DIY barrel bombs were first recorded in late August 2012, and were generally metal barrel, pipes, etc, filled with explosives and frequently shrapnel, and dropped from the back of Mil Mi-8/Mi17 transport helicopters. When I originally investigated these munitions there was a lot debate other whether or not the Syrian air force would use improvised explosive devices as weapons, with even one commentator describing the idea as "Barrel bomb baloney", but eventually videos emerged showing a helicopter crew throwing DIY barrel bombs out the rear of a helicopter, and footage from Taftanaz air base showing DIY barrel bombs in storage after it was overrun by opposition forces.
One flaw with these DIY barrel bombs is they all appeared to be detonated using a simple wick fuse, like lighting a stick of dynamite. The problem with this is if the wick is too short the munition will detonate mid-air, and if it's too long there's a chance the bomb will be smash to pieces before it detonates.
Over the past few months I've been in contact with Richard Lloyd, Warhead Technology Consultant at Tesla Laboratory Inc, and among the various topics we've been discussing, he's highlighted a number of videos that show what appear to be unusually large explosions, and what appears to be DIY barrel bomb being dropped from helicopters that appear much larger than ones we've seen in the past.
Videos have now been posted from the town of Kafr Zita, Hama that appear to confirm the theory that larger DIY barrel bombs have now been deployed
Both videos show large DIY barrel bombs that have failed to detonate. The second video shows one that appears to have partly exploded, peeling back the thick metal, but what's very interesting is the design of the DIY barrel bomb in the first video.
As I mentioned before, one flaw with the barrel bomb was the wick fuse causing problems with detonation. The large DIY barrel bomb in the first video instead appears to have an impact fuze, which is removed from the munition
It appears there might have possibly been two impact fuzes, probably because of the broad front end (something also seen in munitions for the opposition's Hell Cannon), and a lack of aerodynamics to ensure the bomb lands right on the tip of it's nose. That lack of aerodynamics has been partly addressed by whoever put this bomb together by the addition of tail fins
Richard Lloyd believes this would have been able to carry 1250-1750 lbs (approx 565-795kg) of explosive, and suggests the tail fins wouldn't have been very effective because of that. What this does show is the Syrian Air Force is deploying huge DIY bombs, and they are attempting to make the fuzes far more effective than previous model.
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