How much?

[Cdnwolf]

How much material would I need to bring down this bridge? It is 1100 feet long reinforced concrete in sections. It will be done by special forces.

[Cdnwolf]

Now they definately are watching us!!!!

[kato13]

My answer would be probably less than you think.

Raw numbers for an answer would probably be ok, but jf there are specific instruction on how to make the demolition more efficient please keep it in PMs.

[pmulcahy11b]

If you ask a combat engineer, the answer will always be "Twice as much..."

[General Pain]

Originally Posted by pmulcahy11b

If you ask a combat engineer, the answer will always be "Twice as much..."

Yeah I thought I read that somewhere...do the math and then double it

[leonpoi]

what might be useful is (from a source book that I can't remember, plus some of my own interpreation) the following roughly applies:

Penetration needed to take down bridges
Wood: 22-28
Stone: 45-55
Metal: 55-70

the higher range will take down the bridge on a success, the lower range will on an outstanding success.

Now I'm rusty on DP and Pen. but taking reo as metal we might decide we need 70 Pen (strictly according to the rulebook this would give 7x250mm reinforced concrete penetration). if the charge was somehow tamped then the Pen is doubled -> Pen 35 worth of explosives -> 96 DP. A 1 kg block of plastic is 6 DP -> 16 kg of plastic. Who knows if this is realistic, but ignorance is bliss?? using the min amount if 55/2 -> about 60 DP -> 10 kg. So 10kg to damage and maybe destroy, 16kg to destroy. The sourcebook stated that a damaged bridge will collapse if a vehicle >10 ton (or maybe it was 8, I can't remember) is driven over it (high chance of collapse, about 80%. A construction/CVE test to determine how much it can hold), or if damaged again. If you can't tamp then the DP to destroy is 392 -> 65kg, so I hope that you can rationalise a method for doing so.

I'm guessing that this amount would be needed on each pylon if you really wanted to make a mess.

[Legbreaker]

What exactly do you mean by "bring down"?
Do you need the whole thing dropped into the river, pylons included?
Would cratering the road surface so as to prevent movement of traffic for 24 hours (while the engineers lay a new temporary decking over the hole) be sufficent?
Is the desired effect somewhere in the middle?

Time available is also a factor. Using boreholes to place the explosives within the structure itself well require much less explosive than if it were just laid against the surface. Naturally boreholes take time (if drilled) or are exceptionally noisy (if blasted with shaped charges, which still take time for the holes to cool down and allow safe laying of the actual demolition charges).

So, what it really comes down to is what it the teams plan and just how much can they carry?

[jester]

To many factors to give one answer. If I had time there are things I would do to make it much easier and thus require less demo. If you are using stealth to deal with to avoid any enemy sentries and such then you will have to do it old school and use ALOT!!!!

Some examples of bridge and other structure demo, just watch an implosion or the flick "Force 10 From Navarone" which will answer alot.

[pmulcahy11b]

Originally Posted by Cdnwolf

Now they definately are watching us!!!!

A component of my diagnosis is paranoia, so I always think they're watching us!