10-02-2012, 01:36 PM
It's truly hard to know if the collapse of the top sections were an engineered demolition with some sort of pre placed or delivered devices in the planes ot if they were simply from the excessive heat from the fires generated by the plane fuel and contents acting on a vulnerable design.
The vulnerable design was definitely part of the cover up because regardless of the cause of initiation, the structure was not investigated for the likelihood of progressive collapse. There are engineering papers which show this is a distinct possibility in high rise buildings. Those papers were written after the towers were built and before they collapsed (I believe). Obviously no one was going to take then down or reinforce them. We can only assume that there was a decision to not undertake this way too expensive retro fit because the worst case would only manifest if there was a over load presented to the floor system sufficient to destroy one floor and all those below. The likelihood of such an over load was virtually zero... as it required 4 or more collapsed floors falling on a single floor to kink off the progressive floor failure.
The engineers did not expect even a large plane impact to create enough destruction to kick off a progressive floor collapse. They claimed they did not run any simulations about whether fire could cause failure of the floor system (the NIST explanation which is not credible)... or if the core could be weakened by heat to cause it fail. Office type fires seem to produce not enough heat and over larger enough areas to effect enough columns to fail the core. This needs more rigorous scientific investigation to confirm or deny this. NIST did not look at core failure from heat and only truss failures. And of course the reserve strength of the core would be a key factor to how many columns could be destroyed or how much the remaining ones could be weakened to cause the core to buckle. I've read some who claim (from the truth movement side) very FOS of 3 or 5 or even 20. This is simply not true because it means that there would have had to be 1/3 to as much as 10 times the steel weight (cross section) for the columns... or the steel would have had to have been extremely hi tech high strength steel at the same weight and cross section we see. So the FOS was as low as 1.65 and perhaps as high as 2 depending on the building weight. Core failure from buckling IS a calculation driven by the actual yield strength of the steel and the actual mass it is supporting. Yield strength DOES go down with heat... but building mass is more or less constant. Destroyed and or damaged columns reduce total yield strength of the core.
I speculate that this *engineering secret* was something that was something that could be exploited IF someone wanted to take the towers down... without having to use a traditions low down column destruction. The tradition approach would require such massive explosive power that it would be very hard to place without notice. But the progressive floor collapse led by a core destruction up top required much less energy input to kick off the floor collapse which had to be a downward driven process.
I speculate that AQ type terrorists did not need to take the towers down... but the simply hit them and such a plane strike and ensuing fires would make them unusable not to mention unrentable even if they could have been repaired. I speculate that the total destruction of the entire complex would not be a goal of a terrorist. This speculation leads one to think that the supposed hijackers got very lucky and cause way way more damage than then thought would happen... or they had done some engineering and advanced study of the buildings including the electrical systems.
How to account for bldg 7? It was we were told collateral damage from the collapse of tower 1 causing fires at column 79 which proved fatal. But it's likely that bldg 7 collapsed from another design innovation - building a 47 story (actually 42) above a huge Con Edison sub station which served most of lower Manhattan. My speculation is that the first plane caused a huge voltage spike which fatally damaged a series of transformers in the substations in tower 1 (8 of them) and the main one under Building 7. The transformers then released insulating oil and explosive gas which ignited from sparks etc. The pumps for sprinklers lost power, the huge diesel tanks unloaded their fuel down to the generator floors above the sub station which were destroyed and a massive diesel fire burned inside the core. There were massive ventilation grilles on the north side of bldg 7 at floors 6 and 7 to supply oxygen for combustion and the net effect is that the fires failed the massive transfer trusses supporting multiple core columns of the tower above the sub station. Another core failure but this one at the bottom (floor 7 / 8). These fires burned un fought all day. Recall Barry Jennings hear massive explosion below him when he was in the stairwell on the 8th floor shortly after the first plane had hit tower 1 ( exploding gas released from the sub station???) If this failure scenario of bldg 7 is what happened as I speculate, it is almost impossible to accept that this was planned by hijackers. They got lucky or... someone exploited the vulnerability to / ofthe sub station... the transfer trusses and then the core.
Excerpt of a report of the electrical power grid on 9/11:
The vulnerable design was definitely part of the cover up because regardless of the cause of initiation, the structure was not investigated for the likelihood of progressive collapse. There are engineering papers which show this is a distinct possibility in high rise buildings. Those papers were written after the towers were built and before they collapsed (I believe). Obviously no one was going to take then down or reinforce them. We can only assume that there was a decision to not undertake this way too expensive retro fit because the worst case would only manifest if there was a over load presented to the floor system sufficient to destroy one floor and all those below. The likelihood of such an over load was virtually zero... as it required 4 or more collapsed floors falling on a single floor to kink off the progressive floor failure.
The engineers did not expect even a large plane impact to create enough destruction to kick off a progressive floor collapse. They claimed they did not run any simulations about whether fire could cause failure of the floor system (the NIST explanation which is not credible)... or if the core could be weakened by heat to cause it fail. Office type fires seem to produce not enough heat and over larger enough areas to effect enough columns to fail the core. This needs more rigorous scientific investigation to confirm or deny this. NIST did not look at core failure from heat and only truss failures. And of course the reserve strength of the core would be a key factor to how many columns could be destroyed or how much the remaining ones could be weakened to cause the core to buckle. I've read some who claim (from the truth movement side) very FOS of 3 or 5 or even 20. This is simply not true because it means that there would have had to be 1/3 to as much as 10 times the steel weight (cross section) for the columns... or the steel would have had to have been extremely hi tech high strength steel at the same weight and cross section we see. So the FOS was as low as 1.65 and perhaps as high as 2 depending on the building weight. Core failure from buckling IS a calculation driven by the actual yield strength of the steel and the actual mass it is supporting. Yield strength DOES go down with heat... but building mass is more or less constant. Destroyed and or damaged columns reduce total yield strength of the core.
I speculate that this *engineering secret* was something that was something that could be exploited IF someone wanted to take the towers down... without having to use a traditions low down column destruction. The tradition approach would require such massive explosive power that it would be very hard to place without notice. But the progressive floor collapse led by a core destruction up top required much less energy input to kick off the floor collapse which had to be a downward driven process.
I speculate that AQ type terrorists did not need to take the towers down... but the simply hit them and such a plane strike and ensuing fires would make them unusable not to mention unrentable even if they could have been repaired. I speculate that the total destruction of the entire complex would not be a goal of a terrorist. This speculation leads one to think that the supposed hijackers got very lucky and cause way way more damage than then thought would happen... or they had done some engineering and advanced study of the buildings including the electrical systems.
How to account for bldg 7? It was we were told collateral damage from the collapse of tower 1 causing fires at column 79 which proved fatal. But it's likely that bldg 7 collapsed from another design innovation - building a 47 story (actually 42) above a huge Con Edison sub station which served most of lower Manhattan. My speculation is that the first plane caused a huge voltage spike which fatally damaged a series of transformers in the substations in tower 1 (8 of them) and the main one under Building 7. The transformers then released insulating oil and explosive gas which ignited from sparks etc. The pumps for sprinklers lost power, the huge diesel tanks unloaded their fuel down to the generator floors above the sub station which were destroyed and a massive diesel fire burned inside the core. There were massive ventilation grilles on the north side of bldg 7 at floors 6 and 7 to supply oxygen for combustion and the net effect is that the fires failed the massive transfer trusses supporting multiple core columns of the tower above the sub station. Another core failure but this one at the bottom (floor 7 / 8). These fires burned un fought all day. Recall Barry Jennings hear massive explosion below him when he was in the stairwell on the 8th floor shortly after the first plane had hit tower 1 ( exploding gas released from the sub station???) If this failure scenario of bldg 7 is what happened as I speculate, it is almost impossible to accept that this was planned by hijackers. They got lucky or... someone exploited the vulnerability to / ofthe sub station... the transfer trusses and then the core.
Excerpt of a report of the electrical power grid on 9/11:
Timeline on 911112001:
08:46 a.m. Two WTC open/auto (O/A) 13 kW feeders went off
09:02 a.m. Two additional WTC open/auto (O/A) 13 kW went off
09:52 a.m. Four additional open/auto (O/A) 13 kW feeders went off
10:28 a.m. Status: '
Cortlandt 8 of 15 feeders were off
Battery Park City 6 of 8 feeders were off
Bowling Green 6 of 16 feeders were off
Park Place 1 of 12 feeders were off
Con Ed can lose any 2 feeders, and not lose a network grid. It is very expensive to make this investment and have such a robust system. The NYSE was located in the Bowling Green network. Since all 8 feeders were lost prior to WTC South tower falling, it was possible the lights had gone out before. However, the Port Authority controlled the
equipment in the towers and Con Ed did not know exactly what happened inside the towers. They did have maps of the towers and were prepared to help the Port Authority in the event they were needed.
08:46 a.m. Two WTC open/auto (O/A) 13 kW feeders went off
09:02 a.m. Two additional WTC open/auto (O/A) 13 kW went off
09:52 a.m. Four additional open/auto (O/A) 13 kW feeders went off
10:28 a.m. Status: '
Cortlandt 8 of 15 feeders were off
Battery Park City 6 of 8 feeders were off
Bowling Green 6 of 16 feeders were off
Park Place 1 of 12 feeders were off
Con Ed can lose any 2 feeders, and not lose a network grid. It is very expensive to make this investment and have such a robust system. The NYSE was located in the Bowling Green network. Since all 8 feeders were lost prior to WTC South tower falling, it was possible the lights had gone out before. However, the Port Authority controlled the
equipment in the towers and Con Ed did not know exactly what happened inside the towers. They did have maps of the towers and were prepared to help the Port Authority in the event they were needed.