LANGE 1 MOON PHASE is composed of 438 parts coordinated, the error of which does not exceed one hundredth of a millimeter. This watch incorporates the signature features of Lange’s classic LANGE 1 design. The moon phase display only needs to be corrected once every 122.6 years. It is equipped with a unique day / night display, which adds a layer of beauty to the complex functions full of romance. Like all Lange watches, this model is reassembled.
LANGE 1 MOON PHASE ’25th Anniversary’ with blue decorative details, limited edition of 25 pieces
The moon phase display is a complex feature with a long history in the development of timing devices. Many ancient civilizations, such as the ancient Greek civilization, have been trying to grasp the changes in the moon phase. They created the Antikythera Celestial Instrument, which can track the cycle of the sun and the moon. Most time displays are engraved with a calendar scale, including a lunar calendar with a month scale.
LANGE 1 MOON PHASE was launched in 2002 and is Lange’s first moon phase watch. Since then, this watch has become one of the milestones of the LANGE 1 series. In 2017, this watch was equipped with a new L121.3 movement with moon phase and day / night display functions. Like all Lange watches, the secondary assembly of each watch is a delicate and ingenious process that requires exquisite craftsmanship.
Assembling the double barrel
LANGE 1 came out in 1994 with an unusual double barrel design, so the dial is engraved with the German word ‘Doppelfederhaus’ (double barrel). This design is retained in the newly developed movement in 2015. The movement of the LANGE 1 MOON PHASE is also based on this. The two barrels are each equipped with a mainspring; the two together add up to a power reserve of 72 hours. Two barrels are fitted on the main splint, which is decorated with handmade scales.
The surface of the barrel is decorated with sunburst to show the winding function of the watch. The ratchet is installed on each barrel and decorated with a circular pattern (left in the figure). During the first assembly process, the watchmaker carved small marks on the two barrels to ensure that the two barrels were properly seated during the second assembly process.
Assembling the gear train
All-round inheritance of superb watchmaking technology is an integral part of the Lange watch brand philosophy. Although the watch owner may not have the opportunity to see the parts below the 3/4 splint, Lange still uses all kinds of different crafts to hand-carve all these parts.
The first assembly of different pinions into a gear train is a delicate and complicated process. The teeth of each gear must fully mesh with the teeth of adjacent gears.
Adjusting the axial clearance
During the first assembly process, the watchmaker needs to install and dismantle the 3/4 splint several times in a row to calibrate the axial clearance. In order to fully mesh each gear of the gear train with other gears, the axial clearance of each mandrel must be individually adjusted to ensure accurate operation without wear. To this end, jewel bearings are pressed into a gold sleeve to ensure accuracy of one hundredth of a millimeter. For this very time-consuming process, the watchmaker needs to use the gem setting tool with dexterity.
Not only the 3/4 splint, but all the splints and bridges of Lange watches are made of German silver. This is an alloy containing copper, zinc and nickel, and is highly regarded for its excellent characteristics. This material is sensitive to moisture and acids and is one of the main reasons for secondary assembly. A fingerprint can cause flaws, which is why all Lange watchmakers wear finger cots throughout the assembly process.
Assembling 3/4 splint
Between the first and second assembly, the 3/4 splint is decorated with a Glashütte pattern. All parts are cleaned and then returned to the watchmaker for a second assembly. In the second assembly process, the watchmaker polished the gold sleeve and replaced the working screws with new blue steel screws.
German silver is untreated and has a gorgeous golden hue. The aesthetic effect is particularly desirable, because over time, this material will become more elegant, highlighting the Glashütte pattern.
The escape wheel is the last gear in the gear train. A lever made of stainless steel is connected to the balance wheel. Each lever is individually adjusted by aligning and positioning the ruby pallet fork. From this moment on, because this lever has been precisely mounted on a particular watch, it cannot be replaced with another lever.
With each vibration of the balance wheel, the lever swings back and forth, releasing one tooth of the escapement wheel. This in turn passes precisely defined energy to the oscillating system. During assembly, special attention needs to be given to large chamfers, chamfers, matte finishes, and flat polished or ground surfaces.
Assembly balance system
The core of the device-the balance wheel-is fitted in the area not covered by the 3/4 splint. The weight balance wheel is matched with a free swing hairspring developed by Lange Watch Factory and fixed by hand-engraved balance wheel splint. The watch vibrates 21,600 times per hour with audible ticking.
The movement can be adjusted in five directions. By turning the eccentric weight, the centrifugal block moves with the change of the weight position, rotates inward, the balance wheel accelerates, and the balance wheel rotates outward, and the balance wheel decelerates. The special tool used is equipped with a blade to precisely fit the screw slot.
After the movement is embedded in the case, the accuracy of the entire watch is again checked on the automatic timing device. The accuracy of the Lange movement is at least as high as required by the strict observatory test certification.
Assembling power reserve display device
The components of the power reserve display are assembled on the dial side of the movement and on the scaled bottom plate. Each gear is decorated with gorgeous round patterns.
In the picture, the stop lever of the device is being installed. Based on this device structure, the power reserve will be completely exhausted after 72 hours. UP / DOWN on the dial indicates the power reserve lever.
Assemble large calendar display
The large calendar display is a signature feature of the Lange watch. The display of the Lange’s large calendar is approximately three times larger than that of an equivalent-sized watch. The framed double window design is inspired by the five-minute digital clock of the Dresden Semper Opera House, which was created by John Ferretsi Gutkes and Ferdinando Adolf. Lange produced it in 1841.
The device uses two independent display elements: a circular single-digit dial with the numbers 0 to 9 engraved forward each day, and crossed ten-digit dial components with the numbers 1 to 3 and white blanks, every ten days forward Advance one unit. In LANGE 1 MOON PHASE ’25th Anniversary’, the numbers are printed in blue. The one-digit dial and the ten-digit dial that jump at midnight are only 0.15 mm away. The assembly of this delicate device is very skillful.
Assembling the moon phase display device
The 70 components of the moon phase are cleverly integrated in the L121.3 movement, which is slightly larger than the L121.1 movement of the LANGE 1 series. The display layout is based on two main components. Celestial discs made of solid 18K gold coated with blue, which rotates once every 24 hours. On the disc, the interference effect of light makes blue appear in multiple tones to represent different times of the day. In the daytime, the blue sky is clear but the stars are not visible. At night, the laser-cut stars can be seen in the dark blue night sky. The contrast is bright and charming. In the foreground, an independent solid 18K gold moon moves along the orbit, running against a vivid background, which can also be displayed as day / night. With a unique gear transmission, the moon continues to run with an accuracy of 122.6 years.
As a final step, carefully add two pre-assembled lunar component discs to the dial, and then assemble the dial.
During the first assembly, the movement is filled with different types of lubricants and greases. These lubricants and greases contain a variety of additives that provide excellent lubrication for a variety of applications. Some bearings must withstand low pressures and high speeds, while slowly rotating pinions carry huge loads. Some components have to withstand high accelerations and very slow speeds, while others are subjected to a lot of friction.
In the cleaning process after the first assembly, the lubricant and grease are removed, so the lubricant and grease must be refilled during the second assembly. This must be done in accordance with detailed instructions to ensure that 121 parts that need to be filled with lubricating oil and grease are not missed.