Slide Rule Wristwatches (Page 2):
Ollech & Wajs, Sinn, Hacher and Heuer slide rule watches

Ollech & Wajs--Aviation Slide Rule watches

When Breitling went into bankruptcy in 1979, Ollech and Wajs acquired a large stockpile of Breitling parts and the rights to assemble and sell what are essentially rebadged Breitling watches. Some Aviation models are still available "new" nearly 30 years later. (Brochure scans from Ron Engels excellent Ollech & Wajs Aviation history)

Robert from Germany sent this excellent photo of his "Aviation, Ref. 6087, same as Breitling Navitimer 7806-S, powered by Valjoux 7740." Beautiful!

Before their acquisition of the surplus Breitling parts, O & W had a few lower cost slide rule watches they marketed under their name. This is the rare O & W Moon Orbiter 24hr model. Photo from Edwin Datschefski's slide rule watch site.

Here's a page from the Chronosports 1969 catalog courtesy of showing an Ollech and Wajs "automatic computer" watch next to a Breitling Chronomat.


Sinn's flight computer, the 903, was introduced after Sinn bought the rights to use the dial lay-out of Breitlings 806 and 809 Navitimer watches. This was a result of Breitling's bankruptcy in 1979. Unlike the Ollech & Wajs Aviation which was essentially a rebadged Breitling, Sinn used a different watch movement, the handwound Lemania 1873 which is the same movement the Omega Speedmaster used. This was chosen to match the "tri-compax" lay-out of the dial that Sinn now owned the rights to. A "tri-compax" chronograph has subdials at 3, 6, and 9 o'clock. Later, Sinn added automatic versions of the 903 using the Valjoux 7750 movement. (Photo from Hans Mennink's excellent Sinn 903 review)

Some of Sinn's 24hr watch differs from Breitling's Cosmonaute and Ollech and Wajs Aviation 24hr model by positioning 12 o'clock at the top of the dial rather than the bottom. (Photo from

Here are a couple of Sinn's later 903 models, the handwound H2 and H4.

In 2003, Sinn produced a special automatic Hummer version of the 903 H2. Like other automatic 903s, it used the Valjoux 7750 movement.

Before Sinn acquired Breitling's dial lay-out, they produced this rare version of the 903. Micahel Sandler had some correspondence with Sinn about this watch and they responded: "That's a very old version of model 903 with blue dial. Movement Excelsior Park 40-68. A rare model. Production approx 1975-1980." (Thanks to David Alstott for the picture.)


Hacher was started in 1991 by Jürgen Hackbarth-Herzberger an ex Sinn employee. It makes some nice slide rule models that are reasonably priced by Swiss standards. This is one of the first Hacher Aviateur models which featured acrylic crystals. (photo courtesy of Mike)

The current aviateur model lists for €790,00 and comes in a variety of styles.

Heuer / TAG-Heuer

Here's a page from a 1977 Heuer catalog showing the Heuer Calculator Chronograph. The Calculator was listed first listed in Heuer catalogs in 1972. (Chuck Maddox and Jeff Stein have done an amazing job collecting and scanning these catalogs.)

Heuer is one of the few Swiss firms that has made a flight computer to compete with the Navitimer. Here's another from Chuck Maddox's collection, Heuer's 1980 Aviation catalog. In addition to the Calculator model, an "Aviation" model is listed that will later be known as the Heuer Pilot. Both automatic and quartz versions are available.

Here's another page from Chuck Maddox's collection, this one from a 1985 Heuer catalog. Again, the pilot is available in both automatic and quartz versions.

Here's a later catalog from 1991. Heuer is now TAG-Heuer and the pilot is now part of the "Specialist" range with updated styling. Automatic versions are no longer available.

Page 1: Introduction, History and Breitling slide rule watches

Page 2: Ollech & Wajs, Sinn, Hacher and Heuer slide rule watches

Page 3: Other Swiss slide rule watches

Page 4: Japanese slide rule watches--Seiko, Citizen, Casio, Orient and Kentex

Page 5: Other slide rule watches

Corrections, comments and additions to Art Simon