One area where ZENITH excelled in the past was in observatory chronometer competitions, having amassed more awards than any other watchmaker with well over 2’330 chronometry prizes to its name. In the mid-20th century, one movement outshone all others during the golden era of observatory chronometer competitions and reigned supreme: the Calibre 135-O. With over 230 chronometry prizes, the Calibre 135-O holds the most awards of any observatory chronometer calibre in the history of watchmaking.
For the first time in the history of the Calibre 135 and certainly for the “O” variant, the observatory chronometer movement that has been impeccably decorated and finished by Kari Voutilainen is visible through a sapphire display back. Tasking Kari Voutilainen with the restoration and finishing of these historical movements elevated them from raw competition pieces to haute horlogerie creations of the highest order. Cleaned and finished by the master restoration watchmaker, the aesthetic of the historical movement has been refined thanks to the with hand chamfered and polished edges on the gold-coloured bridges, bevelled and polished screw-heads, circular graining on the main plate, snailed brushing on the ratchet and crown wheels and much more.
True to its original era, the Calibre 135 Observatoire is inspired by past commercial wristwatch versions of the Calibre 135, yet unlike anything ever made in the past, the Observatoire Limited Edition draws inspiration from several 1950s references by combining the most emblematic details with contemporary accents.