Tourbillon

In the tourbillon, invented by Breguet in 1795, the escapement (balance, escape wheel, etc.) is mounted on a carriage which carries a pinion driven by the third wheel. The fourth wheel is fixed and is concentric with the carriage shaft. The escape wheel pinion meshes with the fixed fourth wheel which will cause the pinion to rotate and operate the escape wheel and balance in the normal way. (M. Cutmore - Watches 1850-1980 (1989) p. 71)

It must be borne in mind that tourbillons are intended only to correct pocket-watch positional errors which are largely 2-dimensional when carried in a waistcoat pocket. A wristwatch experiences many more varied and frequent positional shifts in normal use.

Karrusel

In the karrusel by Bonniksen (UK patent 21421 of 1892) the carriage is mounted on a karrusel wheel driven by the third wheel pinion. The fourth wheel staff passes through the centre of the karrusel bearing to allow the fourth wheel pinion to mesh with the third wheel and power is transmitted to the escapement in the normal way rather than through the carriage rotation as in the tourbillon. The rate of rotation of the karrusel is about once per hour compared with the tourbillon which may rotate once per minute. Both these designs require considerable skill to manufacture, and are only found in watches of high quality. (M. Cutmore - Watches 1850-1980 (1989) p. 72)

In official chronometer trials in the 1890s-1900s, karrusels consistently out-performed tourbillons. This seems to be because the longer period of rotation consumed less energy and achieved a more representative correction to the positional shifts normally experienced by a pocket-watch.

Flying Tourbillon

This describes a tourbillon carriage that is supported only at the back so that from the dial side it appears to be floating with no visible means of support. The lack of a bridge on the dial side also helps reduce the height of the tourbillon sub-assembly.

Carrousel-tourbillon

This now widely-used term was introduced by Blancpain to describe an otherwise conventional 1-minute tourbillon in which the axis of the balance was offset from the axis of the tourbillon carriage, giving the tourbillon a more karrusel-like appearance. The reason for this modification appears to be to reduce the overall height of the tourbillon.

Flying carrousel-tourbillons were the first type of tourbillon attempted by the Chinese watch industry, no doubt on account of the aesthetics of such an arrangement.

Freak

Ulysse-Nardin describe the escapement on their ‘Freak’ as a kind of carrousel-tourbillon, however that aspect of the design is really closer to Bonniksen’s 60-minute Karrusel. On the Freak, the escapement is the minute hand. This in turn is mounted on yet another carriage that rotates itself once per 12-hours and serves as the hour hand. Thus the entire movement is in the hands. There is no Chinese equivalent to this concept.

Double-tourbillon

Both Beijing and Sea-Gull have developed movements featuring a pair of tourbillons engaging a common third wheel. This might possibly result in better timekeeping, but primarily these watches have been made for their aesthetic appeal. The Beijing TB02 features a patented differential device to prevent conflict between the two escapements.

Dual-axis Tourbillon

To offer any genuine positional correction in a wristwatch, the escapement should rotate in more than one plane. In the Greubel-Forsey Tourbillon, the balance-wheel is inclined at 30deg to the carriage plane. Other watchmakers have created spherical carriages in which two planes of rotation intersect via a rotation within a rotation. The Beijing Watch Factory TB04 is currently China's only dual-axis tourbillon. In this movement a 60 second rotation intersects a 24 hour rotation.

12-hour Karrousel

PTS Resources’ latest innovation takes the traditional Karrusel and moves another wheel from the train onto the carriage, which revolves once every 12 hours and appears to be driven directly by the mainspring barrel. A separate minute hand also looks like it is directly driven. The corrective benefit of this arrangement is negligible, but it must be simpler to build and adjust than a 60-second tourbillon or 60-minute karrusel, yet has most of the visual appeal of those more exotic complications.

Orbital Tourbillon

This is a term first used by Jean Dunand watches in 2005 to decribe a 1 minute tourbillon mounted on a 60-minute carrousel platform orbiting the dial. In 2006 Breguet applied this concept to a double-tourbillon, and in 2007 the Shanghai Watch Factory developed their own versions of both the single and double tourbillon types.