Original Mainsprings in a New Haven Long Drop Octagon Clock

October 22, 2009 . by Bill

I repaired this New Haven long drop octagon clock. Some of the pinions had worn wires, so I replaced the wires in one pinion and reversed the wires in three. I polished the pivots and installed 13 bushings.

The mainsprings appear to be original (they match in color and style and look old).

Time mainspring: 3/4 inch wide by 0.0172 inch thick. This spring provides sufficient power, as the escapement motion is excellent.

Strike mainspring: 3/4 inch wide by 0.0142 inches thick. This spring is very thin, yet the striking speed is fine.

I retained both original mainsprings in this clock. They were in good condition, operated smoothly, and provided enough operating power, so there was no reason to change them. A good old mainspring is no more likely to break than a new one. (Some repair shops install new mainsprings in every clock they repair, I disagree with this practice.)

The case is 33 inches tall, and the minute track diameter is 11 inches.