Warsaw radio mast - AbsoluteAstronomy.com

The Warsaw radio mast was the world's tallest structure until its collapse on 8 August 1991. It is the second tallest land-based structure ever built, being surpassed as tallest by the Burj Khalifa, completed in 2010.

The mast

Radio masts and towers

Radio masts and towers are, typically, tall structures designed to support antennas for telecommunications and broadcasting, including television. They are among the tallest man-made structures...

, which was designed by Jan Polak, was 646.38 metres (2,120.67 ft) tall. Its construction, started in July 1970, was completed on 18 May 1974, and its transmitter entered regular service on 22 July of that year. It was located in Konstantynów, Gąbin

Gabin

Gąbin is a small town in Płock County, Masovian Voivodeship, Poland, with 4,230 inhabitants . It is an ancient town, having been founded in the 13th century.-Current events:...

, Poland

Poland

Poland , officially the Republic of Poland , is a country in Central Europe bordered by Germany to the west; the Czech Republic and Slovakia to the south; Ukraine, Belarus and Lithuania to the east; and the Baltic Sea and Kaliningrad Oblast, a Russian exclave, to the north...

, and was used by Warsaw Radio-Television (Centrum Radiowo-Telewizyjne) for longwave

Longwave

In radio, longwave refers to parts of radio spectrum with relatively long wavelengths. The term is a historic one dating from the early 20th century, when the radio spectrum was considered to consist of long, medium and short wavelengths...

radio broadcasting on a frequency of 227 kHz before 1 February 1988 and 225 kHz afterwards. Its base, according to Google Earth, was 115.2 metres above sea level. Because a voltage potential of 120 kV was desired between the mast and ground, it stood on a 2-metre-high insulator. It operated as a mast radiator

Mast radiator

A mast radiator is a radio mast or tower in which the whole structure itself functions as an antenna. This design is commonly used for transmitting antennas operating at low frequencies, in the VLF, LF and MF ranges, in particular those used for AM broadcasting. The metal mast is electrically...

(half wave radiator), so its height was chosen in order to function as a half-wavelength antenna at its broadcasting frequency. The signals from its 2 megawatt transmitters could be received across all of Europe

Europe

Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...

, North Africa

North Africa

North Africa or Northern Africa is the northernmost region of the African continent, linked by the Sahara to Sub-Saharan Africa. Geopolitically, the United Nations definition of Northern Africa includes eight countries or territories; Algeria, Egypt, Libya, Morocco, South Sudan, Sudan, Tunisia, and...

and as far away as North America

North America

North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...

. Its weight is debated: 380 tonnes, 420 tonnes, 550 tonnes and even 660 tonnes have been cited, probably the result of inaccurate unit conversions by translators

Translation

Translation is the communication of the meaning of a source-language text by means of an equivalent target-language text. Whereas interpreting undoubtedly antedates writing, translation began only after the appearance of written literature; there exist partial translations of the Sumerian Epic of...

. Polish sources claim 420 tonnes.

Construction

The Warsaw radio mast was a guyed steel lattice mast of equilateral triangular cross section, with a face width of 4.8 m. The vertical steel tubes forming the vertices of the mast had a diameter

Diameter

In geometry, a diameter of a circle is any straight line segment that passes through the center of the circle and whose endpoints are on the circle. The diameters are the longest chords of the circle...

of 245 millimetres; the thickness of the walls of these tubes varied between 8 and 34 millimetres depending on height. The mast consisted of 86 elements, each of which had a length of 7.5 metres. The mast had 3 arrays of guy wires, each attached to the mast at 5 levels, 121.78 metres, 256.78 metres, 359.28 metres, 481.28 metres and 594.78 metres above ground.http://www.inzynierbudownictwa.pl/drukuj,257 Each guy was fixed on a separate anchor block at the ground and was 50 mm in diameter. To prevent the guy wires from interfering with the radio transmissions, the guys were insulated at regular intervals. The weight of guys and insulators used to anchor the mast was 80 metric tons. An elevator and separate protected ladders were installed in the interior of the mast to facilitate access to the various mast components, including the aircraft warning lamps. The elevator had a maximum speed of 0.35 m/s and required 30 minutes for a trip from the bottom of the structure to the top.

In the lower half of the mast, there was a vertical steel tube, attached to the mast's outer structure with large insulators. This tube was grounded at the bottom, and connected electrically to the mast structure at half the total height. This technique works by applying a DC

Direct current

Direct current is the unidirectional flow of electric charge. Direct current is produced by such sources as batteries, thermocouples, solar cells, and commutator-type electric machines of the dynamo type. Direct current may flow in a conductor such as a wire, but can also flow through...

ground at a point of minimum radiofrequency voltage, conducting static charge to ground without diminishing the radio energy. Static electrical charge can build up to high values, even at times of no thunderstorm activity, when such tall structures are insulated from ground. Use of this technique provides a better lightning protection than using just a spark gap at the mast feed, which is standard at most mast radiators insulated against ground.

A special overhead radio frequency transmission line

Radio frequency power transmission

Radio frequency power transmission is the transmission of the output power of a transmitter to an antenna. When the antenna is not situated close to the transmitter, special transmission lines are required....

was used to transfer the signal from the transmitter building to the mast. The transmitter building, situated at 52°22′22.9"N 19°48′25"E, had a volume of 17,000 cubic metres and was approximately 600 metres from the mast. The transmitter consisted of two 1,000 kilowatt units built by Brown Boveri and Cie. An atomic clock

Atomic clock

An atomic clock is a clock that uses an electronic transition frequency in the microwave, optical, or ultraviolet region of the electromagnetic spectrum of atoms as a frequency standard for its timekeeping element...

was used to generate the transmission frequency in order to provide a very accurate, stable signal source which could be used as a frequency standard by anyone within signal range. The station, which had an area of 65 hectares, also had a 76 metre lattice tower of rectangular cross-section close to the transmitter building, at 52°22′23.6"N 19°48′24.4"E. This tower was used to provide a radio link for programme feeds from the studio.
To supply power to the station a 110 kV substation was built. The substation was over-engineered due to the strategic importance of the station as Poland's central transmitter. Although the power consumption of the transmitting station was large (estimated 6,000 kW), the substation was capable of supplying much more than was required.

Six small towers were erected around the periphery of the station's grounds in order to support aircraft warning lamps where the guy ropes were located. They are situated at 52°22′17.4"N 19°48′9.7"E, 52°21′53.8"N 19°48′6.3"E, 52°21′57.1"N 19°47′48"E, 52°21′55.8"N 19°48′27.6"E, 52°22′6.1"N 19°48′24.3"E, and 52°22′8.1"N 19°47′54.4"E.

The official name of the facility was Radiofoniczny Ośrodek Nadawczy w Konstantynowie (Radiophonic Transmission Center Konstantynow), Radiowe Centrum Nadawcze w Konstantynowie (Radio Transmission Center Konstantynow) or Warszawska Radiostacja Centralna (WRC) w Gąbinie (Warsaw Central Radio Station Gabin). It broadcast Polskie Radio

Polskie Radio

Polskie Radio Spółka Akcyjna is Poland's national publicly funded radio broadcasting organization.- History :Polskie Radio was founded on 18 August 1925 and began making regular broadcasts from Warsaw on 18 April 1926....

's Program I.

Approximately ten years after completion of the mast, inspections revealed structural damage caused by wind-induced oscillations at the mast, the backstage insulators and the guys. Repair work was very difficult and replacement of the mast by a stronger construction of the same height was considered. However, this was not realized, as a result of Poland's economic situation. In 1988 the mast was repainted, but this could not be done to the desired extent, as there was not enough paint available.

Collapse

On 8 August 1991 at 16:00 UTC a catastrophic failure

Catastrophic failure

A catastrophic failure is a sudden and total failure of some system from which recovery is impossible. Catastrophic failures often lead to cascading systems failure....

, caused by an error in exchanging the guy-wire

Guy-wire

A guy-wire or guy-rope, also known as simply a guy, is a tensioned cable designed to add stability to structures . One end of the cable is attached to the structure, and the other is anchored to the ground at a distance from the structure's base...

s on the highest stock, led to the collapse of the mast. The mast first bent and then snapped at roughly half its height. The helix building

Helix Building

A helix building is a small structure at the base of a longwave or mediumwave radio transmitter. Within, there are capacitors and coils for coupling the signal from the feed cable to the antenna. Active components such as amplifiers are usually not housed in a helix building...

and the transmitter building (including the transmitter devices in it) were not damaged.

An investigating committee determined that blame lay with Mostostal Zabrze, which built and maintained the mast. The construction coordinator and the chief of the Mostostal division that built the mast were accused of causing the collapse. The former was sentenced to two and a half years in prison

Prison

A prison is a place in which people are physically confined and, usually, deprived of a range of personal freedoms. Imprisonment or incarceration is a legal penalty that may be imposed by the state for the commission of a crime...

, the latter to two years.

Since the collapse of the Warsaw radio mast, the tallest structure in Poland has been the FM radio and TV transmission mast at Olsztyn-Pieczewo

FM- and TV-mast Olsztyn-Pieczewo

The FM- and TV-mast Olsztyn-Pieczewo is a 365 metre tall guyed mast for FM and TV situated at Olsztyn-Pieczewo in Poland The FM- and TV-mast Olsztyn-Pieczewo (also known as Maszt RTCN Olsztyn-Pieczewo) is a 365 metre tall guyed mast for FM and TV situated at Olsztyn-Pieczewo in Poland The FM- and...

, measuring 360 metres.

After the collapse, the KVLY-TV mast

KVLY-TV mast

The KVLY-TV mast is a tall television-transmitting mast in Blanchard, Traill County, North Dakota, United States, used by Fargo station KVLY-TV channel 11...

outside Fargo, North Dakota

Fargo, North Dakota

Fargo is the largest city in the U.S. state of North Dakota and the county seat of Cass County. In 2010, its population was 105,549, and it had an estimated metropolitan population of 208,777...

, USA, regained its title as the world's tallest structure, standing 628.8 m (2,063 ft), until the Burj Khalifa exceeded this height in April 2008.

Replacement

After the collapse of the radio mast at Konstantynów, the Polish broadcasting company used the old Raszyn transmitter

Longwave transmitter Raszyn

The longwave transmitter Raszyn is a longwave broadcasting transmitter near Raszyn, Poland. It was built in 1949. Until 1962, its radio mast was, with a height of 335 metres, the tallest structure in Europe....

with its 335-metre-high mast near Warsaw

Warsaw

Warsaw is the capital and largest city of Poland. It is located on the Vistula River, roughly from the Baltic Sea and from the Carpathian Mountains. Its population in 2010 was estimated at 1,716,855 residents with a greater metropolitan area of 2,631,902 residents, making Warsaw the 10th most...

, which had been used since 1978 for daytime transmissions of a second Polish broadcasting service programme in the longwave range on the frequency 198 kHz, for transmissions on 225 kHz with a power of 500 kilowatts. It is not possible to transmit from Raszyn on 198 kHz and 225 kHz simultaneously, so the transmissions on the second longwave frequency 198 kHz had to be discontinued until either a second longwave broadcasting transmitting facility was built in Poland or a special frequency switch, which would allow transmissions on both frequencies, was installed at the Raszyn transmitter. The latter, simpler solution would have decreased the effectiveness and reliability of both transmitters and was therefore found unacceptable.

Because the Polish longwave transmitters are of special importance to Polish people abroad, as early as April 1992 the Polish government planned to rebuild the mast at Konstantynów. In September 1995 the Polish government was set to rebuild the mast. Although refurbishment of the old basements, which could be reused, had already started, the rebuilding of the mast was cancelled due to protests by local residents, who claimed that radiation from the mast was a health hazard. While the accuracy of these claims has not been verified, a new site for the transmitter was sought. Several other locations were considered, but due to the continuing resistance of nearby inhabitants (backed by the Solidarity trade union), planned mast height and transmitter range were both greatly reduced, and an old military site just southeast of Solec Kujawski

Longwave-transmitter Solec Kujawski

The Longwave transmitter Solec Kujawski is a longwave broadcasting facility of the Polish broadcasting company for the 225 kHz frequency. Its construction was necessary after the collapse of the Warsaw radio mast on August 8, 1991 and the resistance of the local population to its reconstruction.The...

was chosen. There, a new longwave transmission facility was built in 1998-99, with a transmitter of 1200 kW output power for the frequency 225 kHz. This facility, which was inaugurated on September 4, 1999, uses two 289-metre-high grounded upfeed masts 330 metres apart, as aerials

Antenna (radio)

An antenna is an electrical device which converts electric currents into radio waves, and vice versa. It is usually used with a radio transmitter or radio receiver...

.

After the inauguration of the transmitter at Solec Kujawski, the transmitter at Raszyn was again used for transmitting on the frequency 198 kHz for the programme Radio Parliament.

Current state

Except for the mast and the radio frequency transmission line that led to it, nearly all components of the facility remain in place, unused and slowly deteriorating.

There are several plans to transform the former transmitter building into a technical museum. In spite of the historic importance of the site, there is no support for this idea from officials.

Replicas

Eldorado do Sul RBS Radio Mast

Eldorado Do Sul RBS Radio Mast

Eldorado do Sul RBS Radio Mast is the tallest man-made object in Brazil. Eldorado do Sul RBS Radio Mast is used by Rede Brasil Sul Communication Group for medium-wave broadcasting on 720 kHz with 100 kW...

, a mast radiator

Mast radiator

in Eldorado do Sul

Eldorado do Sul

Eldorado do Sul is a municipality in the state of Rio Grande do Sul, Brazil. It is located in the metropolitan area of Porto Alegre, the state's capital and largest city, opposite the capital on the right bank of Guaíba River. Population: 33,098 ....

, Brazil

Brazil

Brazil , officially the Federative Republic of Brazil , is the largest country in South America. It is the world's fifth largest country, both by geographical area and by population with over 192 million people...

, is a nearly perfect replica of Warsaw Radio Mast with 35.5% of its height.

Construction

Collapse

Replacement

Current state

Replicas

See also