A. Lange & Söhne: 1815 RATTRAPANTE

With the new 1815 RATTRAPANTE, A. Lange & Söhne’s watchmakers yet again demonstrate their expertise in the field of short-time measurement. Its complex mechanism expands the functionality of a classic chronograph by allowing the measurement of a random number of lap times within a minute. The watch has two superposed chronograph hands, the centre chronograph hand and the centre rattrapante hand. Both hands start together when the pusher at 2 o’clock is actuated. The centre rattrapante hand can now be stopped independently of the centre chronograph hand and then resynchronised with it.

THE SAXON STYLE

Enclosed in a 41.2mm platinum case, the 1815 RATTRAPANTE features a solid silver argenté dial and dark blued hands hands for a perfect legibility. The traditional style elements of the watch include the peripheral railway-track minute scale and the prominent Arabic numerals. 

The development of their own movement makes it possible for the watchmakers to freely choose the positions of the subsidiary dials. Instead of the ordinary positions at 3 and 9 o’clock, the 30-minute counter and the subsidiary seconds dial are at 12 and 6 o’clock, respectively, on the vertical centre axis. Additionally, the peripheral tachometer scale allows average speeds to be determined.  

THE MANUFACTURE CALIBRE L101.2

The 1815 RATTRAPANTE is powered by the manufacture movement L101.2, the seventh calibre with this complication developed and crafted in-house by A. Lange & Söhne. The entire rattrapante chronograph mechanism is configured such that it is visible through the sapphire-crystal caseback. This allows the complex switching processes to be observed in detail. The control of elapsed and lap-time measurements is handled in the classic manner with two column wheels. When fully wound, the mainspring barrel delivers a power reserve of 58 hours. In connection with the screw balance, also manufactured in-house, the freely oscillating Lange balance spring guarantees excellent rate accuracy at a frequency of 21,600 semi-oscillations per hour.

The finissage of the calibre, that was manually assembled twice, reflects the tradition of Ferdinand Adolph Lange: His movements always stood out with prominent design elements as well as inimitable aesthetic details. As befits the 1A quality attribute – the highest quality category of his pocket watches – the calibre L101.2 movement features bridges and cocks made of untreated German silver, a screw balance, screwed gold chatons that secure the jewels and a hand-engraved balance cock. All upper sides of the moving parts of the rattrapante chronograph, such as levers, springs and jumpers, are decorated with straight graining while the peripheral chamfers are polished. Bevel-polishing re-entrant angles is a particular challenge for the finishing specialists. 

The new 1815 RATTRAPANTE comes into the focus as a classic interpretation of the split-seconds mechanism, indeed as a singular complication. Lange’s engineers succeeded in limiting the height of the case to 12.6 mm despite the technical complexity of its 365-part manually wound calibre. Given its horological intricacy, this masterpiece is limited to a global 200-piece edition.