Grönefeld 1941 Decennium Tourbillon

To celebrate the 10th anniversary of their own independent atelier in the Netherlands, Bart and Tim Grönefeld have created the 1941 Decennium Tourbillon, a limited edition of ten timepieces.

The 1941 Decennium Tourbillon features a 1941 case in platinum. The sculpted case is executed using a specially shaped cutter to create the characteristic hollowed, concave recesses and convex surfaces. In between each additional cutting phase, the case is polished prior to the next stage of milling, ensuring the precisely defined contours of the case are retained. This process proves incredibly time-consuming, but the outcome justifies the effort. The platinum 1941 case measures 39.5mm in diameter, with a restrained height of 10.5mm. The watch weighs 118 grams.

Grönefeld 1941 Decennium Tourbillon

Its automatic winding mechanism ensures the mainspring is optimally wound, resulting in less variation in the rate of the movement. The automatic movement is fitted with a 22-carat solid red gold monobloc rotor. The rotor is completely hand finished and turns on a ceramic ball bearing, preventing wear and eliminating the need for lubrication.

Grönefeld 1941 Decennium Tourbillon

The stainless-steel bridges replicate the facades of the Dutch houses, termed ‘bell gables’. They are hand-bevelled, evincing a brilliant gleam. The centres deliver a sublime contrast with their micro-blasted surfaces and are adorned with relief engraving. The cage of the flying tourbillon, a tourbillon without an upper bridge, is made of stainless steel. The Horological Brothers use stainless steel for the cage and the aforementioned bridges because it is not liable to corrosion and, as such, proffers lasting benefits to the owner.

Grönefeld 1941 Decennium Tourbillon

The 5-arm, double spoke gear train wheels exhibit a contemporary character with their circular grained surfaces paying due reverence to fine watchmaking tradition. The movement includes a balance wheel with white gold timing screws and is equipped with a free-sprung over-coil hairspring with triangular stud.

Gold chatons stand testament to the no-compromise specification of this movement. In addition, the mirror polished screws feature chamfered rims and slots. Numerous surfaces gleam, courtesy of the mirror-polishing which has been patiently executed by time-served hands. The inventory of different decorations includes snailed, grained, spotted and frosted surfaces.

Grönefeld 1941 Decennium Tourbillon

The production will be limited to only 10 examples of the Grönefeld 1941 Decennium Tourbillon.

The price of the Decennium Tourbillon in platinum is € 145,000.00 excluding taxes.

Technical details

Model: Grönefeld 1941 Decennium Tourbillon

Caliber G-07
Diameter: 32.0 mm
Thickness: 5.5 mm
Number of parts: 259 parts
Power reserve: 56 hours
Number of jewels: 30 jewels, partially set in solid gold chatons
Automatic system: Uni-directional winding mechanism
Oscillating mass: Entirely decorated by hand. 22 karat solid gold. Pivoted on a high precision ceramic ball bearing to avoid excessive wear and the need of lubrication
Tourbillon cage: One-minute flying tourbillon cage pivoted on ceramic ball bearing. Single arm upper cage bridge. Lower Cage and upper cage are both fabricated in stainless steel
Balance wheel: Variable-inertia balance wheel with four white gold timing screws (diameter 10 mm)
Frequency: 21.600 vibrations/hour
Balance spring: Free sprung with Phillips terminal over coil curve with triangle hairspring stud
Escapement: Jewelled lateral Swiss lever escapement
Main Plate: Spotted and ruthenium electroplated brass main plate
Bridges: Stainless steel, bevels polished by hand, micro-blasted center, circular grain on the top to highlight the bridges shapes and relief engravings

Central hour and minute hands

Material: Platinum Pt950
Diameter: 39.5 mm
Thickness: 10.5 mm
Engraving: Grönefeld, Platinum, Pt950 and serial number
Crown: Platinum Pt950, engraved with The Horological Brothers logo
Domed sapphire crystal on the front with hard anti-reflective coating on both sides
Flat sapphire crystal on the back with hard anti-reflective coating on both sides
Water resistance: 3 atmospheres – 30 meters – 100 feet

Sterling Silver 925, Matte grey lacquered with highly polished hour-markers and circular sector
Hands: Extended Lancette hands. Flame-blued steel and mirror polished centres.

Matte black genuine alligator, black stitching and alligator lining
Width: 20mm-18mm
Buckle: Platinum Pt950 engraved with Grönefeld. 18mm

Total weight
118 Grams

Limited edition
10 pieces only