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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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4798 news items

Trinidad & Tobago Express
Thu, 18 Sep 2014 08:33:45 -0700

Augustina McIntosh was on her way to the village parlour when she stepped on a piece of rotted plywood used to cover the manhole. The plywood broke sending the elderly woman down into the hole. The incident occurred around 5.30 p.m.. Her daughter ...


Wed, 03 Sep 2014 22:06:18 -0700

UPDATE (Thur., September 4, 2014) The director of the Conyers Public Works and Transportation Dept., Brad Sutton, told 11Alive News that he's found out the manhole is an AT&T "vault," a manhole that gives AT&T crews access to underground lines and ...

Get Surrey

Get Surrey
Wed, 17 Sep 2014 06:52:30 -0700

A manhole exploded in West Molesey in the early hours of Wednesday morning leaving 140 homes without electricity. Flames were seen coming out of the electrical manhole, in Balmoral Crescent, and the lid reportedly shot into the air, at around 4am on ...
Mon, 08 Sep 2014 12:53:52 -0700

LAKEVIEW — The leather bar Manhole will return to Boystown later this month, as the location that once housed Spin Night Club undergoes further changes. Spin closed on Memorial Day after 15 years in Boystown. Entrepreneur Jason Zilberbrand took over ...
Fri, 12 Sep 2014 19:26:15 -0700

ST. LOUIS, MO (KTVI)– Raised manholes downtown are causing a bumpy ride for downtown commuters. With a Cardinal/Rockies series in St. Louis this weekend, a lot of people will be using Broadway and 4th Street. If you`re driving downtown and you`re ...
The Daily Freeman
Wed, 10 Sep 2014 19:41:26 -0700

Swenson said the manhole, which extends 30 feet underground to the 100-year-old tunnel, is falling apart and threatens to cause a second major sinkhole on Washington Avenue. The manhole is about 3,000 feet from the Washington Avenue sinkhole near ...

Daily Mail

Daily Mail
Mon, 08 Sep 2014 10:13:41 -0700

Residents have complained they are being kept awake by an 'explosive' manhole which can be heard up to half a mile away. People living in the Homewood Road area of Tenterden, in Kent, has said the sound caused by cars driving over the metal plates is ...

BBC News

BBC News
Thu, 11 Sep 2014 23:17:54 -0700

Emergency services and electrical engineers have been dealing with the aftermath of an explosion at a manhole in Aberdeen. Flames were reported to have been shooting out of the pavement in Auchmill Road at about 06:00. A taxi driver who was passing ...

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