Warsaw radio mast

Poland's longwave broadcasting had rested since 1931 on the Raszyn transmitter, rebuilt in 1949 after the war with a 200 kW transmitter that was soon uprated to 500 kW. The original station had been sited to cover the Eastern Borderlands, and so the authorities had not taken into account reception in the Recovered Territories that the post-war frontiers brought to Poland. Even at 500 kW, Raszyn could not put a usable signal across the whole country.

In the late 1960s the decision was taken to build a new central transmitter near the geographical centre of Poland as its borders now ran. The choice of ground was researched at length, weighing soil resistance, the ownership of property and the quality of local roads. Gąbin was settled on for its central position, for the high conductivity of its soil, and for being clear of industry and of any large settlement.

Earthworks for the foundations began on 5 July 1969. Construction of the tower itself opened on 18 October 1972 with a ceremony at which the mast's footing was laid, and the assembly work ran from that October through to May 1974; the high-voltage supply installations were built between 1971 and 1973 and the station buildings between 1970 and 1973. The mast was designed by Jan Polak of the Mostostal M-1 design office in Zabrze, who had other Polish radio masts behind him, and the construction was directed by Andrzej Szepczyński of Mostostal M-4 in the same city.

What rose at Konstantynów was a guyed steel lattice mast of triangular section, assembled from 86 sections and held upright by fifteen guy cables in five levels of three. It reached 646.38 metres and weighed some 420 tonnes, and stood on insulator columns about two metres high because it carried a potential of up to 120 kV in operation. Its height was half the wavelength it radiated, so that the mast itself worked as a half-wave radiator.

Construction was finished on 18 May 1974. From its completion until it fell, the mast was the tallest structure in the world, having passed the KVLY-TV mast at Blanchard in North Dakota, which took the record back afterwards. Installation of the radio equipment had started in October 1973, the station took over the broadcast from Raszyn on 22 July 1974, and the official inauguration followed on 30 July. The opening drew extensive celebration and was filmed for the Polish Film Chronicle. Its two Brown, Boveri & Cie transmitters of 1,000 kW each, described as the largest in the world at the time, gave 2 MW from only two units in parallel. Carrying Polskie Radio's Program I, the signal reached Poles in Kazakhstan, Polish company workers in Iraq and Iran, almost the whole of Europe and as far as North America.

Zygmunt Duczmalewski managed the station from 1974 to 1980; Witold Czowgan held the post from 1983 to 1986. Thirty engineers and technicians worked the site alongside fifteen administrative staff. Because much of that workforce was recruited from across Poland, a block of flats was built for them at Sochaczew, thirty kilometres away, while the more specialised staff were put up in guest rooms in the transmission building. The guards were hired directly by the Ministry of the Interior, mostly from the local population of Konstantynów.

Inspection crews went up once a month in the Swedish-built Alimak climbing lift to change the bulbs in the aircraft warning lamps and to look for cracks in the steel. When a crack was found the transmitters were shut down, Raszyn took the broadcast, and welders from Mostostal Zabrze patched the fault with sheet metal. The same switchover covered storms, when the mast could not operate. The station worked on 227 kHz until 1 February 1988 and on 225 kHz thereafter; its frequency, generated from an atomic clock and held steady, served as a national frequency standard.

About ten years after completion, inspections turned up structural damage caused by wind-induced oscillation at the mast, at the backstay insulators and in the guys. Repair was judged expensive and difficult, and replacing the mast with a stronger structure of the same height was considered instead, but Poland's worsening economic position meant it was never done. Repainting began in 1988 and could not be finished because there was not enough paint. Shortages of equipment and of training for the maintenance teams left the mast severely degraded by the end of the decade: the poor state of the guys had been recorded as early as 1987, and an inspection in May 1989 found thirteen strands of the upper guys fractured. The top of the mast was also found at one point to lean several metres out of true. Set against all this was a plainer difficulty, that too little was known about the strains acting on a structure of that height.

On 8 August 1991 the mast came down during work to replace guy wires that were in bad condition; by then seven of the guy insulators had been damaged. How the failure began is told two ways. In one account a main cable was to be replaced by two temporary ones, and in the interval after the main cable was disconnected and before the temporary pair was secured, a gust of wind twisted the unmoored mast and pulled the remaining guys loose. In the other, one auxiliary line slipped out of its clamps and the second tore from its mounting, leaving nothing to balance the pull of the main cables still in place. In the first the unsupported mast bent and then snapped at roughly half its height; in the second the upper part broke off and struck the base, the whole structure down in a matter of seconds. Nobody was injured. Hours earlier the manager of the centre, the engineer Zygmunt Grzelak, had advised the six-man crew against going up at all, on the grounds that they could not finish the work before eight in the evening.

The transmitter building and the transmitters inside it survived undamaged, as did the overhead radio-frequency line that fed the mast, although that line was dismantled soon afterwards and only its supporting poles were left standing. A mobile crane belonging to Mostostal Zabrze was destroyed. Because the foreman had kept no construction log, the exact sequence of events was hard to establish afterwards.

The court proceedings ended in a sentence of two and a half years' imprisonment for the man in charge of the maintenance work for Mostostal Zabrze; by one account a second manager from the company responsible for maintaining the mast was convicted alongside him, and the term to which the sentence was later reduced is given as two years in one telling and as six months in another. On 23 March 1992 Adam Brzeziński, then managing director of Mostostal Zabrze, told Dziennik Zachodni that the company should have drawn up a technical report on the risks of repairing a strained mast before the work began. Seventeen years of neglect in operation were also counted among the indirect causes. Because the fall silenced Program I on longwave, a service Polish communities had relied on in distant parts of Europe, the timing invited suspicion in some quarters of a deliberate move to restrict the flow of information, pointed at the Moscow coup roughly a fortnight later and at the dissolution of Comecon and the Warsaw Pact in the preceding months.

Polskie Radio fell back on Raszyn and its 335-metre mast near Warsaw, which since 1978 had carried a second longwave service by day, and put 225 kHz out from there at 500 kW; the second frequency had to be discontinued, because Raszyn could not run both at once without interference. As early as April 1992 the government was planning to rebuild the mast at Konstantynów, precisely because longwave mattered to Poles living outside the country, and by September 1995 a decision to rebuild had been taken. The old foundations could be reused and work on refurbishing them had begun when protests from local residents, who held that radiation from the mast endangered their health, stopped the project; the accuracy of that claim was never established. A ruling of the Supreme Administrative Court's Łódź division on 11 October 1996 quashed the Płock voivode's decision on the rebuilding and closed the matter.

With residents' resistance continuing and backed by the Solidarity trade union, both the planned height and the intended range were cut back sharply and a new site was sought. An old military bombing range south-east of Solec Kujawski was chosen. There were protests there too, eased when Polish Radio gave PLN 3.5 million towards local development. The new facility was built in 1998–1999 and inaugurated on 4 September 1999, transmitting 1,200 kW on 225 kHz from two grounded masts of 330 and 289 metres. Raszyn then returned to the other longwave frequency, carrying Polskie Radio Parlament until it ended longwave transmissions in 2009.

At Gąbin almost everything but the mast and its feed line stayed where it was, unused and slowly deteriorating; the steel of the fallen mast was sold for scrap, and for several years a reduced staff kept the transmitters serviced and switched them on for tests into a dummy aerial. The site was administered from 2001 to 2012 by the real estate department of Telekomunikacja Polska at Płock, and after the 2012 merger with Orange by Orange Polska's Real Estate Sales Office, valued at PLN 3,650,000 and protected only against unauthorised entry. Local people came back to the remains on anniversaries, among them the twentieth in 2011, and a cross stands before the entrance, raised by residents connected with the Association for the Protection of Human Life at the Highest Mast of Europe, itself wound up by 2018. In July of that year Orange Polska handed the Brown Boveri transmitter to the association restoring the Transatlantic Radiotelegraph Station at Babice, which moved it to Warsaw to return it to partial working order for a museum. The relay tower on the site, out of use since 1998, was demolished at the end of September 2021, the 62 hectares of ground and its buildings had been sold on 10 April 2020 for 7 million złoty, and in 2022 demolition of what was left of the station began.