[ExI] Melted steel
jnh at vt11.net
Sun Oct 7 00:00:52 UTC 2007
On Sat, Oct 06, 2007 at 12:49:19PM -0700, Samantha Atkins wrote:
> On Oct 6, 2007, at 9:12 AM, BillK wrote:
> > The WTC was a special case. There was very little load-bearing steel
> > in the interior, except around the elevators. The outer walls
> > supported the weight of the building.
> > The WTC didn't use the 'old-fashioned' steel girders and concrete.
> I have heard that it was part of the known design of WTC that it had
> massive central support structure. I am attempting to find pre-911
> details of WTC construction as I don't automatically trust claims on
> either side afterwards about those details. They should be somewhere
> on the web. I am looking for clean architectural and engineering
> documents preferably.
> - samantha
Scanned copies of the original WTC1 (North Tower) blueprints were
leaked earlier this year, and posted to several web sites, one of
which converted the raw .TIFF files for easier online viewing:
Image quality of these scans isn't the best, and even at 4896x3632
("Original" resolution) some of the text and fine details are hard to
make out, especially on a small monitor. Printing them might help.
On 9/11, the damage to this tower from the plane impact (AA 11)
affected floors 92 through 98.
Some interesting construction details:
- Core box columns are very thick near the bottom, gradually tapering
towards the top; same with the perimeter columns, which are deeper
(but not wider) on the low floors.
I've read that the WTC design called for core columns to support
60% of the static gravity load, with perimeter coluns handling 40%
of gravity and 100% of lateral loads (side-to-side swaying from
- Only one (freight) elevator shaft is contiguous through the entire
height of building. Apart from that, Express Elevators linked the
bottom level to two "sky lobbies" on the 44th and 78th floors
(these went no higher than the 78th), where passengers would switch
to a local elevator to reach their final floor. There were heavy
mechanical floors above each express elevator as well... this
division of each tower into thirds is visible in some exterior
- Within each of the stacked 1/3rd-tower segments, some local
elevator shafts served only the lower floors, allowing for more
open floor space on upper levels.
although that image appears to mis-label the single freight
elevator as an express elevator.
- Not all core columns were adjacent to elevator shafts, although
most were, and these extended all the way up even where nearby
elevator shafts did not.
More information about the extropy-chat