So what was your source? How do you know for certain what kind of switiches were actually inside the elevator shaft of the twin towers? How do you know for certain that they were positioned inside the elevator shaft and that they were located in an exposed position relative to the descending jet fuel? Your claiming that you know that the switches in the towers did not have special safeguards – ok source that claim please instead of "describing" your occuaption.
There are rules and regulations about what equipment can be used in areas that can have explosive atmospoheres present continuously or for long persiods. Areas such as oil rigs, gas plants, refineries etc etc. Equipment in these areas must be designes so as not to produce a spark or heat that could ignite this atmosphere. If you want to see the rules and regulations regarding these regulations then go to the IECEx website and read all about it. Normal offices and houses and indeed most factories will not have explosive atmospheres at any time. Their equipment comes under different regulations. They do not have to have this limits on sparks and heat for ignition of explosive atmospheres. The switches, lighting and mains voltages in the Twin Towers would have been to the same standards as the ones in your home because they are normal office enviroments.
When I set up electrical circuits in Zone 1 areas on an offshore oil rig, I mostly use 4-20mA, 24 VDC systems. Very low current and volts so low power. If there is a failure and a spark is produced then the spark is is of insufficient power to cause ignition. If I want to use higher power circuits then I have to use other types of protection for the circuits such as pressurisation, explosion proof enclosures etc etc.
In the towers the electrical circuits would have been mostly 110 volts AC, up to 13 Amp,normal USA mains voltage for the office power. There would also have been industrial electric circuits for the lifts etc that could have been uo to 415VAC. There are no limits on power potentila of sparks because there is not explosive atmosphere present in normal circumstances.
Now at this point I will try to tell you again. You are barking at the wrong tree here. You are concentrating on the switches. Switches will only cause ignition in normal circumstances when made or switched. These were not the only ignition sources. Lamps or relays are just as likely to have been an ignition source. The flaming debri also. What you really should be thinking of is the fire triangle again. You have ignition sources. You have jet fuel. you haave oxygen. What will normally be the crucial factor in this situation ifs the combination of the jet fuel and the oxygen into the range of the LEL and th UEL. If this occurs then this is when the ignition will take place. Asd the thousands of gallons of jet fuel are cascading down the elevator shafts then this ratio is not correct therefore any ignition source it encounters is moot. Only when the fuel and air can mix in the correct ratio will the ignition occur. If you ask me, in my opinion, I would say there is more likely to have been an explosion in the lower levels than the upper.
If you have a dish with a flammable liquid in it and you set light to it and observe the flame, where is the burning occuring? Surface of the liquid or just above where the liquid and air has mixed? Do you understand the concept of flooding your motor car in an older style carb engine?
TWS said:
Another point you ignore is this – using your common sense, and expertise in light switches – explain to me how the flammable jet fuel travelled down 90+floors without igniting into a fireball. If indeed the light switches were the cause and were alined all the way down the elevator shaft then surely the jet fuel would have deflagrated before it reached B2-3 because it must have been in contact with many many “non-special” light switches??
Again I am not sayimng the switches are the cause just that they are one of many that could have caused. See above for the comment about correct ratio of fuel to oxygen for why it did not ignite. If you have a small flame burning and you take a bucket of petrol and dump the petrol on the flame the flame will be extinguished because you have added too much fuel to the triangle. If however you have the same flame and you bring it near the surface of the petrol in the same bucket it will ignite. This is due to the relationship between the Fire triangle and the LEL and UEL.
TWS said:
Imagine a house 10 storeys high and each floor had several non-special light switches. Unfortunately and by accident there was a gas leak on the 10th floor. However eventhough each floor had several non-special light switches the gas travelled all the way down to the ground floor and despite having come into contact with many non special light switches it suddenly explodes when it reached the basement floor.
I look forward to your response on that one.
Again. You are obsessing on switches. If the gas and air mixture was correct and there was an ignition source present it would ignite at the source of ignition. However I have already told you that normal switches create a spark when they are made or operated. In your experiment if the gas travelled down the floors and there was the correct ratio available on each floor of gas and oxygen then it would ignite when one of the switches was made. It would not matter which floor this was on it would occur at the switch when operated. If a switch was made on the lower floor then it would cause the the explosion there. If it was the top floor, it occur there. You are making the mnistake of concentrating on one aspect of the fire triangle and also ignoring LEL and UEL. Remember the fire triangle states that you must have Fuel, Oxygen and heat (spark) for a fire to occur. It does not state that if you have all three then you will definately have a fire because the fuel and air must be in the correct mixture to allow the ignition to occur. Too much fuel or too much oxygen and the ignition caannot occur. Please tell me you see this?
I said
TWS said:
Nice dodge. The point was how did it gets past all the present and capable ignition sources before it reached the basement?
see above
TWS said:
try using it
I am not forgeting the LEL and UEL. If the entire shaft possessed an explosive atmosphere and that explosive atmosphere was progressing downwards then one would expect that the explosive atmosphere would have exploded into a fireball before it reached the basement after it past and came into contact with numerous ignition sources.
Yes you are. If the entire shaft contained the correct explosive atmosphere then indeed the first source of ignition would have ignitied it. The thousands of gallons of jet fuel cascading down the shaft just after impact does not mean you have this correct atmosphere present all the way down the shaft. See the bucket of petrol experiments above.
TWS said:
Ok – your the expert and the teacher on this subject. Now imagine i am one of your students.
Sorry pal, you are not bright enough to be one of my students but i will play your game anyway. You will recieve an F though
TWS said:
I ask you, excuse me sir, but how did the jet fuel not ignite into a fireball before it reached B2-3 in both towers? It seems strange to me given that the elevator shafts were the only way the jet fuel had access to the basement, given that all the ignition sources where present within the elevator shaft, given they were all capable, and given there was an explosive atmosphere progressing downwards through the elevator– then how is it possible that the jet fuel did not deflagrate sooner? Everybody knows – even NIST - that a fireball did not travel down the elevator shaft from the impact zone?
I would tell you that there was not necessarily and explosive atmosphere travelling down the shaft at that point. I would carry out the bucket of petrol experiment (I would make you pay as petrol is very expensive here) and try again to reiterate the relationship between the LEL, UEL and the fire triangle.
TWS said:
would you sent me out of your classroom for that question?
If you had already asked it before and continued to show a complete and utter failure to show that you could understand basic theories like these, then yes, I would throw you off anf inform your supervisor
Common sense experiments:
if you had a stream of jet fuel running along the road from point A to point B and you had a portable ignition source (flamming torch, a short cicuiting wire, etc) and you exposed the jet fuel to the ignition source starting at point A moving towards point B. I would expect that the jet fuel would ignite at point A, and that the probabilty of reaching point B would decrease as soon as one left point A.
This in different than what occured in the towers. You are correct in what would happen in your experiment because the flame or short circuit would ignite the fuel air vapour at the surface of the fuel on the road. It is possible however that if you shoved the flame into the fuel that you may, in fact, put the flame out. see the bucket experiment again for a more realistic and common sense experiment.
The same logic applies to jet fuel flowing downwards through a tunnel, funnel, or elevator.
No it does not. The fuel on an open road is different than fuel in an enclosed vessel. Also the fuel on the road is not in motion. It has started to create the fuel ratio mixture at the surface already.
TWS said:
Jet fuel vapour experiment:
if you left the gas on at home, and when you entered the room and switched on the lights i would expect that the explosive atmosphere would ignite at the source of ignition .
Correct
TWS said:
If you had the same room full of gas, and instead of switching on a stationary light switch you flicked a match across the room. Will the match ignite at the moment of contact? will it travel half way across the room before ignition? or will it reach the far end of the room before it ignites the explosive atmosphere?
It will ignite as you are striking it and you will be blown to smithereens. Bot these experiments will depend on the correct fuel/air mixture again. If these are not coirrect then the explosion will not occur in either case.
Therefore your experiments are duff for consideration in the case of the towers.
TWS said:
If you have an elevator shaft 100 metres and an explosive atmosphere was travelling downwards from point A to point B while contacting "non-special" light switches every 10 metres along the way. Would you expect the explosive atmosphere to ignite at the first light switch, the 2nd and so forth. Or would you expect the explosive atmosphere to reach the 10th switch before it ignited?
I have already told you that it was not an explosive atmosphere that was travelling it was the fuel in liquid form. the expolosive atmosphere had not been formed yet.
TWS said:
Try the same experiment as above except throw a flamming torch and debris into the explosive atmosphere and observe if the mixture can reach point B before deflagrating.
a repeat of your earlier duff experiment
TWS said:
I am saying that experiments are always possible with enough imagination and resources.
TWS said:
I agree it is not necessary that we discover the exact source of ignition – but i am saying that experiments could be performed to prove how an explosive atmosphere in contact with multiple and capable ignition sources can pass over these multiple ignition sources from point A to point B without exploding. I contend itsumpossible !!
Again you completely miss the whole point because you do not have the technical knowledge.
TWS said:
Thats a strong claim. Now if indeed it is impossible and cannot be proven by experimentation then we return to the question – what caused the “explosion” in the basement? An explosion some witnesses who were actually there in the basement that day, claimed was a bomb!!
ell we know what the evidence is for the jet fuel theory. You have yet to show any evidence for any other theory.