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Muninn’s guide to surviving explosive hazards:
Explosion hazards can be broadly categorized as:
Overpressure (blast)
Fragmentation
Thermal (heat/fire)
I’ll make suggestions to mitigate each hazard, and provide some broad suggestions
#nashvilleexplosion
1/12
Explosion hazards can be broadly categorized as:
Overpressure (blast)
Fragmentation
Thermal (heat/fire)
I’ll make suggestions to mitigate each hazard, and provide some broad suggestions
#nashvilleexplosion
1/12
Overpressure is one of the most lethal and least understood (by the public) part of an explosion. The pressure wave from an explosion is capable of causing significant damage to internal organs - with eardrum rupture being the best outcome, and blast lung the worst.
2/12
2/12
Overpressure is measured in PSI, with a 1 PSI pressure wave being capable of breaking glass. More on this in the Fragmentation section. By the time the sound of an explosion hits you, the pressure wave has passed. You cannot hide or run from it. Pressure waves also reflect.
3/12
3/12
When two pressure waves meet, they form a shock front which is roughly double the PSI of the incident wave. This is called reflective overpressure. It is the reason why internal structure explosions are so catastrophic, and why you should not shelter in a confined space.
4/12
4/12
Fragmentation is caused by the casing/contents of the explosive, but also comes in a secondary form - which is objects thrown by the pressure wave.
A very good catch-all rule to remain safe from fragmentation hazards is:
“If you can see the bomb - the bomb can see you”
5/12
A very good catch-all rule to remain safe from fragmentation hazards is:
“If you can see the bomb - the bomb can see you”
5/12
One of the most common sources of fragmentation injuries in urban areas are windows. If you believe that there is an explosive threat proximal to your location, close the heaviest blinds available - and move to an interior room (if you aren’t able to evacuate).
6/12
6/12
The blinds will absorb most of the glass fragmentation, and will also attenuate some of the overpressure. Being in an interior room will keep you even safer, by providing additional cover. Glass fragmentation is horrific. Think of hundreds of thousands of glass slivers.
7/12
7/12
Heat or thermal energy (with explosives) is produced, as a solid undergoes a state change to a gas - suddenly taking up a lot more space. This reaction is exothermic, even in entropic HME’s. This is capable of causing serious flash burns, as well as igniting combustibles.
8/12
8/12
The best way to mitigate thermal explosive hazards, is by increasing your distance (stand-off) from the anticipated threat.
There is also the possibility that there could be flammable enhancements as a part of the IED, such as fuel containers (or gas tanks in vehicles.)
9/12
There is also the possibility that there could be flammable enhancements as a part of the IED, such as fuel containers (or gas tanks in vehicles.)
9/12
Conclusions:
Stand-off saves lives. This can be measured in feet. Any distance you put between yourself and the suspected device will decrease the risk to life from ALL of the hazards. But particularly overpressure.
Don’t stand by windows, or shelter in confined spaces.
10/12
Stand-off saves lives. This can be measured in feet. Any distance you put between yourself and the suspected device will decrease the risk to life from ALL of the hazards. But particularly overpressure.
Don’t stand by windows, or shelter in confined spaces.
10/12
Conclusions:
If there’s one explosive device, assume that there are more. Remain alert, and avoid crowds. A common hostile attack TTP is to use a bait attack in order to draw a crowd or first responders into the proximity of a secondary device.
Don’t mess with bombs.
11/12
If there’s one explosive device, assume that there are more. Remain alert, and avoid crowds. A common hostile attack TTP is to use a bait attack in order to draw a crowd or first responders into the proximity of a secondary device.
Don’t mess with bombs.
11/12
I’m a retired CAF member, with EOD qualifications, and operational experience in Afghanistan.
This content is designed to exclude details which could assist bad guys.
Also, I feel like I’ve done more for public safety with these tweets, than @polysesouvient ever has.
12/12
This content is designed to exclude details which could assist bad guys.
Also, I feel like I’ve done more for public safety with these tweets, than @polysesouvient ever has.
12/12
