====== IWC 50900 ======
**Cal. 50900** is an oversized [[in-house]] [[eight day]] [[tourbillon]] movement in the [[IWC 50000|Cal. 50000 family]] produced by [[IWC]] since [[2010]].

===== History =====
On its release in [[2000]] in the limited-edition [[IWC Portugieser 2000]], [[IWC]]'s [[IWC 5000|Cal. 5000]] was lauded by the brand's followers. It marked the restart of completely-[[in-house]] watch movement development for the company and brought back the legendary [[Pellaton winding]] system. The movement was seen as a landmark in other ways, with 8-day power reserve, automatic winding, and a massive 16.75 [[ligne]] (38.2 mm) diameter.

In [[2004]], IWC introduced the [[IWC Portugieser Tourbillon Mystère 5042|Portugieser Tourbillon Mystère, Ref. 5042]] with a new version of the Cal. 5000. The new **Cal. 50900** adds a [[tourbillon]] and [[retrograde]] [[power reserve indicator]] to the movement family. The [[tourbillon]] is visible through an [[open heart|opening in the dial]] at 12 00, while the retrograde power reserve needle sits at 4 30. Running [[small seconds]] are placed at 9 00.

In [[2010]], IWC introduced the [[IWC Portugieser Tourbillon Mystère Rétrograde 5044|Portugieser Tourbillon Mystère Rétrograde, Ref. 5044]] with a new version of the Cal. 50900. The new **Cal. 51900** adds a [[retrograde]] [[date by pointer]] at 7 30 to the movement. The [[power reserve indicator]] is also retrograde and is moved back to 3 00.

Cal. 51900 was updated in [[2017]] with a [[perpetual calendar]] module to become **Cal. 51950**. This was used in the limited-edition [[IWC Portugieser Perpetual Calendar Tourbillon 5045|Portugieser Perpetual Calendar Tourbillon "150 Years", Ref. 5045]].

===== Applications =====
  * Cal. 50900 (2004-2009) - Power reserve indicator at 4 30
    * [[IWC Portugieser Tourbillon Mystère 5042]] (2004-2009)
  * Cal. 51900 (2010-present) - Retrograde date at 7 30
    * [[IWC Portugieser Tourbillon Mystère Rétrograde 5044]] (2010-2014)
    * [[IWC Portugieser Tourbillon Mystère Rétrograde 5046]] (2015-present)
  * Cal. 51950 (2015-present) - [[Perpetual calendar]]
    * [[IWC Portugieser Perpetual Calendar Tourbillon 5045|Portugieser Perpetual Calendar Tourbillon "150 Years", Ref. 5045]] (2015-present)


<WRAP ud ud_mov>

**Description:**
  * [[Automatic]] movement
  * Bi-directional winding ([[Pellaton winding system]]) on spring-mounted [[rotor]], cam disc, ruby wheels and 2 latches on ratchet wheel, gear reduction 175 1
  * [[Escapement]] stone lever
  * [[Yoke winding system]]
  * [[Breguet hairspring]]
  * [[Incabloc]] [[shock protection]]
  * Two-armed [[screw balance]] with 16 weight srews and 2 adjustment eccentrics on the escapement arms
  * [[Hairspring]] Nivarox 1 with Breguet bending
  * IWC [[precision adjustment]] hairspring stud and regulator adjustable with eccentric
  * [[Bridge]]s and plate nickel coated, engravings gilded, [[decoration]] of type "[[Côtes circulaires]]"
  * [[Weight segment]] IWC-style (without gold medaillon) with gilded Probus-Scafusia engraving, plate wheel, crown wheels, [[ratchet]], barrel lid and [[differential gear]] with [[solar grinding]]

**Functions:**
  * Hours, minutes
  * [[Tourbillon]] at 12 00
  * 50900
  * [[Retrograde]] [[power reserve]] indicator at 4 30
  * [[Small seconds]] at 9 00
  * 51900
  * [[Retrograde]] [[power reserve]] indicator at 3 00
  * [[Retrograde]] [[date by pointer]] at 7 30

**Data:**
  * 16,75 [[ligne]]s
  * Ø 38.2 mm
  * Height 8.9 mm
  * 44 [[jewels]]
  * 19,800 A/h
  * [[Power reserve]] [[8-day|204 h]], limited to 168 h

**Production period:**
  * Production [[2004]]-Present
</WRAP>
===== See Also =====
  * [[IWC 50000]]


{{tag>Movements Automatic_movements Perpetual_calendar_movements Tourbillon_movements IWC_calibres Pellaton_movements}}