Functions + Techniques: The Deadbeat Seconds Display

On the obnoxiously long list of watch complications out there, few are as obscure and underappreciated as the deadbeat seconds. I myself have said on more than one occasion, “what’s the point?”, though as my knowledge of the industry and its history has grown, the more I’ve come to appreciate this simple-yet-obnoxiously complex bit of watchmaking.

First things first, let’s start with the obvious—what is a deadbeat seconds complication in the first place? For those unfamiliar, it’s quite simple. You know how every conventional quartz watch (not counting Grand Seiko Spring Drive or Accutron), has a second hand that ticks ahead every second? A deadbeat seconds complication replicates this mechanically, and it’s a lot tougher to do than you would think. Run-of-the-mill mechanical movements in watches these days typically run at between 3 and 5Hz, which means their movement splits a second up into between 6 and 10 pulses. Aside from Antoine Martin who launched the Slowrunner in 2013, no watchmaker has even managed to push things down to one Hz, let alone the 0.5 required to achieve a deadbeat seconds indication straight from the balance wheel. This is because of plain old physics—the size of the balance wheel required to achieve that frequency would be larger than could fit into a wristwatch in the first place.

So how does one take a standard-hertz caliber and make a deadbeat seconds complication? There are a few different paths at hand, and none of them are especially simple. A significant amount of time could be spent explaining the specific details of each variation, but for the sake of efficiency, we’ll simply skim the surface of each. The most intriguing of the pack is the one second remontoire. A remontoire is effectively a loading mechanism, more often used to stabilize the delivery of power from a mainspring to the balance wheel, but it can also be used as an assist in a time display. For example, the Lange Zeitwerk uses a 60-seconds remontoire in order to jump the digital minutes indication of its time display. A remontoire can be built to hold for any particular duration, and thus a one-second remontoire can take a standard running beat and turn it into a deadbeat seconds display.

The second means of creating a deadbeat seconds indication is incrementally simpler to execute, but still requires a reasonable amount of care and attention. This method uses a secondary escapement, driven off of the fourth wheel of a movement’s geartrain. The fourth wheel is the one responsible for the running seconds display, and with the correct gearing of an escapement, can take the running seconds and break it down into a deadbeat. Though this version has seen more use in recent years, it was also used in the Rolex Tru-Beat that launched in 1954 and was discontinued after roughly five years of production.

Our last, and “simplest” means of creating deadbeat seconds uses what is referred to as a start and flirt mechanism. Star wheel is linked to the escapement wheel, with a spring-loaded “flirt” (effectively an arm or lever), that holds its position for the duration of a second before unspooling in one quick jump and returning to its new position on the star wheel. For ease of explanation, you can see its function in this video from Lange.

Regardless of the method used, there’s something charming about this complication—something endearing about all of this effort to create something that we all take for granted on account of the advent of quartz. It’s precisely this lack of appreciation that makes a deadbeat a sleeper in the collecting community. It’s one of those “if you know, you know” designs, and one I’ll always tip my hat to.

Jaeger-LeCoultre Geophysic True Seconds

 Starting simple with this list, the JLC Geophysic is a throwback to a late ‘50s reference from the brand that included both a deadbeat seconds complication as well as a reasonable 600 gauss of magnetic resistance. This reference, which launched in 2015, featured an all-new caliber 770 that was built from the ground up to display the deadbeat seconds indication from a central seconds hand rather than the more typical separate subdial. It also uses the Jaeger-LeCoultre Gyrolab balance wheel—an h-shaped balance that was first seen in the Extreme Lab concept watch some 8 years prior, and something that was only fitted into Geophysic models during their relatively brief production run. This piece is so wonderfully under the radar, and at 39.6mm across and 11.5mm thick, it’s one that’s quite well suited to frequent wear.

Arnold & Son DSTB

 A touch more outlandish, albeit with a fair bit of traditional design in the equation, the Arnold & Son DSTB (dead seconds true beat) draws more attention to its obscure complication by moving the dead seconds escapement up above the dial, and using a large seconds subdial that indicates time on a floating sapphire ring. Granted, to bring all of these beautiful details to light, the DSTB comes in 43.5mm across, but as a complete package the larger case size is worth it if you have the wrist size to pull it off. The value proposition for any Arnold & Son has always been strong on the secondary market, and the DSTB is no exception. After all, here’s a brand that would redesign/reengineer each movement from scratch from model to model, rather than having a base design from which to alter or add complications.

Lange & Söhne Richard Lange Jumping Seconds

 Back to something a bit dressier with a lot of historical reference, the Richard Lange Jumping Seconds is a serious dose of German watchmaking. Alongside its deadbeat seconds indication we also see a zero-reset stop seconds mechanism as well as a low power indication that links to its constant force mechanism. Its unique dial design, including separate overlapping registers for hours, minutes, and seconds is actually modeled after a pocket watch that was made in Dresden back in 1807 by Johann Heinrich Seyffert. A few different references of this model have been made since its launch in 2016, starting with a platinum reference that was limited to 100 pieces globally.

F.P. Journe Tourbillon Souverain TN

Given the age and history of the deadbeat seconds complication, there’s little surprise that it’s something that F.P. Journe has played around with over the years. It’s also not much of a surprise that his interpretation of the mechanism is slightly different than that of his competitors. You see, the deadbeat seconds mechanism used by Journe is run off of a remontoire, however it only engages when within its optimal winding state. If and when the hand-wound caliber gets to a point where less than 12-hours of power reserve are available, the remontoire disengages and the seconds hand shifts to a traditional sweeping movement. The logic behind this makes a fair bit of sense if you think about it—the idea of a remontoire is to stabilize the release of power from the mainspring, and when you’re in the lower end of the reserve there’s less tension or power that requires stabilizing. Thus, when the remontoire is no longer needed, it disengages and the movement carries on. “Business as usual,” so to speak. Though the movement also has a prominent power reserve indication on the dial, its wearer is also likely to notice the change in the seconds hand action, which will serve as a reminder to wind the movement once again.

Greubel Forsey Différentiel d’Égalité Limited Edition GF08

 End on a high note? Okay, if you say so! The 33-piece edition of the Greubel Forsey Différentiel d’Égalité was the first deadbeat seconds built by Robert Greubel and Stephen Forsey, paired with their 30-degree inclined balance, constant force mechanism, and power reserve display. The combination of these features come together wonderfully to deliver the same impeccable accuracy that Greubel Forsey is known for. The limited production model was a long time coming. The constant force mechanism found in the movement was first displayed as a part of their Experimental Watch Technology Program in 2009, yet this production model did not launch until 2018. Between its inherent scarcity and the spectacular finishing we consistently see from the brand, there’s good reason this creation commands a much steeper sticker price than most others in this list.