IWC - Portugieser Handwind Automatic 40mm IW545901 RG/LE Blk/Num RMS Asian Tourb

IWC’s Portugieser Hand‑Wound Tourbillon represents the pinnacle of the “clean‑dial” elegance that has defined the Portugieser line since its 1930s origins. Introduced most recently at Watches and Wonders 2024, these watches pair a classic 42.4 mm case with the technical drama of a flying tourbillon—and in one variant even a globe‑shaped day‑and‑night indicator.

1. Heritage & Context

The Portugieser collection dates back to 1939, when two Portuguese merchants commissioned oversized, marine‑chronometer‑grade wristwatches with clear dials and railway‑track minute scales. Over the decades, IWC has expanded the line to include chronographs, perpetual calendars—and, since 2017, hand‑wound tourbillons that celebrate classical haute horlogerie fused with modern materials and finishes.

2. Case & Aesthetics

• Dimensions & Material: 42.4 mm × 10.8 mm, available in polished‑and‑brushed 18 ct Armor Gold® (an extra‑hard, high‑performance gold alloy).

• Bezel & Crystal: Classic gold fluted bezel; dual‑side antireflective sapphire crystal up front and on the display back, water‑resistant to 6 bar (≈60 m).

• Dial Variants: Silver‑plated or Obsidian‑lacquered (“Day & Night” edition) surfaces, with applied feuille hands and Arabic numerals in matching gold tones.

3. Movement & Complications

• Calibres 81905 / 81925: Fully in‑house, manual‑wind movements operating at 4 Hz (28 800 vph) with an 84‑hour power reserve.

• Flying Tourbillon: A one‑minute flying tourbillon at 6 o’clock, 56 parts weighing ≈0.635 g (0.675 g in “Day & Night”), featuring a hacking‑stop mechanism for precise setting.

• Silicon & Diamond Shell®: Silicon pallet lever and escape wheel treated with Diamond Shell® coating to reduce friction and eliminate oil, enhancing energy transmission and longevity.

• (“Day & Night” Edition): Adds a rotating globe at 9 o’clock to display the 24‑hour cycle—visible from both dial and caseback—while retaining full tourbillon functionality.

4. Wearability & Finishing

• Strap & Clasp: Santoni black alligator leather with curved, short lugs for comfort; secured by an 18 ct gold folding clasp, CITES‑compliant.

• Finishing: Bridges adorned with Côtes de Genève, polished bevels, and a solid‑gold “Probus Scafusia” medallion on the movement side.

5. Technical Specifications at a Glance

Feature	Specification
Case	42.4 mm × 10.8 mm, 18 ct Armor Gold®
Dial	Silver‑plated or Obsidian lacquer, gold appliqués
Movement	Calibre 81905/81925, hand‑wound, 4 Hz, 84 h PR
Complications	Flying minute tourbillon (hacking stop), Day‑Night globe (IW545901)
Strap	Black Santoni alligator, gold folding clasp
Water Resistance	6 bar (60 m)

6. Pros & Cons

Pros

• Superb mix of classical design and modern materials (Armor Gold®, silicon components)

• High‑end finish and in‑house craftsmanship, including Geneva stripes and diamond‑coated escapement parts

• Rare hacking tourbillon mechanism for precise time setting

• “Day & Night” globe adds visual interest and uniqueness

Cons

• Premium pricing (≈ CHF 65 000–87 500) places it well above most “entry” high‑complication watches

• Large case may wear big on smaller wrists despite curved lugs

• Manual‑wind requires daily winding for full reserve
  

The IWC Portugieser Hand‑Wound Tourbillon stands as a modern testament to both the purity of the original 1930s design and IWC’s technical prowess. Whether you choose the pure tourbillon version or the more playful Day & Night edition, you’re getting a beautifully finished, mechanically intriguing piece—albeit at a steep price point. Ideal for collectors who appreciate classical proportions, exemplary finishing, and the horological theater of a flying, hacking tourbillon.