[55995] in North American Network Operators' Group
Re: manhole covers
daemon@ATHENA.MIT.EDU (Sean Donelan)
Thu Feb 20 17:44:58 2003
Date: Thu, 20 Feb 2003 17:43:54 -0500 (EST)
From: Sean Donelan <sean@donelan.com>
To: Allen Hamner <hamner_a@wvwc.edu>
Cc: nanog@merit.edu, Bob Perkinson <perkinbob@yahoo.com>
In-Reply-To: <006e01c2d92f$b33a2de0$8b66010a@hamnera>
Errors-To: owner-nanog-outgoing@merit.edu
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
