My first glimpse of World Trade Center blueprints.

  • conservativej...

    Posts: 2465

    Jan 14, 2014 7:03 PM GMT
    One of the most enjoyable occupations I have had in life has been the development and construction of high rise towers. For several years after the 911 tragedy I had wanted to see WTC engineering drawings, which the Port Authority of New York and New Jersey were so hesitant to release. I have finally run across the engineering drawings as png images. The image below is a portion of the plaza level showing primarily WTC1, with WTC2 partially shown in the lower right. What caught my attention are the north side and south side ducts running the full height of the tower. As the tower was breached, these would have been drains for fuel. On impact or shortly thereafter, a heavy steel door was blown open in the basement level machine shop. An explanation at last.

    photo Plaza_A1_Level_zps4b963186.jpg
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    Jan 14, 2014 11:58 PM GMT
    I studied these building in architecture school and was impressed by the structural system. They were state of the art. No blame can be placed on the engineers for designing something substandard.
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    Jan 15, 2014 3:21 AM GMT
    Somewhat related, there's a show on the Science channel called "Strip The City" that breaks down the architecture and blueprints of major cities around the world. I love watching it.

    Here's a clip http://www.sciencechannel.com/tv-shows/strip-the-city/videos/tunneling-under-london.htm
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    Jan 15, 2014 3:31 AM GMT
    Explanation for what?
  • TDSmoove

    Posts: 131

    Jan 15, 2014 7:49 PM GMT
    I too love reading up on designs and techniques that are used in towers from Burj Dubi, Taipei 101 to the current WTC 1. Due to codes we here in Denver can't have towers taller than 55 stories so it's amazing to see these superstructures and how they were done. I have to check out that show on Science
  • Apparition

    Posts: 3525

    Jan 15, 2014 8:58 PM GMT
    ReeBad19 saidExplanation for what?


    perhaps it is an explanation of how a big steel heavy door flew out of the basement and completely destroyed building seven all by itself.

  • conservativej...

    Posts: 2465

    Jan 15, 2014 10:00 PM GMT
    Alpha13 saidI studied these building in architecture school and was impressed by the structural system. They were state of the art. No blame can be placed on the engineers for designing something substandard.


    I agree.
  • conservativej...

    Posts: 2465

    Jan 15, 2014 10:08 PM GMT
    ReeBad19 saidExplanation for what?


    When WTC1 was hit the maintenance crew members who were in a work area several levels below the plaza level in the drawing knew nothing had occurred until a very heavy steel door blew open for no apparent reason as they could see. That was noted in some of the post 9/11 reports I saw somewhere. A vast portion of the aircraft structure and of course fuel never exited the building. The fires would have been generated from hot engine parts being bathed in fuel, which found many pathways down the superstructure including those common ducts on the north and south face of the towers.

    It is more common today to provide HVAC to a tower by pumping water that is used by what is a heat pump to either heat or cool space. It is very uncommon to have large scale central ducting as in the WTC towers. But keep in mind Consolidated Edison provides steam to much of Manhattan that can also be used in the summer to drive adsorption chillers for cooling. All part of the WTC complex.

    Fascinating to study.
  • conservativej...

    Posts: 2465

    Jan 15, 2014 10:09 PM GMT
    TDSmoove saidI too love reading up on designs and techniques that are used in towers from Burj Dubi, Taipei 101 to the current WTC 1. Due to codes we here in Denver can't have towers taller than 55 stories so it's amazing to see these superstructures and how they were done. I have to check out that show on Science


    I was not aware of the 55 story limit in Denver. I assume due to possible seismic events?
  • conservativej...

    Posts: 2465

    Jan 15, 2014 10:12 PM GMT
    Myol saidSomewhat related, there's a show on the Science channel called "Strip The City" that breaks down the architecture and blueprints of major cities around the world. I love watching it.

    Here's a clip http://www.sciencechannel.com/tv-shows/strip-the-city/videos/tunneling-under-london.htm


    Such things are always interesting. I have a very close friend, a Professor Emeritus, who has been in and out of the Fukushima site at the rip old age of 85 studying radiolysis of concrete since the disaster there. He would have life no other way.
  • conservativej...

    Posts: 2465

    Jan 15, 2014 10:26 PM GMT
    Below is a photo during the construction phase of one of my most enjoyable projects. Architecture by A.M. Stern. Structural engineering by a local ATL firm. I received an e-mail from a good friend at McNamara and Salvia wanting to know what I was up to in the world of construction. I replied with this photo that prompted a phone call rather than an e-mail in reply. There is a very very good reason his interest was prompted which you can most visibly see in this photo. What might that be?

    photo PlateDistance_zpsec090c3b.jpg
  • Kwokpot

    Posts: 329

    Jan 16, 2014 1:28 AM GMT
    conservativejock saidBelow is a photo during the construction phase of one of my most enjoyable projects. Architecture by A.M. Stern. Structural engineering by a local ATL firm. I received an e-mail from a good friend at McNamara and Salvia wanting to know what I was up to in the world of construction. I replied with this photo that prompted a phone call rather than an e-mail in reply. There is a very very good reason his interest was prompted which you can most visibly see in this photo. What might that be?

    photo PlateDistance_zpsec090c3b.jpg

    The construction elevators are not supported on the upper levels.
  • Posted by a hidden member.
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    Jan 16, 2014 2:02 AM GMT
    Thats what I was going to say!
  • Posted by a hidden member.
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    Jan 16, 2014 2:02 AM GMT
    What is the name of this Atlanta building and what address?
  • conservativej...

    Posts: 2465

    Jan 16, 2014 4:14 PM GMT
    Kwokpot said
    conservativejock saidBelow is a photo during the construction phase of one of my most enjoyable projects. Architecture by A.M. Stern. Structural engineering by a local ATL firm. I received an e-mail from a good friend at McNamara and Salvia wanting to know what I was up to in the world of construction. I replied with this photo that prompted a phone call rather than an e-mail in reply. There is a very very good reason his interest was prompted which you can most visibly see in this photo. What might that be?

    photo PlateDistance_zpsec090c3b.jpg

    The construction elevators are not supported on the upper levels.


    Not the cranes. Look at the tower itself. In all fairness it would only be obvious to a structural engineer or possibly an architect.
  • conservativej...

    Posts: 2465

    Jan 16, 2014 6:13 PM GMT
    NJDewd saidWhat is the name of this Atlanta building and what address?


    Currently the Mandarin Hotel. It is in the 3300 block of Peachtree Rd. It was foreclosed and popped back on the market. The bidding process was as interesting as the development phase, the former of which I was involved, the latter of which I entered the bidding but laughed at my own bid. ;-) The construction phase burned $165MM.

    Somewhere in this old place in which I reside I still have the individual floor plates for the Mandarin. There are some incredibly unique surprises in those plates, as there is a condo with a 35 foot ceiling located at a transfer floor.

    In the photo the tower is topped out. The top two floors are unit #56. There is also something else shown in that photo at the very top that is key to my original post as to what is odd about the structure.
  • Kwokpot

    Posts: 329

    Jan 16, 2014 7:35 PM GMT
    conservativejock said
    NJDewd saidWhat is the name of this Atlanta building and what address?


    Currently the Mandarin Hotel. It is in the 3300 block of Peachtree Rd. It was foreclosed and popped back on the market. The bidding process was as interesting as the development phase, the former of which I was involved, the latter of which I entered the bidding but laughed at my own bid. ;-) The construction phase burned $165MM.

    Somewhere in this old place in which I reside I still have the individual floor plates for the Mandarin. There are some incredibly unique surprises in those plates, as there is a condo with a 35 foot ceiling located at a transfer floor.

    In the photo the tower is topped out. The top two floors are unit #56. There is also something else shown in that photo at the very top that is key to my original post as to what is odd about the structure.
    Are you talking about the elevator shaft that protrudes beyond the top floor?
  • conservativej...

    Posts: 2465

    Jan 16, 2014 9:25 PM GMT
    Kwokpot said
    conservativejock said
    NJDewd saidWhat is the name of this Atlanta building and what address?


    Currently the Mandarin Hotel. It is in the 3300 block of Peachtree Rd. It was foreclosed and popped back on the market. The bidding process was as interesting as the development phase, the former of which I was involved, the latter of which I entered the bidding but laughed at my own bid. ;-) The construction phase burned $165MM.

    Somewhere in this old place in which I reside I still have the individual floor plates for the Mandarin. There are some incredibly unique surprises in those plates, as there is a condo with a 35 foot ceiling located at a transfer floor.

    In the photo the tower is topped out. The top two floors are unit #56. There is also something else shown in that photo at the very top that is key to my original post as to what is odd about the structure.
    Are you talking about the elevator shaft that protrudes beyond the top floor?


    Ok. Time to explain the rest of the story.

    The rather considerable structural challenge is to build such a thin tower to 575 feet above street level with the distances seen between decks. WTC1 would sit on the site of this tower and cover more area than the entire tower and promenade. I have added below an interior photo of an unfinished penthouse at the top of the tower. The Mandarin, the tower you see here, has deck spans of around one and one-half times that of the WTC. This fact is what generated my buddy at McNamara and Salvia to pick up the phone and enquire as to whom the structural engineering team was composed of.

    Look at the very top floor where the exterior cladding is in place. It is obvious that the height there in the center opening is considerable. This floor in fact is a transfer floor, a floor where column loads from above are redirected to column loads below because the concrete structural elements -- the load baring elements -- do not align all the way down the tower.

    The first twenty floors are composed of a post-tensioned box through which the tower itself rises. What you correctly call the elevator shaft is actually a structural member as well as a shaft that runs over 600 feet to a massive post-tensioned matt at the very bottom. The tower is not pinned to stone as you might expect. The matt or raft floats in soil. It is an integral park of the promenade that covers the entire site from the exposed garden top down four levels. The central core -- the elevator shaft -- is part of an outrigger system composed of the shaft itself and multiple transfer beams down the tower. This section is composed of both ductal concrete, self-compacting concrete, and of course steel reinforcement consisting of both rebar and select formed pieces.

    photo picture-uhdc29fcee23b2b7c35fb37f38b9d0c919-ps1869f2d0c09513744ff04da8a271604d_zpsa1abc243.jpg

    In the upper left hand corner of the photo by the way is a structural tie beam. There is no post tensioning in the deck. This allows the deck to be pierced so the two floors of the penthouse can have a stairwell in addition to the central elevator corridor.

    It should be very obvious that there was a price to pay for a tower with tremendous distances between decks, relatively speaking. The tower necks down as it rises. This leaves the upper floors basically as donuts through which the load bearing structure must pass or in reality become an integral part of.


  • Posted by a hidden member.
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    Jan 25, 2014 12:54 AM GMT
    Wow thatnks. Um, wasnt one of the strongest earthquakes known to record in Charleston SC in the 1880s?? Indeed it was as I found. Question what would an earthquake of this type do then to that building in your professional opinion?

    From Wiki:
    The Charleston Earthquake of 1886 was a powerful intraplate earthquake that hit Charleston, South Carolina, and the East Coast of the US. After the 1811 and 1812 earthquakes in New Madrid, Missouri, it is one of the most powerful and damaging quakes to hit the southeastern United States.[2][3] The shaking occurred at about 9:50 p.m. on August 31, 1886, and lasted just under a minute. The earthquake caused severe damage in Charleston, damaging 2,000 buildings and causing $6 million worth in damage (over $141 million in 2009 dollars), while in the whole city the buildings were only valued at approximately $24 million. Between 60 and 110 lives were lost. Very little to no historical earthquake activity occurred in the Charleston area prior to the 1886 event, which is unusual for any seismic area.