Welcome to a new series, It’s Complicated, in which we dissect a particular watch complication as illustrated via a single watch model or reference. As a refresher, a “complication” is any function of a watch beyond basic time-telling — a date window, for example, or a chronograph. While some of these complications are fairly common, others will add tens (or hundreds) of thousands of dollars to the price of a watch.
In this first installment of It’s Complicated, we’re going to examine a fairly rare combination of two otherwise pedestrian functions, the chronograph-GMT (or GMT-chronograph). This complication — exactly what it sounds like — features both time-recording as well as secondary time zone indicator functionality. There aren’t many mechanical examples of such a complication, but the few that exist from either the vintage or modern era are extraordinarily cool and incredibly useful, even in today’s digital world.
Few timepieces embody the chronograph-GMT better than the Heuer Autavia Reference 2446C from the late ‘60s/early ‘70s. Colorful, robust, and with a considered dial design that remains far from “crowded” despite the relative wealth of displayed information, it’s the type of watch that collectors wish was produced in significantly higher numbers.
The Heuer Autavia GMT Ref. 2446C
Heuer Autavia GMT - IN THE SHOP
Introduced in 1969, the Autavia GMT saw Heuer add a useful travel complication to its famed Autavia collection of automotive/aviation-themed chronographs and dashboard instruments. At first, the Autavia GMT used a screw-down caseback, but Heuer soon changed this to the snap-back ‘compressor’-style 2446C case for chronographs with three registers. Produced through the early 1970s, it went through several case and dial changes categorized by collectors into “executions,” or “Marks” (“MK”).
Without getting too far into the weeds, we can state that the second-execution Autavia GMT ref. 2446C featured several changes to the bezel design to make it easier for watchmakers to swap out this part. The second-execution watches also feature fluted (as opposed to smooth) pushers; a plain caseback without engravings; a more pronounced serif on the dial typography; a glossy (as opposed to a matte) finish; larger sub-registers; and several other minute changes. However, each “Mark” has a common feature set that allows the watch to do its job:
Heuer Atavia GMT Ref.2446C signed crown.
Housed within a 40.5mm stainless steel case with dual pump pushers and a signed crown is an aluminum bezel in red and blue with a 24-hour scale. Bi-directional and rotatable, this bezel is used in concert with a 24-hour GMT hand to indicate a second time zone. Beneath an acrylic crystal, the watch’s black dial features an outer printed 1/5th-seconds track with 5-minute demarcations in red and rectangular tritium hour markers. Three large white sub-dials with black scales include a 30-minute totalizer at 3 o’clock; a 12-hour counter at 6 o’clock; and a running seconds indicator at 9 o’clock. The lumed ‘sword’ handset is large and highly legible against the black and white dial, while the “Pepsi” colorway of the bezel gels beautifully with the dial’s color scheme. The watch was available on a folded-link, stainless steel beads-of-rice bracelet from Gay Frères with a signed, fliplock clasp — a touch that only adds to its overall appeal within the collector community.
Heuer Autavia GMT Ref.2446c Valjoux 72C Manual Winding movement - (Image by Mann About Time)
Powering the Autavia GMT is the venerable Valjoux 724, a modification of the hand-wound Valjoux 72 that adds a second time zone. With its smooth column wheel activation, 18,000 vph beat rate, and reliable (and serviceable) architecture, this movement family found its way into the most venerable chronographs of the day, from the Heuer Carrera to the Rolex Cosmograph Daytona to the Universal Genève Space-Compax.
Due to its “Pepsi” colorway; its unique pairing of complications; it sheer utility; its excellent sizing; and its robustness, the Heuer Autavia GMT has become a beloved collector favorite, though its relative rarity compared to simpler Autavia and Carrera executions means that relatively few surface in truly excellent condition.
Chronograph-GMT Use Cases and Functionality
We’ve debated the merits of the chronograph vs. the GMT complication before with respect to everyday utility and found that each has several use cases that make it supremely handy in modern life. With a 30-minute and 12-hour counter on the same watch, the user can time everything from laundry in the dryer to a dish on the stove to a lap around the track in a vintage 911. A GMT complication, meanwhile, can track both local and home time, or home time as well as that of a colleague or loved one halfway around the world.
The combination of these features truly is the sum of its parts — namely, a wildly utilitarian timepiece that allows the user to time discrete events; track a second time zone; and keep an eye on the local time. (Frankly, it’s a wonder that more watch companies didn’t release models with this feature set while Valjoux was cranking out 72-family movements in the mid-20th century!) These days, chronograph-GMTs are still fairly few and far between, though there are indeed options available that span from sub-$5,000 Sinn models to the $17,600 Bulgari Octo Finissimo Chronograph GMT.
The modern equivalent to the Valjoux 724 — albeit in automatic form and with cam switching rather than column wheel activation — is perhaps the ETA 7754, which provides a triple-register chronograph combined with an independently adjustable GMT hand. Used by brands such as Bremont in its Supermarine Chrono Jet, it provides a relatively affordable combination of chronograph and travel watch functionality. La Joux-Perret’s L121 offers similar functionality, while the L120 adds a date function. (It should be noted that both movements provide “caller” GMT functionality rather than “flyer,” meaning that the GMT hand is independently adjustable rather than the local hour hand. Such is also the case with Valjoux-family movements like that in the Autavia GMT.)
Bvlgari Octo Finissimo 43mm Blue Dial Chronograph GMT - (Image by Mayors)
Bulgari, on the other hand, offers a Chronograph GMT within its award-winning Octo Finissimo range. Powered by the in-house BVL 318 with automatic winding via a peripheral rotor, this unusual arrangement features a triple-register layout with 24-hour (second time zone) subdial at 3 o’clock; a 30-minute totalizer at 6 o’clock; and running seconds at 9 o’clock. Elegant albeit with limited functionality when compared to the aforementioned watches, it manages to provide both a chronograph as well as second time zone in a distinctly uncluttered design.
