Longines 30 CH

The Longines 30 CH calibre: a pioneering chronograph

Developed in the 1940s by the Longines manufacture in Saint-Imier, the 30 CH calibre belongs to a particularly innovative period in the history of the wrist chronograph. Entirely designed in-house, it reflects the brand’s determination to master every technical aspect related to short-time measurement.

This column-wheel chronograph movement, a traditional construction found in high-quality timepieces, stands out for its reliable, well-balanced and durable architecture, designed for professional use.

The flyback patent: a major innovation (1935–1936)

On June 12, 1935, Longines filed a patent describing a chronograph mechanism capable of instant reset and restart with a single push. The patent was officially registered on March 31, 1936, and published on June 16 of the same year.

This system, now known as the flyback function, represents a major step forward in the use of wrist chronographs. It allows the hands to be reset to zero and immediately restarted without first stopping the mechanism.

Originally developed to meet the needs of aviation, this principle significantly improves the speed and reliability of successive time measurements. The 30 CH calibre is directly linked to this technical evolution and is among the early movements to incorporate this functionality derived from the Longines patent.

A complication designed for practical use

Unlike conventional chronographs requiring three separate actions (stop, reset, restart), the flyback system greatly simplifies operation. A single push is sufficient to initiate a new timing sequence, without loss of time or risk of error.

This functionality requires a specific mechanical design, particularly in the coordination of reset hammers, heart cams and control mechanisms.

A robust and well-balanced construction

With a diameter of approximately 29.80 mm and a frequency of 18,000 vibrations per hour, the 30 CH calibre features well-proportioned dimensions and a solid construction.

Its architecture clearly reveals the column wheel and the entire chronograph mechanism. Equipped with a 30-minute counter and small seconds, it fully meets the technical standards of its time.

A highly regarded and historically significant movement

Today, chronographs powered by the 30 CH calibre are highly sought after by collectors. They represent not only a high level of quality, but also an important milestone in the evolution of the wrist chronograph.

Through its direct connection to the flyback patent filed by Longines in the mid-1930s, this calibre illustrates a period when innovation was driven by real technical needs, in a rapidly evolving industrial and technological context.