Kamšt Idrija water-driven pump
The Idrija water-driven pump (Sln. kamšt, derived from Germ. Wasserkunst) is a pump that was set up in 1790 in the Joseph shaft to aid operations in the mercury mine in Idrija. It served to bring ore up from the shaft and pump out water. The oak paddlewheel, with a diameter of 13.6 m, which is recognized as the largest wooden wheel in Europe, is on view in a monumental building located in Mejca Park along the Idrijca River. The wheel, reinforced with strong steel fittings and bindings, was connected to a 69 m long horizontal wooden beam through levers and connecting rods. The beam reached the Joseph shaft. Its horizontal motion was transferred to a vertical wooden beam, which was connected with staged piston pumps, through a special three-pronged transfer device. The pump could pump around 400 liters of water per minute, first from a depth of 235 m (the ninth horizon) and later even from a depth of 283 m (the 11th horizon). In 1847 they replaced the suction action of the pump with pressure action. The equipment operated practically without interruption for 158 years, until the flood of 1948, when the old dam at Kobila broke and the flow of water through the flume was interrupted. The flume was a 3.5 km long canal that was built around 1600 to provide an uninterrupted flow of water to power pumps that were the predecessors of the water-driven pump preserved until today. The water-driven pump operated another decade after that, when the mine had already been equipped with machines using steam and electric engines. The pump had around 75 to 100 horsepower, and the wheel turned 4.5 times per minute.