Warsaw radio mast

The Warsaw Radio Mast (Polish: Maszt radiowy w Warszawie) was a radio mast located near Gąbin, Poland, and was the world's tallest structure at 2,120 ft (646.30 m) from 1974 until its collapse on 8 August 1991. The mast was designed for extreme height in order to broadcast Communist propaganda around the world, including to the remotest areas such as Antarctica. As of 2023, it was the third-tallest artificial structure ever built, after the Burj Khalifa tower in the United Arab Emirates in 2009, and Merdeka 118 tower in Malaysia in 2022.

Designed by Jan Polak, its construction started with earthworks for the foundations on 5 July 1969, while construction of the tower itself began on 18 October 1972 with a ceremony, and was completed on 18 May 1974. Its transmitter, whose installation started in October 1973, entered regular service on 22 July 1974. The opening of the mast was met with extensive celebration and was covered by the Polish Film Chronicle. The tower was used by Warsaw Radio-Television (Centrum Radiowo-Telewizyjne) for radio broadcasting on a frequency of AM-LW (longwave) 227 kHz before 1 February 1988 and 225 kHz (1332m) afterwards. Its base was 115.2 metres (378 ft) above sea level. Because there was a potential difference of 120 kV between the mast and ground, it stood on a 2-metre (6.6 ft)-high insulator. It operated as a mast radiator (half-wave radiator), so its height was half of its 1332m broadcasting wavelength. The signals from its 2 MW transmitters could be received across essentially the entire globe. The structure's weight was debated, with some Polish sources claiming it weighed 420 tonnes (930,000 lb).

The mast was designed for national pride, mainly because of the height of the mast, which made it the tallest structure in the world at the time, surpassing the KVLY-TV mast in Blanchard, North Dakota, US. It was also designed to broadcast the "propaganda of the successes." Due to the mast's height, listeners from all over the world could tune in to Polish radio broadcasts, including those in remote places such as Antarctica.

The official name of the facility was Radiofoniczny Ośrodek Nadawczy w Konstantynowie (Radiophonic Transmission Centre Konstantynów), Radiowe Centrum Nadawcze w Konstantynowie (Radio Transmission Centre Konstantynów; RCN Konstantynów) or Warszawska Radiostacja Centralna (WRC) w Gąbinie (Warsaw Central Radio Station Gąbin). It broadcast Polskie Radio's Program I (unofficially referred to as "Jedynka"). The transmitter was so powerful that Program I could be received in parts of Canada and the United States.