Explosive requirements for larger structures, Ideas? Options

[GrinderTheTroll]

Hi all,

My last thread got me thinking about what might be required to take down a more complex structure. The goal is to develop some way for a team to plant explosives and take-down a structure like an n-story office building.

I think an Extended Demolitions Test would be required and the GM needs to have an idea about what percentage of supports would need to be destroyed to colapse the structure, maybe between 25-35%, but that's a guess. Assuming the worst, you'd need to destroy 100% of the supports.

I'd figure the number of hits and interval would be functions of size and structure complexity and you'd grant dice pool bonuses for have information about the structure handy (blueprints, physical walk through, video) as well as working with other demo experts.

Any ideas or thoughts?

Thanks,

~GTT

[Shadowmeet]

I think that you would also need knowledge of Structural engineering.

Seriously, demolitions may be about getting the most bang for your buck, but if you do not know where to place the stuff, you could end up with an implosion when you want an explosion, or vice versa, not to mention you might take out the wrong supports, and the building crumbles in a way that hinders you, etc.

Architecture and Structural engineering are positives.

[hobgoblin]

and as i have stated in said thread, i think that you would need much less to weaken said supports to the point of collapse then you would need to blow a 1sq.m. hole in the same material.

[Bira]

[Geekkake]

A cargo truck. 1,000 kgs of explosives. Leave it in the underground garage and go home. And by "go home", I mean leave the country, make sure there's no extradition treaty, change your face and fingerprints, and hope you didn't leave any genetic or astral evidence.

[hobgoblin]

hmm, 1000 kg of SR commersial explosives would give a rating of about 35.

70 after the doubling against barriers.

should make a nice big hole even in a blast bunker ;)

[Austere Emancipa...]

Just because I happened to Google "ton TNT", here's 500 tons of TNT in the early stages of forming a fireball. The ships in the picture are light cruisers, somewhere around 150 meters in length. Here's an almost identical detonation from a different angle, and a bit further into the explosion. I think that should be about enough to flatten any surface building smaller than 4 city blocks.

[stevebugge]

http://science.howstuffworks.com/building-...g-implosion.htm

Some Info on the subject, I would estimate that they are using far short of 500 tons for any of these.

[GrinderTheTroll]

[stevebugge]

Here's a thought. Imploding a building could really be a series of demolitions tests. Figure you just have to punch a hole in most or all of the support columns, which depending on the size of the building could range from Average material for places like stripmalls on up to Armored/Reinforced Material for things like Arcologies. The number of columns to be destroyed could be determined by the footprint of the building, and each column could require a separate test or the GM could set an extended test. At any rate a controlled implosion of a large structure should probably take several days of set up time. For the unwieldy truck bomb option go with a regular test and hope no one looks in to why there is suddenly a very large shadow market for explosives in bulk.

[Shrike30]

There's always fertilizer and motor oil... why not just use 8-10 trucks?

[Shadowmeet]

[ornot]

Correct me if I'm wrong, but don't they usually spend a considerable period of time setting up those explosions that bring down old tower blocks? Running tests on the materials, knocking out many of the non-supporting walls and a bunch of other stuff?

I was just thinking in terms of the original post and a team hired to carry out illicit demolitions. Without a lot of the planning and on-site ground work, I'd have thought it'd be tough to bring down a large building in a controlled fashion.

[Austere Emancipa...]

[hobgoblin]

[hobgoblin]

[Austere Emancipa...]

I don't know if "blowing up a square meter hole" is applicable to anything that's got to do with steel. Sure you can do that with sheet metal, but once you get to stuff that's ½cm or thicker all you're likely to do is smash a small hole in it. Vaporizing a 1-meter length of a steel beam is a stupid concept to begin with -- unless the beam's right next to an absolutely massive explosion, it's just going to break off at one point and bend

RDX is only special in this particular context, BTW. It's the main ingredient in nearly all US military plastic explosives, and found inside most explosive warheads used by NATO countries. Most plasticized military explosives have very high detonation velocities. For example, ANFO, which is the most common explosive used in mining and construction (and demolishing concrete, I imagine), has a detonation velocity of about half that of C-4, while RDX detonates less than 10% faster than C-4. C-4 is therefore pretty good for shearing steel beams, but not a good choice for mining.

[hobgoblin]

hmm, so instead one could go with a 1 sq.cm. hole punched for each -1 done to rating maybe?