Antique and Vintage Mechanical Clocks

One of the oldest clocks in my collection is a Scottish tall case (long case) clock made in the late 1840s. I acquired it in 2020, and I was quite excited—it was my first antique tall case clock. It features what is known as an English bell strike, with a rack and snail striking the hour.

These movements are simple and were well constructed over a century ago, but, as with all clocks of this age, wear has taken its toll.

Most of the remedial work was completed in 2020, including new pivot bushings, a new suspension spring, a pendulum rod, a rack tail spring, and, of course, a full rejuvenation of the case.

Many of these old movements suffer from a variety of issues, such as broken wheel teeth, worn pinions, poor past repairs, and heavy-handed solder work.

This particular clock has a rather crude repair to the rack tail—something I am willing to live with. It works!

This year, the strike side began to exhibit a minor problem, prompting me to remove the hood and take a closer look. I discovered that the rack was dropping too far back and was no longer being picked up by the gathering pallet. The problem appears to occur when I wind the strike-side weight too quickly, although there may be another underlying cause. For the time being, I simply removed the weight.

However, I also removed the strike-side weight for another reason. The cable had become frayed where it entered the winding drum, meaning it either needed to be replaced or shortened. I opted for the more economical solution and shortened the cable, taking care not to reduce its length enough to affect the clock’s eight-day running cycle.

Shortening the cable required access to the strike-side winding drum, which, of course, meant disassembling the movement.

The cable consists of three groupings of strands, each made up of about six wires surrounding a central steel core. Two of these groupings, along with the steel core, had broken completely. That left only one grouping intact—and even that was reduced to perhaps three remaining brass wires supporting the load. The photos below tell the story.

All of this was supporting a 13-pound weight. I have enlarged the image above to better illustrate the problem.

The proper solution is to repair or replace the cable. As a temporary measure, the existing cable can be reused—provided the remaining portion is still sound. This involves removing the movement from the case, separating the plates, and opening the strike-side barrel. The cable can then be fed back into the barrel and secured with a knot on the inside. Although this shortens the cable by an inch or two, it should have no meaningful impact on the clock’s running time.

Since I will already have the movement apart, this also presents a good opportunity to clean the movement, address any wear, and re-oil the mechanism. I checked the time-side barrel to see if a similar issue existed and, somewhat surprisingly, found it to be in excellent condition.

The takeaway here is simple but important: weight cables on longcase clocks deserve regular inspection, especially on clocks that run continuously year after year. Fraying often occurs slowly and out of sight, but failure can be sudden and dramatic—potentially causing serious damage to the movement, the case, or anything beneath the falling weight. In this clock, there is nothing to cushion such a fall—a loud bang and a dented hardwood floor would be the likely result.

First is Disassembly

Now, on to the repair. Accessing the movement requires removing the weights. In my case, I had already removed the strike-side weight, and it was a simple matter to unhook the time-side weight. Next, I removed the hour, minute, and second hands.

The movement rests on a seat board, which in this clock is not screwed or bolted to the side rails, so it lifts off easily. Once on the workbench, I removed the heavy steel dial, which is secured with taper pins. Then the seat board itself is removed by releasing two screws from underneath. With that done, the movement plate can be taken off—a rectangular steel piece whose purpose is to support the dial. The back of the steel piece is stamped BIRM, which is no surprise since many bell strike movements were made in Birmingham, England.

Now we are down to the movement itself.

Two surprises greeted me upon separating the plates for inspection. One, the oil was dirtier than I imagined, black in fact, but two, there was negligible wear. So, no bushing work is required.

Bell strike movements are quite large, and it took at least three ultrasonic baths to clean all the parts. Even then, I could not fit the plates into the cleaner, so those had to be cleaned by hand. Full disclosure: my ultrasonic cleaner is not very big.

After cleaning, I checked the solution, which was quite dark, and decided that this would be its last use.

All parts were rinsed and dried.

Cable Repair

On to the cable repair. There is a pin on the winding gear that locks a washer; once the pin is removed, and the washer pushed aside, the drum gear can be separated from the barrel. The cable then has to be fished out of the barrel using tweezers and a surgical clamp. It can then be pulled through, trimmed, knotted, and fed back into the barrel. As mentioned previously, the cable is now a little shorter, but I do not believe this will have an appreciable effect on the run time.

Since no bushing work was required, I pegged all the holes and reassembled the movement. All the adjustments are made outside the plates, so if the movement does not work correctly, only fine-tuning of the levers on the front plate is needed.

The movement has been assembled, and now it is on to testing. I constructed a specially designed stand for tall case clocks.

The next testing phase is trial and error. I may have gotten everything right the first time, but in my experience, there is always some amount of tweaking and adjusting to get things right.

This is a two-part article, and with the movement now assembled, the next phase is testing and adjusting. Even when everything seems right, there is almost always some fine-tuning required to get a clock running properly. I’ll take you through that process in Part Two.