reply to post by sprtpilot
More misinterpreting what is being said... Semantics...
Yes two houses exploded, I agree with that. Just like I also agree that the "Little Boy" that was dropped on Hiroshima exploded 100+ houses within a
1 mile radius. Yes, ONE bomb exploded 100+ houses in Hiroshima, sort of like ONE explosion from ONE house in Indianapolis exploded 2 houses.
If we use your "logic", and the "logic" of other people on this forum, we could probably conclude that there were 100+ explosions in every single
house in Hiroshima based on the fact that 100s of houses exploded. But that would just be silly. There was only one explosion.
You know what we learned from Hiroshima, and other explosion tests? That a 5psi blast overpressure is a significant threshold for structurally
damaging urban buildings. Any urban building experiencing up to 5psi shock wave can be crushed, toppled, or gutted by the force of air pressure.
With Hiroshima, one mile way from ground zero the blast overpressure was still at 5psi, which is fairly strong.
Here is more info about blast overpressure:
10 pounds per square inch (69 kPa)
-Reinforced concrete buildings severely damaged
-Severe heart and lung damage
-Limbs can be blown off
4 pounds per square inch (28 kPa)
-Most buildings collapse except concrete buildings
2 pounds per square inch (14 kPa)
-Residential structures collapse
-Brick walls destroyed
-Fatalities may occur
As you can see, residential structures can completely collapse with only a 2 psi blast overpressure, which is not a lot in the natural gas explosion
Here is the "Gas Explosion Handbook":
...and more information on overpressure:
Reading those sources you will learn that blast waves from gas explosions can cause high pressures far away from the area of the explosion, and learn
about their effect on structures, and much more. You will learn that typical deflagration explosions of gas can reach up to 8 bar, which is 116 psi.
You will learn that typical detonation explosions of gas can be between 15 to 20 bar, which is 290 psi.
According to the data we know about gas explosions and their blast overpressure, and looking at the amount of damage in Indianapolis, and an estimate
of the distance between the two houses that collapsed; I would say it would take a gas explosion with an initial blast overpressure of 1 bar (a
small-medium sized gas explosion) to make BOTH of the houses collapse. In a semi-open environment the 1.0 bar blast overpressure would destroy the
source house, then dissipate to 0.15 bar by the time it reach 50 meters away, which is 2.17 psi, enough to make the house next to it collapse.
edit on 18-11-2012 by illuminated0ne because: (no reason given)