Tiltmeter Application at Norströmsgrund Lighthouse - STRICE Project

The STRICE project installed load panels on half the circumference of the Norströmsgrund lighthouse in the Gulf of Bothnia to make direct measurements of ice forces. Near continuous measurements and observations of ice conditions were also made. As an adjunct to the project, a high-resolution tiltmeter capable of simultaneously measuring tilt in two orthogonal directions was installed inside the lighthouse for the 2002 winter season in order to assess an alternative means of measuring global ice force. For quasi-static ice loading, the tiltmeter provided a good representation of ice force acting on the lighthouse regardless of the direction from which the forces acted. In the case of dynamic ice loading with frequency components up to 3 Hz, a 7-second moving average "filter" provided a good representation of force components up to 0.5 Hz.
2005