The Inside of a Grenade

[trickedaccord92]

Pretty cool when they aren't blowing up killing you ...

*edit* This is not my pic I do not take any credit for creating this image. I am just sharing it because I found it to be a cool pic.

[toycar]

Its crazy that so much damage is caused by such a small amount of material



Cool pic!

[deevergote]

That's really awesome. I can't figure out what causes the delay between throwing it and the explosion, though.

[toycar]

That's really awesome. I can't figure out what causes the delay between throwing it and the explosion, though.

It takes a given amount of time to burn the accelerant before the actual detonation process happens.




The explosion itself is amplified by being contained in the grenade body. The material that explodes is not the material that initially ignites though, and that material takes time to heat the material that does explode. The material that explodes would do nothing if you just dropped it on a fire. It has to reach a point of pressure prior to becoming able to detonate.


Im trying to be vague, but I think im getting the point across here.


Lets use a pipe bomb as a general example. The part that makes a pipe bomb so damaging is NOT the material that explodes, but rather the pressure that is trapped in the pipe because of the material that explodes. The pressure generated by the trapped explosion is 1000x more than the actual pressure from the material that exploded.


Pour a gallon of gas on a fire, fire flares but thats about it.


Pour a tiny bit of gas into a sealed cylinder, (Lets say 240cc) compress it, ignite it and BOOOM, now you are moving thousands of pounds off of the force generated by controlling the small explosion(exactly how an engine powers a car).


Make sense?


That process takes time, and the accelerant they use in a grenade burns slow so that grenades don't blow in peoples hands.

Theres no timer. The event has been R&D'd to a degree that they know how much to add, to buy however much time they need.




I know my explanation is vague, but does that help?

[cp[mike]]

thanks.

is the empty volume within regular air, or some sort of gas? pressurized or vacuum? i'm surprised at how much empty space is contained within, i thought they were much more dense.

[Jarrett]

Disabled or not, the person cutting this thing in half surely had a puckered asshole.

[8ball]

now we just need to find out how grenade launchers work

[toycar]

thanks.

is the empty volume within regular air, or some sort of gas? pressurized or vacuum? i'm surprised at how much empty space is contained within, i thought they were much more dense.

The empty space within is how the mini-explosion starts. There has to be enough oxygen for the accelerant to ignite the actual explosives.


When the mini explosion happens, it expands at a rapid pace and slams into the outer edges of the empty space.


Air compresses during this process and generates a ton of pressure. That pressure is the actual explosion that causes all the damage. That pressure is what blows the grenade apart.


Not the material that explodes inside the grenade, its the pressure that is generate during that process that gets trapped/harnessed and that is what causes all the damage.



Are you familiar with the term hydrolocked?


So, when you hydrolock an engine you suck up water, and since water hardly compresses, shit blows apart in the cylinder on the compression stroke. Why though?


Because the compression stroke is being forced by another explosion that is MORE powerfull than the resistance the water can provide. Since the water WILL NOT compress under these conditions, the head usually lifts, often times cracking and sometimes rod snaps on the cylinder. The controlled explosion in a different cylinder generates enough force to snap a rod, lift/crack the head all through the refusal of the water to compress.


In that scenario, the rods and cylinder head actually become the weakest link and thats why they give.


Think what would happen with a syringe full of gas on an open fire. Not much right?


Compress that same gas in a sealed cylinder and ignite it and you better watch out! That explosion, that expansion of trapped pressure is powerful enough to fly airplanes or drive cars or move submarines.

The explosion being trapped pushes the pressure to extremes in the sealed container. In an engine, this is why valves open/close when they do. Opening at the perfect time allows the pressure to reach a peak safe PSI right before it lets the gasses out of the cylinder. The constant management of this process is how engines move cars.

Tiny explosions in a sequence buidling momentum basically by trapping an explosion and releasing the pressure before the cylinder explodes basically.




How do you think they took fireworks and a pressure cooker and made a bomb that injured 260 and killed 3? Completely blew peoples legs off and shit. It doesnt take much thats for sure. Trapping a small explosion generates a much larger reaction because of the contained pressure generated by the smaller explosion.



The pressure has no limit. It builds until the weakest part of whatever is containing it gives way. A pressure cooker can hold hundreds of pounds of pressure. The pressure in PSI terms builds until it literally blows apart. This process happens pretty quickly, but you get the point right?



It takes thousands of pounds of pressure to literally blow steel apart. So thats what happened. Small explosion gets trapped allowing pressure to spike to a point that the container can no longer hold and when it gives way, the pressure released and there you go. Shit goes flying everywhere(shrapnel and stuff) and the shockwave alone can kill people.

[Raf99]

So what part is the accelerant that burns slowely?

And can anyone identify the other parts in the picture? (Is the red thing the fuse? Is the blue stuff accelerant? The brown stuff at the bottom the explosive powder?)

just curious...., cool pic

[cp[mike]]

So what part is the accelerant that burns slowely?

And can anyone identify the other parts in the picture? (Is the red thing the fuse? Is the blue stuff accelerant? The brown stuff at the bottom the explosive powder?)

just curious...., cool pic

curious as well, haha.

thanks for the explanations toycar. is there anything to the specific volume of empty air? like couldn't they make the overall case much smaller (less airspace), and pressurize it with pure oxygen to have the necessary fuel, to ultimately have the same effect? or does it rely on the compressibility of the existing air at that volume to create the pressure blast you mention? obviously i'm no thermodynamics expert or anything, but obviously the picture is the first time i have ever been exposed to the workings of how a grenade functions and now i'm intrigued. :P

[toycar]

Great questions guys.



So basically you could make the space larger, smaller, equal, whatever. Every thing you change will alter the effect of the grenade.

Some grenades don't explode at all. Like flash grenades or smoke grenades.




The composition of the material used to make the grenade body has a lot to do with how much pressure it will hold before blowing, so even using different alloys will equal different outcomes.



Just as an example, you could have enough empty space to have enough air to allow the grenade to burn out without exploding at all. This would be an example of too much space, not enough explosion.



You could also have too little space, and choke the initial micro-explosion prior to the actual detonation process.



The amont of extra-empty space is determined by the amount of explosives in the grenade. There is a formula to this.





As far as what is what in the grenade cut away pic;

They all work a bit different, so its hard saying exactly whats what. French grenades actually filled the empty cavity shown on this grenade. Different designs = different means of detonating them.



The red is the detonator

The brass looking stuff and the rod in the middle as well as the top/spoon is all part of the ignition process

The grey/brown shit on the bottom is the actual explosives.


As far as I know anyways, I am no pro and there are military people on the forum so maybe someone could chime in that FACTUALLY knows better. Im just a civilian, so my knowledge on grenades is a bit limited.

Just saying, its not like I have EVER played with explosives. EVER


NEVER

[Raf99]

Now i want to see a video of how these are made

[trickedaccord92]

This post has become really informative

[Ralphie]

That's a frag grenade if im not mistaken.

Here is the breakdown of the firing mechanism-

http://en.wikipedia.org/wiki/File:Schema_Grenade-en.svg

Burn process-

Once the soldier throws the grenade, the safety lever releases, the striker throws the safety lever away from the grenade body as it rotates to detonate the primer. The primer explodes and ignites the fuse (sometimes called the delay element). The fuse burns down to the detonator, which explodes the main charge.

Cooking-

Cooking is a term referring to intentionally holding onto an armed grenade after the pin has been pulled and the handle released; allowing the fuse to burn partially to decrease the time to detonation after throwing. This technique is used to reduce the ability of the enemy to take cover or throw the grenade back. It is also used to allow the grenade to burst in the air over defensive positions.[28] This technique is inherently dangerous, since fuses may vary from grenade to grenade. Because of this the U.S. Marines (MCWP 3-35) describe cooking as the "least preferred technique," recommending a "hard throw, skip/bounce technique" to prevent an enemy returning a grenade.

We got to cook off grenades in basic training. Talk about asshole puckering while you hold a LIVE grenade and allow it to cook in your fucking hand.

Man I miss that shit lmao.


Oh and the "handle" or "lever" is actually called the spoon in the military.

Frag's are cool, but my favorite are incendiary grenades....they burn at like 4000*........we use them to destroy things when the enemy might come across them....

Like if we have to leave behind a vehicle out in the field, we can place one on the engine block and the grenade will burn right through the center of the block.

Awesome shit!

http://en.wikipedia.org/wiki/File:AN-M14_grenade.gif

Modern incendiary grenades (or thermite grenades) produce intense heat by means of a chemical reaction. The body is practically the same as that of a smoke grenade. The filler is 600 to 800 grams of thermate, which is an improved version of World War II-era thermite. The chemical reaction that produces the heat is called a thermite reaction. In this reaction, powdered aluminium metal and iron oxide react to produce a stream of molten iron and aluminium oxide. This reaction produces a tremendous amount of heat, burning at 2,200 °C (3,992 °F). This makes incendiary grenades useful for destroying weapons caches, artillery, and vehicles. Other advantages include its ability to function without an external oxygen source, allowing it to burn underwater. Because they are not intended to be thrown, thermite incendiary grenades generally have a shorter delay fuse than other grenades (e.g. two seconds).

So badass

[deevergote]

Iron oxide and powdered aluminum? So if I accidentally file some aluminum shavings off my H22 and it hits my rusted exhaust manifold (iron oxide), it'll produce a thermite reaction?


I got a C in chemistry.