The calibre L951.6
SEEN THROUGH A WATCHMAKER’S LOUPE (2 MB)

THE MANUFACTURE CALIBRE L951.6

The manufacture calibre of the DATOGRAPH UP/DOWN embodies the accrued skills and know-how of Lange’s calibre engineers: its power reserve was increased by 24 hours thanks to a slightly enlarged mainspring barrel. The watch newly incorporates a power-reserve indicator mechanism as well as a proprietary oscillation system that assures optimised rate accuracy: it relies on a balance wheel with eccentric poising weights and a freely oscillating balance spring.

View through the sapphire-crystal caseback

EXPERIENCING COMPLEX MECHANISMS.

A glance through the sapphire-crystal caseback reveals the underside of the movement with the levers and springs of the chronograph, flyback, and minute counter mechanisms. A variable-position switching lever allows the precise jumping point of the minute counter hand to be adjusted without disassembling the movement. Lange received a patent for this invention. Another patent was granted for its twin-disc outsize date. The heart of the movement, a balance wheel with eccentric poising weights, a Lange balance spring and shaped terminal curve, is calibrated to 18,000 semi-oscillations per hour.

FLYBACK ANIMATION (MOV 2.0 MB)
MINUTE-COUNTER ANIMATION (MOV 1.0 MB)
The classic column wheel

VIRTUOSITY IN DECORATION.

All parts of the movement are lavishly decorated. The plates and bridges, made of untreated German silver, are finished with perlage and ribbing. All edges are chamfered and polish-ed. This also applies to the spring of the whiplash precision index adjuster and the classic column wheel. The balance cock is manually engraved with a  free-hand technique, making each DATOGRAPH UP/DOWN a one-of-a-kind watch.