A Day in the Life of a Turret Clock Engineer.

 

I took a day out from the workshop in Twyford to Shadow Chris from Baldwin Clocks, as he made his rounds of three distinctly different local Turret clocks.

We packed our tools, and at 9am, to miss the worst of the traffic, hit the road. Our tools included; a set of Ladders, Extension leads a lamp, 2 sets of Overalls and a host of tools often untouched by the antique clock repairer due to their size.

Cheriton Church

We were greeted by the songs of the local school harvest festival as we were lead up to the clock room. On the stairs hung a delightful, small, early dial clock which has been on loan to the church since the thirties! The Tower clock movement was mounted on huge cast iron brackets bolted through the wall, inconveniently about ten foot above floor level, after building changes had moved the original floors. A set of ladders was needed to reach the clock housing, inside of which was the impressive quarter chiming movement Made by W Potts & Sons of Leeds. Date 1897.

 The gravity escapement of this particular clock is a fussy one, inclined to run through, and requires a good clean every other year to maintain reliable operation. The movement was spiked, rather than taking the weights off, by placing a steel bar in the crossings of a wheel, this keeps tension on the weight lines and stops them coming off the pullies. The escapement was easily removed thanks to the clever engineer-friendly design of Victorian Flat bed clocks, each arbor being removable independently from the others in the train. The separate components and their pivots and holes were thoroughly cleaned and inspected, all were in good condition so the movement was reassembled and oiled, with service attention given to all the other areas.

The clock was observed for fifteen minutes to ensure sound running and that the striking trains were functioning correctly. The Chiming train of this clock is Ting-Tang chiming of Locking plate design, it is otherwise similar to most antique ting-tang clocks, the hammers being lifted alternately by the 'pin-wheel' until the count wheel locks the train on the 'locking detent' after the correct number of double blows. The strike train is of the usual design with another count wheel. The warning system being of the two legged locking arm design not used in house clocks.

The compensation pendulum is of zinc and steel. The design is simple but ingenious, the expansion of the zinc counteracting that of the steel as temperature causes the materials to expand or shrink. A steel rod is suspended from the movement in the usual way, but is surrounded with a sliding sleeve of zinc, supported at the bottom end of the steel rod to allow it to expand upwards, A further sleeve of steel makes up the outer layer, suspended from the top of the zinc sleeve, the pendulum bob is attached to the outer steel sleeve.

 The Auto wind system was installed by Chris Baldwin some twenty years ago, and is to his own design. The Idea is simple although it’s actual design fairly complex. It is applied to the, then best practice under the 'council for the care of churches' guidance. The original clock has not been altered in any way.

The winding square is driven by a chain drive from an epicyclic gearbox. (The gearbox alone is complicated enough to require more than a sentence or two to describe but basically it can have multiple inputs and outputs). Attached to one in/output is a barrel, around which the weight line is now wound, the gearbox provides a 5:1 mechanical advantage from this barrel to the output which drives the winding square of the clock (Allowing a decrease in driving weight and added safety to the entire system). Another input of the gearbox is toothed timing belt driven by an electric motor which winds the line onto the barrel. The motor itself drives a Worm gear reduction box to increase torque and slow down its output shaft. The whole winding action is very majestic. As the weights drop, the line unwinds from, and 'walks' along the barrel. As it does so, it trips a micro-switch, starting the auto-wind system. The same is true after winding, the micro-switch is tripped and the system shuts down. In case of switch failure, a safety system is employed in which the weights, upon continued winding, literally pull the plug on the whole operation.

The chassis for the auto-wind systems (of which there are three units, one for each train of the clock) is 'hung' below the movement. It is important when working with tower clocks that you do not modify anything, so the chassis hangs, clamped on below the large brackets which support the clock. The weight lines run upwards, through and around the movement to the ceiling where they are diverted over pulleys to the original weight chute. The upward pull helps to support the weight of the chassis.

After the entire system was checked for safe and reliable function and carefully lubricated, it was time to move on to the second and most interesting tower clock of the day.

 Winchester Cathedral 

The clock room is accessed via tight spiral staircases, barely wide enough for a grown pair of shoulders, lugging tools and trying to keep a reasonable pace was a peculiar challenge, likely one which is a daily task for tower clock specialists. The Clock room its self was vast, well suited for a team of bell ringers. Framed photographs and book cases decorate the otherwise understated back room of the grand building. By the entrance is a wooden walled room, ceiling high, with a locked door, this is where the Clock is now housed. I am told the clock used to occupy a different position in the building but I do not know where.

On opening the door we were greeted by the swinging pendulum, a sandbox (For falling weights) and a mock dial, full size and decorated in black and gold complete with Thwaites & Reed style painted on hands. Presumably this was originally used as the clock was being fitted, in order to determine the required size of the outdoor dial. In fact passing a light over it we can see a shadow of a smaller dial which has been painted over, presumably, this version was too small.

Up the stair case to the movement, I was instantly drawn to the history of the clock; you can see clearly the very early, wrought iron frame, with additional parts suggesting a possible previous verge and folio updated to a recoil anchor escapement many years ago. There is evidence everywhere of "Evolution and repair" A huge angle iron frame supporting the modern (comparatively) 'climbing monkey' auto-wind system, which is basically Huygens endless rope system, rendering the original maintaining power unnecessary, And a variety or repair marks, brass plaques engraved with details of replacement components and their year of manufacture.

On closer inspection things get very interesting, the iron frames are decorated with finials, and stamped with the marks of the Swedish foundry where the raw material was made. The great wheel of the strike train is drilled in the roots of the teeth to save on materials which were once hard to manufacture and expensive. Drive to the hands is taken from the beautifully crossed out centre wheel via a screw clamped setting facility, and routed upwards through the ceiling by bevel gearing. The centre wheel shows signs of pitting and wear to the teeth and on one tooth, a large chip of brass has broken away but running we think, for some time like it. There are repairs to cracks in the strike great wheel and Chime train Second wheel, both showing different ways of attacking the same problem. One butterfly type repair is very weakening, cutting only millimetres from the roots of the teeth, but it works. The wooden horse on which the movement sits is substantial in thickness and brings the top of the movement to my (5'11") eye level. The movement is large!

The cathedrals pendulum is non compensated for temperature and is about ten feet long. Although I did not take the chance to measure the rate.

The chime and strike trains were out of step with the time and with previous history, indicated a problem. This would suggest that at some time, the train had mislocked or failed to run. So we lifted the hammers to silence the bells, this is simple and commonly done by the bell ringers by hooking the line on to the provided hook. Raising the lifting piece manually to simulate the slow lifting in real use, we watched as the system warned safely, and then ran as expected. Repeating this we soon realised that the locking detent on count-wheel was catching on the leading edge of the count wheel notch when about to strike. After some serious thinking 'there is a lot happening in this systems levers' and a small amount of experimenting, we decided that the detent which rests on the hoop wheel had worn, and on warning was not raising high enough to clear the count-wheel notch. We determined that another 2mm (Vast amounts of material to a house-clock repairer) was to be added to the working face in order to correct the problem and that building it up with mig weld and dressing off was the best way to achieve the desired repair.

The lifting and locking arm had to come with us to be restored. Removal was fairly simple, Undoing and removing the bracket which holds the maintaining power, removing the maintaining power, spreading the frames a little and finally removing the piece we need. The original individually made threads are impressively still functional, and all different in size and pitch. They plainly struggled to make threads back then. 

At this point we locked up and left for a short lunch break and to speak to the Clerk of the works. It makes more sense to clean and oil the movement when all the components are there and it is functioning correctly, so we left the clock silenced but showing the correct time, with Chris to return later in the week. 

 We then moved on to our final call of the day,

 Chilbolton church.

This clock is a JW Benson flatbed of about 1900. Small in size compared to the previous examples, but sufficient for its needs. The rack and snail striking system works in the conventional manner but on a much bigger scale and with a double sided gathering pallet. This clock is still hand wound although the maintaining power being held out of the way suggests it is not being used as originally intended.

The type of 'un-compensated' pendulum used here is the simplest form, a wooden rod. The coefficient of expansion if correctly dried and sealed against the elements is small enough that it can be ignored, the brass bob providing a little compensation for the expansion of the suspension.

This clock is what we call a 'stopper'. There is no obvious reason for it, but it hasn't recently received full attention. So we set about it with a careful eye and gave full attention to every detail. There was no obvious reason for why it had stopped so we gave the pendulum a careful nudge, the clock was in beat. We set the hands to five to the hour and watched as it struck the hour perfectly. We next climbed into the bell tower, where the motion works is placed at the far side, working our way over beams and around the bells we cleaned and oiled the motion works, which were free and showed no signs of sticking. The nest of bevels was full of the dead flies you should expect in clock towers, but showed no resistance to motion and were comparably functionally clean, for turret clocks bevels. They were cleaned and thoroughly oiled anyway. I then climbed into the weight chute, this tower being particularly awkward to navigate, and lubricated the pulleys. Throughout all of this, the movement continued to run effortlessly. We oiled the pivots and watched... we then made small adjustments to the various friction set devices and applied oil liberally as it worked into the necessary areas. And we watched... then we wiped off the dirt and excess oil.

There was only one job left, and that was to oil the hour pipe, this needs to be done from the dial side outside as it is otherwise unreachable. Chris' ladder was too short so we took a stroll through the village to borrow one from a local. Three tiers of ladder high, Chris cleaned the off white dial with soapy water and trickled oil into the hour pipe. The clock then struck the hour at five too, we had reattached the motion work in the wrong register and had to pop back up the ladder inside the tower to correct it.

We packed up and said our goodbyes, and have not heard back from them since, but a call from Chris confirmed all is well. Sometimes clocks just need a little coaxing and TLC. Chris suggested that oiling the hour pipe is the likely savior as it expels dirt and stops ice from forming in the motion works. I can see the logic behind that.


Summary

I had an interesting day as a turret clock repairer; I learned a lot, feeling now as though I could tackle any public clock alone. I was filthy (this form of clock repair puts a new spin on filthy); hair full of cobwebs and sleeves full of dead flies and dried gummy oil and grease. But I had fun. Unfortunately it takes a lot of equipment and a significant amount of travel to work on these clocks so it is not compatible with my work at the shop, working in clean conditions on fine clocks. My clock making education is important to me and learning about the big clocks is as important to antique clock repair as learning about the smaller ones. It should be remembered that Turret clocks are where the origins of our trade lie.