August 8, 1991: The Warsaw Radio Mast collapses. At the time, it was the tallest manmade structure in the world. Even today, the only structure built taller has been the Burj Khakifa which was completed in 2010. The mast was designed by Jan Polak and was 2,120.7 feet tall. Construction began in July 1970. The guyed steel lattice mast was made with equilateral triangular cross sections with a face width of 16 feet. The vertical steel tubes used in forming the vertices had a diameter of 10 inches and thickness of the walls of the tubes varied in width from 0.31 to 1.33 inches, depending on the height. There were 86 elements each measuring 25 feet and the mast had three arrays of guy wires attached at five levels between 399.5 feet and 1,949.7 feet from the ground. Each wire was fixed on a separate anchor block on the ground.
Construction was completed on May 18, 1974 and the transmitters began regular service on July 22. It was used by Warsaw Radio-Television for longwave radio broadcasting. In 1988, the frequency changed from 227 kHz to 225 kHz. Because of voltage potential, the mast was built on an insulated block 6.6 feet high. Signals from broadcasts could be received by the entire globe. The weight of the structure is debated but Polish sources claim it was 420 tons. The mast was also equipped with 16 levels of air traffic warning lights as well as a flashing beacon on the top. A substation was built to supply power to the mast and six small towers were built around the periphery of the grounds to support aircraft warning lamps.
Ten years after construction, examination revealed wind-induced damage secondary to oscillations of the mast, insulators, and the guys. Repair work was difficult and discussions were held about building an improved replacement. Due to Poland’s economy, this was abandoned. In 1988, the tower was to be repainted, but there was not enough paint to complete the job. On this day, repairs were underway. At 4 PM UTC, while exchanging the guy wires on the highest stock, a catastrophic error caused the collapse of the mast. The mast first bent and then snapped at roughly the half way point. The helix building and the transmitter building were not damaged.
An investigation into the cause of the error found that Mostostal Zabrze, the builder and company in charge of maintenance, were at fault. The construction coordinator and the chief of the Mostostal division in charge of construction were each sentenced to prison time. Since the collapse, the tallest structure in Poland has been the FM- and TV-mast Olsztyn-Pieczewo at 1,197.51 feet. Radio broadcasts are important throughout Poland and especially so to those Poles who live abroad. They have been able to maintain radio communication by switching to other sources. Today, the Warsaw site is cleaned up of the wreckage and the rest of the buildings are in disuse and slowly decaying.
A man’s errors are what make him amiable. – Johann Wolfgang von Goethe
Ignorance and error are necessary to life, like bread and water. – Anatole France
Error is the price we pay for progress. – Alfred North Whitehead
What passes for optimism is most often the effect of an intellectual error. – Raymond Aron
Also on this day: Great Train Robbery – Another One – In 1963, another train was robbed.
Around the World – In 1929, the first Zeppelin began a trip around the world.
Inhumanity – In 1938, construction began on Mauthausen Concentration Camp.
High Up – In 1786, Mont Blanc was first climbed.
Abbey Road – In 1969, Iain Macmillan took some pictures.