Utility tunnel

Last updated
This utility tunnel in Prague is equipped with railway tracks for maintenance vehicles Kolektory Praha, 14.jpg
This utility tunnel in Prague is equipped with railway tracks for maintenance vehicles

A utility tunnel, utility corridor, or utilidor is a passage built underground or above ground to carry utility lines such as electricity, steam, water supply pipes, and sewer pipes. Communications utilities like fiber optics, cable television, and telephone cables are also sometimes carried. One may also be referred to as a services tunnel, services trench, services vault, or cable vault. Smaller cable containment is often referred to as a cable duct or underground conduit. Direct-buried cable is a major alternative to ducts or tunnels.

Contents

Usage

Utility tunnels are common in very cold climates where direct burial below the frost line is not feasible (such as in Alaska, where the frost line is often more than 18 ft (5.5 m) below the surface, which is frozen year round). They are also built in places where the water table is too high to bury water and sewer mains, and where utility poles would be too unsightly or pose a danger (like in earthquake prone Tokyo). Tunnels are also built to avoid the disruption caused by recurring construction, repair and upgrading of cables and pipes in direct burial trenches. [1]

Utility tunnels are also often common on large industrial, institutional, or commercial sites, where multiple large-scale services infrastructure (gas, water, power, heat, steam, compressed air, telecommunications cable, etc.) are distributed around the site to multiple buildings, without impeding vehicular or pedestrian traffic above ground. Due to the nature of these services, they may require regular inspection, repair, maintenance, or replacement, and therefore accessible utility tunnels are preferred instead of direct burying of the services in the ground.

Utility tunnels range in size from just large enough to accommodate the utility being carried, to very large tunnels that can also accommodate human and even vehicular traffic.

Industrial, institutional, and municipal environments

Utility tunnels are often installed in large industrial plants, as well as large institutions, such as universities, hospitals, research labs, and other facilities managed in common. Shared facilities, such as district heating, use superheated steam pipes routed through utility tunnels. On some university campuses, such as the Massachusetts Institute of Technology, many of the buildings are connected via large underground passages to allow easy movement of people and equipment.

Some municipalities, such as Prague in the Czech Republic, have installed extensive underground utility tunnels, to allow installation and maintenance of utility lines and equipment without disrupting the historic streets above.

Utility tunnels may attract urban explorers, who enjoy investigating hidden complex networks of spaces.

At Walt Disney World

Some of the largest and most famous utility tunnels are at Disney theme parks. They were first built for Walt Disney World's Magic Kingdom in Florida. Smaller utilidor systems are built under the central section of Epcot's Future World, primarily beneath Spaceship Earth and Innoventions, and formerly at Pleasure Island. Disneyland also has a small utilidor through Tomorrowland. The utilidors are a part of Disney's "backstage" (behind-the-scenes) area. They allow Disney employees ("cast members") to perform park support operations, such as trash removal, out of the sight of guests.

Arctic towns

Flin Flon (in Manitoba, Canada) is built on rock, making excavation costly. The utilidor in the foreground carries municipal sewer and water services and protects piping from freezing in the winter. FlinFlon Stack.jpg
Flin Flon (in Manitoba, Canada) is built on rock, making excavation costly. The utilidor in the foreground carries municipal sewer and water services and protects piping from freezing in the winter.

Utilidors are above-ground enclosed utility conduits that are used in larger communities in the northern polar region where permafrost does not allow the normal practice of burying water and sewer pipes underground. They can in particular be found in Inuvik, Northwest Territories and Iqaluit, Nunavut. Not all older homes are connected, and these must rely on trucks to deliver water and remove sewage. Most homes in rural Alaska (off the road system) are not equipped with plumbing and require fresh water and waste to be transported by personal vehicle such as snowmobile or four-wheeler ATV. Villages with utilidors are considered more advanced.

Utilidors may also be used to carry fuel lines, such as natural gas. They are not normally used to carry wiring for electric, telephone, and television service, which are usually suspended from poles.

Comparison with direct burial of utilities

The advantages of utility tunnels are the reduction of maintenance manholes, one-time relocation, and less excavation and repair, compared to separate cable ducts for each service. 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.

One of the greatest advantages is public safety. Underground power lines, whether in common or separate channels, prevent downed utility cables from blocking roads, thus speeding emergency access after natural disasters such as earthquakes, hurricanes, and tsunamis.

The following table compares the features of utility networks in single purpose buried trenches vs. the features of common ducts or tunnels:

Utility tunnelsDirect burial
Higher initial capital cost for construction of tunnelsCheaper initial capital cost of burying individual infrastructure
Easy location of infrastructureDifficult location of infrastructure
Fast maintenance and replacementSlow maintenance and replacement
Less roadworks and trafficIncreased roadworks and traffic
No manholes on roads. Single manhole for all infrastructureLarge numbers of manholes for various infrastructure types
Easy to coordinate between different infrastructureHard to coordinate projects between infrastructure providers
Easy upgrading and expansion of infrastructureHuge labour costs for re-burial
Easy access to maintenanceRoads constantly need to be ripped up
Dramatically reduced future-maintenance costsIncreased risk of disruption
Shared initial capital costs between infrastructure providersIncreased chaoticness
Reduced impact from outagesLong term costs unjustified
No overhead power lines
The low thermal conductivity of air in tunnels allows heat
transmission with less insulation and cheaper standoffs.
Increased cooperation and collaboration with infrastructure providers
One-time relocation
Reduced excavation and labour costs
Increased public safety
Road-based utility tunnels can be located under walking paths,
so roads do not need to be dug up frequently

Examples

Many examples of utility tunnels are found in Japan, where government officials have sought ways to reduce the catastrophic effects of earthquakes in their tectonically active country. Their use, however, is not limited to that country, and there are many examples of such utility tunnels. These include:

See also

Related Research Articles

<span class="mw-page-title-main">Outside plant</span>

In telecommunication, the term outside plant has the following meanings:

<span class="mw-page-title-main">Plumbing</span> Systems for conveying fluids

Plumbing is any system that conveys fluids for a wide range of applications. Plumbing uses pipes, valves, plumbing fixtures, tanks, and other apparatuses to convey fluids. Heating and cooling (HVAC), waste removal, and potable water delivery are among the most common uses for plumbing, but it is not limited to these applications. The word derives from the Latin for lead, plumbum, as the first effective pipes used in the Roman era were lead pipes.

Subterranean London refers to a number of subterranean structures that lie beneath London. The city has been occupied by humans for two millennia. Over time, the capital has acquired a vast number of these structures and spaces, often as a result of war and conflict.

<span class="mw-page-title-main">Tunnel</span> Underground passage made for traffic

A tunnel is an underground passageway, dug through surrounding soil, earth or rock, and enclosed except for the entrance and exit, commonly at each end. A pipeline is not a tunnel, though some recent tunnels have used immersed tube construction techniques rather than traditional tunnel boring methods.

<span class="mw-page-title-main">Trench</span> Excavated channel in ground

A trench is a type of excavation or depression in the ground that is generally deeper than it is wide, and narrow compared with its length.

<span class="mw-page-title-main">Manhole</span> Opening to a confined space

A manhole is an opening to a confined space such as a shaft, utility vault, or large vessel. Manholes are often used as an access point for an underground public utility, allowing inspection, maintenance, and system upgrades. The majority of underground services have manholes, including water, sewers, telephone, electricity, storm drains, district heating, and gas.

<span class="mw-page-title-main">Sanitary sewer</span> Underground pipe for transporting sewage

A sanitary sewer is an underground pipe or tunnel system for transporting sewage from houses and commercial buildings to a sewage treatment plant or disposal. Sanitary sewers are a type of gravity sewer and are part of an overall system called a "sewage system" or sewerage. Sanitary sewers serving industrial areas may also carry industrial wastewater. In municipalities served by sanitary sewers, separate storm drains may convey surface runoff directly to surface waters. An advantage of sanitary sewer systems is that they avoid combined sewer overflows. Sanitary sewers are typically much smaller in diameter than combined sewers which also transport urban runoff. Backups of raw sewage can occur if excessive stormwater inflow or groundwater infiltration occurs due to leaking joints, defective pipes etc. in aging infrastructure.

<span class="mw-page-title-main">Basement</span> Below-ground floor of a building

A basement or cellar is one or more floors of a building that are completely or partly below the ground floor. It generally is used as a utility space for a building, where such items as the furnace, water heater, breaker panel or fuse box, car park, and air-conditioning system are located; so also are amenities such as the electrical system and cable television distribution point. In cities with high property prices, such as London, basements are often fitted out to a high standard and used as living space.

<span class="mw-page-title-main">Central heating</span> Type of heating system

A central heating system provides warmth to a number of spaces within a building from one main source of heat. It is a component of heating, ventilation, and air conditioning systems, which can both cool and warm interior spaces.

<span class="mw-page-title-main">Utility location</span>

Utility location is the process of identifying and labeling public utility mains that are underground. These mains may include lines for telecommunication, electricity distribution, natural gas, cable television, fiber optics, traffic lights, street lights, storm drains, water mains, and wastewater pipes. In some locations, major oil and gas pipelines, national defense communication lines, mass transit, rail, and road tunnels also compete for space underground.

Trenchless technology is a type of subsurface construction work that requires few trenches or no continuous trenches. It is a rapidly growing sector of the construction and civil engineering industry. It can be defined as "a family of methods, materials, and equipment capable of being used for the installation of new or replacement or rehabilitation of existing underground infrastructure with minimal disruption to surface traffic, business, and other activities."

<span class="mw-page-title-main">Roto-Rooter</span> Plumbing company

Roto-Rooter Plumbing & Water Cleanup is a Cincinnati, Ohio based company providing plumbing repair, sewer and drain services, and water damage cleanup services to residential and commercial customers. Roto-Rooter is a United States company founded in 1935, which originally specialized in clearing tree roots and other obstructions from sewer lines.

<span class="mw-page-title-main">Roof and tunnel hacking</span> Unauthorized exploration of utility spaces

Roof and tunnel hacking is the unauthorized exploration of roof and utility tunnel spaces. The term carries a strong collegiate connotation, stemming from its use at MIT and at the U.S. Naval Academy, where the practice has a long history. It is a form of urban exploration.

<span class="mw-page-title-main">Pipefitter</span> Tradesman who works with mechanical pipes

A pipefitter or steamfitter is a tradesman who installs, assembles, fabricates, maintains, and repairs mechanical piping systems. Pipefitters usually begin as helpers or apprentices. Journeyman pipefitters deal with industrial/commercial/marine piping and heating/cooling systems. Typical industrial process pipe is under high pressure, which requires metals such as carbon steel, stainless steel, and many different alloy metals fused together through precise cutting, threading, grooving, bending, and welding. A plumber concentrates on lower pressure piping systems for sewage and potable tap water in the industrial, commercial, institutional, or residential atmosphere. Utility piping typically consists of copper, PVC, CPVC, polyethylene, and galvanized pipe, which is typically glued, soldered, or threaded. Other types of piping systems include steam, ventilation, hydraulics, chemicals, fuel, and oil.

<span class="mw-page-title-main">Vacuum sewer</span> Method of transporting sewage from its source to a sewage treatment plant

A vacuum sewer or pneumatic sewer system is a method of transporting sewage from its source to a sewage treatment plant. It maintains a partial vacuum, with an air pressure below atmospheric pressure inside the pipe network and vacuum station collection vessel. Valves open and reseal automatically when the system is used, so differential pressure can be maintained without expending much energy pumping. A single central vacuum station can collect the wastewater of several thousand individual homes, depending on terrain and the local situation.

<span class="mw-page-title-main">Undergrounding</span> Replacement of above-ground power and telecommunications cables with underground ones

In civil engineering, undergrounding is the replacement of overhead cables providing electrical power or telecommunications, with underground cables. It helps in wildfire prevention and in making the power lines less susceptible to outages during high winds, thunderstorms or heavy snow or ice storms. An added benefit of undergrounding is the aesthetic quality of the landscape without the powerlines. Undergrounding can increase the capital cost of electric power transmission and distribution but may decrease operating costs over the lifetime of the cables.

<span class="mw-page-title-main">Plastic pipework</span> Tubular section or hollow cylinder made of plastic

Plastic pipe is a tubular section, or hollow cylinder, made of plastic. It is usually, but not necessarily, of circular cross-section, used mainly to convey substances which can flow—liquids and gases (fluids), slurries, powders and masses of small solids. It can also be used for structural applications; hollow pipes are far stiffer per unit weight than solid members.

A suction excavator or vacuum excavator is a construction vehicle that removes heavy debris or other materials from a hole on land.

<span class="mw-page-title-main">Disney utilidor system</span> Utility tunnel system at Magic Kingdom

In Disney theme parks, the utilidor system is a system of some of the world's largest utility tunnels, mainly for Walt Disney World's Magic Kingdom in Florida. The utilidors, short for utility corridors, are a part of Disney's "backstage" (behind-the-scenes) area. They allow Disney employees to perform park support operations, such as trash removal, and for costumed characters to quickly reach their destinations on the surface out of the sight of guests to avoid ruining the illusion that is being created.

<span class="mw-page-title-main">Tunnel construction</span> The construction method for building a tunnel

Tunnels are dug in types of materials varying from soft clay to hard rock. The method of tunnel construction depends on such factors as the ground conditions, the ground water conditions, the length and diameter of the tunnel drive, the depth of the tunnel, the logistics of supporting the tunnel excavation, the final use and shape of the tunnel and appropriate risk management. Tunnel construction is a subset of underground construction.

References

  1. "National Grid - Overview - Why a tunnel?". National Grid plc . Retrieved 2013-03-30.
  2. "Infrastructures: Common Utility Duct". MMA Group. 2006. Retrieved November 30, 2014.
  3. "Tokyo Underground". Big Empire. Retrieved November 30, 2014.
  4. . The Landmark Tower. Archived July 4, 2009, at the Wayback Machine
  5. Mitchell, Sandy (May 2006). "Prince Charles–not your typical radical". National Geographic
  6. "Archived copy" (PDF). Archived from the original (PDF) on 2013-10-17. Retrieved 2013-10-17.{{cite web}}: CS1 maint: archived copy as title (link)
  7. "Gujarat International Finance Tec-city: A Smart GIFT"