Science Fair Project Encyclopedia
Manhole
A manhole or maintenance hole is the top opening to an underground vault used to house an access point for making connections or performing maintenance on underground and buried public utility and other services including sewers, telephone, electricity, storm drains and gas. It is protected by a manhole cover, a (usually metal) plug designed to prevent accidental or unauthorised access to the manhole.
Manholes are generally found in urban areas, in streets and occasionally under sidewalks.
In rural and undeveloped areas, services such as telephone and electric are carried on pylons.
10-26-2009 08:16:03
The contents of this article is licensed from www.wikipedia.org under the GNU Free Documentation License. Click here to see the transparent copy and copyright details
The contents of this article is licensed from www.wikipedia.org under the GNU Free Documentation License. Click here to see the transparent copy and copyright details