Patent ID: 7395605

Claim:
A method of using a damped inclinometer to measure and control pendulum motion of a load suspended from a carriage of a container crane of the type wherein the carriage is configured for horizontal movement along an axis, the method comprising the steps of: providing a magnetically damped inclinometer comprising: a housing fixable to the load, a rotatable shaft extending from said housing, a pendulum fixedly mounted to said shaft, an index member formed of a ferromagnetic material and attached to said shaft, and a magnet attachable to the load, moving the carriage horizontally along the axis; measuring a pendulum swing of the load suspended from the carriage using the inclinometer to produce a feedback signal indicative of the pendulum swing angle of the load; performing a pendulum motion cancellation protocol in response to the feedback signal from the inclinometer, passing the index member past the magnet, and moving said index member from a first position to a second position, thereby increasing a gap between said index member and said magnet.