Whitehurst of Derby Hook and Spike Alarm Clock

I was given this clock by an old neighbour of mine whom I have known all my life and so was very happy to be able to help when he mentioned he had a clock that needed repair. The clock and a matching one had been given to his mother and her sister in 1922 as wedding presents, as they wed around the same time, but it had been sitting in a box for 30 years after a move and was extremely dusty.

It is marked Whitehurst/Derby who are a well known family of good quality clock makers from the 18^th – 19^th century. There is no date on the clock or serial number but I have deducted that the clock was made before 1809 due to this being the first years in which serial numbers were introduced to their work.

The actual clock is interesting as it has a three wheel train with with no centre arbor and an alarm system made with a verge and crown wheel. When the alarm is set off, by means of a cam on the hour wheel, the pallets trip through the crown wheel and a hammer at the end of the verge rings the bell.

Detail of the motionwork - the minute wheel is powered by the great wheel as there is no centre wheel

The repairs to the clock were not too great as although it had not been running for 30 years, before it had been placed in its box it had apparently been working. One major issue was that the third wheel, in a previous repair, had been bushed so that it was no longer perpendicular to the plate. This provided an excellent opportunity to get more familiar with the depthing tool.

The initials of a previous repairer - WSB made in February '66 (1866)

The escape and third wheel in the depthing tool

The biggest struggle I had with this clock was that the alarm quite often went off when it shouldn't which is a  problem as it is very loud and does not stop until the weight hits the floor (quite a long drop). When the alarm stop was adjusted to hold the alarm mechanism more forcefully, the pressure of doing so would push against the hour wheel and would stop the hands from going round the clock. It seemed that no matter what I did, one of these problems would arise and believe me, I spent weeks finely adjusting things!

I finally believed I had sorted the problem, only to bring the clock home and present the owner with it at Christmas, when the hands stopped moving. After some discussion my neighbour was quite happy to link the chains of the alarm weight to prevent the force from stopping the clock as he had no need for a very noisy temperamental alarm. I was very relieved although still a little sad to see the clock go.