The sound of a rotating ventilation fan in operation. It was manufactured by Tevel, Teve Varnost Elektronika, Zagorje, Slovenia, in 1997. It is powered by 7.5kW electric motor, ø 600mm. The air is delivered into the mine by an air-supply hose of the same diameter.
Ventilation fans are used to remove toxic fumes and stagnant air from blind galleries that don't have free flowing air. All such blind structures in the mine longer than 10 metres have to be ventilated in such a manner.
The sound was recorded in the Trbovlje-Hrastnik coal mine which has a long tradition. The first mine in the Trbovlje area, founded by the entrepreneur Franz Maurer from Wiener Neustadt, Austria, started to operate in 1804. It was later followed by several smaller mines. The arrival of the Austrian Southern Railway to the Zasavje region in 1849 was a double gain: it facilitated the transport of coal to clients whilst simultaneously the railway itself was a major customer itself, having a great need for coal. In 1873 all the coal mines in Zasavje were merged under Trboveljska Premogokopna Družba (Trbovlje Coal Mining Company) which remained the proprietor until WWII. After 1946 all coal mines were nationalised by the new socialist authorities. Zasavje coal mines reached their peak of production and technological development in the second half of the 20th century. After 1991 coal was no longer considered the energy source of the future, and so the state decided to gradually close the mine. The extraction of coal ceased in 2010 and the company focused exclusively on closing it down which should be completed by 2018.
Sound recordist: Boštjan Troha
Photographer: Neža Renko