TUDOR History : The Chronographs

The first TUDOR chronograph was named Oysterdate. Featuring a manually-wound Valjoux mechanical calibre 7734 and a cam mechanism chronograph, it was introduced in 1970. Its case dimensions were significant, with a 39 mm diameter more imposing than many standards of the time, the characteristically pronounced bevelled edge of its lugs, and its muscular well-honed lines. The very graphic style of its dial was also unusual. A daring wager, but a wager that paid off since the model immediately found its audience.

There were three variations of this first sporty TUDOR chronograph, differentiated by their types of bezel. Two were produced in large numbers, while the third was never commercialised. Their look is unique and noble, their roots technical and sporty. Reference 7031/0 is characterised by a bezel topped with a Plexiglas insert featuring a 500-unit graduated tachymetric scale, which can be used to calculate the hourly average speed between two points. Reference 7032/0 has a satin-finished steel bezel, also engraved with a 500-unit graduated tachymetric scale. The last one, reference 7033/0, featured a bidirectional rotatable bezel with a black 12-unit graduated insert in anodised aluminium; it never went beyond the prototype stage.

The dials of these first three references were identical and comprised three colours: grey background, black counters and a minute track on a white background. In addition, they had unconventional luminous pentagon-shaped painted hour markers that earned them the nickname “home plate” in collectors’ circles because they were reminiscent of the shape of the home plate on a baseball field. Finally, a last particularity, the chronograph minute counter consisted of 45 minutes, an unusual variation on the more common 30-minute counter.

Thanks to their waterproof Oyster-type cases, and their screw-down winding crowns, these chronographs were waterproof to a depth of 50 metres. Their screw-down pushers prevented any accidental engagement of the chronograph.

In 1976, TUDOR presented a new family of products which constituted a small revolution for the brand. Indeed, these new Prince Oysterdate watches were the first chronographs in the history of TUDOR to be equipped with self-winding movements.

Listed under the name Prince Oysterdate, they were also known by the names “AUTOMATIC CHRONO TIME” or “CHRONO TIME” referring to the signatures displayed on their dials. While their cases retained the general lines of the previous families, they became thicker to accommodate the rotor of the self-winding movement, which earned them the nickname “Big Block” in collectors’ circles. The name “Big Block” endured in the following 79100 series introduced in 1989, which featured only minimal modifications.

Like preceding generations, the 9400 series consists of three references distinguished one from the other by their type of bezel, a feature that is also present on the “Big Block” models of the 79100 series. Likewise, several dial variations were available under the same reference number. Two aesthetic trends characterise them: one freely inspired by the spirit of the dials of the previous two series, sometimes called “Exotic” by collectors; the other, much more illustrated in the catalogue, emphasising a significant dial-counter contrast with black and white or sliver and white combinations.

The movement at the heart of these new chronographs was the Valjoux calibre 7750. Having the same diameter as the manually-wound Valjoux 234, 30.4 mm or 13 lines, it was 1.5 mm thicker than the latter and had a frequency of 28,800 beats per hour. Its chronograph mechanism was a highly reliable cam and oscillating pinion system. The architecture of this new movement brought about a reorganisation of the dial with the addition of an hour counter, the transfer of the group of counters towards the left of the dial, and the relocation of the date aperture to 3 o’clock.