A
utility pole is a
poleA column or pillar in architecture and structural engineering is a vertical structural element that transmits, through compression, the weight of the structure above to other structural elements below. For the purpose of wind or earthquake engineering, columns may be designed to resist lateral forces...
used to support
overhead power lineAn overhead power line is an electric power transmission line suspended by towers or utility poles. Since most of the insulation is provided by air, overhead power lines are generally the lowest-cost method of transmission for large quantities of electric energy...
s and various other public utilities, such as
cableA cable is two or more wires running side by side and bonded, twisted or braided together to form a single assembly. In mechanics cables, otherwise known as wire ropes, are used for lifting, hauling and towing or conveying force through tension. In electrical engineering cables are used to carry...
, fibre optic cable, and related equipment such as transformers and street lights. It can be referred to as a
telephone pole,
power pole,
hydro pole,
telegraph pole, or
telegraph post, depending on its application. A
stobie poleA Stobie pole is a power line pole made of two steel joists held apart by a slab of concrete in the middle. It was invented by Adelaide Electricity Supply Company design engineer James Cyril Stobie . Stobie used materials easily at hand due to the shortage of suitably long, strong, straight and...
is a multi-purpose pole made of two steel joists held apart by a slab of concrete in the middle, generally found in
South AustraliaSouth Australia is a state of Australia in the southern central part of the country. It covers some of the most arid parts of the continent; with a total land area of , it is the fourth largest of Australia's six states and two territories.South Australia shares borders with all of the mainland...
. Electrical cable is routed overhead as an inexpensive way to keep it insulated from the ground and out of the way of people and vehicles. Utility poles can be made of wood, metal, concrete, or composites like fibreglass. They are used for lower voltage power transmission; higher voltage
transmission lineIn communications and electronic engineering, a transmission line is a specialized cable designed to carry alternating current of radio frequency, that is, currents with a frequency high enough that its wave nature must be taken into account...
s are carried on steel
transmission towers or pylonsA transmission tower is a tall structure, usually a steel lattice tower, used to support an overhead power line. They are used in high-voltage AC and DC systems, and come in a wide variety of shapes and sizes...
.
Utility poles were first used in the mid-19th century with telegraph systems, starting with Samuel Morse who attempted to bury a line between Baltimore and
Washington, D.C.Washington, D.C., formally the District of Columbia and commonly referred to as Washington, "the District", or simply D.C., is the capital of the United States. On July 16, 1790, the United States Congress approved the creation of a permanent national capital as permitted by the U.S. Constitution....
, but moved it aboveground when this system proved faulty.
Use
Utility poles are commonly used to carry two types of electric power lines:
distribution linesFile:Electricity grid simple- North America.svg|thumb|380px|right|Simplified diagram of AC electricity distribution from generation stations to consumers...
(or "feeders") and
subtransmission lines. Distribution lines carry power from local
substationsA substation is a part of an electrical generation, transmission, and distribution system. Substations transform voltage from high to low, or the reverse, or perform any of several other important functions...
to customers. They generally carry voltages from 4.6 to 33 kilovolts (kV) for distances up to thirty miles, and include transformers to step the voltage down from the primary voltage of the lines to the lower secondary voltage used by the customer. A
service dropIn an electric power distribution grid, a service drop is an overhead electrical line running from a utility pole, to a customer's building or other premises. It is the point where electric utilities provide power to their customers. The customer connection to an underground distribution system...
carries this lower voltage to the customer's premises. Subtransmission lines carry higher voltage power from regional substations to local substations. They usually carry 46 kV, 69 kV, or 115 kV for distances up to 60 miles. 230kV lines are often supported on H-shaped towers made with two or three poles. Transmission lines carrying voltages of above 230kV are usually not supported by poles, but by metal
pylonsA transmission tower is a tall structure, usually a steel lattice tower, used to support an overhead power line. They are used in high-voltage AC and DC systems, and come in a wide variety of shapes and sizes...
(known as transmission towers in the United States).
For economic or practical reasons, such as to save space in urban areas, a distribution line is often carried on the same poles as a subtransmission line but mounted under the higher voltage lines; a practice called "underbuild". Telecommunication cables are usually carried on the same poles that support power lines; poles shared in this fashion are known as joint use poles. However, they may also have their own dedicated poles.
Description
The standard utility pole in the United States is about 40 ft (12.2 m) long and is buried about 6 ft (1.8 m) in the ground. However, poles can reach heights of 120 ft (36.6 m) or more to satisfy clearance requirements. They are typically spaced about 125 ft (38.1 m) apart in urban areas, or about 300 ft (91.4 m) in rural areas, but distances vary widely based on terrain. Joint use poles are usually owned by one utility, which leases space on it for other cables. In the United States, the National Electrical Safety Code, published by the
Institute of Electrical and Electronics EngineersThe Institute of Electrical and Electronics Engineers is a non-profit professional association headquartered in New York City that is dedicated to advancing technological innovation and excellence...
(IEEE), sets the standards for construction and maintenance of utility poles and their equipment.
Pole materials
Most utility poles are made of wood, pressure-treated with some type of
preservativeAll measures that are taken to ensure a long life of wood fall under the definition wood preservation . Apart from structural wood preservation measures, there are a number of different preservatives and processes that can extend the life of wood, timber, wood structures or engineered wood...
for protection against rot, fungi and insects.
Southern yellow pineSouthern Yellow Pine doesn't refer to any one species of tree, but rather a group of species which are classified as yellow pine , and are native to the Southern United States. They grow very well in the acidic red clay soil found in most of the region. The varieties include Loblolly, Longleaf,...
is the most widely used species in the United States; however, many species of long straight trees are used to make utility poles, including
Douglas-firDouglas-fir is one of the English common names for evergreen coniferous trees of the genus Pseudotsuga in the family Pinaceae. Other common names include Douglas tree, and Oregon pine. There are five species, two in western North America, one in Mexico, and two in eastern Asia...
,
Jack pineJack pine is a North American pine with its native range in Canada east of the Rocky Mountains from Northwest Territories to Nova Scotia, and the northeast of the United States from Minnesota to Maine, with the southernmost part of the range just into northwest Indiana...
,
lodgepole pineLodgepole Pine, Pinus contorta, also known as Shore Pine, is a common tree in western North America. Like all pines, it is evergreen.-Subspecies:...
, western red cedar and
Pacific silver firAbies amabilis, commonly known as the Pacific silver fir, is a fir native to the Pacific Northwest of North America, occurring in the Pacific Coast Ranges and the Cascade Range from the extreme southeast of Alaska, through western British Columbia, Washington and Oregon, to the extreme northwest of...
. Traditionally the preservative used was
creosoteCreosote is the portion of chemical products obtained by the distillation of a tar that remains heavier than water, notably useful for its anti-septic and preservative properties...
, but due to environmental concerns, alternatives such as
pentachlorophenolPentachlorophenol is an organochlorine compound used as a pesticide and a disinfectant. First produced in the 1930s, it is marketed under many trade names...
, copper naphthenate and borates are becoming widespread in the U.S. For over 100 years, the American Wood Protection Association (AWPA) has developed the standards for preserving wood utility poles. Despite the preservatives, wood poles decay and have a life of approximately 25 to 50 years depending on climate and soil conditions, therefore requiring regular inspection and remedial preservative treatments.
Other common utility pole materials are steel and concrete, with composites (such as fibreglass) also becoming more prevalent. One particular patented utility pole variant used in
AustraliaAustralia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
is the
Stobie poleA Stobie pole is a power line pole made of two steel joists held apart by a slab of concrete in the middle. It was invented by Adelaide Electricity Supply Company design engineer James Cyril Stobie . Stobie used materials easily at hand due to the shortage of suitably long, strong, straight and...
, made up of two vertical steel posts with a slab of concrete between them.
Power distribution wires and equipment
On poles carrying both, the electric
power distribution linesAn overhead power line is an electric power transmission line suspended by towers or utility poles. Since most of the insulation is provided by air, overhead power lines are generally the lowest-cost method of transmission for large quantities of electric energy...
and associated equipment are mounted at the top of the pole above the communication cables, for safety. The vertical space on the pole reserved for this equipment is called the
supply space. The wires themselves are usually uninsulated, and supported by insulators, commonly mounted on a horizontal crossarm. Power is transmitted using the
three-phaseThree-phase electric power is a common method of alternating-current electric power generation, transmission, and distribution. It is a type of polyphase system and is the most common method used by grids worldwide to transfer power. It is also used to power large motors and other heavy loads...
system, with three wires, or phases, labeled "A", "B", and "C". Subtransmission lines comprise only these 3 wires, plus sometimes an overhead ground wire (OGW), also called a "static line" or a "neutral", suspended above them. The OGW acts like a lightning rod, providing a low
resistanceThe electrical resistance of an electrical element is the opposition to the passage of an electric current through that element; the inverse quantity is electrical conductance, the ease at which an electric current passes. Electrical resistance shares some conceptual parallels with the mechanical...
path to ground thus protecting the phase conductors from atmospheric static discharges.
Distribution lines use two systems, either grounded-wye ("Y" on
electrical schematicsA circuit diagram is a simplified conventional graphical representation of an electrical circuit...
) or delta (
Greek letterThe Greek alphabet is the script that has been used to write the Greek language since at least 730 BC . The alphabet in its classical and modern form consists of 24 letters ordered in sequence from alpha to omega...
Delta, "Δ"Delta is the fourth letter of the Greek alphabet. In the system of Greek numerals it has a value of 4. It was derived from the Phoenician letter Dalet...
, on electrical schematics). A delta system requires only a conductor for each of the three phases. A grounded-wye system requires a fourth conductor, the
neutralSince the neutral point of an electrical supply system is often connected to earth ground, ground and neutral are closely related. Under certain conditions, a conductor used to connect to a system neutral is also used for grounding of equipment and structures...
, whose source is the center of the "Y" and is grounded. However, "spur lines" branching off the main line to provide power to side streets often carry only one or two phase wires, plus the neutral. A wide range of standard distribution voltages are used, from 2,400 V to 34,500 V. On poles near a
service dropIn an electric power distribution grid, a service drop is an overhead electrical line running from a utility pole, to a customer's building or other premises. It is the point where electric utilities provide power to their customers. The customer connection to an underground distribution system...
, there is a cylindrical
pole-mounted step-down transformerA distribution transformer is a transformer that provides the final voltage transformation in the electric power distribution system, stepping down the voltage used in the distribution lines to the level used by the customer. If mounted on a utility pole, they are called pole-mount transformers...
to provide the required mains voltage, usually 240/120 V split-phase for residential and light commercial service in the US. The transformer's primary is connected to the distribution line through protective devices called
fusedIn electronics and electrical engineering, a fuse is a type of low resistance resistor that acts as a sacrificial device to provide overcurrent protection, of either the load or source circuit...
cutouts. In the event of an overload, the fuse melts and the device pivots open to provide a visual indication of the problem. They can also be opened manually by linemen using a long insulated rod called a
hot stickIn the electric power distribution industry, a hot stick is an insulated pole, usually made of fiberglass, used by electric utility workers when engaged on live-line working on energized high-voltage electric power lines, to protect them from electric shock...
to disconnect the transformer from the line.
The pole may be
groundedIn electrical engineering, ground or earth may be the reference point in an electrical circuit from which other voltages are measured, or a common return path for electric current, or a direct physical connection to the Earth....
with a heavy bare
copperCopper is a chemical element with the symbol Cu and atomic number 29. It is a ductile metal with very high thermal and electrical conductivity. Pure copper is soft and malleable; an exposed surface has a reddish-orange tarnish...
wire running down the pole, attached to the metal pin supporting each insulator, and at the bottom connected to a metal rod driven into the ground. Some countries ground every pole while others only ground every fifth pole and any pole with a transformer on it. This provides a path for leakage currents across the surface of the insulators to get to ground, preventing the current from flowing through the wooden pole which could cause a fire or shock hazard. It provides similar protection in case of flashovers and lightning strikes. A surge arrester (also called a lightning arrester) may also be installed between the line (ahead of the cutout) and the ground wire for lightning protection. The purpose of the device is to conduct extremely high voltages present on the line directly to ground.
If non-insulated conductors touch due to wind or fallen trees, the resultant sparks can start bushfires. To reduce this problem, aerial bundled conductors are being introduced.
Communication cables
The communications cables are attached below the electric power lines, in a space about the pole designated the
communications space. The communications space is separated from the lowest electrical conductor by the
communication worker safety zone, which provides room for workers to maneuver safely while servicing the communication cables, avoiding contact with the power lines. The most common communication cables found on utility poles are copper or fibre optic cable (FOC) for telephone lines and coaxial cables for
cable televisionCable television is a system of providing television programs to consumers via radio frequency signals transmitted to televisions through coaxial cables or digital light pulses through fixed optical fibers located on the subscriber's property, much like the over-the-air method used in traditional...
(CATV). Coaxial or optical fibre cables linking computer networks are also increasingly found on poles in urban areas. The cable linking the
telephone exchangeIn the field of telecommunications, a telephone exchange or telephone switch is a system of electronic components that connects telephone calls...
to local customers is a thick cable lashed to a thin supporting cable, containing hundreds of
twisted pairTwisted pair cabling is a type of wiring in which two conductors are twisted together for the purposes of canceling out electromagnetic interference from external sources; for instance, electromagnetic radiation from unshielded twisted pair cables, and crosstalk between neighboring pairs...
subscriber lines. Each twisted pair line provides a single telephone circuit or
local loopIn telephony, the local loop is the physical link or circuit that connects from the demarcation point of the customer premises to the edge of the carrier or telecommunications service provider's network...
to a customer. There may also be fibre optic cables interconnecting telephone exchanges. Like electrical distribution lines, communication cables connect to service drops when used to provide local service.
Other equipment
Utility poles may also carry other equipment such as street lights, supports for traffic lights and overhead electric trolley wires, and
cellular networkA cellular network is a radio network distributed over land areas called cells, each served by at least one fixed-location transceiver known as a cell site or base station. When joined together these cells provide radio coverage over a wide geographic area...
antennas. They can also carry fixtures and decorations specific for certain holidays or events specific to the city they are located in.
Solar panels mounted on utility poles may power auxiliary equipment where the expense of a power line connection is unwanted.
Streetlights and holiday fixtures are powered directly from secondary distribution.
Access
In some countries, such as the United Kingdom, Telecom poles have sets of brackets arranged in a standard pattern up the pole to act as hand and foot holds so that maintenance and repair workers, can climb the pole to work on the telecom lines. In the UK these steps are regarded as a hazard to the public on Electricity poles. In the United States, such steps have been determined a public hazard and are no longer allowed on new poles. Linemen may use climbing spikes called gaffs to ascend wood poles without steps on them. In the UK, boots fitted with steel loops that go around the pole (known as “Scandinavian Climbers”) are also used for climbing poles. In the USA, linemen use
bucket trucksA cherry picker , is a type of aerial work platform that consists of a platform or bucket at the end of a hydraulic lifting system.- Design :...
for the vast majority of poles that are accessible by vehicle.
Dead-end poles
The poles at the end of a straight section of utility line, where the line ends or angles off in another direction, are called
dead-end poles in the United States. Elsewhere they may be referred to as anchor or termination poles. These must carry the lateral tension of the long straight sections of wire. They are usually made with heavier construction. The power lines are attached to the pole by horizontal strain insulators, either placed on crossarms (which are either doubled, tripled, or replaced with a steel crossarm, to provide more resistance to the tension forces) or attached directly to the pole itself.
Dead-end and other poles that support lateral loads have guy-wires to support them. The guys always have
strain insulatorA strain insulator is an insulator that provides both large electrical insulation and a large load-bearing capacity. Strain insulators were first used in telegraph systems to isolate the signal wire from ground while still supporting the wire...
s inserted in their length to prevent any high voltages caused by electrical faults from reaching the lower portion of the cable that is accessible by the public. In populated areas, guy wires are often encased in a yellow plastic or wood tube reflector attached to their lower end, so that they can be seen more easily, reducing the chance of people and animals walking into them or vehicles crashing into them. Another means of providing support for lateral loads is a 'push brace' pole, a second shorter pole that is attached to the side of the first and runs at an angle to the ground. If there is no space for a lateral support, a stronger pole, e.g. a construction of concrete or iron is used.
History
In 1844, the
United StatesThe United States of America is a federal constitutional republic comprising fifty states and a federal district...
CongressThe United States Congress is the bicameral legislature of the federal government of the United States, consisting of the Senate and the House of Representatives. The Congress meets in the United States Capitol in Washington, D.C....
granted Samuel Morse $30,000 to build a 40-mile telegraph line between Baltimore, Maryland and
Washington, D.C.Washington, D.C., formally the District of Columbia and commonly referred to as Washington, "the District", or simply D.C., is the capital of the United States. On July 16, 1790, the United States Congress approved the creation of a permanent national capital as permitted by the U.S. Constitution....
. Morse began by having a lead-sheathed cable made. After laying seven miles underground, he tested it. He found so many faults with this system that he dug up his cable, stripped off its sheath, bought poles and strung his wires overhead. On February 7, 1844, Morse inserted the following advertisement in the Washington newspaper: "Sealed proposals will be received by the undersigned for furnishing 700 straight and sound chestnut posts with the bark on and of the following dimensions to wit: 'Each post must not be less than eight inches in diameter at the butt and tapering to five or six inches at the top. Six hundred and eighty of said posts to be 24 feet in length, and 20 of them 30 feet in length.' One of the early Bell System lines was the Washington DC-Norfolk line which was for the most part, square sawn tapered poles of yellow pine probably treated to refusal with
creosoteCreosote is the portion of chemical products obtained by the distillation of a tar that remains heavier than water, notably useful for its anti-septic and preservative properties...
. Some of these were still in service after 80 years.
However, in
Eastern EuropeEastern Europe is the eastern part of Europe. The term has widely disparate geopolitical, geographical, cultural and socioeconomic readings, which makes it highly context-dependent and even volatile, and there are "almost as many definitions of Eastern Europe as there are scholars of the region"...
,
RussiaRussia or , officially known as both Russia and the Russian Federation , is a country in northern Eurasia. It is a federal semi-presidential republic, comprising 83 federal subjects...
, and third world countries, there are still many utility poles carrying bare wires mounted on insulators not only along railway lines, but also along roads and sometimes even in urban areas. Errant traffic being uncommon on railways, their poles are usually less tall. In the United States electricity is predominately carried on unshielded aluminum conductors wound around a solid steel core and affixed to rated insulators made from glass, ceramic, or poly. Telephone, CATV and Fiber Optic cables are generally attached directly to the pole without insulators.
In the
United KingdomThe United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...
, much of the rural electricity distribution system is carried on wood poles. These normally carry electricity at 11 or 33 kV (three phases) from 132 kV substations supplied from
pylonsA transmission tower is a tall structure, usually a steel lattice tower, used to support an overhead power line. They are used in high-voltage AC and DC systems, and come in a wide variety of shapes and sizes...
to distribution substations or pole-mounted transformers. The conductors on these are bare metal connected to the posts by insulators. Wood poles can also be used for
low voltageLow voltage when used as an electrical engineering term concerning an electricity supply grid or industrial use, broadly identifies safety considerations of the system based on the voltage used. The meaning of the term "low voltage" is somewhat different when used with regard to a more typical end...
distribution to customers.
Today, utility poles may hold much more than the uninsulated copper wire that they originally supported. Thicker cables holding many
twisted pairTwisted pair cabling is a type of wiring in which two conductors are twisted together for the purposes of canceling out electromagnetic interference from external sources; for instance, electromagnetic radiation from unshielded twisted pair cables, and crosstalk between neighboring pairs...
,
coaxial cableCoaxial cable, or coax, has an inner conductor surrounded by a flexible, tubular insulating layer, surrounded by a tubular conducting shield. The term coaxial comes from the inner conductor and the outer shield sharing the same geometric axis...
, or even fibre-optic, may be carried. Simple analogue repeaters or other
outside plantIn telecommunication, the term outside plant has the following meanings:*In civilian telecommunications, outside plant refers to all of the physical cabling and supporting infrastructure , and any associated hardware located between a demarcation point in a switching facility and a demarcation...
equipment have long been mounted against poles, and often new digital equipment for
multiplexingThe multiplexed signal is transmitted over a communication channel, which may be a physical transmission medium. The multiplexing divides the capacity of the low-level communication channel into several higher-level logical channels, one for each message signal or data stream to be transferred...
/demultiplexing or digital repeaters may now be seen. In many places, as seen in the illustration, providers of electricity, television, telephone, street light, traffic signal and other services share poles, either in joint ownership or by renting space to each other. In the United States, ANSI standard 05.1.2008 governs wood pole sizes and strength loading. Utilities that fall under the Rural Electrification Act must also follow the guidelines set forth in RUS Bulletin 1724E-150 (from the US Department of Agriculture) for pole strength and loading.
Steel utility poles are becoming more prevalent in the United States thanks to improvements in engineering and corrosion prevention coupled with lowered production costs. However, premature failure due to corrosion is a concern when compared to wood.
The National Association of Corrosion Engineers or NACE is developing inspection, maintenance, and prevention procedures similar to those used on wood utility poles to identify and prevent decay.
Pole brandings
British Telecom posts are usually marked with the following information:
- 'BT' - to mark it as a British Telecom UK Post
- a horizontal line marking 3 metres from the bottom of the post
- the pole length and size (e.g. 9L implies a 9 metres long, light post)
- the year of treatment and therefore generally the year of installation (e.g. the pole was treated in 2003 in the picture)
- the batch and type of wood used
The date on the pole is applied by the manufacturer and refers to the date the pole was "preserved" (treated to withstand the elements).
In the United States, utility poles are marked with information concerning the manufacturer, pole height, ANSI strength class, wood species, original preservative, and year manufactured (vintage) in accordance with ANSI standard O5.1.2008; this is called branding, as it is usually burned into the surface. Although the position of the brand is determined by ANSI specification, it is essentially just below "eye level" after installation. A general rule of thumb for understanding a pole's brand is the manufacturer's name or logo at the top with a 2-digit date beneath (sometimes preceded by a month).
Below the date is a 2-character wood species abbreviation and 1 to 3 character preservative. Some wood species may be: "SP" for southern pine, "WC" for western cedar, and "DF" for Douglas fir; common preservative abbreviations are "C" for
creosoteCreosote is the portion of chemical products obtained by the distillation of a tar that remains heavier than water, notably useful for its anti-septic and preservative properties...
, "P" for
pentachlorophenolPentachlorophenol is an organochlorine compound used as a pesticide and a disinfectant. First produced in the 1930s, it is marketed under many trade names...
, and "SK" for
chromated copper arsenateChromated copper arsenate is a wood preservative used for timber treatment since the mid-1930s. It is a mix of chromium, copper and arsenic formulated as oxides or salts. It preserves the wood from decay fungi, wood attacking insects, including termites, and marine borers...
(originally referred to Salts type K). The next line of the brand is usually the pole's ANSI Class, used to determine maximum load; this number ranges from 10 to H6 with a smaller number meaning higher strength. The pole's height (from butt to top) in 5 foot increments is usually to the right of the class separated by a hyphen, although it is not uncommon for older brands to have the height on a separate line. The pole brand is sometimes an aluminum tag nailed in place.
Before the practice of branding, many utilities would set a 2- to 4-digit date nail into the pole upon installation. The use of date nails went out of favor during WWII due to war shortages, but is still used by a few utilities. These nails are considered valuable to collectors, with older dates being more valuable, and unique markings such as the utilities' name also increasing the value. However, regardless of the value to collectors, all attachments on a utility pole are the property of the utility company, and unauthorized removal is a felony.
Coordinates on pole labels
A practice in some areas is to place poles on coordinates upon a grid. The pole at right is located in a rural area of the state of
MarylandMaryland is a U.S. state located in the Mid Atlantic region of the United States, bordering Virginia, West Virginia, and the District of Columbia to its south and west; Pennsylvania to its north; and Delaware to its east...
in the United States. The lower two tags are the "X" and "Y" coordinates along said grid. Just as in a
coordinate planeA Cartesian coordinate system specifies each point uniquely in a plane by a pair of numerical coordinates, which are the signed distances from the point to two fixed perpendicular directed lines, measured in the same unit of length...
used in geometry, X increases as one travels east and Y increases as one travels north. The upper two tags are specific to the subtransmission section of the pole; the first refers to the route number, the second to the specific pole along the route.
However, not all power lines follow the road. In the British region of
East AngliaEast Anglia is a traditional name for a region of eastern England, named after an ancient Anglo-Saxon kingdom, the Kingdom of the East Angles. The Angles took their name from their homeland Angeln, in northern Germany. East Anglia initially consisted of Norfolk and Suffolk, but upon the marriage of...
,
EDF EnergyEDF Energy is an integrated energy company in the United Kingdom, with operations spanning electricity generation and the sale of gas and electricity to homes and businesses throughout the United Kingdom...
Networks often add the
Ordnance SurveyOrdnance Survey , an executive agency and non-ministerial government department of the Government of the United Kingdom, is the national mapping agency for Great Britain, producing maps of Great Britain , and one of the world's largest producers of maps.The name reflects its creation together with...
Grid Reference coordinates of the pole or substation to the name sign.
In some areas, utility pole name plates may provide valuable coordinate information; a poor man's GPS.
Pole route
A
pole route (or
pole line in the USA) is a telephone link or electrical power line between two or more locations by way of multiple uninsulated wires suspended between wooden utility poles. This method of link is common especially in rural areas where burying the cables would be expensive. Another situation in which pole routes were extensively used were on the railways to link signal boxes. Traditionally, prior to around 1965, pole routes were built with open wires along non-electrical operated railways; this necessitated insulation when the wire passed over the pole, thus preventing the signal from becoming attenuated. At electrical operated railways, pole routes were usually not built as too much jamming from the overhead wire would occur. To do this, cables were separated using spars with insulators spaced along them; in general four insulators were used per spar. Only one such pole route still exists on the UK rail network, in the highlands of
ScotlandScotland is a country that is part of the United Kingdom. Occupying the northern third of the island of Great Britain, it shares a border with England to the south and is bounded by the North Sea to the east, the Atlantic Ocean to the north and west, and the North Channel and Irish Sea to the...
. There was also a long section in place between
WymondhamWymondham is a historic market town and civil parish in the English county of Norfolk. It lies 9.5 miles to the south west of the city of Norwich, on the A11 road to Thetford and London.- Before The Great Fire :...
,
NorfolkNorfolk is a low-lying county in the East of England. It has borders with Lincolnshire to the west, Cambridgeshire to the west and southwest and Suffolk to the south. Its northern and eastern boundaries are the North Sea coast and to the north-west the county is bordered by The Wash. The county...
and
BrandonBrandon is a small town and civil parish in the English county of Suffolk. It is in the Forest Heath local government district.Brandon is located in the Breckland area on the border of Suffolk with the adjoining county of Norfolk...
in
SuffolkSuffolk is a non-metropolitan county of historic origin in East Anglia, England. It has borders with Norfolk to the north, Cambridgeshire to the west and Essex to the south. The North Sea lies to the east...
,
United KingdomThe United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...
; however, this was de-wired and removed during March 2009.
Visual pollution
Utility poles and related structures are regarded by some to be a form of
visual pollutionVisual pollution is the term given to unattractive and man-made visual elements of a vista, a landscape, or any other thing that a person does not feel comfortable to look at. Visual pollution is an aesthetic issue, referring to the impacts of pollution that impair one's ability to enjoy a vista or...
. This is combated in several places by placing lines underground; however, burial of power lines is considerably more expensive, and so it is not common.
See also
- 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...
- Stobie pole
A Stobie pole is a power line pole made of two steel joists held apart by a slab of concrete in the middle. It was invented by Adelaide Electricity Supply Company design engineer James Cyril Stobie . Stobie used materials easily at hand due to the shortage of suitably long, strong, straight and...
- Caber toss
The caber toss is a traditional Irish athletic event practised at the Irish Highland Games involving the tossing of a large wooden pole called a caber. It is said to have developed from the need to toss logs across narrow chasms to cross them. In Irishtown the caber is usually made from a Larch tree...
, a sport involving the throwing of large poles.
External links