watching with no idea of the danger they were in only people that have experienced something like the blitz can have any concept of how absolute the destruction was that explosion wave swept up the hill and totally obliterated every house every family that was there the blast wave shattered the houses then there was also a tsunami or a tidal wave as many as 200 people were drowned but we don't know what caused the death of many people we just had too many bodies to do autopsies the death toll around 2000 is still only an estimate it was not possible to identify everyone some of the bodies were simply a bundle of incinerated bones it wasn't even possible to know if it were one body or two some were left headless one body was found 18 months later in the ruins of a building the crew of montblanc did survive they'd rode to shore and laid flat down in a belt of trees but of their ship nothing was left except this section of anchor weighing half a ton thrown two miles south and this heavy gun tossed three miles through the air in the other direction they are a reminder of the astonishing forces unleashed that day and the significance of this disaster wasn't lost on generals and scientists who come the next war pondered how to destroy whole cities not by accident but by design halifax became the proving ground for some of the theories that were going to be used in designing that atomic bomb for hiroshima and nagasaki in fact when you look at those newsreel photos there is a very eerie similarity between what japan experienced and what we experienced only one generation had passed when in 1939 conflict again engulfed the world as in every war it was the fighting men who pulled the triggers fired the shells released the bombs but as this war advanced whole armies of scientists were recruited too their orders were to conquer the new realm of nuclear physics german scientists realized the military potential of nuclear energy triggering a race with the allies to build the first atom bomb as the fortunes of war swayed back and forth the key battleground was in top secret laboratories what now sounds like elementary physics was a formula which could win the war when a particle called a neutron strikes an atom of uranium two more neutrons are released vast energy is produced and then multiplied in a time span almost too short to measure there's a chain [Music] reaction the proving ground for this theory promising unlimited explosive power would be here in new mexico in 1943 the world's most brilliant physicists were gathered in the utmost secrecy at a place called los alamos they understood the science of the atom bomb but what would it do to the enemy we were looking to use these in combat situations and it was thus necessary to know what this energy release would do to targets the scientists staged experiments with large quantities of conventional explosives this is what 100 tons of tnt looks like piled up at the new mexico test site it's less than five percent of the explosives which went off in the halifax disaster but when it blew up the fireball was visible for 60 miles [Music] the chief scientist at los alamos was j robert oppenheimer he and his team had also been studying existing data in the file marked disasters oppenheimer and others actually conducted a mini-history lesson to see what an atomic bomb might look like and the first very large detonation was of course the 1917 halifax explosion why was this one so devastating the scientists noticed something called the mac stem effect the mock stem effect is basically the reflected shock wave coming off the ground and merging with the shock wave in the air for an enhanced powerful blast wave because a ship is above the earth's surface an explosion shock wave shoots down as well as up it's reflected and magnified scientists saw that this could make an atom bomb more devastating too that ultimately led to the decision to have the bomb at hiroshima and nagasaki both those bombs were air blasts i.e above the ground as opposed to a ground blast and they therefore did more damage and caused more loss of life than if they'd been a ground blast as scientists neared the day when they would test their theory there was shocking confirmation of their predictions almost as if fate adored another experiment on a huge and tragic scale [Music] look down from california's mount diablo devil mountain and you'll see an extraordinary piece of history lying just off the u.s navy base known as port chicago what they call the mothball navy [Music] warships many from world war ii rusting at anchor in the war the ships had plenty to do port chicago handled huge quantities of explosives brought in by rail then loaded on supply ships destined for the war in the pacific on july 17 1944 one of these supply ships the e a brian took its turn at the dockside loading the explosives was a punishing business the dock workers all of them black enlisted men were under extreme pressure to make a rapid turnaround [Music] that night the ea brian was receiving cluster bombs depth charges and incendiary bombs and it's interesting to note that the incendiary bombs were what we would call hot that is they were fused uh ready to go into action could be tripped at any moment [Music] with 4 000 tons already aboard 500 more on the dock side and the men rushing to finish something cataclysmic happened it was massive that pillar of cloud rose over two miles above the earth the state capital sacramento about 70 miles north felt it people in nevada two to three hundred miles away on the other side of a massive mountain range felt the concussive seismic force of it in a few seconds port chicago had become a wasteland dockside buildings had been turned to matchwood the ship had vanished all but these two chunks of the keel and hundreds of smaller pieces scattered over five square miles 320 sailors were killed body parts were found in various places in fact along one wire fence skin of a human's face with the eyes nose and mouth holes clearly discernible was was located and of course had to be removed what caused the blast is still unknown an accident in handling the live munitions was judged most likely but scientists were less interested in the cause of the explosion than the effects port chicago was of interest to the scientists at los alamos because it proved to be a model for what an atomic bomb might look like the los alamos director of weapons u.s navy captain william parsons was ordered to make careful measurements of the destruction and then present a report on what he'd learned what they were able to calculate at port chicago very effectively was the effect of terrain and other impediments that get in the way of a blast wave there were actually survivors of this blast very close in who normally you would think would have been killed uh who were shielded uh by structures and managed to survive the column of fire rolls the data confirmed that if the point of explosion had been higher above the ground the shock wave would have been more widespread [Music] the second thing was how far away from the burst you had to keep the air crew so that they could survive [Music] an aircraft flying overhead that night at 9000 feet reports chunks of metal the sizes of small homes or garages flying past the problem of how to escape alive was of special interest to captain parsons he had been selected as one of the flight crew who had dropped the world's first atom bomb that day came on august the 6th 1945 and the lessons learned from both halifax and port chicago would be put into effect the bomb was dropped from 30 thousand feet giving the crew time to escape it has been set to detonate two thousand feet above the ground to maximize its destructive power in the explosion itself and from the after effects 140 000 people died after a second bomb was exploded over the city of nagasaki three days later japan finally surrendered now the world knew the awesome power of america's atom bomb but before long even this would be overshadowed by the ultimate explosion of all time the order of magnitude is almost incomprehensible but one way you can look at it is that the bomb drop by the soviets was on the order of six thousand ferocious all in one shot it was on this frozen desert island in the most dangerous period of the cold war that the ultimate explosion took place nevaya zemla in the arctic barren sea is where the russians demonstrated their nuclear might testing bombs of ever-increasing power [Music] on october the 30th 1961 they pushed the limits of explosive power further than they'd ever gone or will probably ever go again this bomb was codenamed the tsar it contained the equivalent of 58 million tons of tnt or all the explosives used in world war ii multiplied by ten the science of bomb making had changed radically since the first atomic test in new mexico in 1945. five four three two one early atom bombs like this worked through what's called nuclear fission hydrogen bombs use a still more powerful process known as fusion [Music] inside an h-bomb an initial atomic explosion is used to force together isotopes of hydrogen the pressure's so great that the atoms fuse releasing enormous energy [Music] with an atom bomb there is a practical upper limit where you can only put in so much fuel before it would just self-destruct from pre-detonation there's no theoretical upper limit on how big a hydrogen bomb can be although beaten to build the first atom bomb russia caught up then overtook america in building ever bigger hydrogen bombs the tsar the biggest bomb the most powerful device mankind has ever constructed was to be their masterpiece and a political showpiece too six camera crews were assigned to film this unique moment in history the aircrew were hand-picked they'd been warned their safety couldn't be guaranteed they could avoid being blinded by the light but being knocked out of the sky was quite possible the exact moment of release was controlled from the ground the bomb had been given a parachute to slow its descent and give the crew more time to escape [Music] [Applause] they did escape but only just the plume rose right through the cloud layer and kept on rising it flattened out when the cloud was 40 miles high the blast wave was still large enough to be measured on its third passage round the world because the bomb was detonated two miles above the ground there was very little radioactive fallout but the earth directly below the burst was seared by the intense heat rock had been turned to ash the bomb was four times bigger than anything america has ever exploded why something so large the united states could develop very accurate missiles the soviets never mastered that technique very well and to compensate for that they really could level a very large area and take out their intended target without having to actually hit the target itself as a target the size of london here's what would happen the blast wave would obliterate everything in a circle 30 miles wide the fireball would be 110 miles across incinerating everything in its path a similar device aimed at washington would cause equally widespread blast fire and radiation effects the likely death toll in the tens of millions [Music] but why did the quest for ever bigger bombs suddenly cease as the destructive power increased political leaders worried more and more that they were really playing with fire in 1963 the superpowers banned bomb tests in the atmosphere underwater and in outer space i think that the soviet detonation will probably be the biggest ever man-made detonation in the future as well and so the soldiers and scientists have packed up and flown away this island's days as a bomb site are history but history has a way of returning to haunt us nowhere more so than the world war one battlefield of messines ridge the explosion of june the 7th 1917 huge though it was now pales in comparison to those of the following decades but it's here that history won't release its grip ensuring real and present danger [Music] just how many unexploded minds remained was one of the enduring mysteries from the first world war most history books said two but now those books will have to be revised a careful study of old battle plans and war diaries has revealed four maybe more and these are mines which are primed to explode they could be touched off by nothing more than bad weather a cluster of mines is in an area of the british code named bird cage these weren't blown on the day of the attack because the front line had shifted after the mines were placed then when the germans attacked in that area in 1918 they were lost or the positions were lost lost and entirely forgotten until one was struck by lightning in 1955 leaving the other three still armed and dangerous they are in open fields but of course people could be walking across those fields the biggest mine of all is the most menacing the 25 tons of explosives sitting underneath this farmhouse known as petite duve the mine's firing mechanism was damaged before the day of the attack and it was abandoned the petty duve mine was a big charge when they append to be going off the farmhouse would disappear whether they are aware of it i've no idea but i suspect that but now they know the explosives are there why don't they remove them a journey deep underground will show how difficult that would be just across the french border at vimy the british also planted mines on a much smaller scale explosives experts known as the durhand group who tracked down the lost mines of messine have been investigating underground here though the clay tunnels of the scene will now have flooded and all the tunnels collapsed these cut in hard chalk are still accessible just about at the end of this tunnel 25 minutes from the surface lie 4 000 pounds of explosive exactly the same as at machine what you're looking at are bags of amino that's the explosives they used these are rubberized bags clipped at the top and relatively waterproof by and large the contents are still quite viable as far as the machine might go they'll be completely flooded the flooding in the tunnels would actually help to preserve the mines so the probability is that even to this day most of the explosives that are left there are still in good condition the flooding will have created an oxygen free environment preserving what's inside the detonators might deteriorate and what we don't know is whether in fact they might become more sensitive with time as opposed to less sensitive and then if you had a lightning strike in the vicinity static electricity could induce a current in the cable to fire the charge to learn that your home is on top of the world's biggest unexploded bomb is news that's difficult to take in for farmer roger mayur whose family have been here for generations there's not much he can do about it i just asked the farmer uh what he thinks about the fifty thousand pounds of amino which is still under the soil here and he says yeah well that you have to live with such a thing in 1955 when the mind exploded he has heard that here and there was a big trickling of the earth and that's quite a few kilometers away maybe it's just that in this part of the world you get used to living in the shadow of history reminders of war and especially man striving for the ultimate explosion are everywhere this is where the german victims of mercene are buried the plaques reveal how devastating the minds were claiming 10 000 lives on june the 7th 1917. will the minds that lie buried stay silent now that nobody can say

Channel: Spark

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Keywords: Spark, action-packed, air force, aircraft, attack, defense, documentaries, engineering videos, firepower, historical explosions, military, motion, science, speed records, sports car crashes, sports cars, tech videos, thrill, velocity, war machines, war strategies

Id: fadUMBuY7Ng

Length: 47min 40sec (2860 seconds)

Published: Sat Jan 16 2021