From 1905, the government started work on financing several large railway projects, including the Dovre Line, the Rauma Line, the Sørlandet Line and the Nordland Line. On 10 June 1908, Parliament unanimously passed these lines in the Railway Plan of 1908, which included the long section from Sunnan via Snåsa to Grong, albeit without a branch to Namsos. The county stated that they would not grant any district funding to the line unless a branch to Namsos was also passed. This was a high-stake game, as Parliament could as a counter-measure decide to not built the line to Grong. In 1912, the Norwegian Directorate of Mining proposed a branch of the Nordland Line from Grong to Tunnsjøen, where pyrite mining was planned. The decision to build the Namsos Line was taken by Parliament in 1913. Work started in 1916 and it was opened in 1934. The main train service became a daily round trip from Trondheim to Namsos, using four and half hours to Grong.