Engineering extravaganza by the Heath Robinson club

The Heath Robinson inventors and engineers club has restored the old school clock from the bell tower above the main school after the culmination of a year of research, experimentation and collaboration by girls in Senior School.

A tray of dismantled pieces had been given to the club a few years ago, after having been removed in 2014 to be replaced by the new electronic clock motors (one behind each of the three new clock faces that now light up in the dark).  A little research together with information from the Old Girls’ Club revealed that it was installed in 1933 and rang a bell every hour between 7am and 9pm.  It was apparently prevented from ringing at some point in the early 1960s in response to complaints from neighbours who were disturbed by the bells.  The clock continued to mark the time however right into the twenty-first century due to its reliable Smith Electric clock motor.  The mechanism, whose origin is boldly embossed on its base: ‘Synchronome Co. Ltd   LONDON   No. 43/7’ and on the base of another part ‘Operman Gears Ltd.   Clerkenwell  LONDON   Type A‘, consists of cogs and levers, switches and springs, all cleverly designed to ring a bell.  The old cast iron clock faces are kept in storage in school.  There remained however one particular mystery: what happened to the bell?

This background made the tray of pieces feel very special and so a group of girls, under the guidance of Heath Robinson club founder and Physics teacher Mr Le Bas, started work on reconstructing the mechanism in September 2019.  Initially the girls revisited some of Heath Robinson’s pictures involving clocks and exploring other timing devices and the lunchtime club meetings drew together girls from Years 7 to 11 to engage in some light engineering.  While the older girls worked directly on the machine, younger girls were set to make ‘cuckoo’ mechanisms that could ultimately be triggered by the clock – although no one knew quite how it would all turn out.

By the time the school went into lockdown in March 2020, several ‘cuckoos’ had been constructed and the jigsaw of pieces for the chiming mechanism had finally been solved.  Two pieces had needed replacing: a mercury tilting switch and the motor that drove the chiming mechanism, but both of them were found and bought through an online search.  Finally, the clock motor itself had to undergo some additional expertise with Mr Le Bas enlisting help from a clock restorer in Australia and a local specialist in Bedfordshire. This meant that on return to school in September, we could reveal a fully operational tower of engineering extravaganza, combining ancient clock hands and all the cogs and gears of the old mechanism, with some (almost as ancient) meccano, a new hammer and bell and the houses created by the girls from which various animals (none of them actually cuckoos) would emerge whenever the clock struck the hour.

It has been an incredible and thrilling adventure for all involved and efforts are now underway to prepare the whole contraption for display in the foyer of the new STEM facility when it opens later this year.  Well done Heath Robinson engineers!