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LBlankenship
09-25-2010, 10:12 PM
About how much damage could one expect from one or two pounds (half to one kilogram) of TNT that was sitting on a desk in an average office? There are no windows, if that matters.

I'm thinking that anybody in the room would die, of course. But what about structural damage? Would the walls be completely blown out? What about the next set of walls (assuming it's the middle of an average office building)?

Thanks!

Kenn
09-25-2010, 11:05 PM
I think a lot depends on where it is. If you imagine it would be like two or three offensive grenades going off (the kind soldiers throw into buildings to clear them - not the fragmentable ones). The danger would be from the pressure wave and you wouldn't want to be in a small room without any windows when it went off. If it was a big room (like an office), then I imagine you would live if you got well out of the way, but you would have a headache to remember. I think the only way the building would collapse would be if it were placed at a strategic load bearing point (near a beam or rafter). The walls would probably only blow out if they were partitions.

PeterL
09-25-2010, 11:15 PM
Kenn's pretty much right. The walls wouldn't blow out, but it this were a private office, the windows and the door would get popped out. The furniture would be rather messed up, etc. In a large open office cubicles would get messed up. The area dividers would get blown far from where they should be. It would be a real mess, but the walls wouldn't be damaged. Some windows probably would be shattered; that depends on how large an area and what kind of windows. Raise it to ten pounds and make the building an old brick warehouse with an office in one corner, and that corner would be gone.

Put the same ten pounds in an open area in a reinforced concrete parking garage, and you would end up with a small hole in the floor, but any cars that were adjacent would be seriously shredded.

LBlankenship
09-25-2010, 11:57 PM
Thank you for the replies, they give me some perspective on it. I was having trouble visualizing the damage since it is kind of a small amount of explosive.

Lhun
09-26-2010, 01:32 AM
I think a lot depends on where it is. If you imagine it would be like two or three offensive grenades going off (the kind soldiers throw into buildings to clear them - not the fragmentable ones).A kilo of TNT should be closer to thirty, actually.
That aside, a large amount of explosives simply put in the middle of a room is unlikely to bring down a building. While a kilogram is certainly enough to take out a few structural supports of a building, you'd need to drill holes and place the charges inside for that.
Just placed in a room, you'd likely get a hole blown in the floor, furniture smashed, and people inside the room definitly dead. What happens to walls depends a lot on what you mean by "standard office building". Many of those are just wide empty halls, with drywall separators you could kick your way through. You'd see those blown open for quite a distance.
Actual stone walls on the other hand are somewhat sturdier. However, a small room without windows will see a lot more damage to the walls (and floor/ceiling) than a large one, so even stone walls could possibly be damaged.
For visualization i suggest youtube. There's lots of videos like this (http://www.youtube.com/watch?v=xNQJvLpwQbs) and ANFO is comparable to TNT (just a little weaker).

Kenn
09-26-2010, 03:33 PM
A kilo of TNT should be closer to thirty, actually.

Sorry Lhun, this is not correct. There is a higher charge in concussion grenades and they carry up to about 250g.

Lhun
09-26-2010, 03:54 PM
What type? Fragmentation grenades are made with as little as 20-30g of TNT, and as far as i remember even big concussion grenades were only around 100-150g. 250g produces quite a blast for a thrown weapon.

Kenn
09-26-2010, 04:27 PM
What type? Fragmentation grenades are made with as little as 20-30g of TNT, and as far as i remember even big concussion grenades were only around 100-150g. 250g produces quite a blast for a thrown weapon.
I am not an expert on the TNT content of grenades, but I seem to remember the Mills type (fragmentaion device) had about 80g and the German stick type grenade (a concussion device) had about twice that. A later version of the US concussion grenade had about 250g (I think) and was known as a MkIII. I was talking about concussion devices. It is a big blast, but the range is very short in the open. The destructive range of a fragmentation device is far greater, thanks to the splinters (beyond the range of even the thrower!), but it is not as effective indoors where there are passages etc.

whacko
09-26-2010, 05:24 PM
Hi Carlaviii,

Google July Bomb Plot, or Hitler bomb and you'll get a good idea, not only of what damage will be caused, but also of what may not happen.

Regards

Kenn
09-26-2010, 10:30 PM
Google July Bomb Plot, or Hitler bomb and you'll get a good idea, not only of what damage will be caused, but also of what may not happen.
I have to say that is an excellent example.

RJK
09-26-2010, 11:19 PM
Here (http://www.liveleak.com/view?i=0d2_1198134994) is some youtube video of 1/2 pound blocks of TNT going off.

LBlankenship
09-26-2010, 11:53 PM
Thank you to all for the video links and the reference to the attempt on Hitler... they have also reminded me that fire is not necessarily involved in these sorts of explosions (thanks, Hollywood, for the misinformation).

The photos after the attempt on Hitler are impressive, considering those were the days before sheet rock and plywood were major construction materials.

Lhun
09-27-2010, 01:56 AM
Generally speaking, fire is the result of carbon burning slowly with oxygen from the air. Which means the explosive material was shoddy, since you need to burn as much material, as quickly as possible to get a detonation. Fireballs can be expected in fuel-air explosions, or low explosives like gunpowder, not high explosives like TNT.


I am not an expert on the TNT content of grenades, but I seem to remember the Mills type (fragmentaion device) had about 80g and the German stick type grenade (a concussion device) had about twice that. A later version of the US concussion grenade had about 250g (I think) and was known as a MkIII. I was talking about concussion devices. It is a big blast, but the range is very short in the open.Hm, some googling suggest that you can apparently find grenades using anything from 30 to 300g of TNT, depending on type and manufacturer. Didn't know there was such a difference in yield between concussion and fragmentation grenades.
So, 1kg of TNT is equivalent to four, maybe five large concussion grenades.

whacko
09-27-2010, 03:16 AM
I have to say that is an excellent example.

Aw shucks.

I'm either blushing or suffering from high blood pressure here.

With my luck, it's probably both.;)

Regards

Kenn
09-27-2010, 02:39 PM
So, 1kg of TNT is equivalent to four, maybe five large concussion grenades.
More or less, but the original question was about 1 or 2 lbs of TNT ;)