Are demolition charges wired together?

[geronimo]

The programs I have seen of buiildings being prepared for
demolition have showed the charges being placed into drilled holes and
then being physically wired to the computer or whatever initiates the
blast. I was wondering how this can work? I mean, how can you have
charges going off, without also disrupting the critical wiring
connections, thus preventing other subsequent charges from detonating?


If on the other hand, each charge was radio-controlled, the
computer could send a unique digital code triggering detonation via
radio, and there are no interconnections to be disrupted. But....could
any scheme of radio signalling be made secure and fool-proof enough to
ensure that no unintended detonation could occur? It seems like it
could not be made reliable and safe enough.

Is it just BS that buildings can be imploded via radio-controlled

[Herman Family]

Post by geronimo
The programs I have seen of buiildings being prepared for
demolition have showed the charges being placed into drilled holes and
then being physically wired to the computer or whatever initiates the
blast. I was wondering how this can work? I mean, how can you have
charges going off, without also disrupting the critical wiring
connections, thus preventing other subsequent charges from detonating?
If on the other hand, each charge was radio-controlled, the
computer could send a unique digital code triggering detonation via
radio, and there are no interconnections to be disrupted. But....could
any scheme of radio signalling be made secure and fool-proof enough to
ensure that no unintended detonation could occur? It seems like it
could not be made reliable and safe enough.
Is it just BS that buildings can be imploded via radio-controlled

I think you will find that the charges are hard wired to a system which
triggers them at the right moment. The sequencer will set off specific
groups of explosions each at the right moment. It is cheaper and more
secure than the radio method.

You probably could make a radio secure enough to trust for this, but it
would be much easier just to hard wire everything.

Michael

[geronimo]

That much I already knew...they are hard-wired back to a computer
device that precisely sequences them. But the question remains as to
how this works....you have physical wiring snaking around throughout
the building, sections of which are being blown up, along with the
wiring....how is it that a lot of charges don't fail to detonate due
to their wiring being severed/disrupted by other earlier explosions?
Running wiring throughout must take a whole lot of time...which
would be a lot of time saved by using a radio-control for each charge.

On Fri, 10 Nov 2006 04:54:44 GMT, "Herman Family"

Post by Herman Family

Post by geronimo
The programs I have seen of buiildings being prepared for
demolition have showed the charges being placed into drilled holes and
then being physically wired to the computer or whatever initiates the
blast. I was wondering how this can work? I mean, how can you have
charges going off, without also disrupting the critical wiring
connections, thus preventing other subsequent charges from detonating?
If on the other hand, each charge was radio-controlled, the
computer could send a unique digital code triggering detonation via
radio, and there are no interconnections to be disrupted. But....could
any scheme of radio signalling be made secure and fool-proof enough to
ensure that no unintended detonation could occur? It seems like it
could not be made reliable and safe enough.
Is it just BS that buildings can be imploded via radio-controlled

I think you will find that the charges are hard wired to a system which
triggers them at the right moment. The sequencer will set off specific
groups of explosions each at the right moment. It is cheaper and more
secure than the radio method.
You probably could make a radio secure enough to trust for this, but it
would be much easier just to hard wire everything.
Michael

[s***@heart.com]

Post by geronimo
.how is it that a lot of charges don't fail to detonate due
to their wiring being severed

It's called "experience".

[Mike Swift]

Post by geronimo
That much I already knew...they are hard-wired back to a computer
device that precisely sequences them. But the question remains as to
how this works....you have physical wiring snaking around throughout
the building, sections of which are being blown up, along with the
wiring....how is it that a lot of charges don't fail to detonate due
to their wiring being severed/disrupted by other earlier explosions?
Running wiring throughout must take a whole lot of time...which
would be a lot of time saved by using a radio-control for each charge.
On Fri, 10 Nov 2006 04:54:44 GMT, "Herman Family"

Post by Herman Family

Post by geronimo
The programs I have seen of buiildings being prepared for
demolition have showed the charges being placed into drilled holes and
then being physically wired to the computer or whatever initiates the
blast. I was wondering how this can work? I mean, how can you have
charges going off, without also disrupting the critical wiring
connections, thus preventing other subsequent charges from detonating?
If on the other hand, each charge was radio-controlled, the
computer could send a unique digital code triggering detonation via
radio, and there are no interconnections to be disrupted. But....could
any scheme of radio signalling be made secure and fool-proof enough to
ensure that no unintended detonation could occur? It seems like it
could not be made reliable and safe enough.
Is it just BS that buildings can be imploded via radio-controlled

I think you will find that the charges are hard wired to a system which
triggers them at the right moment. The sequencer will set off specific
groups of explosions each at the right moment. It is cheaper and more
secure than the radio method.
You probably could make a radio secure enough to trust for this, but it
would be much easier just to hard wire everything.
Michael

Radios are not normally used in demo work. The procedure used when I
have worked demo was to first weaken the structure with ox-acetaline
torches, cheaper than explosives, then place cutting charges on the
remaining structure. This is done on two or three floors so the building
will fall twenty or thirty feet giving the upper floors sufficient
velocity to continue collapsing. A single length of det cord is run
around each floor with the leaders to each charge tied to it. we would
keep this line at least 6 feet from any of the charges to prevent the
line from being cut off. On each end of this line we would place a
pyrotechnic delay of maybe 200 ms. The output of the delay would set off
the det cord on the floor above then continue to the third floor if
necessary. Next we would place a blasting cap near each end of the first
floor line and wire them in series. When the shot is fired both blasting
caps fire together, and the first floor line sets off all of the first
floor charges. After the delay the second floor line is initiated at
both ends, and the second floor goes. In this way any single failure can
at the most leave one charge unfired, and then only if it is that
charges leader.

In the pyro business we try and use the KISS principle, Keep It Simple
Stupid, and no electronics.