A major upgrade to the plant took place in the period after 1950, following General Director O. T. Jarlsby's ten-year plan. Production was eased throughout the period by increased access to lumber and higher demand. The Anker Mill was rebuilt to produce paperboard. A new lumber cleaning mill opened in 1951, followed by a new central furnace the following year, a pyrite roaster and lumber chopper in 1953 and a new beater in 1954. Tistedalsfoss II Power Station and a spirit factory with an annual production of opened in 1955. A hydrocyclone facility for the sulfite pulp mill, new 10,000 tonne oil tanks and a calcium carbonate management facility for the paper mill were taken into use two years later. A new warehouse was completed in 1958 and the bleaching site expanded the year after. The ten-year plan ended with the expansion of the conditioning facility for the paper mill and expansion of the sulfite pulp mill in 1960. In addition a series of minor upgrades and modernizations were carried out throughout the 1950s, such as extending the paper machines. From 1956 operations ran around-the-clock.