|
North American Network Operators Group Date Prev | Date Next | Date Index | Thread Index | Author Index | Historical Re: manhole covers
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.) > [email protected]
|