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For other uses, see Manhole (disambiguation).
PMG manholes in a city street, Perth, Western Australia.
Manhole in Belo Horizonte, Brazil.
This is a sewer manhole, exposed during construction. Typically, only the top ring and manhole cover (not pictured) would be visible.
Manhole cover of precast concrete in Germany

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.


Manhole closings are protected by a manhole cover (also known as a "biscuit"[citation needed]), a flat plug designed to prevent accidental or unauthorized access to the manhole. Those plugs are traditionally made of metal, but may be constructed from precast concrete, glass reinforced plastic or other composite material (especially in Europe, or where cover theft is of concern).

Manholes are usually outfitted with metal, polypropylene, or fiberglass steps installed in the inner side of the wall to allow easy descent into the utility space. Because of legislation restricting acceptable manual handling weights, Europe has seen a move toward lighter weight composite manhole cover materials, which also have the benefits of greater slip resistance and electrical insulating properties.

The access openings are usually circular in shape to prevent accidental fall of the cover into the hole.

Manholes are generally found in urban areas, in streets and occasionally under sidewalks. In rural and undeveloped areas, services such as telephone and electricity are usually carried on utility poles or even pylons rather than underground.

Composite manholes[edit]

Composite (fiberglass) manholes are commonly used in applications where infiltration, exfiltration, or corrosion by hydrogen sulfide (from sewer gas) are a concern, or where structures need to be factory integrated into a manhole before placement.

Structures commonly integrated into composite manholes include:

  • Flow inverts[1]
  • Flumes[2]
  • Drop structures from higher elevation flows to lower elevation discharge pipes

Occasionally, composite manholes will integrate:

  • Weirs[3]
  • Storm water screening structures[4]
  • Sewage grinders[5]
  • Energy absorbing structures to dissipate undesirable flow stream turbulence or velocity[6]

Hazards caused by stray voltage in manholes[edit]

In urban areas, stray voltage issues have become a significant concern for utilities. In 2004, Jodie S. Lane was electrocuted after stepping on a metal manhole cover, while walking her dog in New York City.[7] One solution is the Electrified Cover Safeguard invention, which is an on-site, real-time stray voltage warning system which is being used in the street lights in New York City and is also being tested by ConEd and other utilities and municipalities in England, Europe, and Japan.[citation needed]

See also[edit]



  • Isles, Paul (2010). "Dover Engineering Works". Dover Life Magazine

Further reading[edit]

  • Ascher, Kate ; researched by Wendy Marech (2007). The works : anatomy of a city (Reprint. ed.). New York: Penguin Press. ISBN 978-0143112709. 

Original courtesy of Wikipedia: http://en.wikipedia.org/wiki/Manhole — Please support Wikipedia.
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7029 news items


Wed, 22 Oct 2014 06:58:37 -0700

According to Knepp, there's a manhole about 75 feet away from the building where the ring was flushed. The men opened it and began sifting through the material inside the 8-inch sewer line. "Material" is a kind word. The men were sifting through stuff ...


Thu, 23 Oct 2014 18:30:00 -0700

KANSAS CITY, Mo. — Kansas City needs your help to makeover its manhole covers. The water services department is holding a design contest to be added to the sewer drain covers throughout the city. The design should include a water quality message.
Thu, 23 Oct 2014 02:22:30 -0700

KANSAS CITY, Mo. - The KCMO Water Department is calling all local artists. They want a new look for their storm drain manhole covers; the metal plates you see sitting above the curbs where rain water flows off the streets. The purpose is to get people ...
Moorpark Acorn
Thu, 23 Oct 2014 20:45:00 -0700

Moorpark resident Keith Ellen's car was damaged by a loose manhole cover on Championship Drive in September, and it's been a rough ride finding the right public agency to cover the more than $1,600 in damage his vehicle sustained. So far, he hasn't had ...


Thu, 23 Oct 2014 12:30:00 -0700

The motive behind the missing manhole cover theory: people are stealing them for scrap. Cincinnati City spokesman Rocky Merz said the city has contacted several local scrap yards to notify them of the recent thefts. Scrap yards aren't allowed to accept ...


Fri, 17 Oct 2014 07:39:32 -0700

Watch Manager Jim Farrell who was at the scene said: “There was lots of very thick, black smoke pulsing from the manhole and crews worked quickly to contain the fire. The Brigade goes to around 50 incidents involving electrical manhole covers every ...

Times of India

Times of India
Sun, 05 Oct 2014 16:48:36 -0700

A 66-year-old man, who was returning home after celebrating Dasara at a relative's house, died after he fell into an open manhole at Himayatnagar. Though he fell on Saturday night, the incident came to light on Sunday when locals and sanitation workers ...

Calgary Herald

Calgary Herald
Sun, 19 Oct 2014 19:44:56 -0700

There are three of them around the core: one just across the CP train tracks from City Hall, one in the shadow of the Husky towers on 9th Avenue S.W., and one near the Louise Bridge — about a block from the manhole the blue smoke of burning plastic ...

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