World's Highest Railway | Man Made Marvels | Free Documentary

[Music] china's tibet railway 1142 kilometers of track with 10 tunnels and a staggering 675 bridges across the most impenetrable land the ching hai tibet plateau it's bitterly cold the altitude so high the thin air can kill the icy ground is so unstable the world said no railway will ever cross the planet's highest plateau but the world was wrong for 50 years china has dreamed of connecting the tibetan city of lhasa to its vast rail network it's not the longest railway but without doubt the most difficult to build it's a man-made marvel how did china build the world's highest railway with this train china is about to write a new chapter in the history of railways this is no ordinary train it's purpose built to tackle one of the last great frontiers in the far south west of china lies the qinghai tibet plateau it's three times bigger than france but it's china's most isolated region at its heart is lhasa a place of spirituality and mystery a magnet for adventurous travelers for buddhist pilgrims has special significance with their own bodies they measure the distance from their homes to lasa's central temple the pilgrims might take a year to get to lhasa this way but getting there by land has always been an odyssey lives have been lost on the dangerous winding road across the qinghai tibet plateau known as the third pole it's one of the most forbidding places on the planet with an average altitude of 4 300 metres the air is perilously low in oxygen the weather is volatile clear one minute blowing a blizzard the next the high winds whip dirt and ice into razors which cut skin and sandblast steel with temperatures that snap to 40 degrees celsius below zero the qinghai tibet plateau is no place for people when china's railway engineers were given the task of building an 1100 kilometer line across what's called the roof of the world they knew the track must climb to more than five kilometers above sea level it would be the highest railway on earth the train would need onboard oxygen and full-time doctors to keep passengers well but what makes the job next to impossible comes not from the conditions above ground but what lies below for 550 kilometers half the railway must cross permafrost solid icy land in winter but mush in summer a quarter of the northern hemisphere is capped by permafrost the frozen icy soil can be more than one and a half kilometers deep it's rock hard in winter but in summer the surface melts and sinks when winter returns it freezes expands and rises again a railway line built on such unsteady ground will bend and buckle railways built with old technology on permafrost are soon abandoned but the chinese are among history's supreme engineers they built the monumental great wall and beijing's forbidden city a palace without power june 29 2001 the chinese government decrees its engineering marvel for the 21st century will be the railway to its isolated tibetan outpost lhasa chinese engineers have to find a way to build the world's most ambitious train track across its highest plateau and they're given just six years to do it [Music] and while altitude sickness among workers would pose life and death challenges for the medical team for the designers the biggest problem comes from the frozen soil the men with the impossible task of building a stable railway line on moving ground our engineer zhao xi yoon and permafrost expert professor john lu shin these are soil samples containing a large amount of eyes so the problem is how to prevent the eyes from melting if the frozen soil melts the railway sinks if 10 centimeters of ice melts it will cause 10 centimeters of sinkage [Music] professor jung has spent almost four decades trying to unravel the mysteries of permafrost he spent five years in the field with teams of surveyors and researchers categorizing the unstable ground and working out how to build on it but permafrost is not the project's worst enemy to build the railway across the qinghai tibet plateau will require 227 000 workers and every day each one of them could be killed by the treacherous conditions at an elevation of 5 000 metres more than half as high as mount everest there's 50 percent less life-giving oxygen in the air as its sea level just visiting the ching hai tibet plateau can make you pass out hard physical work at such high altitudes can kill a man has the immense responsibility of keeping the huge workforce alive and free of altitude sickness the health service and medical support we set up during construction of the qinghai tibet railway is unprecedented in china more than 2 000 medics will be required working around the clock on the front lines of construction on such a massive and dangerous building site the chinese government is determined to avoid the human toll of other man-made marvels [Music] building the usa's hoover dam in the 1930s cost 112 lives and countless injuries [Music] as many as 30 000 workers died building the panama canal [Music] china's own great wall probably killed scores of men during construction but in the china of today people are its biggest asset [Music] as work begins on the world's highest railway the medical team faces a huge challenge on an extremely dangerous high altitude construction site where lack of oxygen can easily kill doctors have to find a way to keep 200 000 workers alive as the experimental train cruises the world's highest altitude railway from qinghai province to tibet's biggest city lhasa it's easy to forget the sheer scale of this monumental project china has been trying to connect its far south western outpost by rail since the 1950s under general mood huge work parties extended china's vast rail network west from the city of singing it was a tough railway to build [Music] a hundred thousand workers laid 800 kilometers of railway from sea to goalmode but that's as far as they got gormud is a high-altitude industrial outpost on the edge of the fickle and fearsome tsinghai tibet plateau the severe cold and dangerously thin atmosphere stopped the qinghai tibet railway in its tracks for 50 years before workers can be sent to this unforgiving construction site doctors have to work out how to stop them from getting altitude sickness caused by lack of oxygen after entering high altitude areas the early symptoms of altitude sickness are headache nausea faster heartbeat and vomiting dr ju howe's first defense against altitude sickness is ensuring they hire only the fittest workers from the lowlands and they spend a week adjusting to the thin air before picking up tools even when they're used to the conditions workers carry oxygen bottles [Music] keeping 200 000 workers supplied with bottled oxygen is a mammoth task but in the tunnels where the air is thinnest doctors soon realize making workers lug heavy metal canisters could kill them at first we had workers carry oxygen bottles on the job but later on we realized that's not ideal because it overloaded them so then we set up oxygen generators and extended long tubes into the tunnel pumping oxygen directly to the work side it greatly reduced the burden on the workers even so men cannot work for long in these conditions a tunnel shift is just four hours on the plateau no one works more than six hours but oxygen and short shifts are not enough workers are under constant threat of fluid forming in the lungs and brain the most extreme form of altitude sickness unless treatment is instant it can quickly kill now fluid forming in the lungs can cause a bad call it produces a rattling sound in the chest patients will have a lot of chest pain and x-ray shows a sharedo in the lungs when it's really serious towards the end there could be blood in a spit the patient will have difficulty breathing and lips turn black the symptoms of lack of oxygen are very serious but on the remote ching hai tibet plateau getting to a hospital is not an option the only solution take the hospital to the work site building 144 infirmaries with almost 500 sick beds helps the chinese doctors keep altitude sickness under control but for critical cases there's one last defense emergency hyperbaric oxygen chambers this model holds up to six people at the same time when the patients come in there are oxygen tubes and oxygen masks after putting on the oxygen masks the patients sit here and the door will be closed filling the patient's lungs with super-enriched oxygen reverses the effects of altitude sickness if it's caught in time before the qinghai tibet railway is complete fourteen thousand workers will be treated in the oxygen chambers spread along the line never before has such a large scale use of oxygen being seen on a construction site but low oxygen is not the only problem for doctors on the plateau with more than 200 000 migrant workers to care for the medical team face the constant threat of outbreaks of diseases like sars and plague it calls for strict hygiene controls and extensive monitoring of workers [Music] since the project began we have achieved three zeros the first zero is zero devs from altitude sickness the second zero incidence of sars the third zero contagious cases of plague these are our achievements 227 000 workers on the world's most forbidding construction site where there's half as much oxygen and not one death from lack of air or disease for the chinese medical team it's a stunning result [Music] with 675 bridges and 10 tunnels the 1142 kilometer railway across the perilous tinhai tibet plateau is without doubt history's most difficult to build but the problem of permafrost the icy ground which melts and sinks in summer is the biggest dilemma of all it's the thick ice layer 1.5 meters below the surface the ice is 10 centimeters thick if it melts the ground will sink 10 centimeters this photo was taken at the construction site there were many people there but few had seen so much ice in the soil professor jung lu shin had to come up with a way to lay train tracks on such unstable ground the solution is amazingly simple tibet railway on permafrost is this to cool the soil of the railway bid and to reduce the amount of heat going into the ground this makes the permafrost stable and stops the railway from sinking in summer it sounds easy enough but keeping a 550 kilometer strip of land frozen during the tibetan summer when temperatures can reach 10 degrees celsius above freezing point is a monumental challenge [Music] the first defense against the heat is building huge embankments for the track there are a thousand kilometers of embankments on a ting high tibet railway the higher they are the more they insulate the permafrost in summer but they're more than just piles of rock and soil purpose-designed insulation panels make up one layer but the most critical section is what's at the bottom of the embankment a bed of crushed rocks called plate stones allows air to circulate between the railway bed and the permafrost the theory is that the spaces between the rocks are all connected and it works like one seamless unit in summer hot air rises and cooler air is trapped in the gaps between the stones keeping the ground cool the rock base is an effective low-tech solution but it won't work for all unstable ground along the ching hai tibet railway to keep more volatile permafrost cool the engineering team found inspiration in the people who have been living in this land for thousands of years to survive the constant bending and buckling of the ground houses built on the plateau have simple but ingenious foundations this is a concrete ventilation pipe foundation you can see the ventilation pipes all lined up we could see something going on here look at the middle part of the house is not distorted at all but at the end it's cracked the railway engineers noticed that if foundation pipes on permafrost are ever blocked the walls crack the air gap insulates the ground from heat generated inside the building as long as the pipes are clear the permafrost does not melt and the house remains stable [Music] adopting the same time-tested strategy the engineers installed ventilation pipes in the railway embankments as an effective and cheap way of keeping the permafrost cold [Music] but for even more fragile zones professor zhang and the railway's chief engineer zhao xi yoon need a more high-tech plan [Music] these are heat radiation fins so how does this device work the heat pipe is filled with liquid ammonia it works like a refrigerator the air temperature can be over 10 or 20 degrees celsius below zero the ground temperature is only a few degrees below zero and there is a temperature difference the ground is warmer the warm soil turns the liquid ammonia at the bottom of the pipe into gas and it rises inside the pipe as the gas passes the radiation fins the heat is released and the ammonia cools and condenses back into liquid then returns to the bottom of the pipe the heat pipe radiates the heat and cools the ground the heat pipes need no power supply they're used on 32 kilometers of the line but some icy ground is so unstable no amount of cooling will keep it solid you simply cannot build a railway bed on terrain like this tasked with the challenge to complete the line to lhasa the engineers have no choice but to come up with another plan the new railway stretching into china's far southwestern territory tibet must cross vast stretches of extremely unstable permafrost and watery ground which cannot hold the weight of railway embankments the designers and engineers need a whole new plan to lay the track in some areas we cannot guarantee the stability of railway beds built on permafrost so we decided to avoid the permafrost altogether and build bridges over the top of it without bridges the ambitious plan to lay a railway across the ching hai to that plateau would be impossible [Music] some cross rivers and ravines but most bridges stand on flat land this is the most unstable permafrost which would collapse under heavy rail embankments there are 675 bridges on the railway crossing the qinghai tibet plateau the longest land bridge on the line runs almost 12 kilometers but building bridges and constantly thawing and freezing permafrost raises a whole new set of problems it all comes down to the concrete pylons the engineers have to work out a precise way of pouring concrete into permafrost it depends on how long it takes the ground temperature to return to its original state when we make the concrete pylon it's frozen in with the permafrost and that's what gives the pylon its load bearing capacity the challenge for professor zhang and his team is how to insert concrete pylons into highly unstable permafrost without melting the icy soil the first step is to drill the holes when it's cold and the holes are dug dry normal drills use water as a lubricant but water melts the underground ice all pylons in permafrost are sunk deep to 20 meters below the surface installing the metal formwork quickly is critical [Music] the whole process depends on minimizing the time the underground ice is exposed to warmer air then the concrete is fast poured concrete is the crucial ingredient of modern construction as it is for the ching hai tibet railway using specific formulas all concrete in the hundreds of thousands of pylons is specially mixed for the harsh tibetan conditions we've used concrete that works in low temperatures it sets quickly it resists corrosion and is very durable the most important factor in pouring the pylons is the temperature of the wet concrete cooled to just five degrees above the melting point of ice the concrete quickly sets and freezes to the same temperature as the permafrost it becomes part of it even when the upper layers of the permafrost melt and sink in summer the deep ends of the pylons remain frozen in and maintain their load-bearing capacity when building a railway in permafrost temperature is your worst enemy or your best friend by manipulating the temperature of the concrete pylons as they're poured the builders of the ching hai tibet railway ingeniously overcome the forces of nature [Music] concrete pylon bridges support 160 kilometers of the railway to lhasa from the train they allow sweeping views across the vast plains [Music] but as the train climbs the plateau towards the tungular mountains it meets rivers and canyons and more daunting problems for the railway engineers a bridge this size usually takes two years to build but the chinese construction teams were given just half that time the her bridge rises 52 meters above the canyon and is almost 700 meters long on a tight deadline china's railway engineers had to work out how to build bridges this size faster than they ever have before it's an india a bridge like this takes two years to build but we were given just one year the lowest temperature here is more than minus 30 degrees and half the year it's too cold for construction so we really only have half a year to build it the engineer's big problem as usual on the freezing ting high tibet plateau is pouring concrete in winter in sub-zero conditions they had to find a way to stop it from freezing before setting properly to make concrete at more than 30 degrees below zero we built a tent for the sand and pebble stones and used hot air fans and ovens to heat them up we used boiling water to mix the concrete to ensure the temperature of the concrete was not too low this is bridge building pushed to the limits heating each and every load of concrete and keeping out the biting cold so it can set to pull it off the engineers have to dig deep into their bag of building tricks inside the hollow pylons we piped in hot steam on the outside we wrapped them in plastic and cotton quilts we lit fires on the scaffolds to heat the concrete it meant we could pour concrete throughout winter once the pylons are in place giant cranes swing into action to position two pre-poured girders from peer-to-peer ready for the tracks [Music] as one of the first trial passenger trains to lhasa cruises the multi-stage track over bridges on water and land and on temperature-controlled embankments it climbs ever higher to the funghora and the tungula mountains this is where world records are set tungle railway station is 5068 meters above sea level this is the view at the world's highest railway station with the world's highest train tracks at this extreme altitude the engineering challenges become even more daunting [Music] the highest permafrost tunnel in the world goes through high altitude permafrost with a high proportion of ice the tunnel is 4905 meters above sea level its entire 1.3 kilometer length is bored through permafrost which is 50 frozen water temperature is required during excavation of the tunnel to prevent the permafrost from melting and collapsing even though the temperature outside the tunnel is a staggering minus 40 degrees celsius at the work phase men and machines heat the air and that could be fatal if the permafrost melts the roof could easily collapse trapping or killing the workers at this part the roof of the tunnel is only six meters from the surface of fenghua mountain that six meter layer of earth contains a lot of ice more than fifty percent it made construction [Music] when we started excavating the tunnel we had to reduce the temperature at the roof or this area would melt and collapse immediately to prevent such a catastrophe the engineers install air conditioners to refrigerate the tunnel and as they excavate they build a steel cage to support the roof and walls then workers spray concrete on to form a hard shell but this step is the tunnel engineer's biggest headache and as always when building in permafrost it's about the temperature after the excavation when laying down the concrete we need a relatively higher temperature which leads to a dilemma at the same construction site two variant temperatures are needed concrete won't set properly below freezing point the engineers had to work out a way to pour concrete in an air temperature close to -40 degrees the tunnel engineers have no option but to keep the concrete warm which means carting giant boilers to the high altitude work site with these two boilers we heat sand and gravel maintaining the temperature of the liquid concrete we also heat the water and the mixing equipment then we raise the temperature of the entire tunnel when we pour the concrete with this device we solved the technical problems of construction in extremely low temperatures on the high plateau with the outer concrete shell in place now the challenge is to make sure any permafrost that does melt can't get into the tunnel look at this part this is the first concrete layer when building normal tunnels we just have one concrete layer but here after the first concrete layer we put in water-resistant material and insulating board and after that we install a second layer of water-resistant material and insulation board the synthetic layers keep out water but that's still not enough to protect the concrete tunnel from cracking when the surrounding permafrost freezes and expands in winter they need a second internal concrete wall we've set up a concrete machine and is ready to build the second concrete layer building tunnels in permafrost is a huge engineering challenge and they're expensive so the design of the ching hai tibet railway calls for as few as possible on the 1100 kilometer line there are less than 10 kilometers of tunnels but with the mountains comes another force of nature out to stop the railway in its tracks [Music] the ching hai tibet plateau is an earthquake zone violent tremors could shake the railway apart and shatter the engineer's dream the ching hai tibet plateau has stopped china for 50 years from extending its rail network to its far southwest region of tibet while the permafrost is the railway's biggest enemy another foe threatens to derail the whole project november 2001 the plateau is rocked by a major earthquake 8.1 on the richter scale houses disintegrate and the land rips like tissue paper the scars are echoes of the creation of the ching hai tibet plateau deep below ground two mammoth slabs of the earth's crust are pushing against each other the indian and eurasian tectonic plates are thrusting upwards forming the himalayas with the world's highest peak mount everest and the highest plateau friction between the opposing tectonic plates unleashes shock waves we call earthquakes the 2001 quake cracks one of the tunnel's walls and progress halts for repairs [Music] but with regular trammers plaguing the tin height to that plateau the designers know constant rebuilding of the line is not an option there has to be a way to minimize destruction by earthquake an unpredictable but certain enemy we are standing on a seismic fracture zone there are more than 140 seismic fracture zones along the qinghai tibet railway and what we see here is just one of them with so many fault lines the master plan calls for evasive action if you can't go through the plateaus minefield of seismic fracture zones you just have to go around them but when bypassing an earthquake zone is impossible that's when you need an engineering backup i know jungle search according to the design plans we should have built a very big bridge here however to protect the railway from earthquakes we decided to build up a railway embankment instead which is easier to repair in an emergency an embankment filled with rock and soil can be quickly repaired if the fault line shakes but a tall bridge built on earthquake-prone ground is more vulnerable to collapse endangering lives and costing far more to repair one by one the engineers overcome the myriad of obstacles with ingenious strategies and the qinghai tibet railway climbs steadily through the plateau's treacherous peaks the mountains of the qinghai tibet plateau are challenging not only to railway engineers passengers on the train can be exposed to dangers of altitude sickness through the lack of life-giving oxygen now our train is at the highest point about 5 000 meters above sea level this atmosphere has very little oxygen in it it's perilously thin air every train on the ching hai tibet railway has a full-time doctor and nurse on board they monitor all passengers and they have an invisible ally in the battle to prevent altitude sickness the train's air conditioners pump oxygen directly into the carriages high altitude tends to cause headache nausea and heart problems it's nothing too serious it's regular altitude sickness move close to the oxygen valve breathe in open the air valve move as close to the valve as you can with onboard oxygen and full-time medical gear passengers on the train to lassa are unlikely to get seriously ill with precious sealed doors and a man-made atmosphere these are unique carriages to work on the highest railway in the world chinese manufacturers have come up with technology seen on no other trains [Music] [Music] they might look like any other train in china but to operate on the world's highest railway on the ching hai tibet plateau where the air is low in oxygen these carriages are packed with sophisticated features airflow inside the cars is the design focus ducting runs through all the walls the air conditioning system pumps enriched oxygen into the train this is part of the oxygen generation system it's an air compressor which generates compressed air of 0.8 to 1 megapascal the compressed air will be channeled through the specially designed pipes beneath the train to the oxygen generator which is inside the train pressurized air coming from the air compressor under the train comes into this oxygen generating system the oxygen enriched air that's produced then goes to the air conditioner and the oxygen vents vents in the roof and ports in the walls release high oxygen air into the carriages [Music] the designers have gone to extra lengths to keep the precious oxygen inside the train the door is to ensure the train on the ting high tibet railway is properly sealed it also increases the efficiency of the oxygen generating system the door is a double sealed sliding door lining the door with rubber on both the inside and the outside keeps the oxygen in even the windows are double sealed and they've been double glazed to block ultraviolet radiation on the plateau five kilometers above sea level the sun's deadly rays are three times as harsh as the high-tech train travels the 1100 kilometer line from gulmu to lhasa cocooning its passengers from the polar conditions of the qinghai tibet plateau its journey is a tribute to the massive human effort it took to lay the rails but the rails themselves tell as remarkable a story to supply the vast quantities of pre-fabricated track would require a purpose-built factory on-site right in the middle of the hostile tinhai tibet plateau this is the highest altitude railway factory in the world at 4704 meters above sea level the end duo track prefabrication plant supplies the backbone of the railway across the qinghai tibet plateau the pre-made panels of track are laid one by one but the railway needs 49 000 of them the sleepers are poured from super strength concrete designed to withstand constant freezing and thawing once again concrete is critical to the [Music] project getting the pre-fabricated track to the work site needs hundreds of flatbed wagons using the new line to get there load by load 80 panels at a time locomotives haul the hundreds of thousands of railway sleepers to the front line of construction by the time the track is ready for installation most of the hard work has been done the bridges and embankments built and the tunnels dug laying the rails is the finishing touch marking the end of a marathon 40 years of planning and five years building the ching hai tibet railway mobile cranes drop the track in place and men bolted in but even this simple job is made hard by the ching hai tibet plateau all it has to do is change the weather [Music] oh the 1100 kilometer railway line from golmud to lhasa is an engineering triumph but there's one more challenge facing the project conditions on the environmentally sensitive tibet plateau are considered to be a litmus test for the overall health of the planet when it comes to climate change and global warming it's a critical problem for the architects of the railway not only must they conquer permafrost and keep the workforce alive in the thin air the whole job has to be done without damaging the ecosystem in this area of railway construction we remove the grass and store it where it can be looked after when the railway has been built then we replant the grass to the slopes of the railway bed we have to ensure the grass stays alive so we've removed a thick layer of earth with roots intact that way the stored grass will live even quarries must be replanted with the original grass when we selected the site to dig sand and earth for the railway we tried to choose those areas with the least amount of plant coverage all the grass salts are moved over there where teams of workers keep it alive the survival rate is pretty high when we're finished with a quarry we'll move the grass back to this area and it'll all grow back [Music] preserving wildlife also poses problems the railway must be diverted around rare bird breeding grounds and the endangered tibetan antelope roams this remote plateau to maintain and protect its migration roots there are special bridges or underpasses but by far the most important ecological challenge involves water the qinghai tibet plateau is the source of three of asia's mightiest rivers the yellow the yangtze and the mekong massive construction can be a dirty business and polluted water must be kept away from catchments to protect the source of the yangtze river the wastewater first stays in the settling pond and the dirt subsides then it goes to a second settling pond for further purification finally our environmentalists will test the water quality before allowing it to flow into the yangtze river [Music] the results show there's no big physical or chemical difference between them not much change in acidity alkalinity or metal content this is the purified water from the settling pond and this is the sample from tortoise river generally speaking if the water from the settling pond flows into torture river it will not pollute the river 40 years in the planning and built in just five years one year ahead of schedule the railway line to lhasa is open overcoming impossible odds unstable permafrost extreme cold low oxygen levels earthquakes and a fragile environment the qinghai tibet railway is testament to chinese engineering with lhasa in sight the 12-hour rail journey from goldboot is now possible the crossing of lhasa river with its tibetan inspired bridge fulfills china's 50-year dream to link its far south western outpost [Music] with the remote and mysterious tibetan city of lhasa now connected to the rest of the world half a million passengers a year are expected to use the new way to get there across one of the final frontiers the qinghai tibet plateau on the world's highest railway [Music] [Applause] [Music] you

Channel: Free Documentary

Views: 196,335

Rating: 4.7865686 out of 5

Keywords: Free Documentary, Documentaries, Full documentary, HD documentary, documentary - topic, documentary (tv genre), engineering, engineering documentary, constructions, construction documentary, megastructures, engineers at work, construction, railway, railway documentary, railway construction, railway megastructures, railway engineering, technology, technology documentary, tech documentary, Qinghai-Tibet railway, highest railway, railway india, highest railway in the world

Id: 2dlfUxcAowg

Length: 47min 47sec (2867 seconds)

Published: Fri Nov 06 2020