• Watch Out for Scammers!

    We've now added a color code for all accounts. Orange accounts are new members, Blue are full members, and Green are Supporters. If you get a message about a sale from an orange account, make sure you pay attention before sending any money!

  • Site updates coming next Wednesday at 8am CT!

    The site will be down for routine maintenance on Wednesday 6/5 starting at 8am CT. If you have any questions, please PM alexj-12!

Runnin' the Numbers,

Sean the Nailer

Sergeant
Full Member
Minuteman
  • May 20, 2006
    6,807
    10,468
    Winnipeg, Mb.
    So, regarding this-here house that explodicated in Indianapolis, who's betting what the cause is?

    Amid the rampant speculation and fears, this will turn out interesting in one form or another. My house was here a minute ago, I swear!!!

    Souvenir 500 lb bomb, in the basement?

    Powder cache?

    Propane tank stored indoors?


    Ball's in your court now
    confused.gif
     
    Re: Runnin' the Numbers,

    Another Mars Bluff incident?

    This is from foreignpolicy.com

    I have high standards for aircraft-related mishaps, but the 1958 incident at Mars Bluff is a doozy. (What's with 1958, huh?) The B-47 crew had failed to secure the bomb in the bay and, while attempting to replace a "locking pin" in flight, accidentally tripped the bomb release. The bomb landed in a residential area in the unincorporated hamlet of Mars Bluff near Myrtle Beach, South Carolina -- and exploded. Fortunately, only the high explosives detonated. But the impact crater can still be seen today. "Not too many people can say they've had a nuclear bomb dropped on them," Walter Gregg, the man who lost his house to the accident, told a local newspaper. "Not too many would want to." Gee, you think?
     
    Re: Runnin' the Numbers,

    <div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: slowyellow</div><div class="ubbcode-body">Good god. But I vote propane and propane accessories. </div></div>

    The lack of seeing any propane tanks in the yards strongly suggests that the area is fed by natural gas. Natural gas is lighter than air and tends to "fill" a home more so than propane which is heavier than air. The remnants of the explosion are similar to previous natural gas explosions that are in current use as training materials for FD's.

    We just had a training on natural gas last Thursday with our local gas company and watched several of the videos. Natural gas explosions is covered rather thoroughly in our arson investigation classes. This has natural gas written all over it. The only thing that is really a big question is whether it was accidental or intentional.
     
    Re: Runnin' the Numbers,

    No visible crater... probably rules out a bomb blast or an 'accidentally dropped' weapon ;-) It looks like some kind of fuel/air explosive. Lots of over-pressure, but not much in the way of crater.

    If it was a Meth lab, it was a doozy! Those don't usually go up that big. Enough to kill cooks and blow out windows, but to damage 30 houses beyond repair? Would have to be a super-lab on an industrial scale...

    My bet goes with gas, propane, etc. The 'smell' is artificially added to gas, so if there was some kind of a 'natural' natural gas seepage into a house or neighborhood, maybe that explains lack of smell. Or it came from a pipeline leading 'to' a refinery or plant where the smell chemicals are added.

    My wildcard answer would be a meteorite ;-)

    Cheers,

    Sirhr
     
    Re: Runnin' the Numbers,

    <div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: timesublime</div><div class="ubbcode-body">Another Mars Bluff incident?

    This is from foreignpolicy.com

    I have high standards for aircraft-related mishaps, but the 1958 incident at Mars Bluff is a doozy. (What's with 1958, huh?) The B-47 crew had failed to secure the bomb in the bay and, while attempting to replace a "locking pin" in flight, accidentally tripped the bomb release. The bomb landed in a residential area in the unincorporated hamlet of Mars Bluff near Myrtle Beach, South Carolina -- and exploded. Fortunately, only the high explosives detonated. But the impact crater can still be seen today. "Not too many people can say they've had a nuclear bomb dropped on them," Walter Gregg, the man who lost his house to the accident, told a local newspaper. "Not too many would want to." Gee, you think? </div></div>

    I just read up on this. It's like Dr. Strangelove... but real
     
    Re: Runnin' the Numbers,

    Looks like a smaller version of what happened with the natural gas pipeline explosion in California a couple of years ago.

    In the spirit of the thread title, let's run some numbers. Assume that a large house might be 800 cubic meters, air is about 1.2 kg/m^3, and natural gas is 0.65x the density of air. The UEL of natural gas is around 4.5% and the UEL is maybe 16%; let's run with 10% natural gas by volume at the time of the explosion. That yields approximately 62.5kg of natural gas in the home. TNT is around 4.5MJ/kg, while natural gas is about 55MJ/kg, so that house may been filled with the equivalent of 750kg (1650lbs) of TNT when it went kaboom.

    While it is unlikely that this fuel-air mixture was dispersed perfectly and ignited uniformly, and thus the energy would have been released considerably slower than in a detonation of dynamite, this little exercise in math should provide a hint as to why so much damage occurred.

    Both natural gas and propane are potentially very dangerous fuels, and need to be treated with respect. They are also incredibly safe when used in modern appliances, as indicated by the fact that such accidents make national headlines. Human body fat is of only moderately lower energy density than typical hydrocarbon fuels, and yet is statistically far more hazardous to human health
    wink.gif
     
    Re: Runnin' the Numbers,

    <div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Sirhrmechanic</div><div class="ubbcode-body">Thanks for running the math!</div></div>

    No problem - making educated guesses at numbers is what I do for a living
    wink.gif
    Admittedly, I was a bit surprised by the result, and it makes me feel slightly better about the flammable gas detector that I installed adjacent to my utility room.
     
    Re: Runnin' the Numbers,

    "Hey honey, watch this" says the husband as he spreads his butcheeks and lights the lighter.
     
    Re: Runnin' the Numbers,

    I just calculated that, I think you're off by a pound..;-)
     
    Re: Runnin' the Numbers,

    Update: 29 surrounding homes 'slated for destruction'.

    here is where they are saying it was "natural gas" as well as "intentional".

    That's gotta hurt.