The vast majority of high-end mechanical grandfather clocks, whether they have cable driven movements or the chain driven movement type, have 8 day movements. This means the movements, when fully wound, will run for eight days. This is true for Howard Miller Grandfather Clocks, Hermle Floor Clocks, the Ridgeway Grandfather Clock Collection, Bulova Grandfather Clocks, and the made-to-order Kieninger Grandfather Clock Collection.
One question we are asked with some regularity is whether a grandfather clock can be damaged if it is allowed to wind down completely, or if it is stopped – by stopping the pendulum – while the weights are, say, halfway down. The short answer is no, this should not hurt the mechanism of one’s grandfather clock. The grandfather clocks are built to both withstand the pressure of the weights if they are partially down or fully down. When winding a chain-driven clock, it is important, as it would be all the time, not to pull the chains too hard so that the weights go higher than they should. But this would not be any different whether the chains are being pulled up after 7 days or after the clock has stopped and fully wound down after eight days.
Many super high quality grandfather clocks in fine condition that have been owned by the person writing this post have been left more or less as decorative pieces vs. timekeepers and chimers, in some cases for years, and these floor clocks are no worse for the wear, or perhaps the lack of wear!
Grandfather clock maintenance is of course still critical, with most experts recommending a cleaning and oiling at least every 3 years, as the oil will tend to dry out over time and cause more wear on the internal mechanism if it is not sufficiently lubricated.
Oh, and to start your grandfather clock up again if it has stopped (aside from any necessary winding, of course), don’t forget to move the pendulum on your mechanical grandfather clock with gentle nudges or pushes or swings from each side until you hear it ticking away and can hear a consistent ticking sound, known in the trade as being “in beat”.
Wishing all clock collectors, admirers, and everone else in the world a happy, healthy, and peaceful 2009!