The mercury mine has throughout its existence dedicated particularly
attention to the functioning of apparatuses for raising the ore from
shafts and to the pumping of pit water. By the end of the 16th century,
as miners reached a depth of 200 meters, they ensured the power for the
aforementioned apparatuses by constructing huge wheels that were driven
by a stream of water. Eminent master, famed throughout Central Europe,
constructed gigantic spade-shaped wheels – KAMŠTI (derived from German
Waserkunst, i.e. 'water craft') in the middle of the town near
Acacius's and Barbara's Shafts, the equals of which could be found at
no other mine in the world. Around the year 1600, the Idrijca river was
dammed at Kobila above the Wild Lake, and a 3.5 km long channel (called
»Rake«) was constructed to ensure the undisturbed flow of the water and
provide the needed power for the wheels. In the 17th century, the
mine's hoisting and pumping apparatuses were admired by numerous
foreign experts and travelling writers, whereas our polyhistor Valvasor
wrote in his Fame of the Duchy of Carniola from 1689 that the wheels of
Idrija's 'kamšt' measured from 7.5 to 9.5 meters.
Today's visitors to Idrija's monuments may view these water wheels as a reminder of the mine's period of greatest prosperity at the end of 18th century. The imposing and technically improved pumping apparatus was installed in 1790 close to the newly constructed Joseph's Shaft and is the sole remaining device of this type in Slovenia that still stands on its original location. The spade-shaped wheel with a diameter of 13.6 meters, and positioned in the monumental brick building, is reputed to be the largest wooden wheel in Europe. This wheel, reinforced with strong steel parts and clamps, was attracted, by means of a handle and a shaft, to a 69-meter-long perpendicular system of wooden poles, extending all the way to Joseph's Shaft. By means of a special three-arm lever system, the horizontal movement was transmitted to the vertical wooden poles, which were linked to multi-stage piston pumps. The wheel complex (»kamšt«) pumped approximately 400 litres of water per minute, first from a depth of 235 meters (9th horizon), and later even from a depth of 283 meters (11th horizon). In the 1847, the suction pump was replaced by a compressive one.
This device operated almost ceaselessly and in unchanged form for a record breaking 158 years, until 1948, when the old dam at Kobila beside the Idrijca river was damaged and the inflow of water via Rake was interrupted. it is interesting to note that this wheel system served its purpose even several decades after the mine had been equipped with machinery powered by steam and electricity. The total power of the wheel complex (»kamšt«) ranged from 75 to 100 HP, wheel itself turned 4.5 times per minute.
More information on the website: www.muzej-idrija-cerkno.si