Most all mechanical new and antique clocks, including a basic cable-driven or chain-driven grandfather clock, have a movement that is driven importantly by a pendulum swinging back and forth. The very definition of a grandfather clock is one in a freestanding case that is both weight-driven and has a pendulum moving in beat from side-to-side.
Nowadays, many clocks offered by even the highest end manufacturers like Howard Miller Clocks and Hermle Clocks and the Ridgeway Clock Company also offer quartz-driven clocks, including grandfather clocks, grandmother clocks, wall clocks, mantle clocks and even cuckoo clocks that have a clock pendulum that is quartz or battery driven and yet the pendulum on the clock still simulates the movement of a mechanical clock, frequently with the help of a magnet based mechanism.
There are certain mechanical clocks, particularly antique carriage clocks and some antique mantel clocks and antique wall clocks that have what is known as a platform escapement, and these great movements do not require or use a pendulum to help the clock run. In the case of carriage clocks, this is a space saving device. These clocks tend to be also of excellent quality, with the only drawback being that it can be harder to fix or replace a platform escapement movement, especially if the balance staff is broken. These mechanical clocks are similar to pocket watches in that regards. And not surprisingly, for both antique clocks and antique pocket watches, replacement parts can be hard to find and require a special skill on the part of the timepiece repair-person.
Another interesting facet of pendulum clocks is whether the pendulum is visible to anyone viewing the clock at a time other than winding. Many new and antique grandfather clocks quite purposefully have a glass door in the front so that the pendulum as well as the weights of the clocks can be readily seen. Not uncommon, especially with antique clocks, is to have a solid door where the viewer or owner will not see the pendulum or weights driving the clock mechanism. Many of the older antique grandfather clock pendulums and weights are actually in our view quite ugly, and there is a good reason not to make them visible.
Interestingly, not only on new grandfather clocks and new grandmother clocks, but also on mantel clocks and especially on wall clocks, being able to view the pendulum and weights are very much part of the design, whether the clocks are mechanical or quartz-driven. Worthy of note if looking at a new quartz grandfather clock, is that while the pendulum’s movement may simulate that of a mechanical grandfather clock, the weights will almost always be for decorative purposes only and will not move either up or down.
One interesting side-note about pendulum grandfather clocks is that one innovation which has taken on some momentum, and which we are strongly urging grandfather clock makers to make more available, minimally as an optional additional feature, is having a crystal center of the pendulum bob. This is one innovation we at 1-800-4CLOCKS.com plan to make much more widespread either with or without the grandfather clock makers. A grandfather clock pendulum of this type adds a very special sparkle to the home in which it lives. with that sparkle adding to the grandfather clock as the heartbeat of the home.
Pendulum Grandfather Clocks by Howard Miller Clocks