SW-4 Shaft – a half kilometre deep in the earth

SW-4 Shaft – a half kilometre deep in the earth

Published 02 November 2009

A tubbing ring No. 326 was built into SW-4 shaft by the miners of KRG Shaft region of PeBeKa Lubin. After 16 months of shaft sinking the level of 500 metres has been reached. It is the next decisive moment of one of the biggest in the country mining undertaking which is within the scope of unproductive development. 

SW-4 Shaft is the key investment made by PeBeKa for KGHM Polska Miedź S.A. It is aimed at improving the mining work conditions and up to now developing disused copper ore deposit. The shaft will function as part of structure of Zakłady Górnicze Polkowice-Sieroszowice. 

- SW-4 shaft sinking realization goes according to programme of Works – assures Jacek Kulicki, the President of PeBeKa – achived progress and work quality are very good, and their measure is a high apprasial made by investor’s service and experienced foreign experts who visit the site. 

SW-4 is built in Łagoszów Mały near Głogów. A worldwide unique shaft sinking technology together with rock formation freezing is used by PeBEKa on the construction. The works have been done since July, 2005. Till September 2007 station of cooling aggregate was installed and set working together with rock formation freezing. The first winning hoppit was extracted from the shaft on 30th June 2008 by crew from PeBeKa. After 16 month another turning point came in construction – sank shaft reached a depth of 0.5 kilometres.

409 metres of the shaft has been sunk thanks to a unique technology of machine mining of rock formation by using a heading machine. The rock mass was constantly freezing while sinking this section, done by closed system in forced circulation of saline solution (cooling down in cooling aggregate station) through piping system of freezing holes built over around the shaft.

After reaching a depth of 409 metres, geological formation such as sand and brown coals layers and varved clays were replaced by solid rock, causes the change of shaft sinking metod. The stage of shaft sinking by using KDS-2 shaft complex has been finished and 
the reconstruction of shaft technology equipment has been made. At the moment winning of rock mass is carried out by shooting and are continuing under the shield of cooling jacket. Using this special shaft sinking method together with rock mass freezing tilll a depth of 650 metres is the great pride of PeBeKa, perfectly showing the possibilities of company at sinking in difficult hydrogeological conditions.

The miners of PeBeKa must still sink over 700 metres of shaft in difficult and changeable conditions. It comes the moment that the changes in technology of work execution will be necessarily done. It is connected with a way out of freezing zone, other changes of geological construction and designed shaft lining. The company is already preaping to go through rock-salt startum at a thickness of over 150 metres for safety and keeping the lining function.

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