Sølvverket's mines on Eiker
Written by Bent Ek
Ever since Kongsberg Sølvverk and Kongsberg were built in 1624, there was a close connection between Bergstaden and the neighboring village of Eiker - among other things, the very first silver finds were smelted in Kongens smelthytte in Vestfossen. In the last half of the 18th century, Sølvverket employed 400 people, and it had several sharps and mines on Eiker - including "Christianus VI and Queen Sophie Magdalena mine" in Skarraenga outside Vestfossen, Kjennerudvannsgruvene in Lurdalen and Schwabegruva on Grasåsen.
The most significant activity, however, was the one that was started around 1770 in the open fields below the farms Skarra and Kolberg, right on the border with Sven parish in Numedal. This became known as "Schara Ertzdyb Grube" or simply "Skarragruvene".
At this time, the Silver Works started up in several areas that were quite far from the main fields in Saggrenda. It was because the operation of these mines was becoming less profitable, and therefore richer deposits were sought. Optimism was great, and at the Skarragruvene, more than 20 shards were taken up, two horizontal shafts with a total length of around 700 meters were driven in and a crushing plant was built, which was powered by hydropower from Dørja. The operation gave work to 50-60 people - at most around 100 miners were active there.
In the long run, the results did not live up to expectations, and in 1898 the Skarra mines were closed down after 30 years of operation. It was part of the liquidation of Kongsberg Silver Works, where the entire operation stopped in 1805. It was not until ten years later that mining started again, but the operation was never as extensive as it had been at the end of the 18th century.