Details of the
differential gravity remontoire and planetary maintaining power systems.
Planetary maintaining power is the most reliable system for this purpose. It also
provides reduction for heavy weights. Normally maintaining power is used only on the time
train. However, when electrical winding is employed, maintaining power must be applied to
all trains since the motor may be winding at a time when the clock is called upon to
strike the bells. In a manual system the human winder would simply avoid winding the
strike trains while they are called upon to strike the bells. The planetary gear
system used for maintaining power in this clock uses an additional spur (reduction) gear
for each train. This gear is slightly smaller and mounted on the same arbor in front
of the main barrel's ring gear that has internally cut teeth. When winding, the spur gear
counter-rotates in the direction of the ring gear, providing a fascinating visual
experience. Planetary maintaining power was not often used for maintaining power in
manually wound systems as this was more expensive than alternative systems. Compare with Potts planetary system. However, it is the most reliable and
thus favored system in unattended electrically wound systems where human intervention in
the case of difficulties is unlikely.