A. Lange Grand Lange 1 “Lumen”

SIHH 2013 preview…

Here’s a first look at the  A. Lange & Söhne Grand Lange 1 Lumen.  Channeling the popular Lange Zeitwek Lumnous of 2010, this watch has a semi-transparent smoked sapphire crystal dial.  Channeling the the Grand Lange 1 Luminous, this watch also has luminous hour markers and other elements.  Channeling the redesigned Grand Lange 1 of 2012, the watch has a non-overlapping dial-design (and also the same L095 caliber).  This is also the first luminescent outsize date display by A. Lange & Söhne.  More analysis and specifications, below! Back with more details and discussion this afternoon.

A. Lange Grand Lange 1 “Lumen”

Limited edition 100 200 pieces

40.9mm platinum case (9.8mm thick); rhodiumed gold hands; hours/minutes/power-reserve indicator
luminous; manual wind Lange L095.2 caliber (72 hour power reserve; German silver plates and bridges, hand engraved balance cock), black crocodile strap with platinum Lange prong buckle

The outer ring and the surfaces of the displays for hours and minutes as well as small seconds are made of blackened silver. The semi-transparent sapphire crystal reveals the disc mechanism of the luminous outsize date (a Lange first, as noted above).   Additionally, the time and the power reserve are also legible in the dark.  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 perlage (hand applied by Lange artisans, of course) which is normally seen only by the watchmaker during the assembly process, is now visible as well.

Lange tells me that 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 (the new days digit would have been hidden for the last 24 hours).   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.

manual wind Lange L095.2 caliber (72 hour power reserve; German silver plates and bridges, hand engraved balance cock)

Official unveiling in January 2013, at the SIHH in Geneva.

Did You Know?

How the A. 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.