Mention the name A. Lange & Söhne and most people will immediately picture images of the Lange 1 in their mind’s eye. For 25 years now, the Lange 1, with its asymmetrical dial and unconventional good looks, has served as the emblematic model of the German haute horology brand. However, if there’s one timepiece that firmly established A. Lange & Söhne’s position in the higher echelons of fine watchmaking in the 21st century, an iconoclastic timepiece that draws from the brand’s classical past but is rooted firmly in the present — it would have to be the Zeitwerk, widely described as the modern face of the brand.

The Zeitwerk is now seen as the modern face of Lange

When it launched ten years ago in 2009, there was nothing quite like it. Here was a timepiece with a precisely jumping digital display and a lavishly finished movement featuring a classical mechanism like the remontoir d’egalité. Even though it eschewed the traditional time display format, it had enough horological wizardry to keep the purists interested. It was hardly surprising that in its debut year, the Zeitwerk would go on to win the prestigious Aiguille d’Or prize at the 2009 Grand Prix d’Horlogerie de Genève (GPHG) Awards. In 10 years the Zeitwerk family has now grown to seven models including a special Handwerkskunst edition and a trio of chiming watches.

ALL IN THE DISPLAY

The Zeitwerk’s distinctive time bridge is one of the most recognizable design signatures in watchmaking. Made of German silver, the time bridge is a part of the movement and integrating it into the dial made it possible to reduce the overall height of the watch and create a design detail that frames all time indications – the digital hours and minutes as well as the analogue small seconds.

The time bridge is the design center of all Zeitwerk models

“The starting point [of the Zeitwerk] was a historic design. At the end of the 19th century, A. Lange & Söhne had built six pocket watches with an instantaneously jumping numeric display. The construction was based on a patent by Dresden watchmaker Johannes Duerrstein with a vertical arrangement of the minutes beneath the hours,” says Anthony De Haas, the Director of Product Development at the company.

The display was inspired by the Five-Minute Clock that sits in Dresden’s Semper Opera. Lange’s engineers worked on an entirely new design, which allowed them to arrange the large numerals horizontally. “This led us to a technical solution that had never been built before. In the end, we questioned everything but the principles of spring drive and escapement.”

The numerals jump instantaneously at the turn of the hour

Jumping numeral displays are not new to horology, they have been used in pocket watches as far back as the 19th century. In 1884, IWC famously introduced a pocket watch based on the Pallweber system (developed by Josef Pallweber) that showed the hours and minutes in large numerals on rotating discs. This pocket watch was the inspiration for the IWC Tribute to Pallweber Edition “150 Years” wristwatch that was unveiled last year.

Back to the Zeitwerk, the large displays for hours and minutes are arranged along the same plane. The minutes are displayed with two discs — the units disc (with numerals 0 to 9) and the tens disc (numerals 0 to 5) share the same axis. It takes a considerable amount of energy to move these discs, a problem the engineers solved by introducing a remontoir d’egalité (Lange refers to this as a constant-force escapement) that is core to all the Zeitwerk movements.

The constant force escapement used in Zeitwerk models

Placed between the mainspring and the escapement, the remontoir spring’s job is to ensure rate stability by supplying the balance with a constant supply of power from the barrel during the entire course of the power reserve. The spring loads and releases energy in one minute intervals to advances the numeral discs instantaneously.

MUSIC TO THE EARS

The Zeitwerk family includes all of Lange’s chiming watches outside the Grand Complication timepiece. The first of this was the Zeitwerk Striking Time in white gold (Ref. 145.029), launched in 2011. Featuring a striking mechanism that was visible on the dial side, the Striking Time indicated the quarter-hours as well as the full hours. It was also available in platinum (Ref 145.025) and later in pink gold (Ref. 145.032). In 2015, the heavy duty Minute Repeater in platinum (Ref. 147.025) was revealed followed by the Decimal Strike (Ref. 143.050) in the brand’s proprietary metal honey gold during SIHH 2018.

The Zeitwerk Minute Repeater is cased in platinum

Chiming watches require additional power to do their thing but the Zeitwerk Minute Repeater doesn’t even need a separate barrel for the minute repeater. “The Zeitwerk movements are little powerhouses, which are predestined for integrating all kinds of chiming mechanisms,” explains Haas.

Even the chiming watches draw power from a single barrel

“In fact, they are so powerful that they have to be tamed by a constant-force escapement, which at the same time controls the switching of the disc mechanism. When the numeral discs are advanced, a sizeable amount of energy is released, so after each switching cycle, there is still plenty energy for other purposes. These energy reserves are being used for tensioning the springs that actuate the two hammers of the different kinds of chiming mechanisms.”

ENDURING APPEAL

As far as Zeitwerk models go, the Minute Repeater was probably the most challenging to develop. “We spared no engineering efforts to make the time easier to understand by combining a digital display with a decimal repeater. The sequence of chimes follows the display with a striking mechanism that sounds the hours, ten-minute intervals, and minutes. Three snails – notched cams that control the striking mechanism – are directly connected with the mechanical display elements. The biggest challenge was to integrate the complicated mechanism into one of our most intricate movements,” recalls Haas.

The Zeitwerk Date was introduced in 2019

To celebrate its 10th anniversary,  Lange introduced a date display into the mix and unveiled the Zeitwerk Date (Ref.148.03).  It carries a newly designed movement that doubles the power reserve (72 hours versus the 36 of existing models). The date indicator is a distinctive one: a ring-shaped date scale made of glass, numbered 1 – 31, encircles the dial with the current date always highlighted in red.

The exclusive Handwerkskunst edition

What explains the Zeitwerk’s enduring appeal? Haas thinks it’s down to the unique design and the fact that it is still unmistakably A. Lange & Söhne. “When you talk to collectors, they will tell you that they like the uniqueness of the underlying technical concept as well as the successful combination of contemporary design and traditional craftsmanship,” he says. “The development of the Zeitwerk was driven by curiosity and a desire to do something no one thinks is possible. At the outset we asked ourselves, how could the principles of a mechanical watch and a modern time-indication format be combined in a new and convincing way? After some detours, the answer was the Zeitwerk as we know it today.”

MEET THE ZEITWERKS

Model: ZEITWERK

Launch: 2009

Case Materials: White gold, yellow gold, pink gold, platinum (limited to 200)

Movement: Caliber L043.1, manual-winding, constant-force escapement, 414 parts, 36 hours power reserve

Functions: Jumping time display, small seconds with stop-seconds, power reserve indicator

Model: ZEITWERK “LUMINOUS”

Launch: 2010

Case Material: Platinum

Movement: Caliber L043.1, manual-winding, constant-force escapement, 414 parts, 36 hours power reserve

Functions: Luminous jumping time display, luminous power reserve indicator and small seconds indication

Limited Edition: 100

The first three Zeitwerk models

Model: ZEITWERK HANDWERKSKUNST

Launch: 2012

Case Material: Platinum with hand-engraved back

Movement: Caliber L043.4, manual-winding, constant-force escapement, 425 parts, 36 hours power reserve

Functions: Jumping time display, small seconds with stop-seconds, power reserve indicator

Limited edition: 30

Model: ZEITWERK STRIKING TIME

Launch: 2011

Case Material: White gold, platinum (limited to 100), pink gold (in 2014)

Movement: Caliber L043.2, manual-winding, 528 parts, constant-force escapement, 36 hours power reserve

Notable functions: Acoustic signal every 15 minutes and at the top of every hour, power reserve indicator

The chiming watches in the family

Model: ZEITWERK MINUTE REPEATER

Launch: 2015

Case Material: Platinum

Movement: Caliber L043.5, manual-winding, 771 parts, constant-force escapement, 36 hours power reserve

Notable function: Decimal minute repeater

Model: ZEITWERK DECIMAL STRIKE

Launch: 2018

Case Material: Honey gold

Movement: L043.7, manual-winding, constant-force escapement, 528 parts, 36 hours power reserve

Notable function: Acoustic signal every 10 minutes and at the top of the hour

10 years apart: The first and the latest Zeitwerk models

Model: ZEITWERK DATE

Launch: 2019

Case Material: White gold

Movement: Caliber L043.8, manual winding, constant-force escapement, 516 parts, 72 hours power reserve

Notable function: Date ring on the periphery of the dial

This article was first published in our FALL 2019 print magazine.