Seiko 7T59 1/100th Second Analog Chronograph

Cazalea provides an in-depth profile of the Seiko 7T59 movement, a remarkable 1/100th second analog quartz chronograph. This article highlights Seiko's engineering prowess, particularly its connection to the 1992 Barcelona Olympics timing equipment.

This edition of the SEIKO PROFILE concerns a 1/100th second Analog Quartz Chronograph powered by the remarkable Seiko 7T59 movement. 

In addition to the 1/100th second hand that moves so quickly your eye can barely see it, the movement also provided hacking seconds, quick Day, Date and GMT setting, and running seconds. Seiko engineers aimed for the highest precision timing mechanism possible, to complement timing equipment developed for use at the 1992 Barcelona Olympics. The result was this gem of a watch, produced in limited quantities (for Seiko) from 1991-1993. It sold for an astronomical price of about $1000 (20+ years ago). I saw an second-hand one sell for the same price a few weeks ago.

There were at least 20 different models of this watch, each being produced in a limited number. The vast majority came on bracelets, but there were a few models with a strap option. The ranges were known as 

Age of Discovery

Designer

Masterpiece

Olympic

Tech Sport

Regular

My particular watch is known as the 7T59-6A00 SHS002J. It's a Tech Sport with two-tone case and bracelet, increased water resistance to 15 bar, hardened  mineral glass crystal (which is slightly scratched on mine), sporty look, dark subdials, etc. 

What do you think? Am I lucky to have the two-tone, or should I have searched for this rare and desirable one - the monochrome model? (picture borrowed from the web).

Getting past the cosmetics, the features of this watch include:

40.9mm x 10.3mm case with 15 Bar water resistance

Non-turning bezel with tachymeter graduations

GMT dial at 9; hour hand adjustable in 1-hr intervals using crown at 4

Luminous hour, minute and stopwatch second hands

Stopwatch/split timing function counts to 12 hours and includes 1/100 & 1/10 hands at 12, central seconds, and minute & hour hands at 6

Day and date indication in a window at 3 with quick setting, and quick change

Integrated bracelet (most models)

Accurate to 15 seconds / month

Other combinations of crowns and buttons are used to reset the zero position of the chrono hands. There's a split seconds feature too but I can never recall how it works. And I don't need splits when barbecuing steaks.

The bracelet links pivot on and adjust with easily removable split "cotter" pins.

It was a large watch in its day, at 41mm, and still wears well even now. It's not too thick and although a little gaudy for my taste, not bad overall. Especially if you like two-tone watches of any sort. The panda dial on mine is fun too. Sadly, the nicely coordinated gold-on-black day and date are a bit hard to read in most light.

INSIDE

Unlike most quartz watches, this movement has dozens of moving parts. Here's a look at the gear train, from the Seiko Technical Manual

As long as its shiny metal cover remains in place, it looks like a normal sort of movement.  Clean, remove caseback, replace battery, lube gasket, reinstall caseback. No problem. If you mistakenly undo those screws that hold down the cover, you're in trouble.

Would you like to see it run? Of course, here we go: