Tank Obus

The Tank as Artillery

The Tank Obus appeared in 1923, two years after the standard Tank Normale entered production. Where the Normale borrowed the proportions of a Renault FT tank viewed from above — parallel vertical brancards flanking a rectangular case — the Obus took a different element from the same battlefield: the artillery shell. The result was a square case flanked by four cylindrical, bullet-shaped lugs that protruded horizontally from the case at the top and bottom.

This was not a refinement of the Tank concept. It was a reinterpretation — and a confrontational one. The bullet lugs gave the watch a three-dimensional presence that the flat, graphic Tank Normale deliberately avoided. Louis Cartier was exploring how far the Tank's military-industrial inspiration could be pushed while remaining wearable, and the Obus represented the outer boundary of that experiment.

Extreme Rarity from the Start

The Tank Obus was never produced in meaningful volume. Cartier manufactured only approximately 2,200 wristwatches total before 1965 across all models — and the Obus, as one of the most specialized variants, accounted for a tiny fraction of that output. Early examples from the 1920s through 1940s featured mechanical movements from the European Watch & Clock Company and LeCoultre, housed in platinum or yellow gold cases. These pieces are now museum-level rarities, appearing at auction only when major collections are dispersed.

The model survived the mid-twentieth century largely as a special-order piece. In the 1980s and 1990s, Cartier produced the Ref. 1630 in 18k yellow gold with a quartz Cal. 157 movement — a commercially viable version that introduced the Obus form to a new generation of collectors while remaining a low-volume production.

The CPCP Revival

The Tank Obus's most significant modern chapter came through the Collection Privée Cartier Paris (CPCP), which produced the Ref. 2380 from approximately 1998 to 2000. The CPCP version returned the Obus to its mechanical roots with the manually wound Cal. 437 MC (a Piaget-based caliber with 19 jewels), housed in an enlarged case with a guilloché silvered dial and blued Breguet hands. Production was limited to an estimated 100–150 pieces, making the CPCP Obus one of the rarest references in the entire CPCP catalog.

The Tank Obus Today

The Tank Obus occupies the far end of the Cartier collector spectrum: a watch known primarily to specialists, traded infrequently, and valued for its historical significance and extreme scarcity rather than broad market recognition. When examples appear — whether quartz-era Ref. 1630s or CPCP Ref. 2380s — they attract focused attention from collectors who understand what they represent: one of Louis Cartier's most audacious design experiments, produced in quantities small enough that every surviving example carries weight.