Anatomy of a WurliTzer Theatre Pipe Organ
BASS / KETTLE DRUM Action.
The large hammer, right, is the BASS DRUM action.
The two smaller hammers, left, provide the KETTLE DRUM Roll action. The left hammer has two contact
strips attached which work on the two contact blocks to cause the two hammers to re-iterate
alternatively. At rest the first contacts are closed which enables the left hammer to be activated.
As the left hammer moves forward the second contacts are closed which activates the right hammer and
the first contacts open allowing the first hammer to return towards the rest position which then
reopens the second contacts. If the action is still activated the cycle repeats.