At Defensetech, Noah Schachtman David Hambling blogs about the SMAW-NE, a new urban combat weapon the Marines are using — but not talking about very much.
This is a version of the standard USMC Shoulder Mounted Assault Weapon but with a new warhead. Described as NE – "Novel Explosive"- it is a thermobaric mixture which ignites the air, producing a shockwave of unparalleled destructive power, especially against buildings.
A post-action report from Iraq describes the effect of the new weapon: "One unit disintegrated a large one-storey masonry type building with one round from 100 meters. They were extremely impressed." Elsewhere it is described by one Marine as "an awesome piece of ordnance."
Link (Thanks, Noah Schachtman)
Reader comment: Chris Nichols says,
The description given of the SMAW-NE is technically incorrect. A thermobaric
weapon works by finely dispersing an explosive throughout a certain volume,
then igniting the explosive. The air itself does not ignite. Unless they've
made a SUPER BOMB, which I suppose is possible. Link to Wikipedia reference.
David Hambling replies:
This should really have said 'ignites in the air' rather than 'ignites the air'. Unlike normal explosives, a key aspect is that the thermobaric mix is not itself explosive* as it lacks oxygen, which it gets from the atmosphere. So the air contributes to the explosion. In practice what you have is an exploding fuel/air mix, whether this counts as 'igniting the air' is moot.
Note that the Wikipedia entry should not be relied upon as it refers only to liquid FAE-type thermobarics and not solid FAE like the SMAW-NE. There are also subtle technical distinctions between enhanced blast, thermobaric and fuel-air explosions to do with timing and phases, but to people on the receiving end these are fairly academic.
The point of the article is the effectiveness of the new warhead and the way it was introduced and used without public discussion.
Another weapon called PEP really does ignite the air, but that's another story.
* In the SMAW-NE the thermobaric component is finely powdered aluminum.
