Manhead

Manhead

A manhole (alternatively utility hole, cable chamber, maintenance hole, inspection chamber, access chamber or confined space) 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.

The opening is protected by a manhole cover, also known as a "biscuit", a plug designed to prevent accidental or unauthorized access to the manhole. Those plugs are usually made of metal or constructed from precast concrete, glass reinforced plastic or other composite material (especially in Europe). Manholes are usually outfitted with metal or polypropylene steps installed in the inner side of the wall to allow easy descent into the manhole. As legislation restricts acceptable manual handling weights Europe has seen a move toward lighterweight composite manhole cover materials which also have the benefit of greater slip resistance and are electrically insulating.

Manholes are generally found in urban areas, in streets and occasionally under sidewalks. They are usually circular in shape to prevent accidental fall of the cover into the hole.

In rural and undeveloped areas, services such as telephone and electricity are usually carried on utility poles or even pylons rather than underground.