IWC is going all out for its 150 anniversary celebrations in 2018, announcing no fewer than 27 limited edition novelties across the Portugieser, Portofino, Da Vinci and Pilot’s collection to be announced as well as the Tribute to Pallweber Edition we’ve already covered here.

Two of the more haute horlogerie offerings to wear the Jubilee Collection’s ‘150 years’ 18ct gold medallion sit within the Portugieser line; a perpetual calendar tourbillon and a constant force tourbillon.

The Portugieser Constant-Force Tourbillon Edition ‘150 Years’ is a 46mm platinum watch limited to just 15 pieces.

IWC have employed a variation of its 94800 calibre (the 94805) which installs a second escapement between the escape wheel and the fourth wheel which winds a balance spring ensuring constant force is supplied. This movement has already graced IWC’s Ingenieur Constant Force Tourbillon and the Portugieser Siderale Scafusia, although this twin barrelled version boasts 96 hours of power reserve, double that of previous iterations. The tourbillon itself is visible through the dial beneath a very bold, open-worked, cross-shaped bridge.

Complementing the platinum case is a white lacquered dial with blued hands, moon phase accurate to one day for 577.5 years.

The second Portugieser within the Jubilee Collection represents the first time IWC has presented a tourbillon on the dial of a perpetual calendar. Housed in an 45mm 18ct rose gold case the Portugieser Perpetual Calendar Tourbillon Edition ‘150 Years’ is a limited edition series of 50 pieces and is powered by the new inhouse 51950 calibre, which is based on the 51900 with the addition of a perpetual calendar mechanism.

To display the tourbillon on the dial IWC’s watchmakers had to open up the perpetual calendar’s advance ring and positioned the moon phase display at the centre of the month display at the six o’clock position. The movement runs at a rather unusual 19,800vph or 2.75hz and features a seven day power reserve.

Each of the watches within the Jubilee Collection feature either white or blue dials, inspired not only by the look of the aforementioned Pallweber pocket watches but the imprinted dials and blued hands of the original 1939 Portugieser models. The Portugieser Perpetual Calendar Tourbillon Edition ‘150 Years’ also comes down on the side of white lacquer with blued hands.

This article was first published on Salon QP