Expert: Martin Meyer - 8/26/2008

Question
QUESTION: We have a Jon Gate (Blackburn)grandfather clock.  In the process of setting it up, the crutch snapped off. Is it possible to replace the existing one or get a new one to replace it.  It has snapped right at the joint, leaving the rectangle and bent wire in tack.  My guess is that it was adjusted one too many times.  It was recently restored, but the man has moved out of town.

ANSWER: Hi Jane,

I am not familiar with this clockmaker's name, but it sounds like you have a bell-strike hall clock from the early 19th or 18th C. I will answer your question assuming that this is correct. I also want to clarify terminology to make sure that I understand your question. If my understanding is incorrect, please follow up with me, and I'll try to improve my answer. "Joint" = where the crutch wire attaches to the arbor (shaft) of the verge anchor. "Rectangle" = the part where the crutch turns from vertical to horizontal, and becomes an open rectangle, through which the pendulum rod passes.

The crutch probably broke, not from being bent too much, but from being bent/adjusted at the wrong point. The crutch should be adjusted by bending only the vertical wire, while holding the wire near the top, so that the upper part of the crutch is never bent.

If the crutch wire had broken farther down, it would be fairly easy to repair it by silver brazing. However, if it broke right where it attaches to the verge shaft, the problem is more serious.

Crutches attach to the verge shaft either by going into a hole in the shaft, and being riveted in place in that hole; or they have a collet (circular piece with a hole in it) at their end which goes snugly around the shaft, and is fixed in place by a pin, by soldering, or by riveting. The crutch must be absolutely rigid on the verge shaft, or the clock will lose power and eventually stop. If your crutch attaches by means of a hole through the verge shaft, it will almost definitely need to be replaced. If it attaches by means of a collet on the shaft, it may be possible to silver-braze the end of the crutch wire to the collet.

Crutches are available from clock supply houses, and they may or may not be compatible with your clock. However, even if compatible, installation will probably be a job for a professional clock repairer. Replacement crutches have simple straight wires, and the complex bending of the crutch to fit the clock can be fairly difficult. I personally often prefer to make a new crutch from scratch, using soft steel wire, rather than attempting to modify a stock part which is not really correct in all dimensions.

Whatever the situation with the crutch is, I would recommend having it repaired by a professional clock repairer, and the repair will certainly be worth it on an antique Bell Strike Hall Clock.  http://www.clockmasteronline.com

---------- FOLLOW-UP ----------

QUESTION: I was using the word "crutch" to mean everything that is one piece, the horizontal rectangle and vertical portion of the same wire that is at a 90 degree angle..  Is that correct?

Answer
Hi again Jane,

You are absolutely correct; I may have made things unclear in the complexities of my answer. The crutch includes the bottom part (Rectangle) through which the pendulum rod passes, and the entire wire, which goes vertically from the "rectangle", and up to the verge shaft, usually having a couple more bends in it, in order to go into the movement and connect with the verge shaft.  http://www.clockmasteronline.com