The Cartier Tank is perhaps one of the most recognisable watch designs ever made. Introduced in 1917, its rectangular case and parallel brancards have remained remarkably consistent for more than a century. Despite this, Cartier has continually found ways to reinterpret the design, from complicated CPCP pieces to some genuinely ambitious examples of skeletonisation.
Introduced at SIHH in 2014, the Tank Louis Cartier Sapphire Skeleton Ref. W5310012 is one of the more unusual modern interpretations of the Tank. Taking the familiar shape of the Tank Louis Cartier, Cartier removes the dial almost entirely and replaces it with the manually wound Calibre 9616 MC, seemingly suspended within the case.
For me, the architecture of the movement is what makes this watch so successful. Rather than simply skeletonising a conventional movement, the 9616 MC was designed around a transparent sapphire plate. This allows the components to appear as though they are floating within the watch, with very little visually connecting the movement to the case surrounding it.
More importantly, there is a real sense of proportion to the skeletonisation. The Tank is fundamentally defined by straight lines and rectangular shapes, yet the movement is dominated almost entirely by circles. A large circular bridge forms the centre of the watch, surrounded by the twin barrels, gear train, balance and small seconds. On paper these two design languages should almost conflict, but in practice the contrast works incredibly well.
The absence of a conventional dial also means that the movement becomes the dial itself. Blued steel sword-shaped hands sit directly above the mechanism, while the small seconds is positioned asymmetrically at approximately 8 o'clock. The twin open barrels occupy the upper portion of the watch, balanced by the escapement and running seconds below. Despite how much is going on, nothing feels particularly crowded or unnecessarily decorative.
All of this is housed within an 18-carat white gold Tank Louis Cartier case measuring 39.2mm by 30mm and just 7.45mm thick. These proportions are particularly important. Skeleton watches can easily become oversized showcases for their movements, but here everything remains contained within the elegant proportions expected of a Tank. The white gold case also keeps the watch relatively discreet, allowing the architecture of the movement to remain the focus.
Powering the watch is the manually wound Calibre 9616 MC, comprising 159 components and 21 jewels and beating at 28,800 vibrations per hour. Its twin barrels provide approximately 72 hours of power reserve, while the extensive hand finishing across the bridges and components gives the movement enough visual detail without overwhelming its underlying architecture.
There is also some historical precedent for the concept. Cartier has experimented with transparency for more than a century, most famously through its Mystery clocks, where hands appeared to float within transparent rock crystal or glass. The Tank LC Skeleton approaches the idea differently, but the principle of exposing a mechanism while simultaneously disguising how it is supported feels distinctly Cartier.
While Cartier has never disclosed production numbers for the Tank Louis Skeleton, very few appear publicly, and it seems clear that production was extremely limited. Even within the already relatively niche world of complicated and skeletonised Cartier watches, this is a reference that rarely surfaces.
For me, this is one of the most successful modern skeleton watches Cartier has produced. There is enough mechanical theatre to make the watch immediately interesting, but the proportions and shapes of the movement are so well considered that it never feels like skeletonisation simply for the sake of it. The circular architecture of the 9616 MC works beautifully against the rectangular Tank case, while the sapphire construction gives the entire movement an almost floating appearance. Combined with its rarity and relatively short production, I struggle to think of many modern Tanks that offer quite the same combination of design, watchmaking and sheer visual interest.
