A transmission tower is a tall structure, usually a lattice tower made of steel that is used to support an overhead power line. In electrical grids, transmission towers carry high-voltage transmission lines that transport bulk electric power from generating stations to electrical substations, from which electricity is delivered to end consumers; moreover, utility poles are used to support lower-voltage sub-transmission and distribution lines that transport electricity from substations to electricity customers.
The Mettlen–Lavorgo powerline, also called the Lukmanier powerline, is the 400 kV three-phase alternating current high voltage electric power transmission line over the Lukmanier Pass in Switzerland, from Mettlen substation, next Inwil, about 7-kilometre (4.3 mi) south of Hochdorf, to Lavorgo substation, next Lavorgo, about 5-kilometre (3.1 mi) south of Faido. Trees falling on the line in 2003 caused a major blackout in Italy.
The Pylons of Cádiz, also known as the Towers of Cádiz, are two 158 m (518 ft)-tall pylons supporting a double-circuit 132 kV three-phase AC powerline over the bay of Cádiz, Spain, running from Puerto Real Substation to the substation of the former Cádiz Thermal Power Station, situated on the peninsula upon which the city of Cádiz stands.
An overhead line crossing is the crossing of an obstacle—such as a traffic route, a river, a valley or a strait—by an overhead power line. The style of crossing depends on the local conditions and regulations at the time the power line is constructed. Overhead line crossings can sometimes require extensive construction and can also have operational issues. In such cases, those in charge of construction should consider whether a crossing of the obstacle would be better accomplished by an underground or submarine cable.
The Suez Canal overhead powerline crossing is a major electrical power line built across the Suez Canal in 1998, located near Suez, Egypt. It is designed for two 500 kV circuits.
Bosporus overhead line crossings refers to the three transmission line crossings of the Bosporus, the strait in Istanbul, Turkey.
The Kerinchi Pylon is a lattice-steel transmission tower located near Menara Telekom in Kerinchi, Kuala Lumpur, Malaysia.
The Yangtze River power line crossings are overhead power lines that cross the Yangtze River in China. There are at least three power line crossings on the Yangtze River at Jiangyin, Nanjing, and Wuhu. The towers of the crossing in Jiangyin are among the highest in the world.
Kootenay Lake Crossing is a powerline crossing of Kootenay Lake, British Columbia, Canada. The idea was to transport electricity from the Hydro dam on the Kootenay River at Brilliant to the Cominco Sullivan Mine at Kimberley. The most direct route was across Kootenay Lake. Originally it was with a span width of 3,248 metres (10,656 ft) the longest powerline span of North America and fixed on three - for each conductor a single one - 19 metres tall towers at the west shore and a 112 metres (367 ft) tall electricity pylon on the east shore. This tower was erected in spite of high mountains on the east shore for building short towers were available, as erecting span terminal towers on them would have required a longer span, for which the use of spliced conductors were required, which was undesired as the splicing point is a potential point of failure. Roebling cable provided the steel support cable for the conductor. The height of conductor over Kootenay Lake was 37 metres (121 ft).
The 400 kV Thames Crossing is an overhead power line crossing of the River Thames, between Botany Marshes in Swanscombe, Kent, and West Thurrock, Essex, England. Its towers are the tallest electricity pylons in the UK.
Aust Severn Powerline Crossing is the longest overhead power line span in the United Kingdom with a length of 1,618 m (5,308 ft).
The Rzeszów–Khmelnytskyi powerline is an electrical power transmission line between Ukraine and Poland. It is the only 750 kV-powerline in Poland, and one of a few in the European Union.
Carquinez Strait Powerline Crossing was the world's first powerline crossing of a large river. It was built in 1901 for a 60 kV powerline operated by Bay Counties Power Company to deliver electric power from their Colgate powerhouse to Oakland, California. For this a crossing of Carquinez Strait was required, which has at its narrowest point at Dillon Point a width of 838 metres (0.52 mi). Such a span width was impossible with wooden poles, which were common in those days. Installing an underwater cable was considered, but for reliability reasons an overhead power line was installed, which used at the north site of the river a 68 metres (223.10 ft) tall lattice tower and at the south site one with a height of 20 metres (66 ft).
The Chūshi Powerline Crossing is a part of the Chūshi mainline, a 220 kV powerline in Japan. It has two circuits running over the Inland Sea from Takehara. It was built in 1962 and consists of two towers, each 226 metres tall, one situated in Takehara, Honshū at 34°19′55.8″N132°59′3.3″E, the other on the island of Ōkunoshima at 34°18′42.8″N132°59′32.2″E. These towers are the tallest electricity pylons in Japan and carry six conductors arranged in three levels. The span between the two towers has a length of 2,357 metres and has a minimum clearance of 42 metres. The conductors have a cross section of 170 mm2, a diameter 35.2 mm and are designed for a maximum current of 645 A.
The 275 kV Forth Crossing is an overhead power line crossing of the River Forth in Scotland. The crossing, located next to the Clackmannanshire Bridge and the Kincardine Bridge, has the tallest electricity towers (pylons) in Scotland.
The Saint Lawrence River HVDC Powerline Crossing is the crossing of Hydro-Québec's Quebec-New England HVDC transmission line over the Saint Lawrence River between Grondines and Lotbinière, Quebec, Canada. The crossing is remarkable, for being first implemented as an overhead crossing, and then later replaced by a cable tunnel. Hydro-Québec wanted to complete the transmission line in time, which was only possible with an overhead crossing of Saint Lawrence River. However, due to the negative visual impact of the large towers of the overhead crossing on the local populations of Grondines and Lotbinière, it was decided to build a cable tunnel under the river, although this made the project more expensive.
HVDC Ekibastuz–Centre is an unfinished HVDC transmission line between Ekibastuz in Kazakhstan and Tambov in Russia whose construction was started in 1978. It was planned to have a length of 2,414 kilometres (1,500 mi), which would have made it the longest powerline of the world with a maximum transmission rate of 6,000 MW and a transmission voltage of 750 kV between conductor and ground. For this line the erection of 4,000 pylons, most 41 metres (135 ft) tall, were required. Several hundred kilometres were built, including a Volga crossing on three 124 metres (407 ft) tall towers near Saratov, which were erected between 1989 and 1991. At Ekibastuz construction work at the terminal was started, while it was not the case at Centre substation, Tambov.
The Zaporizhzhia Pylon Triple is a set of two triples of 74.5 metres (244 ft) tall electricity pylons extending over the Dnieper river standing on a 27m rock in Zaporizhzhia, Ukraine. They are used for the transport of electricity generated at the Dnieper Hydroelectric Station over a span of 900 metres from Khortytsia island to the east bank of the Dnieper. The two triples are an unofficial landmark of Zaporizhzhia.
The Osaki Channel Crossing is a power line crossing over Seto Inland Sea south of Yoshina, Takehara in Japan, which was built in 1997 and runs from Chugoku Electric Power's Ozaki Power Station at 34°15′26.4″N132°52′25.1″E to the Japanese Mainland at 34°18′19.6″N132°52′29.1″E, with two water crossings: the Nagashima Sector, connecting the Power Station to Usujima, with a span width of 1603 metres, and the Yoshina Sector, which spans from Usujima to the mainland at 2145 metres long. At a height of 223 metres, the towers of the Yoshina Sector are just 3 metres shorter than those of the Chūshi Powerline Crossing, making them the second-tallest electricity pylons in Japan. The pylons follow a barrel design with 3 crossbars.
The Zhoushan Island Overhead Powerline Tie is a 220 kV three-phase AC interconnection of the power grid of Zhoushan Island with that of the Chinese mainland. It runs over several islands and consists of several long-distance spans, the longest with a length of 2.7 kilometres (1.7 mi) south of Damao Island. This span uses two 370-metre-tall (1,210 ft) pylons, which were the highest electricity pylons in the world, until a 500 kV line to Zhoushan from mainland was completed. The north tower on Damao Island was completed in 2009, and the south tower on Liangmao Island was completed in 2010. These pylons resemble those of the Messina Strait, but are steel-tube lattice structures.
