IWC 94800

Cal. 94800 is a specialty high-end manufacture double barrel tourbillon movement produced by IWC since 2013.

Details

IWC has been transitioning to in-house movements since 2000, enhancing the reputation and technical features of their watches. Part of this development includes the production of specialty high-end movements. The Cal. 94000 family is the basis for many of these since its launch in 2011. It uses two mainspring barrels, providing power for complications including a tourbillon and specialty digital time display. This was a departure for the company, which had previously relied on a single barrel design for long power reserve movements but suffered poor isochronism as a result.

Cal. 94800 debuted in 2013 powering the Ingenieur Constant-Force Tourbillon, Ref. 5900. The two mainspring barrels are coupled, with a constant force mechanism integrated into the tourbillon to ensure stability of amplitude. This mechanism causes the tourbillon to advance once per second, even though the watch escapement, running at 18,000 A/h, "ticks" five times per second. After 48 hours of runtime on a fully-wound mainspring, the constant-force mechanism disengages and the tourbillon reverts to 1/5 second jumps. This continues through 96 hours of runtime.

The tourbillon is located at 9:00 on the dial and provides the running seconds display. A double moon phase indicator at 1:00 is accurate for 577.5 years before needing correction. A 96 hour retrograde power reserve indicator is at 5:00. It is a large movement, measuring 37.8 mm in diameter though it is just 7.7 mm thick.

The movement was updated in 2018 as Cal. 94805 with a single moon phase display for the Portugieser Constant-Force Tourbillon, Ref. 5902.