nanog mailing list archives

Re: manhole covers


From: Marshall Eubanks <tme () multicasttech com>
Date: Fri, 21 Feb 2003 20:50:21 -0500


The interesting thing is that this happens every few weeks (at least -
sometimes multiple times per week), and generally they don't know why.

Not in Adams Morgan. Not in Foggy Bottom. Not even
in Georgetown Heights. Only in Georgetown, Its become a local joke.

                                 Regards
                                 Marshall Eubanks

On Thursday, February 20, 2003, at 05:43  PM, Sean Donelan wrote:


Check out Georgetown in Washington DC, the exploding manhole capital of
the world.  They have a lot of experience with exploding manholes, from
many different causes. The most recent incident was in the last couple of
days.  There is a lot of energy in being pumped into utility lines.  A
short circuit can release that energy into the underground vaults, and
blow the manhole cover a considerable distance.

http://www.washingtonpost.com/wp-dyn/articles/A33073-2003Feb19.html

The Washington Post also has a special report covering exploding manholes

http://www.washingtonpost.com/wp-dyn/metro/specials/manholes/



On Thu, 20 Feb 2003, Allen Hamner wrote:

I am a chemist who consults with the mayor of Bluefield WV where an
incident two weeks ago (a cold day) blew a 70 pound iron cover 10 feet
from an conduit tunnel containing several public untility lines.  We
believe we can exclude a natural gas leak.  Rumor has it that hydrogen
is involved, which may arise by electrolysis (?) or pyrolysis of
insulation (?).  A previous incident had done no damage but this
explosion destroyed a nearby plate-glass window.

There is no coal in the area so mine gas seepage is excluded.  Sewer
gas is tentatively not an issue.  The source of the spark is unknown.

I would like to participate in the exchange on this topic.

Allen Hamner (Ph.D.)
hamner_a () wvwc edu



T.M. Eubanks
Multicast Technologies, Inc.
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Fairfax, Virginia 22030
Phone : 703-293-9624       Fax     : 703-293-9609
e-mail : tme () multicasttech com
http://www.multicasttech.com

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