One aspect of the building 7 discussion which struck me as odd is the absence of discussion of the structure of the tower from floor 8 to the foundations.
We've seen the typical floor plans and the discussions about the NIST col 79 failure... but for some reason aside from a few FEMA cartoons of the structure of flrs 6&7 showing the transfer trusses and cantilever girders there is a paucity of information about the building below floor 8.
There are some very unusual aspects to building 7 and 9/11.
1. It has no basement and is built over top of and existing Con Ed sub station which receives power from the Motthaven station in the Bronx and steps down the power to 13.8kv feeds to various buildings in the neighborhood including building 7 (4) and the WTC complex, Verizon, the WFC and so forth.
2. Building over the 3 story tall massive transformers did not permit all the columns of the tower built over it to be brought straight down to bed rock. Instead they were supported in some cases by 2 story tall massive transfer trusses and a series of 8 massive cantilever girders which supported the perimeter columns opposite the core on the north side. The transfer trusses and the cantilever girders were on the 6th and 7th floors.
3. The electrical power equipment for B7 switchgear and step down transformers were located on floors 4&5. This sort of equipment is often located in the basements of high rise towers and feeds additional step down transformers location on various floors providing *line* voltage to power office equipment and lighting.
4. After the tower was completed the Mayor lobbied for and got floor 23 for his office of emergency management OEM. The OEM had it's own emergency power which was from a diesel fueled generator. This generator was located on floors 6 or 7 where the building's HVAC machinery was located. Several other companies had back up generators located on these floors.
5. The diesel for the OEM was stored in massive tanks (20,000 gal) located below the loading dock for the building. The main 20,000 gal tanks supplied a 275 gal day tank located adjacent to the generators. There apparently was a system which would pump the fuel up from the main tank to the day tanks when the level or pressure in the day tank dropped. I don't think that the mechanics and specs of this system are available. This would be interesting to know.
6. The main elevator lobby was south of the sub station... flr 3 or 4 (I suppose)... with several freight cars running to the street level.
7. The east penthouse and column 79 (remember that one?) were connected to column 76 which was supported by transfer trusses 1.
8. The 8MG27 cantilever trusses were supported the portion of the north curtain wall which shows the inward bowing during the "descent* stage of the collapse.
9. There were two 8 story truss structures on the east and west perimeters. These apparently provided lateral stiffness to the base of the tower.
10. Con Edison reports open (shorted?) 13.8kv feeders beginning at 8:46am... the moment of the plane strike into tower 1.
11. William Rodriguez reported hearing a massive explosion and a second or so later the sound of the plane strike in tower 1's sub basement. The sub basement contained step down transformers and electrical switch gear, power supplied by the Con Ed sub station and to the 8 tower 1 sub stations located on mech floors 7-9, 42-43, 75-76 and 108-109.
12. Immediately after the plane strike to tower 1 thick black smoke is seen coming from floors 108-109. Was this a transformer explosion/fire?
13. NYC employees Jennings and Hess reported to the OEM when they heard of a plane hitting Tower 1. They arrived apparently before tower 2 was struck or shortly thereafter only to find that the OEM was abandoned. Apparently the elevators were working and they used them to ascend to flr 23 OEM.
14. Apparently upon calling someone in the city they learned of the 2nd plane strike and that it was believed to be part of a terrorist attack. They were told to leave the OEM and Bldg7... but discovered that now there was no elevator service. They took the stairs.
15. Jennings and Hess report that when they reached floor 7 (in the region of TT#1 and MG53) or so there was a massive explosion below them which destroyed the stairs (located within the core) and they barely managed to climb back up to the 8th floor. This apparently was before tower 1 had collapsed.
16. They could not get out and perhaps called for help and were eventually rescued by FDNY at about noon after tower 1 and tower 2 had collapsed.
17. The sprinkler system to Bldg 7 was disabled early in the AM... from an event before tower 1 came down or as a result of tower 1 coming down. There was no effort to fight any fires in the building that day.
18. There are unconfirmed reports of the Bldg 7 being surveyed with a transit during the day by the NYC DOB presumably to determine if the structure was distorted... damaged and in danger of collapse.
19. Con Edison claims to have shut the power going into the the Bldg 7 sub station at 4pm because it was believed that the tower was going to collapse. We don't know how this decisions was taken.
20. The building's owner Larry Silverstein said "pull it" late in the after noon before the collapse.
21. Jane Stanley of the BBC did a stand up with the Bldg 7 in the background announcing it HAD collapsed and it then came down. How was this possible? Was this a prepared text being read because the officials had told her the tower would not last another hour or two? How did they know?
22. There were no videos of the south side of Bldg 7 during the day as a result of the destruction of the WTC campus. There was one news video walk through at street level on the East side.
23. There are unconfirmed reports that virtually all the diesel fuel was recovered from two of the large tanks, but the amount of fuel consumed is indeterminate. No explanation of where it was recovered or how or when it was recovered.
24. The main Con Ed sub station transformers were oil cooled. This oil can burn and produced explosive gas. No reports about the fate of the cooling oil.
25. There was apparently steel recovered from Bldg 7 which shows eutectic burning and loss of material on one structural members web and perhaps flange.
26. NASA imaging shows a very high heat signature below the pile after days after the collapse
27. Bldg 7 had a non structural curtain wall bolted to light steel angles welded to the spandrels
28. Bldg 7 was a column free open office space design from floors 8-47.
29. Building structural engineer Irwin Cantor stated that diesel fires destroyed the transfer trusses which caused the collapse of the tower
30. NIST claims the tower's collapse was caused by a failure around column 79 on floor 13.
Questions:
Was the collapse of Bldg 7 triggered by failure of the transfer trusses and the cantilever girders? Could the Con Ed substation short or explode if a plane shorted out main risers in Tower 1? Could the Bldg 7 power equipment on flr 4&5 start fires on floors 6&7... Could an explosion in the Con Ed sub station or floors 6&7 crack the floors where the day tanks and the generators where located? Could the pumps of the main diesel tank supply diesel all day to the generators on 6&7? Could this be controlled remotely? Or would this automatically operate if the main power feed was down? Could a breach in the diesel riser pipes from the main tank leak diesel onto flrs 6&7? Could that fuel ignite and burn for hours? Could that fire weaken a truss component and fail it... and then entire truss? Can diesel fires weaken the structural steel on floors 6&7? Enough to fail it? Why don't we see more evidence of black smoke from diesel if it was in fact burning? What was the puff of smoke emanating from nw corner at floor 7 or so just before the descent? Why did NIST decide that the floors below 8 were of no interest in their investigation?
@ SanderO Can you finally provide any data/source links for review which back-up your claims? Especially regarding the structure of WTC7 and Con-Ed? You made these assertions many times on this forum but you didn't show any supporting information.
SanderO wrote:22. There were no videos of the south side of B7 during the day as a result of the destruction of the WTC campus. There was one news video walk through at street level on the East side.
28. B7 was a column free open office space design from floors 8-47.
There are many photos of the structure below floor 8 during construction on this forum. You might be interested in this critique of the FEMA report Chapter 5 which was taken down (it conflicted with the NIST report).
I suspect that the FEMA report about WTC7 is a bit sketchy on the structural details but some of the very unusal features can be seen in the diagrams in the above reports.
Mr K... what claim that I have made do you want *support* for?
SanderO wrote:Mr K... what claim that I have made do you want *support* for?
OK, I will be more specific then:
SanderO wrote:We've seen the typical floor plans and the discussions about the NIST col 79 failure... but for some reason aside from a few FEMA cartoons of the structure of flrs 6&7 showing the transfer trusses and cantilever girders there is a paucity of information about the building below floor 8.
Source, please.
SanderO wrote:built over top of and existing Con Ed sub station
Source, please. The tower was built over the substation but what I have seen on drawings and photos is that most of the columns were placed around the substation (west, east and southern portions), or on top of the existing Con-Ed columns below 3rd floor slab of WTC7.
SanderO wrote:2. Building over the 3 story tall massive transformers did not permit all the columns of the tower built over it to be brought straight down to bed rock. Instead they were supported in some cased by 2 story tall massive transfer trusses and a series of 8 massive cantilever girders which supported the perimeter columns opposite the core on the north side. The transfer trusses and the cantilever girders were on the 6th and 7th floors.
Source, please. How many columns (perimeter and core) had no direct bedrock/caissons support?
SanderO wrote:3. The electrical power equipment for B7 switchgear and step down transformers were located on floors 4&5.
Source, please.
SanderO wrote:4. After the tower was completed the Mayor lobbied for and got floor 23 for his office of emergency management OEM. The OEM had it's own emergency power which was from a diesel fueled generator. This generator was located on floors 6 or 7 where the building's HVAC machinery was located. Several other companies had back up generators located on these floors.
Source, please.
SanderO wrote:5. The diesel for the OEM was stored in massive tanks (20,000 gal) located below the loading dock for the building. The main 20,000 gal tanks supplied a 275 gal day tank located adjacent to the generators. There apparently was a system which would pump the fuel up from the main tank to the day tanks when the level in the day tank dropped. I don't think that the mechanics and specs of this system are available. This would be interesting to know.
Source, please.
SanderO wrote:7. The east penthouse and column 79 (remember that one?) were supported by one of the transfer trusses.
Source, please.
Neither column 80 nor 81. Column 81 had a girder/diagonal member connector for Truss #2, that's it.
SanderO wrote:9. There were apparently a series of space frames - 3 dimensional truss structures at the perimeter of the building surrounding the Con Ed sub station. These apparently provided lateral stiffness to the base of the tower.
Source, please. "Apparently", that's very vague. Many of the structural drawings and lower floors photographs are available over 1 1/2 / 1 year on this forum:
SanderO wrote:10. Con Edison reports open (shorted?) 13.8kv feeders beginning at 8:46am... the moment of the plane strike into tower 1.
11. William Rodriguez reported hearing a massive explosion and a second or so later the sound of the plane strike in tower 1's sub basement.
I don't see here any connection between Con-Ed station and the damage/injuries at the basement levels inside WTC1 (over 500 feet/152 meters distance), except some power supply lines.
SanderO wrote:The sub basement contained step down transformers and electrical switch gear, power supplied by the Con Ed sub station and to the 8 tower 1 sub stations located on mech floors 7-9, 42-43, 75-76 and 108-109.
Source, please.
SanderO wrote:12. Immediately after the plane strike to tower 1 thick black smoke is seen coming from floors 108-109. Was this a transformer explosion/fire?
Source, please.
The transformers in the twin towers were aircooled, btw. Excerpts from WTC Property Risk Report made by Alternative Insurance Works (AIW) for Silverstein Properties. NIST WTCI Database name: WTCI-008-S http://ebookbrowse.com/wtci-008-s-pdf-d254486190
Excerpts from pages 15011 and 15012, "Electrical service" section: Page 15011:
SanderO wrote:22. There were no videos of the south side of B7 during the day as a result of the destruction of the WTC campus.
CBS LaGanga video shot around 10:15am, shots of WTC7 lobby and south side/promenade (NIST estimation)?
WABC Chopper 7 footage, some frames that femr has linked above? Or the photograhes made available here: wtc-7-south-side-views-t203.html
SanderO wrote:23. There are unconfirmed reports that virtually all the diesel fuel was recovered. No explanation of where it was recovered or how or when it was recovered.
Source, please.
SanderO wrote:24. The main Con Ed sub station transformers were oil cooled. This oil can burn and produced explosive gas. No reports about the fate of the cooling oil.
Source, please.
SanderO wrote:25. There was apparently steel recovered from B7 which shows eutectic burning and loss of material on one structural members web and perhaps flange.
Why apparently?
SanderO wrote:27. B7 had a non structural curtain wall bolted to light steel angles welded to the spandrels
Source, please.
SanderO wrote:28. B7 was a column free open office space design from floors 8-47.
Yes, ouside the core. But why should this be an "unusual aspect" of WTC7 according to you? Were WTC 1, 2 and 7 the only buildings with such desgin in the US/world?
SanderO previoously stated wrote:There are some very unusual aspects to building 7 and 9/11.
SanderO wrote:29. Building structural engineer Irwin Cantor stated that diesel fires destroyed the transfer trusses which caused the collapse of the tower
Source, please. Was this his own statement, based on his expertise and research into the collapse, or did he just parroting FEMA/ASCE hypothesis at the time for the media?
For examle, in this outtake he never mentions "diesel fires destroyed trasnfer trusses which caused the collapse of the tower". Starts at 1:20 in video:
So, what is the correct source for his statement, SanderO?
SanderO wrote:Could the Con Ed substation short or explode if a plane shorted out main risers in Tower 1?
The overloading impulse (correct wording?) would surely go through a number of circuit breakers, before it reaches the substation. Wouldn't it?
SanderO wrote:Could the B7 power equipment on flr 4&5 start fires on floors 6&7...
Source for fires on these floors, please. Or is it just pure speculation?
SanderO wrote:Could an explosion in the Con Ed sub station or floors 6&7 crack the floors where the day tanks and the generators where located?
I doubt that transformer explosions could generate such amount of pressure to heavily damage the surrounding, like powerful bombs... Escpecially when the transformers were loacted inside a steel-reinforced concrete (?), bunker-like building at the first two floors of WTC7, ilocated in the northern half of its footprint and isolated from the rest of the skyscraper.
SanderO wrote:Could the pumps of the main diesel tank supply diesel all day to the generators on 6&7?
No leak detectors on the pressurized lines?
SanderO wrote:Could that fuel ignite and burn for hours? Could that weaken a truss component and fail it... and the entire truss?
Weaken it with intact fireproofing on it that was surely rated for 3 hours?
SanderO wrote:Why don't we see more evidence of black smoke from diesel if it was in fact burning?
Was it burning after all?
SanderO wrote:What was the puff of smoke emanating from nw corner at floor 7 or so just before the descent?
I have commented on almost of your points, but not all. The commented points are those which I have problems with.
SanderO wrote:There are many photos of the structure below floor 8 during construction on this forum. You might be interested in this critique of the FEMA report Chapter 5 which was taken down (it conflicted with the NIST report).
I suspect that the FEMA report about WTC7 is a bit sketchy on the structural details but some of the very unusal features can be seen in the diagrams in the above reports.
Was it directed to me? I would rather hear your understanding of the structure, not FEMA or NIST. And of course, with underlying infos. Thank you.
I do not consider myself a researcher intending to publish anything. My interest in personal in trying to understand what happened to the 2 towers. I found that the explanations offered did not ring true. The official ones have been shown to be incorrect and not even based on the actual building movements.
My thinking is informed by my training as an architect. I am not a structural engineer nor a physicist. My information has come from my internet reading, several presentations on the topic by truthers and experience working with AE911T being a board member for a brief period and my email correspondence with various other people on the topics of interest.
I was only aware of 2 explanations about building 7 as recently as perhaps a year ago when I decided neither of them made sense.... fires at columns 79 on the 13th floor as NIST explained and 81 columns over 8 floors destroyed in an instant according to AE911T.
The work here showing movement before the obvious roof line decent of 100' or so seemed to be the signs of a progressive collapse occurring very low in the tower. At the time I was unaware of the structure, had not heard the congressional testimony linked to on this site recently, nor hear of Irwin Cantor. I found a website which critiqued the FEMA chapter 5 which has since been removed. This chapter seemed to suggest that the failures occurred below floor 8 and this hypothesis was superseded by the NIST column 79 one and removed... wiped out from memory. This critique's diagrams from the FEMA chapter 79 were the basis for my TTF thesis.
I then came upon the remark by Cantor which agreed with my idea. And just a few weeks ago Gorley seemed to be suggesting the same thing back in 02. I have seen no photos from inside the floors in question or inside the con ed sub station before or on that day. I have read no accounts from witness who observed the region in question on that day. I imagine the FDNY and DOB had some basis to have the area evacuated... and I suspect it was based on inspections which showed extensive damage from heat or fires burning out of control heating the steel.
Something happened inside of wtc 7 coinciding with the plane strike to tower 1. Con Ed DID report loss of 8 high voltage feeds and this certainly could be from shorts or open circuits caused by the plane damage. Transformers explode all the time and it doesn't matter if they are air or oil cooled. I never stated that I believe the con ed transformer explosions if they occurred cause significant damage to the structure. They may have dislodged fire proofing. They may have caused fuel pipes... natural gas and or diesel fuel to rupture and ignite and burn for up to 7 hrs.
If the structure is as depicted on the drawings you linked to a truss failure WOULD definitely lead to the failures propagating through the structure. East penthouse WAS above column 79 and 80 which are mis labled in the photo in the last post. Both of those columns DID not go down to bed rock but were supported by transfer trusses.
Most of your questions don't have to be answer with sources. The answers is that is that I gleaned from material I read on the www.
A transfer truss performs a beam action and has multiple parts and connections. All the bolts in the frame were 3/4" diameter. My guess is that the splices/ beam stubs / bolts /welds / gusset plates were the weak link not the actual steel sections which were very stout. But if one of these elements fail it will render the truss incapable of transferring the loads and it will buckle/collapse/fail and the loads it carries have no support and drop... such as the penthouses did. When the column lines drop. the beams connected to it and the floors resting on those beams lose support and they too will likely drop. This is how the failure progresses through the structure.
I don't know how the failure occurred. My guess is was a heat cause and it was building up over time as the source of heat persisted and was un extinguished. As the heat increased strength was lost. The swaying of the tower could only be a few causes.. shifting foundations (not likely)... excessive wind loads (not likely)... or loss of axial load paths and redistribution of the loads through the frame (likely).
Not having images of an intact undamaged stone cold structure in the 5,6 & 7th floor region I am suggesting that this is the area where the damage occurred (heating) to produce the observed movements. I don't see why there could have been fires moving through the structure all day. There was no sprinkler system to suppress them.
I also don't see why the TTF could not be a man made event... the CD cause for collapse by attacking the transfer trusses. But I don't see evidence for this... do you? I also don't know what the condition of the SRFM was after the 10am explosion reported by Jennings and Hess. Perhaps some of it was blown off exposing some critical connections to local flames which lasted for hours. My thinking is that the heating was cumulative... took many hours... like leaving a pot on the stove with the flame on for 7 hrs. Again... This is not supported by evidence. It is an hypothesis. I am sure someone, somewhere has tested the effects of localized heat over 7 hrs on beam, truss and connection. I can't imagine that it would maintain its design strength rating. Fireproofing seems to be designed to 1, 2 , 3 or 4 hrs of protection. What happens after the rated protection has been "used up"? Something happened in WTC 7 right around the time the first plane hit tower 1. Con Ed feeds were lost after that... why? Shorts? circuit protection blown? Did you ever feel the temp of a blown fuse? DO you know how hot electric arcs are from shorts? A sort on a 12 volt battery can melt steel in an instant.
I can't solve this from my desk top. I don't have the background, and certainly not the resources.
When you see some missing material one can't assume it was all vaporized. Perhaps it was weakened and then parts broken free from mechanical collisions for example. How can you tell?
You ask was it burning at all? Heck if I know. But there was smoke so SOMETHING was burning. If it was a axial load path destruction failure... I don't think someone unbolted the connections. Could it have been charges placed on the connections? I suppose so. We have no sound recordings of lots of explosions.
Are you asking me how the power was wired? I have a friend who is a manager for Comstock who was called in by Con Ed when they had problems in WTC. I can ask him. Fuses can be used to protect a wire from over heating or from too much current reaching circuits in electrical equipment. I don't think Con Ed is giving out this information. Have you seen the wiring schematics for the grid from Con Ed wtc 7? or the WTC?
WTC 7 had 4 - 13.8kv feeds according to Joe from Comstock.. who told me this was to power all sorts of computers and so forth in the tower. He said that they were above the Con Ed sub station and I believe they were on flr 5. Look it up if you want to know.
You expect me to tell you the source information made in a of a statement made by Irwin Cantor? Go ask him!
Mr. K... I am not writing a dissertation or publishing a treatise on the collapse of WTC7. I am just an individual who tried to connect some dots... perhaps imagined some as well to produce a coherent explanation.
Your distances from WTC 1 to WTC 7 are off.. it was not over 500 feet away... and for electricity.. even 500 feet is like nothing when you are traveling close to the speed of light.
Finally can you not see that several columns were bearing on transfer beams or trusses and not on bed rock? Does it matter which columns it was precisely? What difference would it make if the transfer beam or trusses these columns bore down on failed?
Hope that satisfies your curious mind. Thanks for your interest.
Now here's one for you... What do you attribute the collapse of WTC7 to?
Interesting, none of my requests for underlying data was answered by you. Instead, I and other readers got a long monologue which almost completely ignores those.
SanderO wrote:Mr K.
I do not consider myself a researcher intending to publish anything.
That should be not an excuse for making up bare assertions and let others do most of the research work. I'm not ask you for publishing a paper but finally to provide informations, like drawings, pictures or documents to backing-up claims which was raised by your person, here and in other topics on this forum. Especially regarding the WTC7 framework. I thought, it was simple formulated by me. Is here might be a problem in understanding at your side?
SanderO wrote:My interest in personal in trying to understand what happened to the 2 towers. I found that the explanations offered did not ring true. The official ones have been shown to be incorrect and not even based on the actual building movements.
My thinking is informed by my training as an architect. I am not a structural engineer nor a physicist. My information has come from my internet reading, several presentations on the topic by truthers and experience working with AE911T being a board member for a brief period and my email correspondence with various other people on the topics of interest.
I was only aware of 2 explanations about building 7 as recently as perhaps a year ago when I decided neither of them made sense.... fires at columns 79 on the 13th floor as NIST explained and 81 columns over 8 floors destroyed in an instant according to AE911T.
These excerpts from your biography have nothing to do with my requests as stated above, twice.
SanderO wrote:The work here showing movement before the obvious roof line decent of 100' or so seemed to be the signs of a progressive collapse occurring very low in the tower. At the time I was unaware of the structure, had not heard the congressional testimony linked to on this site recently, nor hear of Irwin Cantor. I found a website which critiqued the FEMA chapter 5 which has since been removed. This chapter seemed to suggest that the failures occurred below floor 8 and this hypothesis was superseded by the NIST column 79 one and removed... wiped out from memory. This critique's diagrams from the FEMA chapter 79 were the basis for my TTF thesis.
I then came upon the remark by Cantor which agreed with my idea. And just a few weeks ago Gorley seemed to be suggesting the same thing back in 02. I have seen no photos from inside the floors in question or inside the con ed sub station before or on that day. I have read no accounts from witness who observed the region in question on that day. I imagine the FDNY and DOB had some basis to have the area evacuated... and I suspect it was based on inspections which showed extensive damage from heat or fires burning out of control heating the steel.
Again, that has nothing to do with my comments above.
SanderO wrote:Something happened inside of wtc 7 coinciding with the plane strike to tower 1.
Inside WTC7? Or Con-Ed? I'm not aware of any reports from building staff/occupants/rescue personnel mentioning fire, smoke or damage conditions on lower floors of WTC7 at least before 10:00am, with exception of Jennings account who have witnessed an explosion/stair collapse in one of the stairways, likely before WTC2 destruction at 9:59am. Nor did Con-Ed workers report such things inside the substation, that was shut down and evacuated around 4:40pm.
SanderO wrote:Con Ed DID report loss of 8 high voltage feeds and this certainly could be from shorts or open circuits caused by the plane damage. Transformers explode all the time and it doesn't matter if they are air or oil cooled.
I didn't question here if transformers could explode or not, I questioned if transformer explosion force could cause heavy damage to the surrounding structure.
SanderO wrote:I never stated that I believe the con ed transformer explosions if they occurred cause significant damage to the structure. They may have dislodged fire proofing. They may have caused fuel pipes... natural gas and or diesel fuel to rupture and ignite and burn for up to 7 hrs.
Written by yours in inital post:
SanderO wrote:24. The main Con Ed sub station transformers were oil cooled. This oil can burn and produced explosive gas. No reports about the fate of the cooling oil.
SanderO wrote:Could an explosion in the Con Ed sub station or floors 6&7 crack the floors where the day tanks and the generators where located?
What else could explode inside the substation if not the transformers in your mind? Natural gas inside a transformer station or WTC7?
SanderO wrote:If the structure is as depicted on the drawings you linked to a truss failure WOULD definitely lead to the failures propagating through the structure.
That was not the question that I have previously made. I asked you for underlying data for your claim below:
SanderO previously wrote:7. The east penthouse and column 79 (remember that one?) were supported by one of the transfer trusses.
But instead I've received the very same baseless claim as response, now with some capilatizations for emphasis:
SanderO wrote:East penthouse WAS above column 79 and 80 which are mis labled in the photo in the last post. Both of those columns DID not go down to bed rock but were supported by transfer trusses.
I never doubted the fact that E-PH was above these columns. Did I? You forgot Column 81, btw. I doubted your claim that the columns 79 and 80 were supported by load-transfer trusses on floors 5-6 (not 6-7, as stated countless times by yours). That is not what the photos and drawings show. All three eastern-most core columns (79-80-81) were directly supported by caissons, and mainly those three provided support for E-PH. Truss #2 main girder and east truss diagonal was mounted to column 80 at 5th floor, so column 80 carried a portion of the gravity loads from columns 77 & Girder M-23 with Col. 78 down to the ground.
And if I've mislabeled something on the linked photos, than please feel free and show me and other readers here what exactly was wrong and provide correction. But the correctional input should be based on drawings or other documents, not on your personal opinion. It's that simple. Here is the previos linked photo once again: Taken from this post: wtc7-construction-photographs-t501.html#p14789
I give you the urgent advise to look on the drawings first before making-up unsupported assertions or even worse, conclusions (for instance: column schedules, truss details): nist-foia-wtc7-shop-and-structural-drawings-t502.html
SanderO wrote:Most of your questions don't have to be answer with sources.
Why not? Please specify. I think, it's a very basic but important principle in science and even journalism to show sources. How can one take anybody seriuosly if that particular person fails to provide supporting data or sources for his theory? And by the way, you offered not a single source, document or visual asset. Not a one. I think, it would be better for you to invest your free time in less writting but in more studying and reading of documents or photos, such as the original drawings or construction photos of old WTC7.
SanderO wrote:The answers is that is that I gleaned from material I read on the www.
Nice and good. But not helpful for me or for any reader of this topic. I can't understand your aversion (?) against the study of original documents or visual records. Or is it just laziness? Time factor? I don't know... Or do you give more credibility to your (unknown) sources than to the original drawings?
SanderO wrote:A transfer truss performs a beam action and has multiple parts and connections. All the bolts in the frame were 3/4" diameter. My guess is that the splices/ beam stubs / bolts /welds / gusset plates were the weak link not the actual steel sections which were very stout. But if one of these elements fail it will render the truss incapable of transferring the loads and it will buckle/collapse/fail and the loads it carries have no support and drop... such as the penthouses did. When the column lines drop. the beams connected to it and the floors resting on those beams lose support and they too will likely drop. This is how the failure progresses through the structure.
That was not my question either, about how the trusses did work or fail.
SanderO wrote:I don't know how the failure occurred. My guess is was a heat cause and it was building up over time as the source of heat persisted and was un extinguished. As the heat increased strength was lost. The swaying of the tower could only be a few causes.. shifting foundations (not likely)... excessive wind loads (not likely)... or loss of axial load paths and redistribution of the loads through the frame (likely).
That was not one of my questions, also.
SanderO wrote:Not having images of an intact undamaged stone cold structure in the 5,6 & 7th floor region I am suggesting that this is the area where the damage occurred (heating) to produce the observed movements. I don't see why there could have been fires moving through the structure all day. There was no sprinkler system to suppress them.
Because of lack of visible flames/smoke eminating from louvers at floors 5 and 6, through the day, at least at the east, north and west faces after 10:28am. From 8:46am to the collapse at 5:20pm. The same case at the louvers of transformer vaults inside Con-Ed station, at north and west sides.
That was likely one of the reasons, why NIST had later dismissed the fire theory on these two MER floors, which contain the load transfer structures for some columns (3 trusses, 4 girders, 8 cantilevers).
SanderO wrote:I also don't see why the TTF could not be a man made event... the CD cause for collapse by attacking the transfer trusses. But I don't see evidence for this... do you?
My opinion on this is irrelevant. Please stay on topic and provide requested sources.
SanderO wrote:I also don't know what the condition of the SRFM was after the 10am explosion reported by Jennings and Hess. Perhaps some of it was blown off exposing some critical connections to local flames which lasted for hours.
How do you know that the explosion, witnessed by Jennings and Hess, took place at "10am"? Jennings' account suggests before 9:59am ("both towers were standing").
SanderO wrote:My thinking is that the heating was cumulative... took many hours... like leaving a pot on the stove with the flame on for 7 hrs. Again... This is not supported by evidence. It is an hypothesis.
I am sure someone, somewhere has tested the effects of localized heat over 7 hrs on beam, truss and connection. I can't imagine that it would maintain its design strength rating. Fireproofing seems to be designed to 1, 2 , 3 or 4 hrs of protection. What happens after the rated protection has been "used up"? Something happened in WTC 7 right around the time the first plane hit tower 1. Con Ed feeds were lost after that... why? Shorts? circuit protection blown?
Long lasting fires without any smoke or visible flames on floors 5 and 6, and in Con-Ed station?
SanderO wrote:Did you ever feel the temp of a blown fuse? DO you know how hot electric arcs are from shorts? A sort on a 12 volt battery can melt steel in an instant.
Irrelevant. If it's even true, were the fuses mounted on columns or were pressed against them? I doubt, that a shortening of transformer could melt steel columns like at the arc welding process, and precisely. But I have no knowledge on this topic.
SanderO wrote:I can't solve this from my desk top. I don't have the background, and certainly not the resources.
You have photos, drawings and other documents, made available by people who do FOIA requests to NIST and other agencies. I linked some of them many times here...
SanderO wrote:When you see some missing material one can't assume it was all vaporized. Perhaps it was weakened and then parts broken free from mechanical collisions for example. How can you tell?
Irrelevant. Because never mentionend vaporization of material.
SanderO wrote:You ask was it burning at all? Heck if I know. But there was smoke so SOMETHING was burning.
The visual data show no smoke or flames at the floors 5-6. Nor does it show such conditions at Con-Ed station.
SanderO wrote:If it was a axial load path destruction failure... I don't think someone unbolted the connections. Could it have been charges placed on the connections? I suppose so.
Irrelevant speculations.
SanderO wrote:We have no sound recordings of lots of explosions.
We have no continuous HQ video with clear audio either, till today. And why do you need a lot of explosions if you could bring down the building by destroying or heat-weakening the LT trusses only, according to your assumption?
The videos and clips of WTC7 collapse and pre-collapse stage that waere released by NIST are nothing more as overused or overcopied, some chopped-off crap. Sorry to say so. At least there is that CBS clip released by NIST:
A brief analyses of this sound and seismic spike made by achimspok in 2009 (before the clip above was released in 2010), by using the same recording from CBS2 news aired on Sept. 12, 2001.
Can't check for errors. Maybe interesting for you.
And there are few individuals on record who have described explosion sounds at collapse initiation (Kevin McPadden, Craig Bartmer and the NYU medical student Darel, who was interviewed by 1010 WINS radio).
SanderO wrote:Are you asking me how the power was wired? I have a friend who is a manager for Comstock who was called in by Con Ed when they had problems in WTC. I can ask him. Fuses can be used to protect a wire from over heating or from too much current reaching circuits in electrical equipment. I don't think Con Ed is giving out this information. Have you seen the wiring schematics for the grid from Con Ed wtc 7? or the WTC?
WTC 7 had 4 - 13.8kv feeds according to Joe from Comstock.. who told me this was to power all sorts of computers and so forth in the tower. He said that they were above the Con Ed sub station and I believe they were on flr 5. Look it up if you want to know.
Did I ask you this? No. Stay on topic.
SanderO wrote:You expect me to tell you the source information made in a of a statement made by Irwin Cantor? Go ask him!
You have quoted him here to support your Fire-Weakened-LT-Trusses theory at floors 5-6 (not at 6-7!) and I requested the source from you. So, why should I ask HIM and not YOU?
SanderO previously wrote:29. Building structural engineer Irwin Cantor stated that diesel fires destroyed the transfer trusses which caused the collapse of the tower
My response:
MrKoenig previously wrote:Source, please. Was this his own statement, based on his expertise and research into the collapse, or did he just parroting FEMA/ASCE hypothesis at the time for the media?
So, what is the correct source for his statement, SanderO?
I don't get it...
SanderO wrote:Mr. K... I am not writing a dissertation or publishing a treatise on the collapse of WTC7. I am just an individual who tried to connect some dots... perhaps imagined some as well to produce a coherent explanation.
If you cannot even provide the proof for existence of some these dots, then any try to connect them is useless.
SanderO wrote:Your distances from WTC 1 to WTC 7 are off.. it was not over 500 feet away... and for electricity.. even 500 feet is like nothing when you are traveling close to the speed of light.
How far away was it then? My measurement was based on the Google Earth, measured from center of WTC7 trapezoid lot to the northern edge of the center hole of North Pool at 9/11 Memorial. Criticism without any base or correctional input from critic is annoying. Don't you think?
SanderO wrote:Finally can you not see that several columns were bearing on transfer beams or trusses and not on bed rock?
I see them on drawings, but not the columns as claimed by yours. And that was the reason for requesting of your sources. Unsupported claims, some of them spoken out with certainty.
SanderO wrote:Does it matter which columns it was precisely?
It does matter, even more if you give the actual numbering, as you have done it here and elsewhere.
SanderO wrote:What difference would it make if the transfer beam or trusses these columns bore down on failed?
My opinion is here irrelevant. Out of topic.
SanderO wrote:Hope that satisfies your curious mind. Thanks for your interest.
No. Absolutely not. Reasons are given here more than one time.
SanderO wrote:Now here's one for you... What do you attribute the collapse of WTC7 to?
Again, my personal opinion on this is irrelevant.
Excuse me, but I cannot take you seriously as far as you continue refusing to provide your supporting data. Thank you for your patience.
LAST UPDATED ON: 11-27-2012, 01:43pm CET (Douple-posted video removed and replaced by another one).
You don't have to take anyone seriously.... especially me. That is entirely your prerogative. I produced the TTF theory because I think this is the best explanation for the collapse according to the movements which are documented in this forum.
I offered the theory with speculation of a heat weakening cause, some incorrect column and truss numbers...but I stand by the TTF model of a progressive collapse which cascaded through the region of the load transfer structures leading to a global collapse.
My interest in offering this is to provoke discussion and yes... others who feel so inclined can assemble evidence to support or refute the basic model... and even publish their work here, or in the Journal of 9111 Studies, other 9/11 Forums or on their own webs sites. I don't have the time, the resources, the inclination nor the background to produce a complete analysis and research on the collapse of building 7. I am not holding myself out to be an expert as David Ray Griffin, a retired theologian does on the "The Mysterious Collapse of World Trade Center 7..."
I don't know what your interest in the building is or how you intend to go about formulating a thesis of how it came down. My approach was to try to link the movements to the structure which I only got a vague inkling of and then put the TTF theory out for discussion.
The girder walk of NIST produced with millions of dollars, scores of PhD and PEs and so forth massive computers and access to the evidence turns out to be flawed. Scratch that one. They did however provide some useful information about the building... and clearly hid or did not have access (and publish) all the information which might possibly be useful. I only saw some very poor reproductions of the plans several months ago for the first time.
Danny Jowenko who was sure it was a CD had not studied the building when he gave the often referenced video interview. He did not know the structure and so forth. His response was based on nothing more than the fact that the tower collapsd straight down fairly quickly... assuming that a CD is the only way... as AE911T claims... that this could occur. Gage, speaking for 1700+ architects who also have not studied the tower's structure issued a declarative statement and back in 2008 and has repeated it last week in Kuala Limpur (find it yourself if you're interested).. that the only explanation for the *free fall* collapse was the instantaneous removal of 80 columns over 8 floors. Where is the evidence for that Mr K... and why are you not dismissing AE911T and his supporters (signers) as non serious? Surely you don't find that a *serious* possibility... do you?
After I put the TTF hypothesis forward 6 months ago I discovered the information referenced in this thread prepared by FEMA showing the T trusses..., testimony by Cantor the building's structural designer, and Gorley from a 2002 congressional hearing where they both suggested a truss failure... suggesting heat as the cause WITHOUT citing specific evidence. Perhaps it was assumed at the time that NIST would investigate this and if they found no evidence of TTF then they would publish it... But they never did... they simply concocted the flawed column 79 explanation after 7 years of *research* published on Nov 20, 2008.. and declared there was nothing of interest below floor 8.
One take away from the global collapse of steel framed structures... and we have 3 to examine is that they share some common attributes.
They all produced massive amounts of shattered concrete... mostly rendered to dust They all left a massive amount heat residue below the debris piles They all produced a massive pile of steel beams and sections virtually completely intact broken from one another at their connections
I'd like the investigation to focus on the performance of connections and one can see them in the trusses in the pics referenced in this thread. While the steel sections connected might be plates of several inches thick... they were held together by much thinner splice plates a few score of 3/4" and 1" Ø bolts and perhaps some fillet welds. This may be all well and good when the structure is erected in sequence and the connections are not seeing any out of spec loads. But the take away is that when a frame loses members the redistributed stresses seem to fail the connections and not the actual steel sections themselves.
This is particularly troubling for a transfer truss. And it was one connection location on a truss in the CitiCorp building which if failed would have led (predicted by the engineer) to the collapse of the entire tower. I repeat:
It was one connection location on a truss in the CitiCorp building which if failed would have led (predicted by the engineer) to the collapse of the entire tower.
You want me to post the reference for you Mr K or can you google this on your own?
In the CitiCorp building the fear of failure was the predicted wind shear load of a 100yr storm. In the case of Bldg 7 the possibility for a connection failure could be from heat weakening and or load redistribution or a bomb!. But of course we don't have any visual evidence from that region on the day of 9-11... and we don't have the steel from that region to examine... nor reports from NIST who might have examined it. We have pix of smoke or no pics of no smoke or pics of no smoke and non expert witness testimony INCLUDING firefighters who are not structural engineers SPECIFICALLY trained for such work.
Your line of questioning sounds strangely like OneShortSlice.. an armchair researcher who has assembled pics of the building and testimony in an attempt to prove NIST wrong and discredit any explanation which involves a heat cause.. because heat means fire and fire means smoke... and that's NIST allover again. I suggest you take your sleuthing skills to Pilotsfor911T and help them out over there as they prove the demolition of building 7 right before the public's eyes.
Meanwhile, I will stick with TTF which rings true to me for bldg 7 as ROOSD does for the twin towers. (do you need more evidence for ROOSD as well?) As with ROOSD it is not about the initiation but the mechanism of collapse. And ROOSD led to the falling away of the facade and the Euler buckling of the core. Bldg 7 is much more difficult because the collapse took place completely behind the facade and requires IMAGINATION... something which you apparently lack since you seem to need every little detail.. i's dotted and t's crossed all handed to you on a silver platter. That is not happening from this poster who doesn't spell check and can't type..and who doesn't engage in snippet cut and paste gotcha arguments in internet forums.
21 days to go till the end of the world according to the Mayans! Not much time left. Let's party like it's 1999!
It appears to me that the failure was in the region of MG53, perhaps columns E3 and or E4 which led to the collapse of MG53, then TT#1 rotated on column 78 pushing column 79 out of column on floor 7 and pulling the entire line of columns and MG27 girders on the north side of the core off column alignment including TT#3 and then both the east and west wall trusses up to floor 8 caved inward.
Glad that you found finally back to the actual topic...
Where did you get the debris picture?
I saw your cartoon and found many errors in it. Mostly issues with column numbering, and wrong vertical and horizontal placement of E-PH and Con-Ed substation. So, I did correct them and added some additional information (green font): https://skydrive.live.com/redir?resid=4 ... A3qvZXQKgo
Thanks for the comments and corrections on the cartoon. I based it on the FEMA cartoon and added information from the Cantor drawings which I recently downloaded. Your comments clarifying the 3 cartoons, especially adding 78a and the MG 23 transfer girder framing into TT#2 which 77 rests on 80. I have revised the WTC 7 cartoon accordingly. I did not include all the notes on the sketch on the right side.
The cartoon was hastily drawn using the Cantor plans on a monitor which was rather difficult... hence the various errors.
Canter refers to the 8 story structures at the east and west as wind bracing. They were braced frame structures with diagonals and not all column lines on the east side were brought down to the foundation... and the Con Ed reach right to the west facade with a few column lines appearing not to extend the the foundation as well. I suspect those braces folded and hence the 100 foot descent of the facade at FF.
My take away is that this interconnected frame with multiple horizontal load transfer structures was prone to (and did) experience a runaway cascading progressive failure, Cantor eludes to this but there has been no graphic which has attempted to show these relationships.
Establishing the cause of the initial failure would be the *prize* here. Could this be related to diesel fires from the back up generator equipment? Where was this equipment and the piping to it located? What was the cause of the Jennings Hess Explosion? Could this have weakened any of the connections in the TT#1 and TT#2 region... dislodged fire proofing and led to some sort of diesel fueled fires in that region? The emergency exit stair was between TT#1 and TT#2 I believe. Was the eutectic / sulfidated steel from any of these structures?
But as with the twins we can't really see past the facade into the region of interest here and we have little reliable data about what was going on there... so it's mostly educated guesses I would believe.
SandrO Quote: Canter refers to the 8 story structures at the east and west as wind bracing. They were braced frame structures with diagonals and not all column lines on the east side were brought down to the foundation... and the Con Ed reach right to the west facade with a few column lines appearing not to extend the the foundation as well. I suspect those braces folded and hence the 100 foot descent of the facade at FF.
If the east wind braces failed first, causing the 100 foot of free fall, how did the east face remain standing until last? The east face fell last, rotated NW and struck the Fiterman Building.
The structure above those *braced frames* apparently separated from the upper sections at floor 8 or so on the east side. Do you think they stood perfectly straight and aligned and they were neatly severed at the top?
Perhaps the beams and girders anchored to the columns 79,80 and 81 pulled the columns above these frames out of column and the falling mass fell inside the braced frames and the they came down last on top of the rest?
Unfortunately we don't have visual evidence to know what the exact sequence was. Maybe you have an explanation for the sequence of movements of the building parts?
If these elements are on the top of the pile, then they would be the last to fall. No?
There were 14 story sections of tower one that stood after the collapse ... This may have been analogous... but they folded in and the rotation likely indicated to which side gave way first.
By the way... do you think what you are looking at the the pic of the facade laying over the pile is the braced frame? Really? Looks to me like a brick curtain wall the way it's bent.... probably toppled because it could not stand on its own. The braced frame was too massive to fold like that.
The twin towers facade was structure. WTC 7's was not. The facade of 7 was a curtain wall and supported on clips attached to the spandrel beams which connect the perimeter columns. The connections of the facade to the spandrels was robut enough to support the weight of each story of the curtain wall. At the base, it's likely that the lowest construction of the brick veneer was likely bearing on some sort of footing and tied back to what was the braced frame to support it laterally. Masonry walls cannot be built as 2-3 courses in depth for more than a few stories. And in the case of the brick on WTC 7 it was a veneer and probably only one brick in depth with some sort of lath which was attached to the steel and which the bricks were bonded to.
What we see lying over the top of the pile that Kawika refers to the East wall folding to the NW at the end is mostly likely just the thin veneer which broke free from the braced frame.
If there was a runaway collapse of the structure at the levels 5, 6 & 7 inside the building what we see dropping in all those vids is surely not MOST of the building but the curtain wall and perhaps the perimeter column line all connected by the spandrels. I don't think we can even know how much of the floor beams and floor slabs were still connected to the inside of the curtain wall and perimeter frame from the videos.
The core, or course, was mostly shafts and so there was little there there... so the *bulk* of the collapse would be the floor areas outside the core and of course the curtain wall.... which we do and can see. If the core side collapsed down after the runaway cascading failure raced westward on levels 5, 6 & 7 beginning at the TT1 region it likely pulled some of the core sides of the beams and floor slabs with it. I would find it hard to imagine that the perimeter frame had the strength to cantilever all the floors. And... we have some evidence that the east region was gone when the East penthouse collapsed.
This all tends to reinforce the *implosion* or inward collapse (pulling in toward the core) of the floors... probably separating from the curtain wall and spandrels. Certainly the inward bowing of the descending north facade suggests that the floor plates behind the facade were destroy to enable the inward deflection of the curtain wall.
