Developers of the new World Trade Center learned a sight of lessons from the numerous attacks and eventual prostration of the original building — reexamining every aspect of the security and safety systems . Here ’s what they ’ve figured out .
A Befitting Pedestal
The September 11th attacks were not the first successful assault on the complex . In 1993 , a Ryder truck laden with 1,500 pounds of explosives and driven by Ramzi “ Fuck Face ” Yousef break loose in the North Tower ’s underground garage , killing six , open a 100 - understructure full gash in the construction ’s base , and threatening the structural integrity ofthe Bathtub .
https://gizmodo.com/how-new-york-city-built-a-massive-3-8-billion-undergro-5837791
That scenario is extremely unlikely to occur again . Mostly on account of the construction ’s new locating 90 - pes from the edge of the street ( as react to the previous construction ’s 25 - foot setback from a state main road near the Hudson River ) and ultra - hard reinforced concrete and 70 - ton steel beam base that the novel WTC tower sits upon . The windowless base is 200 - feet by 200 - metrical foot , the same measurements of the original WTC , rising to a tiptop of 186 base , and is designed to absorb and obviate the flak from even the with child vehicular bombs . Designers plan to cover this impenetrable pill corner with a serial of 2,000 , 13 - foot marvellous glass prisms coated inthe same plastic as engage in automotive safety glassand , though it wo n’t allow much light in — due to the monumental concrete wall behind them — the prisms should create an heart - catch deflection pattern .
Above this strong base get up a rich column of brand moment frame with multiple levels of redundancy — beam and column weld and bolted together and designed , harmonise to theLower Manhattan Development Corporation ,
to fend sidelong loads through bending of the frame elements . Paired with a concrete - core shear wall , the moment frame lends significant rigidness and redundancy to the overall construction structure while put up column - free home span for maximum flexibleness .
This will help forbid the Total Progressive Collapse that cause the first Towers to conk out . When Flight 11 struck the North Tower , the impact go down on off the building ’s installed fireproofing and dumped 128,000 pounds of burn up fuel into the building . This massive flaming payload super - heated the WTC ’s steel supporting column — up to 1500F — which softened them to the point of buckling . The top floor then crock up downward , pull the exterior columns inwards and smashing the floor below before being themselves put down as they excise the 1.8 million - pound debris pile .
In all , 1 WTC will utilize more than45,000 piles of morphological steel — as much as 22,500 Lincoln Town Cars , twice what was used in the Chrysler Building — and over 200,000 cubic yard of concrete like New York has never seen . According to Eduardo del Valle , Director of Design Management for One World Trade Center , it ’s “ strong than any concrete engineered in New York City — ever . ”
Vehicle Security Center
Another reason that flat coat - based attack against the composite are importantly less likely to meet with success is the The World Trade Center Vehicular Security Center and Tour Bus Parking Facility ( VSC ) . Thissubterranian state - of - the - prowess facilitywill screen every fomite — every gondola truck and charabanc — entering the hugger-mugger parking complex fortraditional as well as radioactive explosive . The adeptness ’s foundation utilizes 10,701 tons of structural steel reinforcing BAR — that ’s 1/10th of the total weight of the Eiffel Tower . Once through cover , vehicles will be able to access a connection of underground roadways that serve all seven towers within the WTC site .
Visitors Entrance
The footer entrance summons will be no less tight . visitant to both the WTC buildings and the 9/11 Memorial will first pass throughairport - style metal detectors and X - ray machinesand have every bag , briefcase , and delivered parcel screen . Museum patrons wo n’t even be permit into the key shopping mall without fade security . In addition , the WTC construction “ visitor will be issued a photograph ID for the day or for a limited amount of hours and the turnstiles will respond to those ID ’s only for that time shape in which card entree is reserve , ” explained del Valle .
resident of the tugboat — those that work there daily — will receiveCLEAR posting - same trust security badges that will allow them to short-circuit the normal screening lines . What ’s awesome is that as the worker happen through the certificate turnstile , a proximity chip in the ID card activates the Destination Dispatch System that controls lift service . “ So , if you work on the 38th floor , it will automatically tell you which elevator to go to that will take you directly to the 38th trading floor . ” del Valle aver , “ It ’s a security feature so that people who are in the building for a specific purpose get there only . ” Stair access will be restricted as well and memorialize the time of entryway , duration , and exit floor of workers who use them .
Watching over this process will be an unrevealed number of the670 NYPD officers who make up the Lower Manhattan force-out — more than in any other district in the city and more than the entire urban center of Oakland , CA . More than 400 unsympathetic - lap surveillance television camera positioned in and around the composite will provide live feeds to a 24 - hour monitoring command center located nearby . The feeds will also be supervise byvideo analytical softwarethat is design to know suspicious people , activity and unattended baggage .
Elevators
The elevators of the novel WTC are as numerous as they are secure — withten elevators service the Observation Deck and Restaurant alone . According to del Valle , the Destination Dispatch System works as such :
Basically , the elevator operation — the individual cabs — are controlled by package that determines very quickly — within seconds — which cabriolet is most efficient to function a particular call based on other calls that have been registered by the system at the turnstile . So really it ’s the turnstile that sends the signal to the destination dispatch software and that then handle — digitally - the lift that is assign to a group of people or you individually , bet on your finish . That maximizes the service content of the elevator and downplay the use of electrical energy and office so that elevator are not slay at random or by the demand of a single caller
Every elevator in the WTC is protect within the central core structure , which is fundamentally a vertical concrete bunker . The Rebar reenforcement are as thick as a valet de chambre ’s forearm , spaced very closely together and filled in with the same topnotch - strong concrete as the building ’s infrastructure . In accession , the entire MEP organisation ( mechanical , electrical , plumbery ) as well as the life sentence and safety system of rules is housed there as well . “ So , if there was any event that compromise the ring , none of the critical systems will be compromise , ” del Valle conclude .
Stairs
Even the steps are designed in excess of New York building codes and built to prevent the issues presented by the 9/11 attacks . They ’re 50 % wide than required , which not only allows more masses to exit down them at the same time , they also permit for the great unwashed in wheelchairs to be transported down them as well . In addition , at every landing place of the staircase , there is an “ country of refuge ” where a wheelchair - bound person could wait to be rescued by first responders or assign edifice personnel if they can not otherwise leave the building . What ’s more , the stairwells are internally pressurise to keep smoke out of the stairwell and will feature humble level emergency ignition — astonishingly not present in the original Tower — as well as concrete protection for all sprinklers and parking brake risers . Every stairwell is interconnect to provide redundancy and cash in one’s chips directly to the street .
First Responder Systems
The novel World Trade Center is build with first responders in judgement and speak the problems present in the original Tower — namely , NYPD and FDNY radio receiver did not commune with one another and the FDNY radios had pathetic receipt within the structure , hindering saving efforts and preventing warnings of an impending flop to reach those on the interior . Now , a series of antennae and repeaters will bunk the full height of the building — from the cellar to the 104th floor , providing a vital means of communicating .
There ’s also a consecrated first responder stairwell so that if , say , the public step are unaccessible rescue crews can still reach the upper floors . And , for those responder that do n’t want to climb up 104 flights , a dedicated , water- and fire - proof elevator will allow access to the full meridian of the structure .
In the outcome of a fire , the construction feature H2O tanks with double the capacity required by NY building computer code — again , for the sake of redundancy — and the sprinkler and hand brake risers are all protect by concrete sheaths . The WTC is even equipped withchemical filtersin the air supply organisation in the consequence of a biologic tone-beginning .
lesson study
Obviously , no amount of applied science can ever completely secure a edifice 100 % against external threats — specially against a lot of psychotic Zealot who are willing to hijack planes and kill themselves to make a point , but the new World Trade Center complex has been designed with virtually every contingency in mind . So , while the raw WTC remain squarely in the cross - hairs , it ’s become an incrediblyhard target .
Monster Machinesis all about the most exceptional machines in the world , from massive gadgets of destruction to diminutive machines of precision , and everything in between .
A civilisation can differentiate itself by how well it responds to catastrophe , and 10 years later , 9/11 is as much a story about recovery and rebuilding as it a story of terrible loss and tragedy . As a nation , our political and economic reaction has been imperfect — possibly even dead incorrect — but we ’re focalize on the mechanical marvels that have helped us bounce back .
you’re able to keep up with Andrew Tarantola , the author of this post , onTwitter , Facebook , orGoogle+ .
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