Manufacturing Process

William Gray Replicas did not make all the components of the clock from scratch. The brochure states that “the bell is cast by the same foundry which cast many of the original ones”. From this, I deduce that the Whitechapel foundry supplied the bells, although no-one has been able to confirm this; nor has the Whitechapel foundry kept its records for clock bell production.
The frets were said to have been cast by Lunts of Birmingham, and the wheels cut by Biddle and Mumford. The dial, chapter ring and fret engraving was said to be mostly carried out in London, although there is a suggestion that John Chernowski executed some of the engraving himself. The dial plates indeed show stylistic evidence of more than one (possibly as many as four) individual engravers.
The original drawings suggest that the crown wheels were cut by “Rycroft” who is recalled by others as a Scottish horological wheel cutter. As the drawings have been updated and added to over the years, it is not clear whether this was for the original production of clocks or the later production of kits.
IPD supplied parts to its sister company William Gray Replicas, including the brass cased lead weights; which are said to have been cast from a cauldron of molten lead in the yard. The finials and pillar caps were produced, not with IPD’s CNC expertise, but using two piece and one piece form tools. Similarly, the pillars and arbors were tuned on traditional Swiss automatic lathes, not on IPD’s newer CNC lathes.
Although the brochure shows the clock assembly being carried out on a bench by a craftsman with a traditional depthing tool at his side, the truth was more C20th, as the original drawings testify. The pivot hole positions were calculated to 0.01mm and pre-drilled in the plates. However, the accuracy of wheel cutting turned out to be insufficient for this engineering approach to horology. As a result, the assembly of all clocks made by William Gray Replicas was carried out by trial and error; using a lantern clock frame in which the pivot holes in the plates were cut through to the edges of the movement bars. This jig enabled wheels to be quickly swapped around, until a free running train was achieved.
The finials and other machined components were produced on the IPD equipment by John Chernowski. However, there soon proved to be insufficient room for component finishing and assembly alongside the core IPD business in the Newcombe Road factory. At this time, John Chernowski was also carrying out setting for another business run by Don Soper in Gloucester Road, Luton. This Gloucester Road factory was subsequently taken over by IPD; who relocated both the clock and microwave business there in 1973. IPD remains at that address to this day.