During the past six decades, Grand Seiko has constantly been pursuing the creation of the world?s most accurate wristwatch, pushing the development of quartz, mechanical and Spring Drive movements. Now, the Japanese
giant is ready to finally enter the haute horlogerie segment.

The T0 is Grand Seiko’s first constant-force tourbillon movement.

In September 2020, Seiko Watch Corporation revealed the T-zero Constant-force Tourbillon (abbreviated as ?T0?) as a concept creation of Grand Seiko. It is the world?s first watch movement with a fully integrated constant-force mechanism and a tourbillon on the same axis, aiming to create a mechanical watch with the highest accuracy (and prestige) possible. The constant-force mechanism provides an even energy distribution to the escapement, regardless of how much the mainspring is wound, and the tourbillon aims to eliminate the error in precision caused by gravity by incorporating the escapement parts and balance in a rotating carriage.
The T0 obviously isn?t the first tourbillon from Seiko ?that would be the Credor Fugaku tourbillon from 2016. Nor is it the first wristwatch to combine a remontoire and a tourbillon (with F.P. Journe most likely having made the first), but this undoubtedly is a first for Grand Seiko, and the brand claims that this is the only time a remontoire and a tourbillon have been brought together on the same axis. In most cases, when a constant-force mechanism is added, it is usually placed away from...