Historical, legal and organisational determinants of mining and conservation protection of historical pits in the Bochnia Salt Mine

The objective of this article is to present hitherto accomplishments in the area of protection of the mine understood as a monument in a legal sense. They are presented in reference to securing activities in the mine, effected throughout the history of its functioning. These issues have not been presented in a synthetic manner so far. The basic source material for the study was information accumulated in the course of documentation work conducted by the employees of the Cracow Saltworks Museum Wieliczka (in cooperation with engineers and technical employees from the Bochnia Salt Mine) underground. The manner of presentation of issues discussed in the study derives from an analogous article pertaining to the Wieliczka Salt Mine, presented in volume XXIII of this yearbook. The necessity of securing the mining pits in the Bochnia Salt Mine has been apparent since the very beginning of its commercial operation. Various solutions were applied, frequently quite untypical, adjusted to the specific geological structure of the deposit. The basic material was wood, used to line the rising headings, as well as drifts in the weak rock mass. Extensive chambers were propped up with support columns, usually filled with mining spoil and contaminated salt types. The specific nature of the Bochnia Salt Mine was that the support columns were constructed of thin alder and birch trunks. Support columns made of thick pine, spruce or fir wood were rarely used. Some of the selected areas were liquidated by being completely filled with waste rocks and post-production waste. Smaller of them, left without any means of protection, were completely clamped after several centuries. The original form of securing the chambers from the progressing destruction was leaving them at the edge of a thin salt shell. Until the 18th century, transport routes were designated in some of them via lining or support columns, which connected exploitation areas located on various depths. Conservation work in the legal sense began only after inclusion of the mine in the list of monuments in 1981, even though some of the projects undertaken earlier had this objective in mind, especially in the underground chapels. Mining and conservation work is performed in a zone included under protection, i.e. on levels from I to IX, in most valuable mining pits, selected on the basis of substantive criteria with respect to the values of the mining pits. The selection was made by the employees of the Cracow Saltworks Museum Wieliczka on the basis of materials accumulated during the systematic scientific and technical stock-taking conducted in the 1970s and 1980s; the list was approved by the Małopolska Province Monument Conservator in Kraków. It includes 65 chambers, 112 drifts, 3 shafts and 4 fore-shafts. Furthermore, the most valuable regions of the mine with respect to natural assets were encompassed by a detailed stocktaking in 2005 and subjected to additional legal protection on the basis of the Nature Conservation Act in the form of 27 documentation sites. The conservation authorities have also formulated guidelines pertaining to the procedure of preparing and performing work in the historical pits. The starting point is preparation of a historical and conservation study and subsequently a technical design relying on its recommendations. On this basis, permits are issued for the conduct of work in protected shafts, chambers and drifts. Direct supervision over the performance of work until 1999 was the obligation of the Province Monument Conservator in Tarnów, and later the Małopolska Province Monument Conservator in Kraków and, since 2016, the Cracow Saltworks Museum Wieliczka. The basic source of financing for the conservation projects are funds deriving from the state budget, which may be formally assigned for such a purpose since 2000. Earlier (since 1991) they were fully assigned to liquidation work. As of 2000, funds assigned for specific projects from the National Environmental Protection and Water Management Fund constitute a significant supplement for the financing. Relatively small funds are also generated by the tourist and spa activities pursued since 1995. The majority of mining and conservation work was performed by the mining team of the Bochnia Salt Mine. Tasks calling for specialist equipment and special qualifications of employees were commissioned from external companies. The basic part of the work was concentrated on levels from I to IV, in mining pits that are the most valuable with respect to the presented historical values. The speed of work gained momentum after the mine was classified as the monument of history (2000). Initially, the work focused on securing pits that are assigned for being made available to tourists on level IV, i.e. the August Chamber, and on level VI: the Sienkiewicz Chamber and the Dobosz Inter-level. As a result of them, in 1995 the conditions in the mine allowed for admission of organised groups to the mine for the first time in history. Later, work was conducted in drifts and chambers assigned for thematically oriented exhibitions. In the first period, the greatest mining and conservation projects included securing the central part of the August Drift, along with adjoining corridors and the extensive Ważyn Chamber. Its adjustment to perform recreational and sanatorium-type functions required a lot of effort. In the second stage, work performed in the complex of mining pits called Zejście Kalwaria, spreading from level I Danielowiec to level IV August, was of great importance, as well as work at eleven sections of Regis Stairs connecting these levels. It is also necessary to mention professional conservation of the 18th century Passionis Chamber and opening the 17th century Krucyfiks Chamber for tourists. Performance of mining and conservation work has acquired a special rank and should be an absolute priority after inclusion of the Salt Mine in the UNESCO World Heritage List in 2013