Bul­gari’s lat­est ad­di­tion to their fleet of com­pli­cated watches braves the treach­er­ous wa­ters of un­usual es­cape­ments and son­ner­ies

Revolution (Hong Kong) - - TIME COMPLICATION - By SUZANNE WONG

For some ab­surd rea­son, there are some peo­ple who still don’t think of Bul­gari as be­ing a company that pro­duces tech­ni­cal watches. This is de­spite the fact that they have cre­ated — with the aid of their as­sim­i­lated work­shops from Daniel Roth and Gérald Genta — watches such as the au­tomata re­peaters “Il Gio­ca­tore” and the Com­me­dia dell’Arte se­ries. In their reper­toire of com­pli­cated watches, they also boast a per­pet­ual-cal­en­dar grande et pe­tite son­nerie with West­min­ster chimes and a par­tic­u­larly beau­ti­ful-sound­ing tour­bil­lon minute re­peater with car­il­lon (that is, play­ing more than two notes) chimes. One can only con­clude that those peo­ple who don’t think of Bul­gari as a company ca­pa­ble of the most tech­ni­cally im­pres­sive watches prob­a­bly just don’t know very much about Bul­gari at all.

Some­thing is go­ing to change all that this year, and that some­thing is called L’Am­mi­raglio del Tempo, the Ad­mi­ral of Time. It is a chim­ing watch, and lately Bul­gari have spe­cial­ized in some of the best-sound­ing minute re­peaters I’ve heard, ever. They look spec­tac­u­lar as well. Case in point: the Daniel Roth Car­il­lon Tour­bil­lon is one of those watches — par­tially open­worked, al­ter­nately darkly matte and brightly pol­ished with a widesprawled, hand­some tour­bil­lon — that makes you want to wait un­til a minute when no one’s watch­ing, cram it into your mouth and then furtively walk away.

The Am­mi­raglio del Tempo is built along the same lines, with a rather stricter de­meanor; but that’s okay, be­cause the time­piece has some se­ri­ous business to do. You can im­me­di­ately see that it’s a chim­ing watch, be­cause of the vis­i­ble gongs and ham­mers vis­i­ble through the front of the watch. In fact, you can see it’s a car­il­lon re­peater be­cause of the num­ber of ham­mers and gongs. But where’s the ex­pected minute-re­peater slide? There’s no lever as we know it. There’s no push-but­ton. The re­peater ac­tu­a­tor isn’t built into the crown. Peer­ing at the move­ment, you see the re­peater main lever dip­ping out of sight un­der the bezel — but where’s the slide?

In a mas­ter­ful stroke that made me want to push my chair over and eu­phor­i­cally swear at the top of my voice when I first dis­cov­ered it (still does, to be per­fectly hon­est), the re­peater

ac­tu­a­tor is hid­den in plain sight — it is the bot­tom-left lug of the watch. Just you grab that lug and slide it about 30° clock­wise. Then, ladies and gen­tle­men, boys and girls, you will see some good fun. The Am­mi­raglio del Tempo is a West­min­ster minute re­peater, mean­ing it chimes the tune of the Big Ben clock (one bar of four notes for each quar­ter, and all four bars on the hour). It sounds stu­pen­dous — but you don’t have to take my word for it. Check out the many live videos of its chime on­line and hear it for your­self. It’s loud, it sounds good and it’s the per­fect speed — I don’t know what they’re feed­ing the high-com­pli­ca­tion watch­mak­ers at Bul­gari, but clearly it’s the good stuff.

By it­self, this would al­ready be pretty im­pres­sive. Ladies and gen­tle­men of the jury, this is not all. Look at the bal­ance at six o’clock and tell me what you see. Is it — could it be — is it re­ally? A piv­ot­ing de­tent es­cape­ment with con­stant-force mech­a­nism to sup­ply even torque to the no­to­ri­ously high-main­te­nance de­tent es­cape­ment, did you say? That is ab­so­lutely cor­rect. How high main­te­nance is the de­tent es­cape­ment? If the de­tent es­cape­ment were a woman she’d be Naomi Camp­bell, how about that.

And now, let’s go on a lit­tle ex­pe­di­tion down the isth­mus of com­pli­ca­tion and into the treach­er­ous straits of es­cape­ment. Warn­ing: his­tory and me­chan­i­cal en­gi­neer­ing the­ory ahead.

The vast majority of me­chan­i­cal time­pieces use Swiss lever es­cape­ments to sup­ply power to the reg­u­lat­ing or­gan. How vast ex­actly is this majority, you ask? Let’s put it this way — the num­ber that ex­presses the re­main­ing, mi­nor­ity per­cent­age only con­sists of non-zero in­te­gers when you look at least five spa­ces to the right of the dec­i­mal point. This ex­tremely small re­main­ing per­cent­age of me­chan­i­cal watches that do not use the Swiss lever es­cape­ment, use in­stead vari­a­tions of the Robin es­cape­ment (such as in the case of the Aude­mars Piguet ChronAP), Abra­ham-Louis Breguet’s nat­u­ral es­cape­ment (the Lau­rent Fer­rier Galet Mi­croRo­tor) or the de­tent es­cape­ment. The first rec­og­nized de­tent es­cape­ment was a 1748 in­ven­tion of pi­o­neer­ing clock­maker Pierre Le Roy. The mech­a­nism was sub­se­quently re­fined by horo­log­i­cal lu­mi­nar­ies such as John Arnold, Fer­di­nand Berthoud and Thomas Earn­shaw (of the bimetal­lic self-com­pen­sat­ing bal­ance), and it’s safe to say that, had the de­tent es­cape­ment not been in­vented, the world as we know it to­day would be very dif­fer­ent.

By the early years of the 18th cen­tury, mar­itime ex­plor­ers were con­fi­dent in nav­i­gat­ing through dif­fer­ent lat­i­tudes with great ac­cu­racy, since the oc­tant and sim­i­lar in­stru­ments con­structed on the prin­ci­ples of astro­nom­i­cal ge­om­e­try en­abled them to de­ter­mine lat­i­tu­di­nal po­si­tions with ref­er­ence to the sun or the North Star. Sea voy­ages could be safely con­ducted on a mostly north-south axis, with pe­ri­odic ref­er­ences to the coast to de­ter­mine ex­act lo­ca­tion. The prob­lem arose when it was nec­es­sary to sail east or west. Cal­cu­lat­ing lon­gi­tude while at sea was the­o­ret­i­cally pos­si­ble — all one had to do was in­vent an ac­cu­rate-enough time­keeper that, com­bined with the height of the sun in the sky, would al­low the nav­i­ga­tor to cal­cu­late his dis­tance from a ref­er­ence des­ti­na­tion, in terms of lon­gi­tu­di­nal de­grees. How­ever, no one had yet man­aged to build a time­piece that would keep time scrupu­lously in spite of the pitch­ing and yaw­ing of a large ship.

When John Har­ri­son pre­sented the first suc­cess­ful marine chronome­ter, the H4, the flood­gates were opened. The H4 used a novel es­cape­ment of Har­ri­son’s own in­ven­tion, but sub­se­quent high-per­for­mance marine chronome­ters used re­fined ver­sions of the de­tent es­cape­ment, and the prac­ti­cal­ity of th­ese de­signs even­tu­ally meant that most marine chronome­ters were dis­tin­guished by the use of a de­tent es­cape­ment. (To this day, another name for the de­tent es­cape­ment is “chronome­ter es­cape­ment.”) The de­tent es­cape­ment, then, was what ac­cel­er­ated the Age of Dis­cov­ery and the era of em­pire build­ing. The world pow­ers of the 19th cen­tury, the sign­posts for the foun­da­tion of the mod­ern era, were pre­cip­i­tated by the re­al­iza­tion of ac­cu­rate marine time­keep­ing.

With the Am­mi­raglio del Tempo spear­head­ing Bul­gari’s fleet of high com­pli­ca­tions, poised to open up new realms of horo­log­i­cal con­quest, it’s only ap­pro­pri­ate that the de­tent es­cape­ment guides the beat­ing of this time­piece. The de­tent es­cape­ment is built upon three fun­da­men­tal horo­log­i­cal prin­ci­ples. Firstly, the bal­ance should be dis­turbed as lit­tle as pos­si­ble and left to os­cil­late as freely as it can — the en­tire cat­e­gory of de­tached es­cape­ments cen­ters on this ax­iom, and is the rea­son be­hind the ex­ceed­ingly poor per­for­mance of early es­cape­ments such as the verge or cylin­der. Se­condly, the lock­ing of the es­cape wheel and the im­pulse of the bal­ance should be sep­a­rated for higher en­ergy ef­fi­ciency. Thirdly, di­rect-im­pulse es­cape­ments are su­pe­rior in that they do not re­quire lu­bri­ca­tion, and hence, avoid all the prob­lems as­so­ci­ated with the de­te­ri­o­ra­tion of watch oils.

For the above three rea­sons, the de­tent es­cape­ment is par­tic­u­larly well suited for high- per­for­mance time­pieces. The dis­ad­van­tages of the de­tent es­cape­ment, how­ever, are that it is ex­tremely sen­si­tive to shock, dif­fi­cult to minia­tur­ize and that, tra­di­tion­ally, it does not self- start. The first dis­ad­van­tage is es­pe­cially prob­lem­atic in a wrist­watch, since the wrist is sub­ject to one of the high­est amounts of po­si­tional vari­a­tion among all the parts of the hu­man body. Upon re­ceiv­ing a sud­den shock, the es­cape wheel is li­able to un­lock ac­ci­den­tally, al­low­ing the main­spring to rapidly wind down, stop­ping the move­ment and po­ten­tially dam­ag­ing it in the process. Bul­gari have ad­dressed this prob­lem by mod­i­fy­ing the de­tent arm and in­cor­po­rat­ing an ad­di­tional level to the safety roller. The de­tent arm ter­mi­nates in a curved lever of a very pre­cise shape that trav­els along the outer edge of the ad­di­tional level on the safety roller. In the case of a sud­den shock that might, in tra­di­tional de­tent es­cape­ments, dis­lodge the de­tent arm and un­lock the es­cape wheel, the lever presses against the safety roller and pre­vents the lock­ing jewel from slip­ping out from un­der the teeth of the es­cape wheel. The safety roller fea­tures a cutout to ac­com­mo­date the lever when the roller jewel re­leases the de­tent arm and un­locks the es­cape wheel.

The bal­ance in the Am­mi­raglio del Tempo uti­lizes a cylin­dri­cal hair­spring — as in the marine chronome­ters of old — and while this type of hair­spring is char­ac­ter­ized by im­proved con­cen­tric­ity in breath­ing, it also tends to­ward ex­treme am­pli­tudes. De­tent es­cape­ments fit­ted with cylin­dri­cal hair­springs are dou­bly vul­ner­a­ble to anoma­lous os­cil­la­tion, since the bal­ance is only im­pulsed in one di­rec­tion and os­cil­lates unchecked in the other di­rec­tion. The large vi­bra­tional am­pli­tude that a cylin­dri­cal hair­spring can cre­ate may send the bal­ance more than 360° around its axis, trip­ping the es­cape wheel in an ac­tion that fran­co­phone watch­mak­ers de­scribe as galop (“gal­lop”) — a word that con­veys ex­treme dis­ap­proval, es­pe­cially when used in con­text of the or­derly business of watch­mak­ing. Help­ing to reg­u­late this, the bal­ance assem­bly is geared to a se­cu­rity wheel via a pin­ion near the base of the bal­ance staff. The se­cu­rity wheel is ten­sioned with a spring and pre­vents ex­ces­sive ro­ta­tion of the bal­ance, while al­low­ing it to os­cil­late freely at stan­dard am­pli­tudes.

As I men­tioned be­fore, Bul­gari have been mak­ing com­pli­cated watches for quite a while now, and the Am­mi­raglio del Tempo is yet another high-wa­ter mark for the brand. If there’s still any more doubt in any­one’s mind about whether Bul­gari is ca­pa­ble of cre­at­ing as­tound­ing time­pieces at the very pin­na­cle of horo­log­i­cal achieve­ment, let the Am­mi­raglio del Tempo fi­nally put those doubts to rest — in Davy Jones’s locker.

The move­ment of the Am­mi­raglio del Tempo; with the bal­ance re­moved, the de­tent lever is clearly vis­i­ble; the bal­ance with cylin­dri­cal hair­spring, de­tent lever and es­cape wheel

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