Manhole

PMG manhole in a city street, Perth, Western Australia.

A manhole (alternatively utility hole, maintenance hole or access chamber) is the top opening to an underground utility 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 unauthorized access to the manhole. Manholes are usually outfitted with metal or polypropylene steps installed in the inner side of the wall to allow easy descent into 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 electricity may be carried on pylons rather than underground.

Hazards caused by manholes

In urban areas, stray voltage issues have become a significant concern for utilities.

In 2005, Jody Lane was electrocuted after stepping on a manhole cover, while walking her dog in New York City. As a result Con Edison and many other power companies are searching for ways to minimize the danger [1].

Man holes are usually in circular shape to prevent accidental fall of the cover in the hole.

Feminist issue with manhole name

In 1990, the city of Sacramento, California officially renamed all their manholes to "maintenance holes" out of concern for the equality of both genders [2]. The name "maintenance hole" was selected because the term shares the same initials as the word "manhole," thereby eliminating the need to change the MH labels on the city's utility maps.

See also

• SPQR, a common Roman inscription on the manhole covers

External links

• Electrified Cover Safeguard stray voltage warning systems for manholes

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