Seiko Caliber 19xx - World's first ladies 36,000 bph movment

In 1966 Girard Perregaux released the first commercial 36,000 bph (5Hz) based watch. While not necessarily more accurate high beat watches are less influenced by external factors and provide improvements in isochronism and this results in a highly accurate movement under a wider range of conditions.

In 1967 Seiko released their first 36,000 Hi-Beat movement in the 5740C and during the same year they also released the world's first ladies watch with a 36,000 Hi-Beat movement, the caliber 1944.

First announced in the Suwa Seiko company magazine in the 1967 August issue the R-100 Hi-Beat model with the caliber 1944 is shown. This watch was publicly announced in the September 1967 issue of the Seiko Sales newsletter and had a price of 17,000 yen.

To be able to produce a 36,000 bph ladies movement a number of hurdles had to be overcome. The first was creating a spring that was strong enough to power the movement. As a high beat movement runs at a higher frequency than a traditional movement it requires a higher power reserve. To meet this requirement the calibre 19xx was fitted with a powerful mainspring that provided 80g/cm of force. This is the same type of power level that regular full sized men's movement provide. The spring was made of Seiko’s Diaflex material and measured 260mm long with a width of 1.60mm and a thickness of 0.10mm. This mainspring was able to provide a power reserve of approximately 40 hours.

The drive train also uses a very small gear sized at just 0.65mm and the accurate production of the gear was another manufacturing hurdle that had to be overcome. The escapement was also modified to greatly improve its performance and the number of teeth on this gear was set to 20.

As it is a ladies movement, despite having a frequency of 36,000 bph, the size of the balance is also comparatively small. It has an outer diameter of 6.80mm and a thickness of 0.375mm. The balance weighs 39mg and provides 265mg per square mm of inertia.

All of these items combined to create a 23 jewel movement that was just 12.90mm wide, 19.20mm long and 4.40mm thick. The movement also has a micro regulation device.

Even though the movement was able to be designed it still had to go through testing to ensure that it could be used just like a traditional timepiece with no special handling required. The high speed gear train, escapement and powerful mainspring all had to prove that they were durable enough for everyday usage.

The caliber 19xx was released in the following movement variations:

  • 1944 - used in general high end ladies models including Chronometers and Superior Chronometers

  • 1964 - used in the 19GS the first ladies Grand Seiko model released in 1969

  • 1984 - used in the 19GS VFA that was rated at +- 2 min month released in 1972

Below is the list of models that used the caliber 19xx.

Model MVMT-CASE Type Case Description Dial Markings Production Years List Price (¥)
19GS R-100 1964-0010 Grand Seiko SS Round case, leather strap Seiko, GS, Hi-Beat, 36,000, Daini logo 1969-1971 35,000
19GS R-100 1964-0010 Grand Seiko GP Round case, leather strap Seiko, GS, Hi-Beat, 36,000, Daini logo 1970-1970 40,000
19GS R-100 1964-0010 Grand Seiko PMP Round case, leather strap Seiko, GS, Hi-Beat, Daini logo 1972-1975 40,000
19GS R-101 1964-0020 Grand Seiko SS Round case, leather strap Seiko, GS, Hi-Beat, 36,000, Daini logo 1970-1971 35,000
19GS R-101 1964-0020 Grand Seiko PMP Round case, leather strap Seiko, GS, Hi-Beat, 36,000, Daini logo 1971-1971 40,000
19GS S-400 VFA 1984-3000 Grand Seiko VFA SS Square case, leather strap Seiko, GS, VFA, Daini logo 1972-1973 85,000
19CM R-101 1944-0020 Superior Chronometer SS Oval case, bracelet Seiko, Superior, Chronometer, Hi-Beat, Daini logo 1970-1972 23,000
19CM R-101 1944-0020 Superior Chronometer SS Oval case, leather strap Seiko, Superior, Chronometer, Hi-Beat, Daini logo 1969-1972 22,000
19CM S-401 1944-3020 Chronometer SS Tonneau case, leather strap Seiko, Chronometer, Hi-Beat, Daini logo 1971-1972 20,000
1944 R-100 1944-0012 Standard SS Round case, mesh bracelet Seiko, Hi-Beat, 36000, Daini logo 1967-1973 17,000
1944 R-101 1944-0040 Standard SS Round Case, leather strap Seiko, Hi-Beat, 36000, Daini logo (arabic numerals) 1973-1974 21,000
1944 R-102 1944-0040 Standard SS Round Case, leather strap Seiko, Hi-Beat, 36000, Daini logo 1973-1974 21,000
1944 S-400 1944-3000 Standard SS Tonneau case, leather strap Seiko, Hi-Beat, 36000, Daini logo 1968-1973 15,000
1944 S-401 1944-3010 Standard SS Square case, leather strap Seiko, Hi-Beat, 36000, Daini logo 1969-1973 16,000

These models are able to be seen in the various Seiko catalogs from the period.

I first became interested in the 19xx based models when doing some research into the different vintage Grand Seiko models that were released. During this investigation I found a range of different information about these and decided to compile this as it was not available elsewhere. At this time I also purchased a 1944 R-100 model for just a few dollars, while ladies watches are not really part of my collection I though it was interesting to see the world's first 36,000 bph ladies watch.

During my research I have been unable to find any information on any other brands that released a specially designed ladies 36,000 bph caliber. So in addition to being the world's first it is possible that this series are also the only caliber ever released. If anyone has any information on any other competing models please let me know.

References:
Micromechatronics Volume 43 (1967) Pages 96-97 Journal of the Horological Institute of Japan
Seiko Suwa Magazine 1967.08
Seiko Sales 1967.09 No.111 Seiko Clock Campaign Announcement Proposal
Seiko Domestic Catalogs 1967 - 1975 Vol.2