Transmission tower

The pylon ( colloquially power pole ) is a structure for the suspension of an electrical transmission line.

Takes the pylon a pure support function, it is called a supporting mast. Overhead line masts to which sections of conductor cables end, is called Abspannmast. There are also branch masts for the realization of cable branches and Endmasten for the transition underground cable transmission line.

Depending on the electrical voltage of the overhead line different pylons are used. Depending on the existing raw materials, the masts of steel, concrete or even wood are produced. In the DA -CH region of the steel mast is up to the highest voltage levels the most common. Increasingly, mast types, the necessary conservation adapted to represent, for example, migratory birds as little hindrance.

• 7.1 By Function
• 7.2 After the material used
• 7.3 After arrangement of the conductors
• 7.4 After site
• 7.5 by Use

• 9.1 Special constructions

Types

Signaling

Low voltage (operating voltage up to 1000 V )

In low-voltage electrical three-phase four-wire systems are becoming system ( the neutral is always separate wire ) running. There are also two pole stubs for the supply of individual houses with single phase.

For this reason, three-phase overhead lines for low voltage always four conductors: three phases and a neutral. A possible arrangement of the conductors is in two levels (two on the top, two on the bottom crossbar ). In addition, laying in one plane is practiced occasionally. A fifth or even sixth conductor cable may be present when the street lighting is also fed from the overhead line. In the north and east of Germany is the reciprocal of the mast assembly - left-right at 45 ° - preferably with individual isolators.

Three-phase overhead lines in the low voltage range usually have only one circuit. If two circuits are to be performed in parallel on a mast, the two-level arrangement is usually chosen, each mast carries half of a circuit. Insulators mostly standing, rare hanging isolators are used.

As masts mostly wood poles or concrete poles are used. The use of steel pipe and steel framework masts is rare for pylons for low voltage. Frequently low voltage overhead lines are also called means mounted on rooftops small steel tubular poles, roof rack, laid.

Two-pole low-voltage lines always have an overhead conductor for one phase and one for the neutral. They are either transferred to A -level arrangement or have two single screwed into the pole insulators. As mast mast types all types mentioned above can come into question. Also two-pole overhead lines are sometimes used for the supply of street lamps, lighting fixtures are designed as always for two pin power connectors. These are either attached to the lampposts in the amount of lighting or even on false constructions on the road, where even the lighting fixtures hang out.

Often, the street lighting in full and half power ( strength ) is to be operable. In these cases, an additional line must be used, so that such a management system has three conductors.

Ground wires are not used for lines with operating voltages below 1000 volts.

Medium voltage ( 1 kV to 50 kV)

In medium voltage systems three-wire systems are used for three-phase systems always. The neutral point is earthed either low or inductively in the substations. The masts are therefore required for the inclusion of three conductor cables (or an integer multiple thereof, if they carry several circuits ) be equipped. For wires with a circuit usually the collinear arrangement is used. If only a small line width possible so an arrangement is in three planes offset at the mast useful. For two circuits collinear poles, masts Danube, fir poles and masts tons are used.

When wood poles, steel tube or concrete poles ( in the concrete plant manufacturing ), rare steel framework masts are mostly used.

In addition, such lines can also poles for high voltage ( 110 kV), its mostly installed on the lowest crossbar. In principle, with masts, which are designed for more than one circuit, not all circuits are installed on the same during the construction of the line. A subsequent installation of missing circuits at a later date is common.

Insulators stationary as well hanging insulators are used. The former allow a lower overall height of the towers, but the risk of lightning strikes in size. The latter provide greater security against lightning strikes and can carry larger loads. The lines on stationary insulators also represent a risk for large birds that land on the traverse between the insulators or leave and it can easily cause ground or short circuits. To avoid some lines are covered in the mast area with plastic covers or mounted a raised hide rod at a safe distance above the upper crosshead.

Ground wires are used in transmission towers for medium voltage systems only in exceptional cases.

A special feature of overhead lines in this voltage range are pylons, on a platform as a staging wear ( pole transformer ) and pylons on which one of the ground -to-use with a long pole isolating switch ( pole isolator ) is mounted.

High and very high voltage lines (50 kV and above )

As in the medium voltage level as three-phase systems are also in the high voltage level is always three-wire systems. The masts used must therefore also for the inclusion of three conductor cables (or an integer multiple thereof, if they carry several circuits ) be equipped. As insulators suspension insulators are always used as masts mostly steel truss towers ( pylons ), rarely tubular steel poles or concrete poles. Wooden poles are used in Germany only in exceptional cases.

Almost always a ground wire for lightning protection is used. For increased requirements for the lightning protection is the use of two earth wires, which are either mounted on top of the uppermost cross arm, a V-shaped or Erdseiltraverse Erdseilspitzen possible.

In Germany pylons for high and extra high voltage transmission lines are usually designed for the reception of two or more circuits. For two circuits of the Danube mast, the rare tree mast, tons mast or pole for a level arrangement is used in West Germany mostly. In East Germany is for overhead lines the collinear arrangement, a typical appearance. For masts for several circuits, it is not necessary to install all the circuits in the construction of the line on the masts. The practice of a subsequent installation of individual circuits is widespread.

And medium voltage lines are often carried out in parallel with these on pylons for 110 kV lines. Also, a parallel guidance of 380 kV, 220 kV and 110 kV lines on the same pole is common. Sometimes also carried out, in particular at 110 kV circuits, a parallel guide to railway power lines.

Traction current

Pylons for traction current lines correspond in their construction poles for 110- kV high- voltage power lines. It steel framework masts, rare tubular steel or concrete poles are mostly used. However, traction current systems are two-pole AC systems, so traction power poles for the addition of two conductor cables (or an integral multiple thereof, usually 4, 8 or 12) must be designed. As a rule, the masts of traction current lines carry two electric circuits, so they have four conductors. These are usually arranged in a plane, where a circuit is the right and the left half mast occupied. In four circuits traction power, the two-level and at six circuits traction power is the three-level arrangement possible. In confined spaces, the arrangement of a circuit in two levels is possible.

When run parallel to high-voltage lines for three separate cross-member is provided for the web circuits mostly. If traction current lines are led parallel to 380 kV lines, the insulation on 220 kV must be strengthened, since in case of failure of the three-phase line can carry dangerous power surges. Railway power lines are usually equipped with a ground wire. In Austria the use of two ground wires in railway power lines is common.

Railway power lines can be installed on a crossbar on extended catenary masts. This type of installation is useful for the supply of sub-stations of AC-powered commuter trains. Here, each of the two catenary masts equipped for a beam with a circuit mostly in two-circuit rail power lines along double-track railway lines. Occasionally, a two-level arrangement of the two circuits is used. The otherwise common at traction current lines a level arrangement is because oberleitungsmasten a smaller cross -section than conventional traction power pylons, for this purpose rather unusual.

High -voltage direct current transmission system

High -voltage direct current transmissions are (HVDC ), either one-or two -pole systems. For this reason, one or both pole lines are used here. In bipolar systems, a level arrangement of conductor cables is mostly used and on each half mast ever used a pole. Pylons for high-voltage direct current transmissions are mostly, sometimes equipped with a with two earth wires. In some systems, the ground wires are or used as a conduit for grounding electrode. This need to in order to prevent electrical corrosion of the masts to be attached to spark gaps bridged with isolators on the mast. In addition, the electrode lead may also be implemented as an additional conductor. With single-pole high-voltage direct current transmissions poles can be used with only one conductor cable. But the masts are already designed for a later two-pole expansion of the line frequently in such plants. In these cases, the conductors are static reasons often on two mast halves installed, with one pole is operated by the two-pole expansion as a conduit for grounding electrode or in parallel with the other pole either. In the latter case, the line of the converter station is adapted for grounding electrode as underground cables, or as a separate transmission line using the ground wire.

Electrode lines

In some HVDC line of the converter station for the ground electrode is partially or entirely implemented as a transmission line on a separate route. Such lines are similar in execution medium voltage lines, but with only one or two conductors. This, in order to prevent electrical corrosion of the masts to be always fixed by insulators thereon. As with medium voltage overhead lines masts can be performed for electrode leads as wooden pole, concrete pole or lattice tower.

Compact mast

Space-optimized or compact masts are defined as mast construction methods that lead to reductions of line widths for the same mast height or lower pole heights with the same line width. In the field of high voltage can be reduced by up to 50 % by compact mast construction methods with the same mast height, the route including protection zone. The width of the protective strip is approximately 18 m on either side of the mast axis at a height of masts between 40 and 60 meters - in compliance with all currently valid normative and technical specifications. The footprint of the compact poles is significantly less than that of conventional poles. The compact design ( depending on the arrangement of the conductors ) can also lead to a faster decrease of the electro- magnetic field strength compared to standard construction methods. At the same time gives a different visual appearance, which - was evaluated in public surveys tend to be more positive and modern, and thereby contribute to a higher acceptance in the population - depending on the solution. This was further demonstrated in numerous projects with compact masts in the high voltage range ( 110kV ). The lifetime of the compact poles is around 80-100 years. In the European network space-optimized lines are already being used in Italy, France, Denmark, Poland, Finland, Switzerland and the Netherlands.

Assembly

Pylons made ​​of wood or concrete to be delivered as a whole in the normally and erected at the site. This also applies to steel tubular poles. Also, lattice towers can be assembled lying down and then erected by cable. Although this method is interesting today because of the reduction of working above floor level, it is rarely used as a rule, because of the necessary installation space. Frequent lattice masts are hammered. That is, the individual boom sections ( shots, boom and tip) are lifted up individually by means of a mobile crane. Above the parts are attached and screwed by fitters. If enough space for a pre-assembly be present, you can also optionally together the individual parts of the so-called " upper part " with a loading crane. The advantage of this type of installation is the time and therefore money savings, since most cable construction companies need to hire a mobile crane. But this also increases the crop damage many times. High voltage towers in inaccessible places, such as in the mountains, are mounted with helicopters. It is also common, lattice masts by inserting additional elements to increase in height, for example, to increase the line height for construction projects under the line. Such work is usually done with a crane, sometimes with a helicopter.

Lattice towers can be disassembled if necessary and where appropriate rebuilt at a new location. However, this in practice quite usual approach is only useful for designs that are in good condition.

Identification

In addition to the obligatory high voltage warning sign pylons often have a sign with the name of the line to facilitate damage reports (either the end points of the line or the internal designation of the RU ) and the pole number.

Also use some regional operators color markings in the form of strips at the mast base or balls in the trusses.

In some countries must pylons, which are designed as steel truss structure, be provided to the corner posts with a few strands of barbed wire to prevent the unauthorized climbing. In Germany such constructions are only sometimes the case with pylons near fairgrounds or similar places.

Sign, Color markers and endpoints

Colored balls

Caption of masts

Stability

To check the stability of pylons there are special test stations where masts are built and the mechanical strength can be checked the same.

In certain weather conditions in cold weather snow freeze to the lines and run in conjunction with wind or storm in extreme cases, demolition of the lines or even collapse of masts. Examples:

• Snow disaster in North Germany, 1978 ( Northern Germany and East Germany); in winter 1978/79 there were three snowy fronts with some disastrous consequences.

• On 25 and 26 November 2005 and in the following days, there was, for example, in the cathedral country and surrounding areas to such weather situation in which buckled 82 poles or broke (see Munsterlander snow chaos. According to this ' snow chaos ' was known how old many of standing in Germany electricity pylons and that they are often built up in the 1970s from ( low-grade and relatively brittle ) Thomas Stahl ( see here).

To reduce the ice load in winter overhead lines can be held with de-icing systems. An example of a system for controlled de-icing of overhead lines is the Lévis - icer in Canada.

Special constructions

For the Implementation of branches occasionally quite impressive constructions must be built. This is true in three levels at times for Verdrillmasten in the arrangement of conductors.

Occasionally (especially on steel lattice towers for the highest voltage levels ) transmitting equipment installed on pylons. Mostly systems for mobile communications or the operating radio of the power company, but occasionally for other wireless services. So already transmitting antennas for FM radio and television stations have been installed on low power pylons. On the supporting mast of the Elbe crossing 1 is a radar installation of the Waterways and Shipping Office Hamburg. For crossing broad valleys, a large distance between the conductors must be chosen so that they can not beat even in a storm and cause a short circuit. In these cases, a separate pole for each phase is sometimes used.

For crossing wide rivers and straits very high pylons must be built in shallow coastal topography, since a large headroom is needed for shipping. Such poles shall be equipped with flight safety lamps. They have often also for maintenance of these facilities and stairs with railings provided catwalks. Two well-known intersections broad rivers are the Elbe crossing 1 and Elbe crossing 2 The latter has the highest overhead line masts in Europe (height: 227 meters).

Of particular interest are the two construction built in the 1950s pylons of Cádiz, Spain. For them it is about 160 meters high carrying pylons with a crossbar, which consist of a truncated cone-shaped truss structure.

The last remaining hyperbolic constructed Pylon used for crossing the Oka by the Nigres near Nizhny Novgorod, Russia.

The largest spans with overhead lines were in the overvoltage of the Norwegian Sognefjord ( at Leikanger span between two towers 4597 meters) and implemented in Greenland at Ameralik ( 5376 meters). In Germany, the overhead line erected in 1992, EnBW AG, the Eyachtal spans in courtyards, with 1444 meters, has the largest wingspan.

To perform down overhead lines into steep deep valleys, inclined pylons also be built occasionally. Such masts can be found for example in the United States at the Hoover Dam. In Switzerland, stands near Sargans an inclined by 20 degrees relative to the vertical pylon of the NOK. The two highest 380 kV pylons in Switzerland on the preliminary than running around 18 degrees inclined to the vertical 32-meter high masts Delta.

Sometimes the chimneys of power plants with the extension for the recording of stranded conductors of the outgoing lines were fitted. Because of possible problems with corrosion by the flue gases, such constructions are very rare.

Special pylons at which the conductors are guided in a framework is often found where there is a cable car across via an overhead line. They allow in the event of damage to the cable car to the continued operation of the line without any risk to rescuers and rescued.

Special locations

If it require culture- geographic conditions, then pylons also be placed in unusual locations. So already pylons were built over streams. The navigable Huddersfield Narrow Canal runs under the legs of a guy mast through. In the lake of Santa Maria in Switzerland a 47 -meter-high tension tower of a 380 - kV line to 28 -meter-high concrete plinths was built in the waters of the reservoir. Pylons for operating voltages above 1 kV are almost invariably set up as independent structures, although it would be theoretically possible to mount them on roofs of houses, factories or other buildings. One of the few exceptions is the mast 9108 the traction current by Fulda.

Near Hergisdorf there was a pylon under whose legs passing a standard gauge railway line. Also on bridges can be pylons. This is normal for catenary poles and telephone poles, but can also constructions exist on bridges, which allow the recording of circuits of high voltage lines. They are implemented as either small poles on the bridge or a bridge mounted on the support arm. A bridge is equipped with such arms, is the Danish Storstrømsbroen.

The Budapest street Margo Tivadar utca (47 ° 26 ' 20 " N, 19 ° 10' 21" O47.43888888888919.1725 ) runs between the legs of a single-circuit 110 kV line portal mast. Still bizarre is the location of three pylons in Dresden- Loebtau. You are right on the Grumbacher road.

Among the legs of the eastern pylon of the Rhine overhead line crossing a rice wood siding for a substation runs through it. In Uchihara, Ibaraki, Japan runs under the legs of a 45 meter high pylon a two-lane road

Designations

By Function

• Pylon
• Abspannmast
• Wide Abspannmast
• Verdrillmast
• Branch mast
• Credits portal
• Finishing period
• Pole transformer
• Pole isolator

Branch mast ( left) Pylon (right)

Branch mast

Credits portal

Finishing period ( at the substation )

Finishing period beginning with underground cables

Pole transformer

Transformer pole with pole isolator

Pole isolator

After the material used

• Wooden pole
• Concrete pole
• Steel tube mast
• Lattice mast

Concrete pole (110 20 kV)

Steel tubular poles

Lattice mast

After arrangement of the conductors

• Portal mast
• Delta mast
• A Bene mast
• Danube mast
• Three ebony pole
• Tons of mast
• Fir mast
• Compact mast

Delta mast

A Bene mast

Danube mast

Three ebony pole

Tons of mast

Fir mast

Tannenbaum mast of a hybrid cable with 4 levels and two lightning protection cables. The lowest level is a traction power line of DB energy.

Compact mast with Danube arrangement. Height 99 m, range 437 meters.

After site

• Roof rack
• Intersection mast

Intersection mast ( overhead lines only )

By Use

• Traction power pole
• Catenary Mast
• Hybrid mast
• Telephone Pole
• Telegraph pole ( usually no longer in operation)

Catenary Mast

Telephone Pole

Telegraph pole

Pylons in art and culture

• For the film Among Giants a now dismantled electricity pylon in the United Kingdom pink has disappeared ( Pink pylon ).
• In the Ruhr-Park is decorated with balls of mast 69 of the 2610 plant of RWE AG.
• In the coat of arms of North Korea, a Pylon is along with a hydropower plant.

Special Freileitungsmasten

Special constructions

Elbekreuzung 2

Hyperboloid electricity pylon

Pylons of Cádiz

Mast 4ZO251B

Eyachtal - Überpannung

C3 - mast

Sculpture " Geometric penetration" in Bochum

Mast with mobile phone antennas

Mast on the Strait of Messina