manhole covers

Sat Feb 22 01:50:21 UTC 2003

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 at wvwc.edu
>
>

T.M. Eubanks
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