Some articles on tinnos:

Bratsbergbanen - History - Negotiations
... The proposal for the Bratsberg Line was to incorporate the Tinnos Line, allowing seamless operations ... create a company that would build the new railway and take over ownership of the Tinnos Line ... shares and half in common shares—for the incorporation of the Tinnos Line and NOK 4.2 million was for the state financed part of the Sørland Line from Notodden to Nordagutu ...