The Ocean Falls paper mill and the town site was supplied with water from Link lake located above the dam. A small portion of water was supplied as treated water to the town. Two penstocks fed lake water down to hydro turbines and turbines driving ground wood grinders. The penstocks were installed when the mill was built and consisted of two riveted, mild steel tubes, one 12 ft diameter, the other 14 ft diameter. The water could be shut off at the dam with large taintor gates.
The operation of the mill was very much dependent on the water available from the lake. The water volume in the lake would vary with the change of seasons. Thus, the present and predicted water volumes were carefully calculated and monitored. Aerial surveys were performed to determine the amount of snow pack on the surrounding mountains. It was not uncommon that the mill had to curtail production, usually late in the summer due to low water levels. One or more paper machines would be shut down to save on the water. A few times there were also serious problems with too high lake levels. Mill staff had to place sandbags on top of the dam to prevent an overflow.
The mill was using large amounts of water for it's process and for the hydro electric power. In addition, the mill produced what is called mechanical pulp by grinding wood into pulp on machines driving large grinding stones. Some of these grinders were driven by electrical motors, however, some were also driven by hydro turbines. It takes a large amount of power to drive such grinders with the resulting need for large water volumes.
It was a sad day when it was realized, that the Ocean Falls mill would have to shut down due to poor economics. The mill had just gone through a major capital investment and modernization program which was completed and in operation. The groundwood mill had just received a major upgrade. The very old and small groundwood steam pocket grinders were replaced by much larger and modern grinders.
One set of these new grinders were driven by a new and very large water turbine. It was an exciting time when this large turbine was test run. A world renown turbine designer who had designed the turbine for the mill, personally came to witness and supervise the trial runs. From an engineering viewpoint the operation of this turbine was quite complex and the control systems were very modern for their time. The flow of water through the turbine was controlled by numerous guide vanes surrounding the inlet to the turbine. Most commonly, hydro turbines are controlled by the electrical load placed on them. In this case, the turbine was controlled by the power required to grind wood in a grinder. The load from such an operation is exposed to large variations and the turbine had to adjust to these variations. Most hydro turbines run slow and gently. But the quiet operation and slow speed hides the enormous power created within them. A run-away turbine is a serious situation and to shut down a hydro turbine too fast can create serious problems upstream in the penstocks which feeds the turbine. The turbine test runs were very successful due to the capability of the American turbine designer.