2012/12/19 - A. Lange & Söhne the Grand Lange 1 "Lumen"

 

The limited GRAND LANGE 1 “Lumen” offers enlightenment: a semi-transparent dial exposes the ingenious mechanism of the first luminescent outsize date display by A. Lange & Söhne.

Legible even in the dark: GRAND LANGE 1 “Lumen”

When it was first presented, it evoked excitement and kicked off a trend that soon found many imitators: the Lange outsize date. Together with the asymmetric dial, it elevated the LANGE 1 to the status of an icon of classic design. However, the secret behind the complex mechanism responsible for this unprecedented date display format remained hidden beneath the solid-silver dial. Now, the GRAND LANGE 1 with the Latin attribute “Lumen” reveals this secret. The name of the timepiece, which comes in a limited edition of 200 watches in platinum cases, says it all. Parts of its dial consist of semi-transparent sapphire crystal. Only the outer ring and the surfaces of the displays for hours and minutes as well as small seconds are made of blackened silver. The sapphire crystal surfaces reveal the disc mechanism of the first outsize date that glows in the dark. Additionally, the time and the power reserve are also legible in the dark.

This is how the Lange outsize date works

The Lange outsize date was inspired by the Five-Minute Clock in Dresden’s Semper Opera House to which Ferdinand A. Lange contributed his expertise in 1841. To maximise the format of the date, the date mechanism uses two separate display elements, just like its famous role model: the ring-shaped units disc with the numerals 0 to 9 switches once a day. But at the transition from the 31st to the 1st day, it stands still for a day. The tens cross with the numerals 1 to 3 and a white blank space advances by one increment only every ten days. When it displays the 3, the tens cross advances to the blank space after only 2 days. The irregular switching sequence is controlled by two programme wheels with a precisely calculated toothing pattern.

The technical challenge encountered during the development of the GRAND LANGE 1 “Lumen” was to ensure maximum luminosity for the date display, even immediately after the daily switching operation. Lange’s product developers solved this issue in an exceptional way. While the tens cross was coated with a white luminous compound and subsequently imprinted with black numerals, the units disc consists of transparent glass imprinted with black numerals and rotates before a luminous background.

The sapphire crystal sections of the dial are treated with a special coating that blocks most of the visible spectrum of light. For the invisible UV light spectrum, however, the coating does not represent a barrier. Therefore, UV radiation can pass through to the luminous surfaces of the outsize date unhindered. This produces an interesting side effect: the date platform with its manually applied perlage, normally seen only by the watchmaker during the assembly process, is now visible to the owner as well. The small, overlapping circular graining produced by hand using a rotating abrasive peg is normally concealed underneath the dial.

The craftsmanship and virtuosity invested in the L095.2 manufacture movement, which is assembled twice, can also be admired from the other side through the sapphire-crystal caseback. Indeed, the GRAND LANGE 1 “Lumen” radiates charisma from every angle. Only last year, A. Lange & Söhne endowed the GRAND LANGE 1 with a totally new, manually wound calibre. The omission of the second mainspring barrel as well as the effective arrangement of the parts reduced the overall height of the calibre without any compromise in terms of power reserve, making it possible to transpose the graceful dial architecture of the LANGE 1 to the enlarged model. The dial of the GRAND LANGE 1 “Lumen” presents the indications of the hours, minutes, seconds, outsize date, and power reserve without any overlaps.

 

 

 

 

 

Technical Specifications

Ref. : 117.035
Limited edition : 200 watches

• Movement Lange manufacture calibre L095.2, manually wound, crafted to the most exacting Lange quality standards, decorated and assembled by hand; precision-adjusted in five positions; plates and bridges made of untreated German silver; balance cock engraved by hand
  
• Movement parts : 400
  
• Jewels : 42
  
• Screwed gold chatons : 7
  
• Escapement : Lever escapement
  
• Oscillator : Shock-resistant screw balance; superior-quality balance spring manufactured in-house, frequency 21,600 semi-oscillations per hour, precision beat adjustment system with lateral setscrew and whiplash spring
  
• Power reserve : 72 hours when fully wound
  
• Functions : Time indicated in hours, minutes, and subsidiary seconds with stop seconds; power-reserve indicator; outsize date
  
• Operating elements: Crown for winding the watch and setting the time; push piece for rapid correction of the outsize date
  
• Case dimensions : Diameter : 40.9 millimetres; height: 9.8 millimetres
  
• Movement dimensions : Diameter: 34.1 millimetres; height: 4.7 millimetres
  
• Crystal and back : Sapphire crystal (hardness 9)
  
• Case : Platinum
  
• Dial : Basic dial (outer ring, hour, minutes, small seconds) of solid silver (black), recessed parts of sapphire crystal with semitransparent coating; luminous outsize date and indications for hours and power-reserve
  
• Hands : Rhodiumed gold; hours, minutes, power-reserve indicator luminous
  
• Strap : Hand-stitched crocodile strap, black
  
• Buckle : Lange prong buckle in platinum