In telecommunication, the term outside plant has the following meanings:
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.
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.
An underground city is a series of linked subterranean spaces that may provide a defensive refuge; a place for living, working or shopping; a transit system; mausolea; wine or storage cellars; cisterns or drainage channels; or several of these. Underground cities may be currently active modern creations or they may be historic including ancient sites, some of which may be all or partially open to the public.
A manhole cover or maintenance hole cover is a removable plate forming the lid over the opening of a manhole, an opening large enough for a person to pass through that is used as an access point for an underground vault or pipe. It is designed to prevent anyone or anything from falling in, and to keep out unauthorized persons and material.
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.
A number of military citadels are known to have been constructed underground in central London, dating mostly from the Second World War and the Cold War. Unlike traditional above-ground citadels, these sites are primarily secure centres for defence coordination.
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.
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.
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.
Underground living refers to living below the ground's surface, whether in natural or manmade caves or structures. Underground dwellings are an alternative to above-ground dwellings for some home seekers, including those who are looking to minimize impact on the environment. Factories and office buildings can benefit from underground facilities for many of the same reasons as underground dwellings such as noise abatement, energy use, and security.
The Houston tunnel system is a network of subterranean, climate-controlled, pedestrian walkways that links 95 full city blocks 20 feet (6 m) below Houston's downtown streets. It is approximately six miles (9.7 km) long. There are similar systems in Chicago, Dallas, Oklahoma City, Montreal, and Toronto. Architectural historian Stephen Fox has stated that the idea for the tunnel system came when the Bank of the Southwest Building was "linked by tunnel to the 1010 Garage and the Mellie Esperson Building" in 1961.
Fiber to the x or fiber in the loop is a generic term for any broadband network architecture using optical fiber to provide all or part of the local loop used for last mile telecommunications. As fiber optic cables are able to carry much more data than copper cables, especially over long distances, copper telephone networks built in the 20th century are being replaced by fiber.
Precast concrete is a construction product produced by casting concrete in a reusable mold or "form" which is then cured in a controlled environment, transported to the construction site and maneuvered into place; examples include precast beams, and wall panels for tilt up construction. In contrast, cast-in-place concrete is poured into site-specific forms and cured on site.
Empire City Subway is an American 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.
An electrical room is a room or space in a building dedicated to electrical equipment. Its size is usually proportional to the size of the building; large buildings may have a main electrical room and subsidiary electrical rooms. Electrical equipment may be for power distribution equipment, or for communications equipment.
An electrical conduit is a tube used to protect and route electrical wiring in a building or structure. Electrical conduit may be made of metal, plastic, fiber, or fired clay. Most conduit is rigid, but flexible conduit is used for some purposes.
The White House to Treasury Building tunnel is a 761-foot (232 m) subterranean structure in Washington, D.C. that connects a sub-basement of the East Wing of the White House to the areaway which surrounds the United States Treasury Building. It was initially constructed in 1941 to allow the evacuation of the president from the White House to underground vaults inside the Treasury in an emergency.
Pavement lights (UK), vault lights (US), floor lights, or sidewalk prisms are flat-topped walk-on skylights, usually set into pavement (sidewalks) or floors to let sunlight into the space below. They often use anidolic lighting prisms to throw the light sideways under the building. They were developed in the 19th century, but declined in popularity with the advent of cheap electric lighting in the early 20th. Older cities and smaller centers around the world have, or once had, pavement lights. In the early 21st century, such lights are approximately a century old, although lights are being installed in some new construction.
Telecommunications power cable, as described in Telcordia GR-347 & GR-347, consist of a stranded copper conductor used in AC/DC circuits up to 600 V that are insulated with non-halogen, limited smoke, polyolefin materials that are heat-resistant, moisture-resistant, and flame-retardant. These cables are provided as either Class B (standard) or Class I (flexible) products.
