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50 Years of The Tudor Chronograph Part 3: The Big Block

Posted: 27/05/2020

In 1976, the House of Wilsdorf launched its first automatic chronograph. And it wasn’t a Rolex, it was a Tudor self-winding chronograph, a full 12 years before Rolex introduced their first automatic Daytona; the Zenith-powered 16500 series in 1988. This was a real coup for Tudor and put them ahead of other chronograph manufacturers of the 1970s. In fact, it was this automatic movement that led to the watch’s nickname. The rotor and autowind mechanism of the movement meant that Tudor needed to design a new watchcase that was deeper, hence the collector term ‘Big Block’. A second aesthetic change that occurred with the Big Block was the introduction of a third chronograph register on the dial – an hour indicator. The previous two series, the Home Plates and Mote Carlos, were effectively 45-minute stopwatches, but the new watches could measure much longer periods of time.

The First Three Series of Tudor Chronos

Reference 9430 – Exotic Big Block

Series One – Reference 9000


The first Big Block watches were the 9000 series. As we discussed in previous parts of the Tudor Chronograph story, the references were differentiated by the bezel type. The 9000 series watches were references:

9420 – Plastic tachymeter bezel

9421 – 12 hour calibrated bi-directional bezel

9430 – Steel tachymeter scale bezel

All vintage Tudor chronographs featured a date and Oysterdate appeared on all the dials going back to the Homeplate watches in 1970. The third series chronos were also Oysterdates, but very early dials had the words ‘Chrono Time’ or ‘Automatic Chrono Time’ in an arc over the bottom chrono register.

A brace of Big Blocks (Bulang and Sons)

Exotic Examples


Anybody with even a passing interest in vintage Rolex and Tudor watches will be aware of the importance of the ‘exotic dial’ chronographs. In Rolex terms it is the Paul Newman and with Tudor, the Home Plates and Monte Carlos. Tudor continued to produce exotic dials that picked up where the Monte Carlos had left off. Collectors also refer to these dials Big Block Monte Carlos or Exotic Big Blocks.

The Exotic Dial Big Block 9420

There were two variations of Big Block Exotic dials, a version with painted hour markers that were very reminiscent of the 7100 series watches and a version with applied metal hour markers. The dials with painted hour markers were available in two colourways – grey/black/orange and grey/blue/orange. Both dial colours were available in all three references. The black version was always teamed with a black tachymeter or 12-hour scale bezel and the blue dials with blue tachymeter bezels. These watches are now very rare and are sought after by collectors, especially the blue 9420. The dials with applied metal hour markers were only produced in black, which featured white sub dials and orange numbers on the outer minute track. This dial was only featured in two references – the 9420 watch (with a black plastic tachymeter bezel) and the 9430 (with stainless steel tachymeter bezel).

The reference 9421 Exotic Big Block

Series Two – Reference 79100


In the late 1980’s Tudor replaced the 94300 series watches with the 79100 series. These watches retained the successful Big Block case, however these watches were only available with the two colour, non-exotic dial configuration.

Big Block 79160 ‘Panda’ Dial (Bulang and Sons)

As with the 9400 series, there were three references which were all differentiated by their bezel type:

79160 – Black plastic tachymeter bezel

79170 – Black graduated 12 hour bi-directional bezel

79180 – Steel tachymeter bezel

Reference 79180 Big Block

By the time the 79100 Big Block series was released the dials all featured ‘Oysterdate’ under the date window and ‘Automatic – Chrono Time’ above the bottom chronograph register. These watches are an important chapter in the Tudor story as a demonstration of both Tudor’s freedom to experiment with more exotic and playful design and also the fact that they were the first automatic chronograph out of the Rolex camp. What’s not to love?





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