Using Thermite to Drop Suspension Bridges...and U.S. plans to do so

[Tim May]

Cypherpunks,

Here's an item I sent to another forum about using thermite to cut the 
cables on suspension bridges. A couple of folks had claimed that using 
explosives on the piers and other support structures would be 
extraordinarily difficult to arrange (and detectable by bridge security 
personnel). I agreed, but noted in my piece that thermite quickly placed 
on the main cables could cut or weaken the cables significantly. (Merely 
damaging the cables by more than about 30% might require, for liability 
and public perception reasons, the shut down of the Golden Gate Bridge 
for as many months or years as it might take to replace the main 
cable--the cable is a continuous one, and is not "segment-replaceable." 
It is possible that some clamp bypass might be possible, but I would be 
skeptical that clamps could handle the tension.)

An interesting part of the URL chunk included below is that the DOD 
endorses use of "peacetime" operations to collapse bridges...surely an 
act of "terrorism" comparable to bringing down the World Trade Center. 
(Oh, I forgot, if the CIA does it to a country we are not at war with, 
it's "nation-building," not terrorism.)

I found this URL, and several equally-interesting ones, as part of my 
research on using thermite to collapse suspension bridges. Looks like 
the U.S. military has been planning similar ops for a while...could be 
why the alerts are being taken seriously by the gubmint.

--begin excerpt--
From: Tim May <tcmay at got.net>
Date: Fri Nov 02, 2001  12:26:29 AM US/Pacific
To: tcmay at got.net
Subject: Re: Dropping the Bridges is Easy

[[ This message was also posted as:
    <021120010026271382%tcmay at got.net> ]]


More comments on using thermite to drop the bridges:

In article <011120012309364728%tcmay at got.net>, Tim May <tcmay at got.net>
wrote:

A conventional medium- or low-velocity explosion would not hurt the
piers, obviously. Too massive, and MV and LV explosions, by definition,
have little effect on such structures. Even a high-velocity explosion
would have a hard time wrecking the piers.

However, suspension bridges are obviously subject to having the
suspension cables cut. Enough RDX would do the job even on the massive
GG Bridge.

However, there are lower-tech ways to do it even more easily:

A thermite blanket wrapped around one of the main suspension cables of
the Golden Gate would probably drop the span. Hitting both cables would
be best, and matches the M.O. of the 911 attacks.

A truck pulls up, stops, a few men wrap the cable with 60 pounds of
thermite. Once ignited, should cut through the thousands of strands
like butter. (A thermal lance might also do the job, but would require
a man to aim the lance for long enough. This man could be taken out and
the plan thwarted. Wrapping the cable is preferable...once that
thermite process starts, essentially nothing stops it.)

I found some sources showing that the intelligence services around the
world are already planning to use such methods ("in peacetime," which
many would call "terrorism," unless it's done by the U.S. of A.).

Some quotes from http://www.ndu.edu/inss/books/milgeo/milgeoch11.html

The Institute for National Strategic Studies, part of the National
Defense University at Fort McNair and in Norfolk, VA.

Note the mention of thermite, and the cutting of suspension cables.
Note also that the manual is talking about doing these things as an act
of terrorism (covert, against civil facilities).

"Covert operations that conceal the identity of, or permit plausible
denial by, perpetrators moreover may be politically prudent, especially
in "peacetime." ....Brittle cast iron breaks easily, but acetylene
torches or thermite may be needed to slice nickel-molybdenum steel,
which strongly resists conventional explosives. Proper placement is at
least as important as destructive power..... Professionals whose
mission is to stop road and river traffic temporarily cut supports at
one end of truss bridges so affected spans fall in the water; they cut
trusses at midspan to make bridges buckle if long-lasting destruction
is the intent. Massive towers and thick cables on major suspension
bridges resist powerful explosive charges, but slender suspenders that
hang therefrom do not--roadway sections collapse if they are cut."



--end excerpt--


--Tim May
""Guard with jealous attention the public liberty. Suspect everyone who 
approaches that jewel. Unfortunately, nothing will preserve it but 
downright force. Whenever you give up that force, you are ruined." 
--Patrick Henry