Calibre 12.68Z

Notes

The 12.68Z was designed around 1928 and it was a miniaturized version of the pocket watch sized 18.68Z movement which was designed in 1927 and 1928 to modernize and simplify production of the pocket watch sized movements of the brand. The 12.68Z was similarly made with the intention of replacing a number of similarly sized calibres then produced by the company in the range of 11 to 13 lignes. The technical department by the time it designed this movement had decided to embark on a project to standardize and rationalize production across the whole range of movements rather than just one or two categories, so that they could more easily and cost effectively produce a larger number of movements. Eventually they would settle on 7 base calibres, One Rectangular (25.17), four round (37.9, 12.68Z, 10.68Z, 8.68Z), and two oval (12.19, 15.18). This broader rationalization process began with the 12.68Z which was sized for mens wristwatches. The calibre would remain in continuous production for nearly 30 years and it is possibly the single most produced in-house Longines wristwatch calibre. The earliest examples of the 12.68Z will have one case screw while later version has two case screws. Latest versions had incabloc shock protection. Earlier shock protection system started around 1947 and were used originally for an arctic expedition. Some chronometer versions known.