Now we're cooking with gas

The recent service on Ed's tambour clock by your local horologist caught the interest of another clock owner and that's how we met Peter Green.

In a manner of speaking.

Jane met me through Ed and asked if I would consider looking at an old family tall case clock. Very old.

A few days later, drawn like a moth to a flame, your lepidopterological clock nut visited the home of Jane and Paul here in the Peninsula area.

Whoa.

This was an 18th century, English bell strike and chime, brass dial, tall case clock. Three enormous weights for Time, Strike and Chime. Six bells for the chiming and one giant one on top for the strike. 

Plus a calendar ring and a beautifully hand-painted moon dial. 

Wow.

The name Peter Green elegantly inscribed on the brass dial. In a very large, old oak case. Probably well over 7 feet tall.

Here is the face of the clock with the hood removed.

Breathing restored, your clock doc asked... S'up?

Turns out the clock has stopped running. They can start it but it stops after a few minutes.

The clock has been serviced a couple times by a reputable local clockmaker but Jane and Paul have not been entirely satisfied with the outcomes.

Could YLH here take a look? 

Certainly but let's level set... It might be something this clock detective could uncover while the clock sits in its case but it might require a visit to the shop.

Understood.

Scores of questions were volleyed. Paul definitely knew a lot about the clock.

It has been in Paul's family for at least 7 generations. His family comes from Denmark.

Ah ha.

Born and raised in Liverpool, Peter Green was a reputable clockmaker who moved to Apenrade (now Aabenraa), Denmark around 1745. He worked there for another 30 years. His son William and his grandson Jakob continued to make clocks in Denmark through 1847.

A fine example of another Peter Green from the same era and a smidge more of his bio can be found here. Note that there is a closeup of the dial in that listing and you can see the nearly identical features to our current example. What's missing on that clock is that it has no chiming function and its hands appear to be replacements.

The timepiece facing your YLH looked all original.

Wow.

After a (probably too lengthy) explanation of what can cause clocks to stop, YLH took a gander.

Let's see the problem in action.

Yep after coaxing the pendulum to start the clock ticking it slowed and stopped within a minute or so.

Hmm...

To inspect the movement we took the hood off.

However with the dial on the clock and the clock remaining in the case there's really only 2 points of inspection. 

So there's a lot to see but practically your horological contortionist was still pretty limited in terms of what could be checked.

Look at those six chiming bells. They sounded amazing.

No obvious issues from either angle.

Overall the movement looked to be in very good shape for a clock that's at least 250 years old. 

How can we make this date estimate other than what Paul has reported? 

By around 1770 brass dials were all but eliminated in tall case clocks by the rapid adoption of white painted dials (many other interesting "how to date a grandfather clock" items on that page).

Meanwhile Dr. Curious peppered Paul with more questions and checked the pendulum top to bottom.

That crutch fork, which transmits power from the movement to the pendulum rod, looks oddly angled upwards.

The crutch looks like a J in the photo below. Should look like a reversed L. 

Paul says it's been like that for as long as he can remember and if the fork were bent down to an L shape it might make little to no contact with the flat brass suspension block.

Ok that's probably not the problem.

After about 30 mins of inspecting as much as possible given the gymnastics YLH could muster... 

Uh hang on.

Could it be...

Yes.

The pendulum rod is very gently scraping the edge of the cut out on the movements wood seat. The cut out is there to allow the pendulum to swing freely.

That would stop the clock.

But why is the pendulum touching / scraping there? Is the clock tilted?

Dr. Prepared had brought along a handy, small level. Nope, the clock / movement is level.

As tall as YLH happens to be, the part that needed seeing required lifting the phone / camera way up and angled downwards to capture this:

The top of the pendulum rod has a suspension spring (as most do) and to attach the pendulum to the clock you slide the spring through the slot on the suspension bridge. The spring is held in place / prevented from sliding down (falling) by an anchor of some kind that is (in this case) a piece of brass riveted to the top of the spring.

Two things of note:

1. That suspension bridge is tilted very slightly upward so that it slopes gently towards the movement.

2. The anchor is curved along the bottom.

Zo... this engineer can well imagine that over years of pendulum swinging that anchor could microscopically inch its way towards the movement, eventually bringing the pendulum rod in contact with the cut out in the wood seat.

"Oh yeah that's happened before" says Paul.

!!!

Ahem. 

A quick adjustment of the anchor sliding it about a centimeter back and...

The clock ran perfectly.

Jane and Paul were very pleased with the detectoring and "repair" as was your correspondent.

A quick email check on the patient a week later and all seems fine and greatly appreciated.

But wait!

A couple weeks later Jane reaches back out.

The clock has suddenly stopped striking correctly and the moon dial isn't (has long now not been) working. Would you take a look?

Tune in next time!