Thread by @UnderwaterLance

Thermobarics: a primer

First, here is a great chemistry thread by @johnismay.

Summary: thermobarics are a type of explosive that seek to lengthen the time for which the blast produces HEAT ("thermo") and PRESSURE ("baric")

But why does this increase injuries & damage?...(1/10)

https://twitter.com/johnismay/status/1498499801058525186

(2/10) All explosives cause damage through the pressure wave they produce (in addition to things like shrapnel). The outwardly expanding pressure wave is why you might escape w/burns if you hold a firecracker on an open palm, but you will lose your hand if you close your fingers.

(3/10) If the pressure wave lasts a long time, it is hitting targets with that elevated pressure for a longer time.

Think of pressure washers: focus the flow on one spot, that spot can get damaged. Longer pressure waves mean more energy/damage imparted to anything that gets hit.

(4/10)The effect is extra powerful in enclosed spaces, b/c when ANY blast occurs in an enclosed space, the reflections add to each other.

If the initial pressure wave lasts longer, each reflection adds, building a higher pressure, instead of occurring as separate, smaller waves.

(5/10) Thermobarics, with their ultra-long pressure waves, are like getting hit by a football team rather than one individual football player, because each reflection is another player jumping onto the dog pile.

(6/10) The smaller the space, the more quickly the reflections occur and add up, rather than spacing out one at a time like small waves lapping at a shore. This is what happened to the crew of the HL Hunley in their small space, even without thermobarics.

amazon.com/Waves-Quest-So…

(7/10)Fuel-Air Explosives (FAE) spray a cloud of fuel to enhance the explosion and create this effect. Other types mix things into the explosives itself to achieve the same goal of keeping the burn going for longer. Even in an open space, the longer waveform alone is more lethal.

(8/10) B/c of the long pressure waveform, thermobarics are even more likely to cause primary blast injuries. Primary blast trauma is trauma from the blast's pressure wave itself, and it often looks like people fallen dead where they stood.

(9/10) In fact, these injury reports were common during WWII, especially inside bomb shelters, and during the troubles in Northern Ireland. Up to 20% of the case reports in Northern Ireland were people who fell dead where they stood, no external markings.

That is primary blast.

(10/10) The blast wave doesn't "suck the air out" of the lungs (@nypost) and the term thermobarics certainly does not mean heart (@CNN).

Here is a good, open resource for more info:
jmvh.org/article/muniti…

(thread above) #thermobaric #ThermobaricBomb #ThermobaricWeapon #Ukraine #Trauma #BombNerd