Calibre B12 is an automatic chronograph movement with a 24 hour hand produced by Breitling since 2016.
Breitling introduced their calibre 01 (commonly called Cal. B01) in April 2009 in the Chronomat. It is a modern automatic chronograph movement with a column wheel and vertical clutch. It operates at 28,800 A/h, boasts a power reserve of 70 hours, and is a COSC-certified chronometer. The movement shares many characteristics with the Rolex Cal. 4130, and it has been reported that many of the same engineers worked on both movements.
Functions and Complications
Cal. B12 modifies the basic Cal. B01 in that the central hour hand traces 24 hours in a day rather than 12 hours twice. Thus it requires a special dial with 24 hour markings. The movement is 0.10 mm thicker at 7.30 mm.
Cal. B12 features the following displays on the dial:
- 30 minute chronograph counter at 3:00
- Date window at 4:30
- 12 hour chronograph counter at 6:00
- Small seconds at 9:00
The 24-hour hand is independently adjustable backward and forward independently of the minute hand.
Cal. B12 Applications
Breitling has only used Cal. B12 in the Avenger Hurricane 24H models.
Breitling B01 Family Overview
Starting in 2017, Breitling began supplying a version of Cal. B01 to Tudor. The resulting movement, Cal. MT5813, has a free sprung balance with a silicon hairspring, as is common in modern Rolex and Tudor movements. It is also decorated differently. Strangely, it is often quoted as having different dimensions: 30.40 mm diameter and 7.23 mm thickness.
| Calibre | Year Introduced | Jewels | Height | Winding | Date | Complications |
|---|---|---|---|---|---|---|
| B01 | 2009 | 47 or 41 | 7.20 | Automatic | Yes | Some Without Hour Counter |
| B02 | 2013? | 47 | Manual | Yes | 24 Hour | |
| B03 | 2017 | 47 | 9.15 | Automatic | Yes | Split Seconds |
| B04 | 2011 | 47 | 7.20 | Automatic | Yes | GMT |
| B05 | 2013? | 56 | Automatic | Yes | World Time | |
| B06 | 2015 | 47 | Automatic | Yes | 30 Sec Chrono | |
| B09 | 2019? | 47 | Manual | No | ||
| B12 | 2016 | 47 | 7.30 | Automatic | Yes | 24 Hour |
| MT5813 | 2017 | 41 | 7.23 | Automatic | Yes | No Hour Counter |