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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, sewer hole or confined space) is the top opening to an underground utility vault used to house an access point for making connections, inspection, valve adjustments or performing maintenance on underground and buried public utility and other services including sewers, telephone, electricity, storm drains, district heating and gas.


Manhole closings are protected by a manhole cover, 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]

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.
This page uses Creative Commons Licensed content from Wikipedia. A portion of the proceeds from advertising on Digplanet goes to supporting Wikipedia.

888600 news items


Wed, 01 Jul 2015 10:48:45 -0700

Onondaga County sewer workers use a pole-mounted camera today to search in a manhole on East Fayette Street for the body of Brandon Closure, who fell into the manhole Tuesday night. Teams are searching the sewer system between Fayette Street and ...


Wed, 01 Jul 2015 04:37:30 -0700

(CNN) — David Sweat and Richard Matt didn't just pull off a grandiose prison escape — they actually did it twice. And through it all, Sweat was the mastermind — or at least that's what he's telling investigators, a local district attorney said. From ...

New York's PIX11 / WPIX-TV

New York's PIX11 / WPIX-TV
Wed, 01 Jul 2015 14:22:30 -0700

The fires broke out in Con Edison manholes on Bergen Street, halting service along the F line between Jay St. and 4th Avenue. “If at all possible, customers are asked to delay their commute home,” the MTA said. Passengers for Bergen St, Carroll St, and ...
Thu, 02 Jul 2015 09:41:15 -0700

In 1957, the Nevada Test Site saw a series of nuclear explosions that, according to legend, launched a manhole cover into space. Except it probably didn't. Here's where the story came from—and why the inadvertent source of the story has been trying to ...


Wed, 01 Jul 2015 14:49:17 -0700

Several manhole fires at Bergen Street in Brooklyn around 5:30 p.m. damaged the signals at the Jay Street Metrotech station, causing disruptions for the F and G lines. About a half-hour later, an Amtrak train struck a trespasser near Jersey Avenue in ...

News 12 Bronx (registration)

News 12 Bronx (registration)
Tue, 30 Jun 2015 11:16:59 -0700

Firefighters say they got to the fire just before 6:30 a.m., and found the flames had spread to a car. (June 30, 2015 2:32 PM). A manhole fire broke out at the intersection of Dewey and Calhoun avenues this morning. Firefighters say they got to the ...
Tue, 30 Jun 2015 19:48:45 -0700

On Monday, High Plains Contractors will begin to set up traffic control devices along South Seminole Street to install sewer manholes. Crews will install manholes at multiple locations in the southbound shoulder of Seminole from Longhorn Trail to ...

Atlanta Journal Constitution

Atlanta Journal Constitution
Thu, 04 Jun 2015 13:18:30 -0700

But both were moving as they were each pulled up from a manhole and loaded onto stretchers and into waiting ambulances about 15 minutes apart. The two were underground for about 30 minutes, according to Janet Ward, spokeswoman for the Atlanta fire ...

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