digplanet beta 1: Athena
Share digplanet:


Applied sciences






















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.
This page uses Creative Commons Licensed content from Wikipedia. A portion of the proceeds from advertising on Digplanet goes to supporting Wikipedia.
123143 videos foundNext > 

Grace Slick_ Manhole (1974) full album

Manhole is an album by Grace Slick. Her first solo record, it was released in 1974 1. "Jay" Grace Slick Grace Slick 2:43 2. "Theme from the Movie Manhole" Gr...

MANHOLE - Put Your Head Out (HD)

MANHOLE - Put Your Head Out Video Edition : K.P.I..

Manhole Installation Training Video - By Distribution Design Consultants, Inc.

APS Manhole Installation Training Video - Produced by Distribution Design Consultants, Inc. for Arizona Public Service - APS - Phoenix, AZ.

Manhole - Grace Slick

Theme from the Movie Manhole. A tribute to Grace, for her magnificent voice in this wonderful song, and to all the "open mind pionneers" of the seventies. Do...

Typical Manhole Box Installation. MGF Ltd.

Typical Assembly, Installation and Extraction of MGF's Manhole Box. http://www.mgf.ltd.uk/

Manhole - Hypocrite

Grace Slick - Manhole Theme (1974)

Sometimes it's easy to believe it, sound may be the warmest thing he's found. He just starts Playing, then he says to me, "Ready your body for love, there is...

How It's Made Manhole Covers

Discovery / Science Channel's "How It's Made" Manhole Covers.


A typical installation of Stanton Bonna's low carbon footprint Perfect Manhole System. The Perfect Manhole System provides a fully sealed and watertight manh...

Manhole - Kiss or Kill (OFFICIAL VIDEO)

From the original album "All Is Not Well" released in 1996 on Noise Records and produced by Ross Robinson. This video is an homage to the movie "Angel Heart"...

123143 videos foundNext > 

5442 news items

CTV News

CTV News
Tue, 02 Sep 2014 18:07:30 -0700

A man has been taken to hospital with serious injuries after falling approximately nine metres down a manhole Tuesday night. Toronto EMS says the incident happened at 1750 The Queensway. The worker, who is in his 30s, injured his leg and possibly his ...
Swindon Advertiser
Mon, 01 Sep 2014 21:37:57 -0700

A TOWN centre nightclub had to be evacuated on Saturday night after an electrical fire blew a manhole cover out of the ground. At around 11.30pm on Saturday, police and the fire service were called to the Liquor Lounge on Henry Street after black smoke ...
Tue, 02 Sep 2014 00:10:53 -0700

A major road near Shrewsbury was closed this morning due to a raised manhole cover. Tweet. The Highways Agency were called by police to close the A49 near Dorrington to allow the responsible utilities company to come in and make the road safe.
The Star-Ledger
Thu, 28 Aug 2014 05:33:45 -0700

The DOT reported at 7:38 a.m. that a manhole had collapsed on the express side near Exit 45 for Route 637/Beverwyck Road, closing the right lane. State Police at Totowa barracks said the incident occurred near mile-marker 44.6, and that there was no ...
Wed, 27 Aug 2014 07:37:30 -0700

A Denver Area resident captures floodwaters gurgling under, then blowing a manhole cover into the air. Denver has been coping with several days of heavy rain and flooding. About Us · Careers · Contact · Privacy Policy – UPDATED · Terms of Service ...
Hertfordshire Mercury
Tue, 02 Sep 2014 02:07:58 -0700

Displaced manhole cover causing problems on A507 near Buntingford. By HertfordshireMercury | Posted: September 02, 2014. By Web Reporter. Comments (0). A displaced manhole cover caused problems on the A507 this morning. Police were called to the ...
Fri, 29 Aug 2014 15:19:04 -0700

ST. LOUIS (KMOV.com) – Crews have begun removing paving around manholes in downtown St. Louis in preparation for a pavement project this weekend. The project will primarily be focusing on 4th Street and Broadway which is the street along the east ...

Belleville News Democrat

Thu, 21 Aug 2014 11:10:33 -0700

SAUGET • A sewer gas explosion early this morning in Sauget sent several manhole covers flying, at least one of which damaged a power line and cut off electricity to a factory. Sauget Police Chief Patrick Delaney said the village's sewer system lost ...

Oops, we seem to be having trouble contacting Twitter

Talk About Manhole

You can talk about Manhole with people all over the world in our discussions.

Support Wikipedia

A portion of the proceeds from advertising on Digplanet goes to supporting Wikipedia. Please add your support for Wikipedia!