The pumping of pit water holds a very important place in mining and technology in general. Within the scope of extensive modernisation works after its nationalisation in the late 16th century, the mine, which continuously followed the latest technical achievements of the time, built a dam on the Idrijca River above Wild Lake and a 3.5 kilometre-long channel named »Rake« for driving the kamšt in the center of Idrija. The preserved kamšt – a wooden water wheel for pumping pit water (German: Wasserkunst) – dates from the period of the mine's exceptional prosperity in the late 18th century, when excavation works were begun in Joseph's Shaft. The kamšt was erected in 1790 and operated until 1948.
Standing in the stone building is an overshot water wheel with cavities (diameter: 13.6 m), reputed as being the largest preserved wooden water wheel of its kind in Europe. The rotation of the driving wheel's shaft was transmitted, via a handle, pole and a system of horizontal rods in a length of 75 m, to the pumping rods by means of two three-arm levers. Pumping was carried out in three stages, and the piston pumps were positioned on levels XI, IX and III, one of which was illuminated. The water-driven wheel made 4-5 turns in a minute, and the pumps had a pumping capacity of approximately 300 litres of pit water per minute from a depth of 283 metres below the surface. This is the only pump of its kind in Slovenia, and still stands on its original location. Today, the dam near Kobila on the Idrijca River and the 400-year-old Rake channel continue to provide inflowing water for the needs of the town's hydro power plant.
Mine Locomotives
On display in the former loading station of the cableway of Joseph's Shaft are four locomotives and five cars for transporting ore.
In the mid 19th century (around 1850), the Idrija Mine set up a horse-drawn railway for the transport of ore from its shafts to the smelting plant. Large wooden freight cars, also called horsecars, were used to transport fine-grained ore. One such car has been preserved, and is the oldest preserved freight car of the horse-drawn railway in Slovenia.
The invention of voltage transformers enabled the development of electric street railways. For almost half a century, the streets of Idrija and the rare road traffic of that time were dominated by the mine railway. As a replacement for horse-drawn cars, the Mine purchased in 1902 two electric locomotives from the Siemens&Halske factory in Vienna for the transport of ore from Joseph's shaft to the separation plant (ore sorting and crushing facility). In the same year, the Mine also purchased from the same factory two big locomotives for 1000 mm-wide tracks for the transport of ore from the separation plant to the smelting plant. The length of the railway line travelled by the electric locomotive from the bunkers of Joseph's Shaft to the separation plant was 700 m, and from there to the smelting plant 850 m, altogether 1550 m. Both locomotives are the oldest preserved electric locomotives in Slovenia.
For the transport of ore in the smelting plant, the Mine purchased in 1912 two petrol-powered locomotives from the Deutz Werke factory for 500 mm-wide tracks. In 1916 an additional locomotive was purchased from the same manufacturer, and has been preserved to this day.
On 31 January 1957, ore was transported by the big electric locomotive for the last time. The very next day, a cableway began to operate from the new loading station to the separation and crushing plant above the smeltery in a length of 1100 m.