UK 105mm Gun Explodes in Afghanistan
- Thread starter tomahawk6
- Start date
The ammunition was old. The black powder delay pellet crumbled and part of it was able to move, striking the fixed firing pin in the delay ignition train. At the same time the booster, which both amplified the initial explosion and acted as a safety device in that it did not arm until the round left the bore, actually armed before the delay sequence reached it. (When armed, the booster allowed a clear path for the flash sequence to detonate the explosive filler. (Geo, I know you understand the difference between an explosion and a detonation.)
The solution was to introduce a booster which completed its arming sequence after the delay train would have functioned, thus eliminating the cause of the prematures.
I assisted an ATO in his investigation, which is why I can still state the reasons. It was an excellent lesson in coupling deductive reasoning and technical knowledge for this second lieutenant. We first established the actual distance of detonation outside the muzzle. We stuck straws in the splinter holes in ammo boxes, etc on the gun line and established the distance of the burst forward of the muzzle. We then calculated the time by dividing the muzzle velocity from the gun history book by the distance to the burst. This time (.05 seconds) coincided with the time required for both the booster to arm and for the delay element to function.
The solution was to introduce a booster which completed its arming sequence after the delay train would have functioned, thus eliminating the cause of the prematures.
I assisted an ATO in his investigation, which is why I can still state the reasons. It was an excellent lesson in coupling deductive reasoning and technical knowledge for this second lieutenant. We first established the actual distance of detonation outside the muzzle. We stuck straws in the splinter holes in ammo boxes, etc on the gun line and established the distance of the burst forward of the muzzle. We then calculated the time by dividing the muzzle velocity from the gun history book by the distance to the burst. This time (.05 seconds) coincided with the time required for both the booster to arm and for the delay element to function.
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Heh... sooo... after CSI Miami, CSI Vegas & CSI NewYork we have CSI Gagetown.
Have a fairly good grasp of the dynamics leading from detonation to explosion
Have seen and been involved in a couple of investigations when ammunition or explosives have behaved in unexpected (though sometimes predictable) ways.
Interesting findings - must have been a very interesting process for a young 2Lt to go through... Through lessons learned, we (should) become better soldiers
Have a fairly good grasp of the dynamics leading from detonation to explosion
Have seen and been involved in a couple of investigations when ammunition or explosives have behaved in unexpected (though sometimes predictable) ways.
Interesting findings - must have been a very interesting process for a young 2Lt to go through... Through lessons learned, we (should) become better soldiers
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I was with the RAA for 6 yrs in total, and knew this gun (L118/119).
From the RAEME side of things, its a maintenance nightmare, and from the GNR side of things, its fragile. However WRT this incident......
A few years back, we had the same problem, the rd cooked off 1/2 up the tube, and fragged. Blew the gun to hell, but no one was killed, although one GNR got a fractured hip out of it, and a fire was started.
Cause at the end of the investigation was ammo. A fault in the manufacture process at yes, ADI :
The UK 105 is not precussuion fired, but fired electrically. The UK gun has a longer barrrel, and its called the Abbot ordnance here. A good punch at charge super, and adds km's on to the max range. If I remember right 17km vice 11km with the US M1 precussion type ammo with the 'M1' shorter ordnance.
Lucky that no one bought the farm over this one.
Cheers,
Wes
EDIT: US 105mm ammo, and UK 105mm ammo - two different kettles of fish, and DO NOT interchange.
From the RAEME side of things, its a maintenance nightmare, and from the GNR side of things, its fragile. However WRT this incident......
A few years back, we had the same problem, the rd cooked off 1/2 up the tube, and fragged. Blew the gun to hell, but no one was killed, although one GNR got a fractured hip out of it, and a fire was started.
Cause at the end of the investigation was ammo. A fault in the manufacture process at yes, ADI :
The UK 105 is not precussuion fired, but fired electrically. The UK gun has a longer barrrel, and its called the Abbot ordnance here. A good punch at charge super, and adds km's on to the max range. If I remember right 17km vice 11km with the US M1 precussion type ammo with the 'M1' shorter ordnance.
Lucky that no one bought the farm over this one.
Cheers,
Wes
EDIT: US 105mm ammo, and UK 105mm ammo - two different kettles of fish, and DO NOT interchange.
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If I remember, the UK had problems with .50cal ammo last summer (?) I believe they had bought Ammo from Pakistan... In the end, they came to the CF for replacement Ammo while their Ordonance people got their act together and found another source. I just wonder if theis 105 problem is related to Ammo procurment again...
THAT would be upsetting, wouldn't it?
THAT would be upsetting, wouldn't it?
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WRT the accident involving Australian Gunners, which happened approx May 2002, the following info is provided:
At approx 1050h the Regt was a firing Regt IN (immediate neutralisation) mission at Charge 7 in spt of C/S 24 when a HE round in the breech of Bravo Det 107 Fd Bty appeared to function prematurely. A loud bang, flash and cloud of smoke ensued with the barrel being thrown 10m into the air, the breech shearing off from the barrel (and landing near the ammunition shelter), the top of the sight shearing off, the cam net frame being thrown 10m to the rear, and the recuperator being thrown 20m forward of the gun. The detachment had 20 rounds prepared and these started to catch alight. Prompt action by the surrounding detachments put out both the fire in the ammunition, and the fire on the No 4 (including cutting off his smouldering cams). Injuries sustained were mercifully very light with shock being the major injury. In addition, the No 2 was injured by the breech as it flew rearwards and has a suspected broken hip. The No 3 was hit in the face by fragments of the sight as it shattered. All members suffered from inhaling the super-charged air as it was expelled form the barrel/breech. The luckiest man in the world is the No 7 who was standing by the ammunition shelter next to the breech's final resting place. He emerged from the smoke cloud unscathed and apparently only having lost his watch (blown off by the blast). The SATO has placed a ban on the use of M739 fuses and all HE proj. From his advice it would seem that initial indications are that the detonation was a secondary explosion i.e. the round did not high order, but this has yet to be confirmed. The round exploded not far from the commencement of rifling i.e. it had just left the breech and commenced its movement up the barrel. It appears that the primer was cleanly struck, and as the round was the third in a method of 3 Rd FFE it is unlikely that there was any obstruction in the barrel. The rearward section of the round remains in the barrel, less its driving band. The fuse and the forward section of the round have yet to be found. The gun is effectively written-off. The tyres have been shredded and the trails are badly damaged. The two equilibrators are facing skywards with much of the remainder of the super-structure of the gun missing. Debris is scattered over a 40/50m radius.
At approx 1050h the Regt was a firing Regt IN (immediate neutralisation) mission at Charge 7 in spt of C/S 24 when a HE round in the breech of Bravo Det 107 Fd Bty appeared to function prematurely. A loud bang, flash and cloud of smoke ensued with the barrel being thrown 10m into the air, the breech shearing off from the barrel (and landing near the ammunition shelter), the top of the sight shearing off, the cam net frame being thrown 10m to the rear, and the recuperator being thrown 20m forward of the gun. The detachment had 20 rounds prepared and these started to catch alight. Prompt action by the surrounding detachments put out both the fire in the ammunition, and the fire on the No 4 (including cutting off his smouldering cams). Injuries sustained were mercifully very light with shock being the major injury. In addition, the No 2 was injured by the breech as it flew rearwards and has a suspected broken hip. The No 3 was hit in the face by fragments of the sight as it shattered. All members suffered from inhaling the super-charged air as it was expelled form the barrel/breech. The luckiest man in the world is the No 7 who was standing by the ammunition shelter next to the breech's final resting place. He emerged from the smoke cloud unscathed and apparently only having lost his watch (blown off by the blast). The SATO has placed a ban on the use of M739 fuses and all HE proj. From his advice it would seem that initial indications are that the detonation was a secondary explosion i.e. the round did not high order, but this has yet to be confirmed. The round exploded not far from the commencement of rifling i.e. it had just left the breech and commenced its movement up the barrel. It appears that the primer was cleanly struck, and as the round was the third in a method of 3 Rd FFE it is unlikely that there was any obstruction in the barrel. The rearward section of the round remains in the barrel, less its driving band. The fuse and the forward section of the round have yet to be found. The gun is effectively written-off. The tyres have been shredded and the trails are badly damaged. The two equilibrators are facing skywards with much of the remainder of the super-structure of the gun missing. Debris is scattered over a 40/50m radius.
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I had the M109 next to me fire at loading angle on an exercise in CFBG a long time ago. I think the round impacted about 260m to the front of the gun position. The recoil knocked the No. 1 back out of the cab. Was anyone around then?
Bruce Monkhouse said:
- After jumping in north of Earlton in Feb 84, 6 of the 7 Lynx of 1Tp (Para) Recce Sqn 8 CH(PL) were used as 'gun tractors' to tow the L5s of 'E' Bty on a night move. The gun bunnies rode on top of the Lynx with their det toboggans. Stowing of the 'horsehair' padding beside the Lynx exhaust and under the tobaggan caused a fire on my C/S. I turned around in the hatch to see ten foot high flames and bodies leaping off my back deck at 20 MPH. The first two fire extinguishers I used piffed. Tpr Atkins arrived with another and put the fire out. The quart cans of Iosol (naptha) stored in the toboggan were bloated round by then. Tpr Atkins - a vol fire fighter back home - figured I had maybe thirty seconds left on top of that Lynx, one way or another.
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TCBF said:
I was with 'D' Bty up there and all I can say is, at least you would have been warm for a few seconds.
Colin Parkinson
Army.ca Myth
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The only artillery related incident I witnessed was a 105 C2, slamming into battery so hard as to tilt the gun on the axle shoving the barrel into the ground and the trails pointing into the air. I helped the gun plumber strip down the gun and they discovered metal filings had etched the inside of the recoil mech bore. A clear failure of the workshops that had assembled the gun.
AmmoTech90
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Just in case people are curious, the cause of the accident has been released.
The recoil mech was filled with oxygen rather than compressed air. That's it.
The recoil mech was filled with oxygen rather than compressed air. That's it.
Ammo Tech 90
Are you saying that compressed oxygen instead of compressed air was used in the recoil system? Did the further compression cause 'dieseling' or was there a spark as well? There are advantages to the use of nitrogen as the gas in a recoil system.
Are you saying that compressed oxygen instead of compressed air was used in the recoil system? Did the further compression cause 'dieseling' or was there a spark as well? There are advantages to the use of nitrogen as the gas in a recoil system.
AmmoTech90
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Old Sweat,
Yes compressed oxygen was used instead of compressed air, the spark probably came from the firing of the weapon, it didn't happen on the first round down range, but it did happen when the weapon fired. I don't think nitrogen would have made a difference in this case, it's pretty had to ignite air and has never happened before. Just a screw up with the air bottles. If you have access to the British KIT (an equipment care magazine) there's a write up in there of it.
Yes compressed oxygen was used instead of compressed air, the spark probably came from the firing of the weapon, it didn't happen on the first round down range, but it did happen when the weapon fired. I don't think nitrogen would have made a difference in this case, it's pretty had to ignite air and has never happened before. Just a screw up with the air bottles. If you have access to the British KIT (an equipment care magazine) there's a write up in there of it.
