Hong Kong's $11BN Underwater Railway Explained

hong kong back when mega projects like the birds nest were a mere glint in china's eye this was the original poster child for construction in asia but don't let the bamboo scaffolding fool you this tiny territory has long punched above its weight generations of engineers and architects have cut their teeth here with landmark buildings like the hsbc and bank of china towers the city also boasts the mtr while the best public transport systems in the world and it's just got even better the new multi-billion dollar shut-in to central link will transform transport in hong kong from its outer reaches to its neon heart it's fast efficient and has the kind of fan following that would turn the london underground green with envy but it hasn't exactly gone to plan the constructions had to contend with extreme weather and a deadly pandemic and that seems to have been the easy bit the building of this line gave rise to one of the biggest construction scandals in living memory an episode which has shaken hong kong's building industry to its reinforced concrete core so how was this remarkable new railway built and how did it nearly go so very wrong [Music] [Applause] [Music] to get a sense of how important this new line is we're going to have to start with a quick geography lesson hong kong is made up of hong kong island kowloon peninsula and the new territories as well as a couple of hundred sparsely populated islands now here's the problem hong kong island is the territory's main business hub so how do you get people who live here and here to and from work every day with this in the way well you could take one of the road tunnels catch one of the high frequency mtr trains or if you're feeling wistful take a trip on the trusty star ferry an icon of hong kong since it first opened back in 1888. simple easy efficient [Music] historically in hong kong railway has been the backbone of the transportation network in hong kong we do have the daily patronage excess of four million people for a city that's about seven point seven million people to keep up with demand the shatin to central link was devised a massive 10 billion railway which would transform transport across kowloon and the new territories and provide a much needed additional link to hong kong island phase one would join two existing rail lines to create the new twen mar line this will provide a new east-west link across the new territories on what would be the mtr's longest line but phase two would extend the east rail line from kowloon across victoria harbour and create the much needed fourth rail link to hong kong island let's just say people were pretty excited about it [Music] don't worry we'll come back to that later it was the cross harbour extension that saw some of the biggest engineering challenges of this whole project for starters how do you build a tunnel across one of the most iconic harbours in the world as the railway had to connect to hong hom an existing station on the north side of the crossing a tunnel solution was needed that would be shallow enough to avoid trains diving sharply under the harbour like a roller coaster instead of drilling through the bedrock the team opted for an immersed tube tunnel having the immersed tube tunnel methodology it does give us that flexibility to ensure we meet the railway alignment to connect the hong kong station to the landing point on the hong kong island here's how it works a trench is dug out of the seabed and prefabricated sections of tunnel are towed out at sea level these tunnel sections are then sunk fitted together and covered over with excavated earth once the whole thing's watertight water is pumped out and bang you've got an underwater railway the 11 tunnel sections were created here at the site of a former quarry around 160 metres long 9 metres tall and 20 meters wide each of the units weighed an incredible 23 000 tons once constructed the quarry was flooded and the tunnels were towed to the north side of the island meanwhile a specially constructed gravel spreader was preparing the seabed to ensure it was stable enough to take the enormous weight of the new tunnel before the immersed tube units are placed into its final position we have to have a gravel bed this gravel spreader was able to use a computerized system so that you can not only place the gravel but also have the gravel to the right thickness and the right level before the final units are put in place this machine also replaced dangerous work previously carried out by divers who would manually check the thickness of the gravel bed as if all of this weren't complicated enough the construction also had to contend with a tropical storm the transportation of the precast unit from sheckle casting basin to victoria harbor that would take about one week during one of the units where it was transported uh that one of the titans came quite quickly but fortunately the unit was able to you know we had more in quite a sheltered area called junk bay after the units were lowered into place a hydraulic jack was used to slide them together a gasket created a watertight seal and the remaining water was pumped out from here it was over to athena and gerner the project's two tunnel boring machines to create the two kilometer long tunnel to the east rail line's new terminal at aberrantly station that is of course two kilometers through one of the most densely built areas on the planet after the tunnel had managed to squeeze its way through this it then somehow had to plug into a station that was so busy it'd become meme worthy without disrupting any services to the three other lines that were all in active service historically admiralty station had originally two lines going in there with a chain one line and island line then we had the in in 2016 we also commissioned the south island line part of that work under the south island line project had created the space required for these saturn central link platforms you know which we built over the last few years and that work involved underpinning the existing stack tunnel of the island line over a length about approximately 60 meters the earth beneath these platforms was divided into two series of columns earth was excavated and reinforcements installed in an alternating sequence in total 650 000 tons of rock was removed and replaced with 5 000 tons of steel beams and supports and this is the result a giant station linking east rail with three other lines so another triumph for hong kong cue adoring crowds and congratulations all round well not quite in 2018 during the construction of hong kong station a whistleblower scandal erupted which cast a shadow over the whole thing everything started when jason poon a subcontractor working on the site went public with what he saw as a number of dangerous safety standards being breached the accusations centered around work on the station platform poon alleged that construction workers were not properly installing the steel bars or rebar which connected the structure of the platform to the station wall instead of screwing the rebar into couplers which joined the two sections together workers were cutting the rebar so it only appeared that they were connected once the structure was filled with concrete to create the platform this could have created an unstable structure which could potentially collapse with devastating consequences in july of that year as news of the allegations spread the hong kong government launched an inquiry led by retired judge michael hartman and what they found was pretty bad an inspection in april 2019 revealed that out of 191 steel bars which were excavated for investigation 39 were too short and it didn't stop there as the investigation widened they discovered paperwork was missing for the northern tunnel approach and there were further examples of unauthorized work such as changes to the design of the rebar structure at hong hong station the inquiry concluded that while no direct orders were given by mtr to cut corners it was ultimately responsible for signing off for work as was the hong kong government frank chen the hong kong secretary for transport and housing and jacob kam ceo of mtr corporation both publicly apologized for the scandal with chan promising an internal review to prevent something like this ever happening again during the commission of inquiry at that stage mtr did a lot of review ourselves and what we recognized was when there's certain parts of the work which was not done according to the code and standards then we took the initiative to do the remedial works and so we really took the initiative to make sure that there's no questions left before the station was commissioned after remedial works were carried out to reinforce the station the judge declared it fit for purpose and safe to open as it stands we respect all the findings and recommendations in the inquiry and we have taken those on board as well to go forward before next set of projects [Music] as shocking as this scandal was it doesn't seem to have damaged public enthusiasm for the new rail line yes what you're seeing is correct the steady growth of the mtr has nurtured a new wave of train enthusiasts in hong kong's youth as the expanding rail network provides connectivity to towns in further flung corners of the city it's grateful new passengers are all too happy to celebrate it the west island line and also the shutting central link connecting different types of different towns in hong kong these type of new projects and new lines make kings so many teenagers showing their interests on railways so they always show their love by sharing their photos their videos on the internet one community of fans created a virtual version of the entire mtr network in minecraft while others have taken to song to show their excitement for the shot in to central link another fan jason law scored a viral hit with his song i'm really excited about the opening of twen ma which quickly became a meme his tune got so big it was given the showbiz treatment and even became the official anthem of the opening of the cross harbour extension [Music] when the east rail line extension opened for service on the 15th of may 2022 thousands of eager fans turned up to try and get a place on the first train at 5 30 am the earliest arrive at around 8pm on the 14th of the of may that is one day before the opening yeah it's quite crazy yeah it may be two years late and nearly 1.5 billion dollars over budget but it looks like the shot in central link has the seal of approval and its diehard fans have set a new bar for the openings of infrastructure mega projects i do have a lot of sentiments behind this line because crossing harbor and when i was young living in the territories and having to take the train and then the ferry to cross harbor now that i can do it so efficiently but i think really is for the community and for the people who are involved in engineering construction they can feel good about it hong kong island has got the new harbour crossing it's so badly needed and a banging new song it never knew it want it [Music] if you enjoyed this video and you want to get more from the definitive video channel for construction subscribe to the b1m [Music] you

Channel: The B1M

Views: 1,093,994

Keywords: B1M, TheB1M, Construction, architecture, engineering, The B1M, Fred Mills, building, hong kong, shatin, sha tin to central link, sha tin central, scandal, hun hom, railway, infrastructure, megaproject, mtr, underground, admiralty station, exhibition centre opening, hung hom, east rail line, crossharbour extension

Id: 03AtIZjziJw

Length: 13min 22sec (802 seconds)

Published: Wed Jul 06 2022