Grenadier Vest: Ticking Time Bomb?

[SOG]

I had a quick question about grenadier vests as pictured here:
http://images.google.com/images?hl=en&ie=UTF-8&q=grenadier%20vest&sa=N&tab=wi&um=1

1. Seems pretty bad ass as you have a lot of firepower. If one of the grenades takes a bullet I am assuming the bullet doesn't have enough energy to act as a primer setting the grenade off?

2. Are there any issues with having so many high explosive munitions sitting across your chest? If a grenadier gets 'grenaded' does he go boom x20 grenades?

3. Are these types of vests used in many countries armies?

4. Do you have any issues being nearby someone using these?

Anyway, I just saw one of the vests on a Russian and thought they almost looked like a suicide soldier just because of all the explosives carried on the chest. Then I wondered if that posed any sort of risk to those nearby or the grenadier themselves.

[DnA]

I haven't heard of anyone getting blown up due to the grenades on them.

And for the most part you won't see people wearing a vest like that older USGI one, etc. Most guys tend to wear them in a belt/bandalier so if they get hit an go down someone else can pick up their weapon an the bandalier, etc. Some guys also have 203 rounds in a MOLLE pouch on their LBE/Body Armour aswell.

[little icebear]

Many years ago, I asked an NCO the very same question. He said that Grenades should not explode in case they would be hit by a bullet.

However, the way he stressed the "should not" you got the idea that it isn´t anything you´d want to try.
Anyway, it was told that modern explosives should not be triggered by getting shot at. With blackpowder it would certainly be different.

[Lirelou]

Last year, I saw tests to check if firing at mines with infantry weapons could destroy them without explosion. (an extreme mean to clear a minefield for example). Some weapons were tested: 5.56 assault rifle, minimi, .50 sniper rifle, .50 machinegun, 7.62 sniper rifle. All gave the same result: it's hard to hit these little targets, but when they are hit, no explosion. That just break the explosive material into some parts.

That works, mines do not explode. So I think it's the same thing for grenades, because both are secondary type explosives (I don't know if it's the english translation for an explosive which need an other one, primary type, to be ignited). I don't know if it's the same thing with explosive ammunitions fired at some grenades because of the "sympathy" phenomenon, but I think you will be dead before having checked it...


See u on the beach

[STEPAN1983]

Ive read the memories of a russian WWII veteran who used a vest, full of small mortar ammo, so he says it protected him from some shrapnel

[Wahnsinn]

Last year, I saw tests to check if firing at mines with infantry weapons could destroy them without explosion. (an extreme mean to clear a minefield for example). Some weapons were tested: 5.56 assault rifle, minimi, .50 sniper rifle, .50 machinegun, 7.62 sniper rifle. All gave the same result: it's hard to hit these little targets, but when they are hit, no explosion. That just break the explosive material into some parts.

That works, mines do not explode. So I think it's the same thing for grenades, because both are secondary type explosives (I don't know if it's the english translation for an explosive which need an other one, primary type, to be ignited). I don't know if it's the same thing with explosive ammunitions fired at some grenades because of the "sympathy" phenomenon, but I think you will be dead before having checked it...


See u on the beach

Did these tests include walking across at the end? :)

If they don't explode when hit, all movies have ever taught me about the military is wrong! :-(

rofl

[SOG]

Thanks for the replies.

I'm thinking since most grenades are shrapnel/concussive based that they would have a similar effect to bullets unless they hit dead on. Very cool, thanks.

[dave81]

Those projectile grenades have to rotate a certain number of times at a certain rate of speed in order to set its fuse off and arm itself, kind of like those yo-yos that light up when you spin them really, really fast. If the grenade doesn't travel far enough, to spin enough times to arm itself before it hits its target, then it won't explode. You ever seen The Hunt For Red October? There's a scene where James Bond's submarine confronts another submarine head to head, and Bond has been targeted dead-on by a torpedo; instead of taking evasive maneuvers he commands his sub driver to increase speed directly face on into the path of the torpedo. Everybody thinks he's crazy or suicidal, making his boat race to meet the torpedo, but it turns out he was closing the distance so the torpedo wouldn't have time to arm itself. As a result, the non-armed torpedos bounce impotently off the nose of the submarineinstead of exploding and destroying the sub. Same thing applies to projectile grenades: If you ever see one fired at you, you should run towards it. You might just get away with a hole in the chest instead of an exploded corpse. p-)

[Dan2004]

Ive read the memories of a russian WWII veteran who used a vest, full of small mortar ammo, so he says it protected him from some shrapnel

Kind of like the old Chicom AK chest pouches; "Poor man's body armor." p-)

[Michigander]

The Box O' Truth #9 - Magazines vs. Rifle Rounds

http://www.theboxotruth.com/docs/bot9.htm

The short answer: rifle mags do not offer remotely adequate protection against 5.56 and 7.62x39 rifle rounds.

[Marsuitor]

I'm not sure about what type of pyro/explosives are used in a standard NATO-type 40mm frag specifically. But lets for simplicity sake say that the primer at the back of the grenade is something along the lines of a standard lead-styphnate compound (like in most small-arms ammunition), the propellant is smokeless powder and the explosive charge in the grenade itself is RDX-/CompB-based.

Having a bullet pass through a 40mm on the projectile itself would most likely not result in anything apart from a perforated 40mm and a gunshot wound on the guy wearing the vest. Military explosives especially are designed from the ground up to be very stable, taking alot for it to go high.
Shooting at a block of C4 will not make it go off, neither will lighting it with a lighter/setting it on fire make it go high either. With sufficiant heat, it will catch fire and burn, and under certain circumstances, a combustion can turn into a detonation (by blocking the the off-gasing of the burning explosives, in other words letting a pressure build-up within the explosive itself, for instance by trying to put out an explosive fire by use of water).

Having the bullet pass through the casing and going through the propellant probably the same as above - "only" a gunshot wound and nothing more, although it takes alot less to ignite black powder than secondary explosives (a spark from static electricity is enough, as an example). Worst case, the propellant might catch fire, but seeing as there are now two holes through the casing the combustion will most likely bleed out through these holes rather than propelling the projectile along (with full power).

Hitting the primer with the bullet, in some obscure and far-fetched scenario, is the most likely way of getting the projectile to fly along, although not as far as you can get a standard 40mm (~350m) as the projectile has no barrel it is being pushed through by that rapid combustion of gunpowder.
The primer consists of that which is called primary explosives, which are much more sensitive than secondary explosives. The compound which is used in small-arms ammunition primers are especially sensitive to impact and friction;
- The metal base of the primer gets hit by the firing pin.
- The metal base is deformed as a result, compressing the primary explosives inside the primer.
- The friction in-between the primary explosive molecules as they are compressed is enough to set it off.
- The heat from the primer-blast sets off the propellant.
- And so on...

In the scenario above, say the bullet passes directly through the primer. The kinetic energy of the bullet passing through is most likely enough to set off, but then again, maybe the passing bullet has severed the path from primer to propellant, or the speed at which the bullet passes through obliterates the primer before it can set off, and nothing happens in the end etc. etc. etc.
To be honest, and in reality this is only stupid theoretisizing and not something i would care so much or be worried about in the real world. The important thing to keep in mind is that 40mm grenades 99% certain won't go off, or atleast won't go high, if they are struck by a bullet.

And since fuses are mentioned, as the user above says, the standard rifle-type 40mm grenade has a rotation fuse, in addition to several other safety mechanisms. Actually, the fuse of the NATO 40mm (i say NATO as they all have different names and number in different countries) is one of the most advanced and safe fuses out there, because the grenade has to be so failsafe for the type of role it is to be used in (tossed around, dropped, dragged along the ground).
And in general regarding fuses, the rule of thumb is that NATO-fuses are much more complex and safety-aware than Eastern Bloc/Russian/Chinese/Etc fuses - if an EOD-tech has a good grasp on western stuff, learning eastern ordnance and fuses is a relatively easy task.

With this in mind, the above scenario on an "eastern" grenade might be somewhat different, although the explosives, propellant and primer will probably be just the same as on a NATO-type grenade.

[GazB]

The grenades in those pouches have two sorts of explosive in them. High explosive and low explosive. Low explosive is like black powder or mercury fulminate or lead fulminate as used in primers. Low doesn't mean weak. Low means a spark or a blow will set them off. Nitro glycerine is also a low explosive because a blow will also detonate it too.
A bullet impact will not set off a high explosive because a high explosive is relatively insensitive. That is why bombs dropped from aircraft need fuses to set them off rather than just letting impact with the ground do it. (because it wont).

Most explosive weapons have what is called a firing or fuse train. Some sort of initiator, a fuse of some sort, a primary explosive and a main explosive. The primary explosive is a low explosive and the main explosive is the HE.

Needless to say a HE round powerful enough to set off the grenades on a chest belt will likely be powerful enough to kill the person wearing that chest belt anyway.

Once fired the Soviet 40mm grenade is rotated by the rifling in the launcher. After a few spins an internal safety is made unsafe over a certain flight distance (usually 10-30m) at which time the warhead is armed and the impact fuse will detonate the primary and main charges. There is a secondary fuse that is ignited by the propellent on firing the grenade that burns slowly and will self destruct the round after a fixed period of time incase the main fuse fails so if you get close and it hits you but just bounces off you had better move. It might have been a dud fuse but the secondary fuse might still detonate the round.
There are two main Russian 40mm grenade types, one is a standard HE round that will explode on impact. The other has a small charge in the nose that blows the grenade up into the air and detonates the main charge at about 1.5-2m above the ground like a bounding betty mine.

[drunkpunk]

Kind of like the old Chicom AK chest pouches; "Poor man's body armor." p-)

no one claimed that the "chicom" chest rig is intended for use as a body armor. it's simply a magazine carrier. :roll:





The Box O' Truth #9 - Magazines vs. Rifle Rounds

http://www.theboxotruth.com/docs/bot9.htm

The short answer: rifle mags do not offer remotely adequate protection against 5.56 and 7.62x39 rifle rounds.

yes it doesn't. but the "chicom" type-56 chest rigs used by VC/NVA and iraqi personnel were not designed to stop a bullet in the first place. so there's nothing to argue about it. :)

[GrimReaper]

Why go as far as dedicated grenadier vest posing a threat? A year and half ago a reserve soldier from my brigade was killed, when an enemy bullet struck a frag grenade in his regular vest causing it to explode.

[Marsuitor]

Handgrenades differ from 40mm grenades in that with a handgrenade the detonator goes through almost it's entire length. It's pretty much a standard blastcap with a firing pin, primer and a delay on top (blastcap filled with more sensitive primary explosives, usually a lead-azide compound) stuck down into the main charge consisting of secondary explosives, as opposed to the 40mm which has far less primary explosives in it. As such, shooting a hand grenade is much more likely to cause it to explode than shooting a 40mm grenade.

[GazB]

Indeed as mentioned to set off the main charge there needs to be a primary charge to set it off. A blasting cap or something ignited by a fuse of some sort, or in the case of an impact fuse there would be no delay.

Just seriously bad luck really.