While we mostly understand the point of most watch complications, there are some that need extra explanation. The dead-beat seconds is surely of the later. So let’s see how it works, why is it so rare, and what it has to do with quartz?
Everyone interested in watches knows the basic rule: if the seconds hand moves smoothly around the dial, you are looking at the piece with a mechanical caliber, and if it instantly crosses the distance between the seconds marks – a quartz one. So at first glance, the concept of a complex mechanical function mimicking the affordable quartz caliber may seem peculiar to say the least. Indeed, why strive, with incredible engineering tricks, to obtain such a contradictory effect in a luxury timepiece? In fact, the technology of deadbeat seconds (French: Seconde morte) was born in the XVII century with a practical goal in mind – to make it easier for the user to measure exact time intervals.
In 1675, the English mathematician and astronomer Richard Towneley created two pieces for the Greenwich Royal Observatory. The second hand not only was jumping, – it stopped, if desired, to fix the result. In a sense, with his deadbeat escapement, the scientist anticipated the advent of the chronograph. Later, Towneley's design was seriously improved by the great George Graham, and in 1776 Swiss clockmaker Jean-Moïse Pouzait fundamentally rethought the design and introduced the second independent gear-train. Stopping the dead seconds hand from now on did not interfere with the rest of the movement. A lot of horological heavyweights ranging from Abraham-Louis Breguet to Pierre Le Roy had left their mark in this field, but the industry in general did not experience much enthusiasm for the technology, and the antique pocket pieces equipped with this complication, even though sometimes found in museums and auctions, yet remain rather exotic.
Even when in the mid-XX century, just before the advent of quartz timepieces, two watchmaking grandees tried this grounds, the complication did not cause much demand. In 1954, Rolex launched the True-beat, which has now become a great collection value due to very short number produced. The same year, the story repeated with the premiere of the Synchrobeat from Omega. Hardly a thousand of copies had been sold before the brand began to recall timepieces. Subsequently, almost all of them were destroyed or dismantled for spare parts. All leading auctions of the world are still chasing after the miraculously surviving 17 pieces.Although the approach of each brand is deeply individual, most pieces of this kind still use one of the two basic mechanical principles. The secret of the first and most common is the gear train, similar to a constant force mechanism. For example, in A. Lange & Söhne Richard Lange Jumping Seconds a key role is assigned to a wheel in the form of a five-pointed star. Coupled with the lever and mainspring, it moves, obeying the teeth of the traditional seconds wheel. In a few of its steps, the spring stretches and again works off, moving the hand strictly from one graduation mark to the next. And so on ad infinitum.
This whole mechanical interaction goes full circle literally in a second, inevitably imposing increased obligations on the manufacturer in terms of reliability. The hands are usually made very thin and lightweight, – each extra millimeter can shorten the life cycle of the piece, – and at the same time are equipped with a counterbalance for, well, an ideal balance.A different design principle, actually continuing the workings of Jean-Moïse Pouzait, was extremely elegantly implemented in One Hertz by the Dutch watchmaker brothers Bart and Tim Grönefeld. The main movement operates at a frequency of 3 Hz or 21,600 bph, while the second hand rotates due to a separate barrel and a separate gear train receiving energy from its spring.
Due to the centuries-old genealogy, the complication naturally looks more at home in more dressy-designed pieces with enamel dials and gold cases like Jaquet Droz Grande Seconde Deadbeat. Even De Bethune, renowned masters of bold designs, had used this complication in their dressiest piece – DB25T Zodiac Tourbillon. But since we are talking about complicated and, let’s say, statement pieces, any company still tries to approach the issue as creatively as possible. So, there is always some interesting examples around: from Arnold & Son CTB Chronograph 'Central True Beat' equipped with two central hands at once – the jumping one, and the regular chronograph one, to DeWitt Academia Out of Time Sparkling, featuring the corresponding indicator in a separate, and by the way magnificently decorated, register.