The Tadeusz Zastawnik intake ventilation shaft of ZG Polkowice-Sieroszowice, sunk to 1,216 metres to supply the Głogów Głęboki-Przemysłowy copper deposit.
Szyb SW-4, named Tadeusz Zastawnik, is a deep intake ventilation shaft of the ZG Polkowice-Sieroszowice mine operated by KGHM Polska Miedź S.A. in Lower Silesia. Preparatory works began in 2005 and shaft sinking commenced in June 2008. The shaft was sunk to a depth of 1,216 metres using ground-freezing techniques to 650 metres depth, mechanical cutting to 408 metres, blasting below that, and a specialised arch-profile lining through a 155-metre rock salt layer at 1,027–1,182 metres.
The technical breakthrough connecting the shaft to the underground workings of ZG Polkowice-Sieroszowice was achieved on 17 July 2013. On 25 July 2013 the shaft was ceremonially named in honour of Tadeusz Zastawnik, director-general of the Kombinat Górniczo-Hutniczy Miedzi from 1962 to 1975, credited with securing state support for the development of the entire copper district. The shaft's designed ventilation capacity is 72,000 cubic metres of fresh air per minute.
It was the thirtieth shaft constructed in the Legnica-Głogów Copper Belt by Przedsiębiorstwo Budowy Kopalń PeBeKa.
The site for szyb SW-4 was identified in 2004 as a strategically essential shaft for accessing the Obszar Górniczy Głogów Głęboki-Przemysłowy, a deep copper ore deposit north of the existing ZG Polkowice-Sieroszowice workings. This deposit, assessed at over one billion tonnes of copper ore and containing approximately 25 per cent of KGHM's copper reserves and over 30 per cent of its silver reserves in Poland, could not be reached without an additional deep ventilation shaft to supply fresh air to the deepest working levels. Preparatory works at the shaft site began in 2005: ground survey, macrolevelling, and laying the concrete slab required for drilling the ground-freezing boreholes.
Ground freezing of the water-saturated overburden commenced in October 2007. Construction of the headframe and surface infrastructure proceeded in parallel. Shaft sinking began on 30 June 2008, when the first bucket of spoil was raised.
The first section of sinking, to a depth of 408 metres, was carried out using a mechanical heading system employing a roadheader cutting head adapted from coal-mining technology. Below 408 metres, where the ground became harder sandstone, the method was changed to blasting. Ground freezing was maintained throughout the frozen section to prevent water inflow; the frozen zone extended to 650 metres depth.
A tubing lining was installed over the first 665 metres of the shaft to protect against the highly mineralised groundwater of the Tertiary and Triassic formations. Below 650 metres, freezing was discontinued and concrete and reinforced concrete lining was used instead. By July 2012 the shaft had reached 1,000 metres depth.
At that depth, construction encountered a 155-metre rock salt layer between 1,027 and 1,182 metres. The compressive rheological behaviour of salt required the adoption of an arch-profile lining using V 25 profiles, a technology applied for the first time at this scale in the Legnica-Głogów Copper Belt. A KDS-2 roadheader was lowered into the shaft and used to cut the salt section.
The shaft required a widened diameter of 10 metres during this phase before returning to its operational diameter of 7.5 metres. On 17 July 2013 the technical breakthrough — the zbicie, or connection of the vertical shaft to the horizontal workings of the ZG Polkowice-Sieroszowice mine — was achieved at a depth of 1,216 metres. SW-4 was the thirtieth shaft built by Przedsiębiorstwo Budowy Kopalń PeBeKa in the Copper Belt.
On 25 July 2013 the shaft was formally opened and named Tadeusz Zastawnik, in honour of the director-general of the Kombinat Górniczo-Hutniczy Miedzi in Lubin from 1962 to 1975. Zastawnik, credited as the builder of the copper district's three original mines and smelters, had persuaded the Polish state authorities to continue the investment in copper mining at a time when its future was in question. A commemorative plaque was unveiled at the shaft on the occasion of the naming ceremony.
In its initial operational phase following the breakthrough, SW-4 supplied approximately 10,000 cubic metres of fresh air per minute to the underground workings below 1,100 metres, with capacity planned to increase to 20,000 and ultimately to 70,000–72,000 cubic metres per minute following completion of equipping works. Completion of the shaft's steel reinforcement, surface structures, and pithead buildings was planned for 2015.