A grande sonnerie strikes the hours and the quarters as they pass, without ever being asked to, and this is one of them in a steel case. F.P. Journe introduced the Sonnerie Souveraine in 2006 after six years of development, took the Aiguille d'Or with it that year, and built it until 2019. The case is steel at 42 mm and 12.25 mm deep, offered on a strap or a steel bracelet, with a dial of white gold and whitened guilloche silver and blued steel hands. Hours and minutes sit at 3 o'clock and the small seconds at 6, and the dial also carries a power reserve indication, a strike mode selector, and an opening through which the hammers can be watched at work. The calibre is the 1505, and the reference has not been built since 2019.
A grande sonnerie is the hardest thing in watchmaking and the reason is that it never stops. A minute repeater strikes when a slide is pushed and is otherwise dormant; a grande sonnerie strikes the hour and the quarter every fifteen minutes, all day and all night, on its own initiative. That means the mechanism is doing work ninety-six times a day before anybody asks it for anything, and every one of those strikes has to be correct, complete and unhurried. It also has to know the time in a way an ordinary movement does not: a repeater reads the time only at the moment it is asked, while a sonnerie must read it continuously and be right at each quarter without being consulted. On top of all that, this watch adds a petite sonnerie, which strikes the hours only and stays quiet at the quarters, a silence position that shuts the striking down altogether, and an on-demand minute repeater. Four striking behaviors from one train, selected by a control on the dial. Getting any single one of them to work is a serious undertaking. Getting all four to share a mechanism, and to hand over cleanly between them without anything jamming, is the part that took six years.
Energy is the constraint that governs everything else, and the figures show how tight it is. One single mainspring drives both the going train and the striking train, which is itself a deliberate choice rather than an economy: a good many sonneries use two separate barrels precisely to keep the two functions from interfering with one another. Run this one in silence and it holds 120 hours. Let it strike in grande sonnerie and that figure falls to roughly 48. When the striking energy is exhausted the watch keeps time for about another 24 hours, which is the sequence a wearer needs, since a chiming watch that stops telling the time because it has been busy chiming is no use to anybody. Ninety-six full strikes a day out of a single barrel is the number worth holding onto, because it reframes what the watch is actually doing. It is not a complication that operates occasionally. It is a mechanism running a scheduled task four times an hour, indefinitely, on stored energy. It explains why the movement is 35.80 mm across and 8.60 mm high, carries 40 jewels, and is built in 18K rose gold, and it explains why the case comes to 12.25 mm on a watch with no calendar and no second time zone.
Ten European patents cover this watch and almost all of them are about safety rather than about striking. That is an unusual emphasis and it comes from a specific brief: Journe wanted a sonnerie that could not be damaged by its owner. Chiming watches have historically been fragile in a particular way, which is that the sequences they run are interruptible and the controls are live at the wrong moments, so setting the time mid-strike or forcing a selector can break a component that only a specialist can replace. Journe's stated requirement was that the movement should be safe in the hands of an eight-year-old child, which is a memorable way of setting a very high engineering bar. The patents cover the interlocks that make that true. It is a very different kind of achievement from the acoustic one, and arguably it is the more important of the two, because it changed a grande sonnerie from an object that has to be handled with constant care into one that can simply be put on and worn. That is why the watch ran for thirteen years rather than existing as a demonstration piece, and why examples turn up having actually been used rather than kept in a safe. A sonnerie that cannot be broken by its owner is a sonnerie people wear.
Buy this one by ear and by paperwork, in that order. Listen to it in a quiet room across a full hour, through all four quarters, and confirm that the passing strikes arrive on time and at an even volume throughout. Run the repeater on demand as well, and cycle the selector through grande sonnerie, petite sonnerie and silence in turn, checking that each position engages cleanly and holds. Any hesitation there is worth taking seriously. Then wind it fully and leave it striking to see whether the reserve behaves as it should. On the case, steel is the forgiving option and can be refinished properly, but check the slide and the selector carefully for wear, since those are the parts that actually get used. Look at the dial as well, where the whitened guilloche silver should still resolve crisply under raking light. Establish the service history in detail and confirm exactly who carried out the work, because a sonnerie is the least forgiving movement F.P. Journe has ever built and there are very few people qualified to open one.
