Swiss steel chronometer with split seconds chronograph Circa 1940

Large pocket watch with fifteen minute counter
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A large rare chronometer with split seconds chronograph and fifteen minute counter, made by Ulysse Nardin in Locle, Switzerland, circa 1940. The plain open faced case of this watch was crafted from steel. The numbered white enamel Chronometer dial has Arabic hour and minute numerals, a subsidiary seconds dial at six o’clock and a fifteen minute counter at twelve o’clock. The movement has an anker chronometer escapement, Geneva striping, a fine adjusting device, a high speed oscillator with a split seconds chronograph and an extremely rare 15 minute register and a device for electrical conduction in seconds and tenths of a second intervals.
Dial and movement have matching numbers and the dial is signed.
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Diameter: 65 mm
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Weight: 231 g
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Signed: Ulysse Nardin, Locle Suisse
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The present watch is very unusual because it is calibrated to record 30 seconds per revolution of the chronograph hand instead of the usual 60 seconds per revolution. This is achieved by a high speed escapement, while the hour and minute hands work in the usual way. This chronograph was specially developed for timing events with an accuracy of 1/10 of a second and was only produced in a very small edition( probably only 60 pieces).