The mechanical movements produced by German watchmaker A. Lange & Sohne have many distinctive style elements but one that stands out prominently and has become a real hallmark is the three-quarter plate.
Compared to designs with several bridges, this plate - made of untreated German silver - covers about three-quarters of the movement storing barrel, crown wheel and the whole gear train. The bearing of the balance wheel and the anchor are in a cock.
What are the reasons that suggested Ferdinand Adolph Lange (1815-1875), the founder of the brand, to develop this technical solution? And how did the plate shape evolve over the years?
To answer, it is helpful to consider his background. While completing his engineering studies at Dresden’s Technical University, the “Technische Bildungsanstalt”, the 15-year old Ferdinand Adolph started an apprenticeship with renowned master clockmaker Johann Christian Friedrich Gutkaes which quickly recognised the talent of this young student.
When he finished training, the young Ferdinand spent four years travelling through Europe, learning from many of the most famous watchmakers of the time in Switzerland, England and France. During these journeys, strongly motivated by an exceptional thirst for knowledge, he started writing a diary rich of drawings of mechanisms, tables and calculations, a real treasure for his descendants.
After establishing his own manufactory in Glashütte on 7 December 1845, Lange soon started realising his clean vision for the development of the perfect pocket watch well summarising it with a famous statement: “The entire pursuit of a watchmaker should be the perfection of each and every watch”.
The extensive training received over the years had shown Ferdinand the possibility to improve and, in several case, to radically innovate watchmaking.
He was particularly bothered by the fact that bearings and wheels in the movements were configured under separate bridges and cocks.
Ferdinand realised that this approach had several disadvantages. First of all, during the assembly process the watchmaker had to handle and place the various bridges and their respective wheels into the right positions relative to one another. This was not only tiresome but also error-prone because as soon as the alignment of a single cock was changed, all the others had to be checked and possibly reoriented as well. Ever worst, since cocks were known to migrate slightly in the course of time, watches had to be readjusted more frequently.
For these reasons and with the goal of manufacturing timepieces whose high-quality could last as long as possible, Lange kept refining the design of this plate during a period of about 20 years.
For the first ten years he used a triangular plate that was designed to be as small as possible with the ends of the tentacle-shaped extensions to hold all bearings for the most important wheels.
The triangular plate was followed - for pieces produced from 1856 to 1860 - by a plate covering half of the movement. The bridge for the escapement components had almost found its definitive shape.
1860 saw the introduction of a two-thirds plate extending across the centerline of the movement. Lange also started to use screwed gold chatons for holding the jewels. The bridge for the escapement components achieved its definitive shape.
In 1864, the plate finally covered three quarters of the movement. Being larger in size, the three-quarter plate could accommodate all of the arbors of the wheel train, thus keeping all of the gears in stable contact. Only the balance cock with the oscillation system remained exposed, located beneath a cock. The winding wheels also found their definitive positioning.
The definitive shape of the three-quarter plate - the same that is used today - was achieved!
In March 1875, Ferdinand Adolph Lange was granted a US patent. In his application, he described a solution for watches with a three-quarter plate which had to be dismantled completely even if one only needed to take out the barrel. Lange later designed a barrel that could be removed separately by simply releasing two screws under the ratchet.
The three-quarter plate is still one of the most important traditional elements at A. Lange & Söhne.
Thanks to advanced milling and wire-EDM machines, today it can be manufactured with exceptional accuracy and tolerances expressed in thousandths of a millimetre.
It is made of untreated German silver, an alloy containing copper, nickel and zinc, traditionally used by Lange for all frame parts. The material is characterised by high stability and resistance to corrosion. In the course of time, it takes on a protective, gold-yellow patina and does not require any electrolytic anti-corrosive coating.
Decorated with Glashütte ribbing, it sets a perfect stage for the thermally blued screws that secure the gold chatons in which the ruby-red bearing jewels are embedded.
Over the years, it has matured to such a degree that A. Lange & Söhne now also uses the basic calibre with the three-quarter plate for all supplementary indications and precision timepieces.
A hallmark of German watchmaking, each three-quarter plate pays tribute to the founder of the Saxon precision watchmaking industry who was born more than 200 years ago.
Compared to designs with several bridges, this plate - made of untreated German silver - covers about three-quarters of the movement storing barrel, crown wheel and the whole gear train. The bearing of the balance wheel and the anchor are in a cock.
To answer, it is helpful to consider his background. While completing his engineering studies at Dresden’s Technical University, the “Technische Bildungsanstalt”, the 15-year old Ferdinand Adolph started an apprenticeship with renowned master clockmaker Johann Christian Friedrich Gutkaes which quickly recognised the talent of this young student.
When he finished training, the young Ferdinand spent four years travelling through Europe, learning from many of the most famous watchmakers of the time in Switzerland, England and France. During these journeys, strongly motivated by an exceptional thirst for knowledge, he started writing a diary rich of drawings of mechanisms, tables and calculations, a real treasure for his descendants.
After establishing his own manufactory in Glashütte on 7 December 1845, Lange soon started realising his clean vision for the development of the perfect pocket watch well summarising it with a famous statement: “The entire pursuit of a watchmaker should be the perfection of each and every watch”.
The extensive training received over the years had shown Ferdinand the possibility to improve and, in several case, to radically innovate watchmaking.
He was particularly bothered by the fact that bearings and wheels in the movements were configured under separate bridges and cocks.
Ferdinand realised that this approach had several disadvantages. First of all, during the assembly process the watchmaker had to handle and place the various bridges and their respective wheels into the right positions relative to one another. This was not only tiresome but also error-prone because as soon as the alignment of a single cock was changed, all the others had to be checked and possibly reoriented as well. Ever worst, since cocks were known to migrate slightly in the course of time, watches had to be readjusted more frequently.
For these reasons and with the goal of manufacturing timepieces whose high-quality could last as long as possible, Lange kept refining the design of this plate during a period of about 20 years.
For the first ten years he used a triangular plate that was designed to be as small as possible with the ends of the tentacle-shaped extensions to hold all bearings for the most important wheels.
The triangular plate was followed - for pieces produced from 1856 to 1860 - by a plate covering half of the movement. The bridge for the escapement components had almost found its definitive shape.
In 1864, the plate finally covered three quarters of the movement. Being larger in size, the three-quarter plate could accommodate all of the arbors of the wheel train, thus keeping all of the gears in stable contact. Only the balance cock with the oscillation system remained exposed, located beneath a cock. The winding wheels also found their definitive positioning.
The definitive shape of the three-quarter plate - the same that is used today - was achieved!
Ferdinand Adolph Lange
Thanks to advanced milling and wire-EDM machines, today it can be manufactured with exceptional accuracy and tolerances expressed in thousandths of a millimetre.
It is made of untreated German silver, an alloy containing copper, nickel and zinc, traditionally used by Lange for all frame parts. The material is characterised by high stability and resistance to corrosion. In the course of time, it takes on a protective, gold-yellow patina and does not require any electrolytic anti-corrosive coating.
Decorated with Glashütte ribbing, it sets a perfect stage for the thermally blued screws that secure the gold chatons in which the ruby-red bearing jewels are embedded.
Over the years, it has matured to such a degree that A. Lange & Söhne now also uses the basic calibre with the three-quarter plate for all supplementary indications and precision timepieces.
Above and below, two examples of A. Lange & Söhne movements with three-quarter plates: the hand-wound Calibre L051.1 and the self-winding Calibre L086.5
A hallmark of German watchmaking, each three-quarter plate pays tribute to the founder of the Saxon precision watchmaking industry who was born more than 200 years ago.