PDA

View Full Version : Things that go BOOM



AceTachyon
02-02-2007, 08:49 PM
An M79 Blooper should fit into a medium-sized gym bag, yes?

Does anyone know of a table or chart showing the blast radius of certain amounts of C4? For instance, if I need to know the blast radius of half a block, one block, one and a half blocks, etc.

In the opening scene of the first Tomb Raider, when Lara dukes it out with the robot, she reloads her H&K from magazines attached to her belt that swivel out into position. (Later on, in the Temple sequence, she has a backpack that drops a tree of magazines) Question: How exactly would that work? Would the attachment or the tree clip to the base of the magazine? Wouldn't the attachment at the base interfere with proper seating in the magazine well?

Or is that too Hollywood? Is it better to have a few double-mag pouches at your waist, find cover, and then reload?

A.M. Wildman
02-02-2007, 09:12 PM
An M79 Blooper should fit into a medium-sized gym bag, yes?

Does anyone know of a table or chart showing the blast radius of certain amounts of C4? For instance, if I need to know the blast radius of half a block, one block, one and a half blocks, etc.

In the opening scene of the first Tomb Raider, when Lara dukes it out with the robot, she reloads her H&K from magazines attached to her belt that swivel out into position. (Later on, in the Temple sequence, she has a backpack that drops a tree of magazines) Question: How exactly would that work? Would the attachment or the tree clip to the base of the magazine? Wouldn't the attachment at the base interfere with proper seating in the magazine well?

Or is that too Hollywood? Is it better to have a few double-mag pouches at your waist, find cover, and then reload?

Let's see in reverse. The tomb Raider magazines are Hollyweird flash. You're better off with them at your waist or somewhere else where you can grab them quickly. And it's always best to reload while behind cover, especially if the bolt on the weapon has locked open. You'll have to release it again once the new magazine is inserted.

Looked up the M79 here because I couldn't remember off the top of my head http://en.wikipedia.org/wiki/M79_Grenade_launcher About everything you'll need to know there.

A pound block of C4 or Semtex Plastique will do a major amount of damage, especially if it is "tamped" down. But, you'll need quite a bit for a half block, block radius depending on what you are blowing up. I'll keep looking see if I can't find anything.

No luck and I'll probably have the F.B.I. here asking me questions. ;) Your best bet with that might be to ask a pro: http://www.controlled-demolition.com/ somebody there should be able to answer your question or get you in touch with someone that can

Histry Nerd
02-02-2007, 09:37 PM
An M79 Blooper should fit into a medium-sized gym bag, yes?

Does anyone know of a table or chart showing the blast radius of certain amounts of C4? For instance, if I need to know the blast radius of half a block, one block, one and a half blocks, etc.

In the opening scene of the first Tomb Raider, when Lara dukes it out with the robot, she reloads her H&K from magazines attached to her belt that swivel out into position. (Later on, in the Temple sequence, she has a backpack that drops a tree of magazines) Question: How exactly would that work? Would the attachment or the tree clip to the base of the magazine? Wouldn't the attachment at the base interfere with proper seating in the magazine well?

Or is that too Hollywood? Is it better to have a few double-mag pouches at your waist, find cover, and then reload?

Ace -

On the M79: yes, it will fit into a medium gym bag, but it will probably create some suspicious bulging, especially if you have more than a couple of rounds in there. Remember 40mm rounds are heavy and take up a lot of space (as projectiles go).

On C4: I can't think of the blast radii off the top of my head, but you can probably get them from one of the U.S. Army's Combat Engineers Field Manuals. Most FMs are public documents and are posted online, so you should be able to find them without too much trouble. A block of C4 is 1 1/4 lbs, just in case you find a reference by weight.

On magazines and reloading: I never saw the first Tomb Raider movie, but pretty much every fancy reloading trick you see in Hollywood is crap. Best bet, as Wildman said, is to get behind cover and reload when you have the opportunity. Magazines attached to a fancy multi-mag rig would have a tendency to get dirt in them, and dirty magazines don't work right. Ammo pouches both secure the mags and protect them. You can buy quick-pulls that fit over the mags and make them easier to get out of the pouches, or you can loop a piece of cord under the baseplate of the magazine to make your own quick-pull.

There is a connector that allows you to hook two M16 magazines together so one can be inserted. This allows for a quick first reload, but I don't think it will fit in a standard ammo pouch, so you will still be doing it the old-fashioned way for the second and subsequent reloads. A lot of guys I knew used these in Iraq, but we were not in frequent rifle contact--the machine guns on our vehicles saw a lot more use than our rifles did.

For what it's worth.
HN

A.M. Wildman
02-02-2007, 09:41 PM
Ace -


On C4: I can't think of the blast radii off the top of my head, but you can probably get them from one of the U.S. Army's Combat Engineers Field Manuals. Most FMs are public documents and are posted online, so you should be able to find them without too much trouble. A block of C4 is 1 1/4 lbs, just in case you find a reference by weight.

HN


Thanks HN I forgot about that. What I get for being out for a decade.

Jamesaritchie
02-02-2007, 10:39 PM
Geeze, I've used C4, and I can't answer these questions exactly. One pound of C4 is certainly capable of killing people from half a block, but will usually do so with shrapnel. The shock wave is very strong, and shrapnel can travel half a mile or more. At half a block, the shock wave will knock you flat, and could kill you.

Movies almost never get the shock wave right. If they did, three fourths of the movies you see would have a dead protagonist after the first explosion. With powerful explosives, you can actually see the shock wave. It's super compressed air traveling incredibly fast.

The best way to see is is from above. Watch the History Channel, etc., and see what happens when a bomb hits the ground. That whitish ring you see traveling away from the blast in a circle is super compressed air, the blast wave. Watch how fast it travels.

That shock wave can travel at several times the speed of sound, and you can be dead before you ever hear the sound of the explosion.

Shock waves from a large detonation can, in fact, travel faster than a mile a second.

But so much depends on what type of buildings are in the block, where the C4 is placed, etc., that's it's very difficult o say what it will do at half a block.

AceTachyon
02-02-2007, 10:40 PM
The tomb Raider magazines are Hollyweird flash. You're better off with them at your waist or somewhere else where you can grab them quickly.


On magazines and reloading: I never saw the first Tomb Raider movie, but pretty much every fancy reloading trick you see in Hollywood is crap.

That's what I figured. I think I'll go with my original idea and have my MC keep two sets of double-mag pouches on her belt (she's using pistols). And yes, she knows to seek cover and reload when the opp presents itself. As in a brief lull in the fight.


On C4: I can't think of the blast radii off the top of my head, but you can probably get them from one of the U.S. Army's Combat Engineers Field Manuals. Most FMs are public documents and are posted online, so you should be able to find them without too much trouble.

I've already got a link to a site that has a bunch of FMs. Used it to look at Attack Helicopter Operations for another project. I'll see if I can find one for the Combat Engineers.


On the M79: yes, it will fit into a medium gym bag, but it will probably create some suspicious bulging, especially if you have more than a couple of rounds in there. Remember 40mm rounds are heavy and take up a lot of space (as projectiles go).

Just the Blooper and maybe three rounds (2, plus 1 in the launcher)

Wildman--thanks for the tip on the website. I'll check it out

AceTachyon
02-02-2007, 10:56 PM
But so much depends on what type of buildings are in the block, where the C4 is placed, etc., that's it's very difficult o say what it will do at half a block.

Good point, James. Lemme clarify what I'm looking for.

The baddie has placed 'X' amount of C4 in a moderate-sized restaurant (total capacity: 90-110 people). The restaurant occupies the ground floor of a two-story building at the end of a city block (a corner building). It sits up against a building on the left, regular sidewalk and road on the right, alley in back, then another builiding. He'll set off the explosive (remote or timed, I'm not sure yet--I'm thinking remote) to kill as many people inside the restaurant as he can.

Say there are 30 folks in the restaurant when he blows it. How many people are killed and what is the extent of the explosion if he used half a block of C4 (is half the restaurant toasted? all of it? blasts the cars parked just outside? etc)? If he used a full block? And so on.

A.M. Wildman
02-02-2007, 11:14 PM
Good point, James. Lemme clarify what I'm looking for.

The baddie has placed 'X' amount of C4 in a moderate-sized restaurant (total capacity: 90-110 people). The restaurant occupies the ground floor of a two-story building at the end of a city block (a corner building). It sits up against a building on the left, regular sidewalk and road on the right, alley in back, then another builiding. He'll set off the explosive (remote or timed, I'm not sure yet--I'm thinking remote) to kill as many people inside the restaurant as he can.

Say there are 30 folks in the restaurant when he blows it. How many people are killed and what is the extent of the explosion if he used half a block of C4 (is half the restaurant toasted? all of it? blasts the cars parked just outside? etc)? If he used a full block? And so on.

Depends on placement of the charge, and any secondary explosions. Half a block placed properly on a structural support would possibly bring the building down. ALthough, success would be better guaranteed if the bad guy placed several smaller charges on each support structure.

Deaths will depend on closesness to the blast, and any secondary explosions. ( Natural Gas lines, oil heater etc) Some will be killed or severely injured from flying shrapnel, glass, and falling rubble. The shock wave would probably blow out the windows of cars directly outside the building and may cause damage to nearby buildings.

Look up news on bombings in Israel etc. Although mostly car bombings, you can get an idea at the damage possibilties, etc.

ETA: Here's a link to the manual FM 5-250 http://stevespages.com/page7c.htm It's explosives and demolitions and it's in a downloadable .pdf format. worked fine with adobe acrobat.

Histry Nerd
02-02-2007, 11:44 PM
Explosives effects outside the immediate area of the blast are extremely variable. A suicide bomber boarding a bus with 50 lbs of C4 should be able to destroy the bus utterly, but passengers have survived just that sort of attack.

Off the top of my head, I would think he would need one or two hundred pounds of C4 to guarantee everybody in the restaurant died. Such a large amount might or might not bring down the building; if he has the expertise, knowledge of the building's support structure, and the opportunity to set it up, I imagine it could. Damage to surrounding structures would probably be significant, but not severe.

HN

Vanatru
02-03-2007, 02:22 AM
An M79 Blooper should fit into a medium-sized gym bag, yes?

Yeah, figure it's about 2 feet long, maybe just a bit over and around 6pounds, with an average HE round at about .5 lb each.

It'll fix, but it'll be clunky.



Does anyone know of a table or chart showing the blast radius of certain amounts of C4? For instance, if I need to know the blast radius of half a block, one block, one and a half blocks, etc.

Standard brick of C4 is just over a pound. Of course, there's two types. There's the 112 brick, and then theres the 118 brick.

As for the blast radius.......that'll vary on more factors than I deal with. Sorry.



In the opening scene of the first Tomb Raider, when Lara dukes it out with the robot, she reloads her H&K from magazines attached to her belt that swivel out into position. (Later on, in the Temple sequence, she has a backpack that drops a tree of magazines) Question: How exactly would that work? Would the attachment or the tree clip to the base of the magazine? Wouldn't the attachment at the base interfere with proper seating in the magazine well?

Or is that too Hollywood? Is it better to have a few double-mag pouches at your waist, find cover, and then reload?

Hollywood is fiction based on fact.....or fiction based on fiction. Rarely is fact based on fact. IMO at least.

Most of us are using 9mms and have double mag pouches x2. None of that magazine taped to magazine stuff. It's too awkward and I really haven't seen many guys doing that. Some had taped the initial magazines in their weapons, with all subsequent magazines coming from pouches....though some have carried ammo dump pouches with taped mags, but not often. If you train enough, you can pop a mag out of pouch pretty darn quick.

If it's life or death stuff, it should be on your harness, belt, or in hand. Having it behind you, in buttpack, or backpack can be a real mistake in the middle of a bad situation. Specially if you have to dump that pack in a hurry and leave it behind.

JB_Finesse
02-03-2007, 03:39 AM
I see no reason why an M79 wouldn't. They're pretty short, right? As for the grenades, I would think you could fit more than 3. Maybe around 5.

As for any magazine rig that leaves them exposed...

http://carmelgunclub.com/Advice%20from%20War/advice9.jpg

If you can't tell, the spring popped out of the other magazine.

Even though you're talking about pistols, I'd like to mention that there's a thing for standard M16/AR15 mags that lets you hook them side by side, instead of having one upside down like you have to with duct tape.

Jamesaritchie
02-04-2007, 03:05 AM
Good point, James. Lemme clarify what I'm looking for.

The baddie has placed 'X' amount of C4 in a moderate-sized restaurant (total capacity: 90-110 people). The restaurant occupies the ground floor of a two-story building at the end of a city block (a corner building). It sits up against a building on the left, regular sidewalk and road on the right, alley in back, then another builiding. He'll set off the explosive (remote or timed, I'm not sure yet--I'm thinking remote) to kill as many people inside the restaurant as he can.

Say there are 30 folks in the restaurant when he blows it. How many people are killed and what is the extent of the explosion if he used half a block of C4 (is half the restaurant toasted? all of it? blasts the cars parked just outside? etc)? If he used a full block? And so on.

Half a block of C4? First, no two explosions are exactly the same, even when the same charge is used. I'm going to assume this is a well-build, solid building, and not something thrown together from cheap wood with no real substance. I'll also assume the charge is centered.

It's going to tear the hell out of the restaurant inside, but the outside will most likely be intact, except for the windows. An onlooker will probably swear that no one could be alive inside because every window will be gone, there will likely be dirt and dust, possibly smoke, possibly a fire, and odds are high that several will be dead, several will be badly wounded, probably to die later, several more will be walking wounded, and it's weird, but a few may come out basically unharmed.

The windows will all blow out. The doors might or might not. Cars directly in front of the restaurant will likely be damaged, but I can't say how great the damage will be. Probably not as much as you think. The damage will look worse than it really is.

Shrapnel from the explosion may well kill people outside, across the street, and at half a block or more, if things go right. A chunk of metal or piece of brick or half a saucer can travel a long, long way if it comes out a window.

Most of the shock wave will be contained by the building, other than what comes through the windows. The ceiling will be gone above the blast, the roof may be damaged, but probably won't collapse.

But again, so much depends on the building. And on where and how the charge is set. Most people don't realize how crucial it is to know what you're doing, and where to place a charge for maximum effect.

As for the M79, you may already know this, but the thing is only 29 inches assembled, and about half this length broken down. It weighs less than seven pounds loaded.

The typical 40mm grenade only weighs half a pound. Exactly that, if I recall correctly. The launcher itself and and two dozen grenades weighs only eighteen pounds, so even an average woman could carry this in a fairly small bag, and do without any real trouble.