A
common utility duct, sometimes called a common utility conduit, is any structure – above, on, or below ground – that carries more than two types of
public utilityA public utility is an organization that maintains the infrastructure for a public service . Public utilities are subject to forms of public control and regulation ranging from local community-based groups to state-wide government monopolies...
lines. However, the phrase often refers specifically to underground tunnels.
The advantages of such facilities are the reduction of maintenance
manholeA manhole is an opening used to gain access to sewers or other underground structures, usually for maintenance.Manhole may also refer to:* Manhole , a metal band from Los Angeles* The Manhole, a computer game...
s, one-time relocation, and less
excavationBuilding services engineering is the engineering of the internal environment and environmental impact of a building. It essentially brings buildings and structures to life....
and repair, compared to separate cable ducts for each service.
A
common utility duct, sometimes called a common utility conduit, is any structure – above, on, or below ground – that carries more than two types of
public utilityA public utility is an organization that maintains the infrastructure for a public service . Public utilities are subject to forms of public control and regulation ranging from local community-based groups to state-wide government monopolies...
lines. However, the phrase often refers specifically to underground tunnels.
Advantages of common utility ducts
The advantages of such facilities are the reduction of maintenance
manholeA manhole is an opening used to gain access to sewers or other underground structures, usually for maintenance.Manhole may also refer to:* Manhole , a metal band from Los Angeles* The Manhole, a computer game...
s, one-time relocation, and less
excavationBuilding services engineering is the engineering of the internal environment and environmental impact of a building. It essentially brings buildings and structures to life....
and repair, compared to separate cable ducts for each service. One of the greatest advantages is
public safetyPublic safety involves the prevention of and protection from events that could endanger the safety of the general public from significant danger, injury/harm, or damage, such as crimes or disasters .-Core public safety services:...
. Underground
power lineElectric power transmission is the bulk transfer of electrical energy, a process in the delivery of electricity to consumers. A power transmission network typically connects power plants to multiple substations near a populated area...
s, be the ducts common or separate, prevent downed utilities from blocking
roadA road is an identifiable route, way or path between places.
s, thus speeding
emergencyAn emergency is a situation which poses an immediate risk to health, life, property or environment. Most emergencies require urgent intervention to prevent a worsening of the situation, although in some situations, mitigation may not be possible and agencies may only be able to offer palliative...
access after
natural disasterA natural disaster is the effect of a natural hazard that affects the environment, and leads to financial, environmental and/or human losses...
s such as
earthquakeAn earthquake is the result of a sudden release of energy in the Earth's crust that creates seismic waves. Earthquakes are recorded with a seismometer, also known as a seismograph...
s, hurricanes, and
tsunamiA is a series of water waves that is caused by the displacement of a large volume of a body of water, such as an ocean. The original Japanese term literally translates as "harbor wave." Tsunamis are a frequent occurrence in Japan; approximately 195 events have been recorded...
s. When they are well mapped they also allow rapid access to all utilities without having to dig access trenches or resort to confused and often inaccurate utility maps.
The following table compares the features of housing utility networks in single purpose covered trenches with the features of common ducts:
| Trench |
Duct |
| The precise locations of many utility networks are unknown. They also consume excessive space. This hampers maintenance and extension of the networks and all forms of property development and construction. |
The locations of the ducts and thus of the networks are much easier to monitor. Utility networks occupy less space. |
| Every access to a network requires cutting open the road or pavement surface, breaking open the concrete platform and excavating a trench, followed by reinstatement of the trench, concrete platform and road surface afterwards. (This is where most of the financial cost of network renewals and maintenance is incurred.) |
Access to networks is via access points (like those already in use by British Telecom). Where ducts are installed, excavations are a thing of the past. |
| Road surfaces are damaged by frequent trenching. More frequent resurfacing is required. Pavement slabs are broken and badly aligned. |
Road surfaces and pavements are not disturbed to get at utility networks. |
| The UK's roads are subject to 5 million roadworks per year (mainly for utility works). |
Huge reductions in the number of roadworks where ducts are installed. |
| Road users suffer repeated delays, particularly in cities. |
Traffic delays from roadworks for maintenance of networks are greatly reduced. |
| Non-renewable sand, aggregate, cement and tarmac are consumed in large quantities. |
Huge reductions in non-renewable materials usage. |
| Water companies project infrastructure renewals expenditure of £2.2billion over five years . Electricity companies are allowed to charge customers an additional £5billion over five years for networks maintenance. |
Huge reductions in the cost of maintaining networks and hence in charges to consumers. The usage of ducts would be covered by annual rentals which would be far less than today’s costs. |
| Rural properties are denied access to, usually, gas or cable because these cannot be economically justified independently of other networks. |
All services could be supplied to rural properties through single multi purpose ducts. |
| Rural networks for electricity and telecoms are often above ground, with increased risk of disruption, even though there are usually local underground water and gas networks serving the same properties. |
All networks are underground in multi-purpose ducts. Above ground electricity and telecoms poles are redundant and dismantled. |
| New types of network require new and independent trenches or ducts. These have included cable telephone and television and potentially include local heating transfer systems from offices to residential. Power generation may also become much more localised, requiring reconfiguration of electricity distribution networks. |
New and evolving networks can usually be accommodated in existing ducts. |
| The heat generated by underground networks is wasted as it remains trapped underground. |
The heat generated by underground networks housed in ducts could often be extracted and cycled into space heating systems. |
Examples of common utility ducts
Many examples of common utility ducts are found in
Japanis an island country in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, People's Republic of China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...
, where government officials have sought ways to reduce the catastrophic effects of earthquakes in their
tectonically activePlate tectonics is a theory which describes the large scale motions of Earth's lithosphere...
country. Their use, however, is not limited to that country and there are many examples of such common utility ducts. These include:
- Incorporated with Xinyi
The Taipei Metro Xinyi Line is a high-capacity line currently under construction. It is the extension of the Danshui Line and part of the Red Line. Upon completion, the line will alleviate congestion on the Nangang Line by providing another east-west route through the Xinyi District...
and Sonshan MRTThe Taipei Rapid Transit System, also known as the MRT or the Taipei Metro, is a rapid transit system serving a large part of the Taipei metropolitan area, Republic of China. The network includes 92.9 km of rail with 80 stations and includes both underground, at-grade, and elevated routes...
rapid transitA rapid transit, metro, subway, underground, or elevated railway system is an electric passenger railway in an urban area with high capacity and frequency, and which is grade separated from other traffic. Rapid transit systems are typically either in underground tunnels or elevated above street level...
lines in Taipei, Taiwan
- Azabu-Hibiya Common Utility Duct in Tokyo, Japan
- Minatomirai District lines in Yokohama, Japan
- Poundbury
Poundbury is an experimental new town — or more correctly an urban extension — on the outskirts of Dorchester in the county of Dorset, England....
Village in Duchy of CornwallThe duchy of Cornwall is, with the duchy of Lancaster, one of the two royal duchies in the United Kingdom. The eldest son of the reigning British monarch inherits the duchy and title of Duke of Cornwall at the time of his birth, or of his parent's succession to the throne...
, Prince Charles' master planned community in EnglandEngland is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west and the North Sea to the east, with the English Channel to the south separating it from continental...
incorporates common utility ducts
- "Utilidor
A Utilidor is a utility corridor built underground or aboveground to carry utility lines such as electricity, water and sewer. Communications utilities like fiber optics, cable television and telephone cables are also sometimes carried...
s" in Disney theme parks
- German cities such as Bremen
The City Municipality of Bremen is a Hanseatic city in northwestern Germany. A port city along the river Weser, about south from its mouth on the North Sea, Bremen is part of the Bremen-Oldenburg metropolitan area...
. This city has near perfect surfaces on its footways, cycleways and streets. Virtually no repairs or disturbances are visible. The number of streetworks in progress is trivial. This can only be achieved by (a) vehicles not driving on footways or cycleways (b) utility ducts making it unnecessary to disturb the surfaces in order to access the networks below for repairs, maintenance and alterations. Utility networks are housed in a cluster of pipes which are located under footways and cycleways.
See also
- District heating
District heating is a system for distributing heat generated in a centralized location for residential and commercial heating requirements such as space heating and water heating...
- Electricity distribution
File:Electricity grid simple- North America.svg|thumb|380px|right|Simplified diagram of AC electricity distribution from generation stations to consumersrect 2 243 235 438 Power stationrect 276 317 412 556 Transformer...
- Empire City Subway
Empire City Subway is a company in New York City which is responsible for maintaining underground conduits in Manhattan and The Bronx, and the manholes by which those conduits are accessed. The company was formed in 1891 as part of a plan for common utility ducts to consolidate all utilities...
- Public utility
A public utility is an organization that maintains the infrastructure for a public service . Public utilities are subject to forms of public control and regulation ranging from local community-based groups to state-wide government monopolies...
- Tunnel
A tunnel is an underground passageway. The definition of what constitutes a tunnel is not universally agreed upon. However, in general tunnels are at least twice as long as they are wide. In addition, they should be completely enclosed on all sides, save for the openings at each end...
- Utility tunnel
A utility tunnel is a space for wires, conduits, pipes, and other conveyances used in the delivery of utilities with enough room for a human to enter. Modern pipes and cables need less attention and space than older varieties, so the construction of utility tunnels declined in the late 20th century...