A Brief History of the Mechanical Watch’s Struggle Against Magnetism | WatchTime

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In our latest tour of the WatchTime World Archives, learn how watchmaking has combated the threat of magnetism over the years, from using metals like palladium in 1915 to silicon in 2015.

Magnetism has been the sworn enemy of mechanical timekeeping over the years. It is to the mechanical watch what Professor Moriarty is to Sherlock Holmes. Although the watch industry has responded to this threat with many innovations over the years, readers and aspiring watch enthusiasts have always asked us this question: how real is the threat of magnetic fields in our everyday life ?

The industry has used everything from soft iron shields to silicon exhausts in their fight.

Before answering these questions, let’s take a look at what happens to a mechanical watch when it’s exposed to a magnetic field. The simple truth is that certain parts of the escapement, such as the balance wheel and hairspring, become magnetized upon such exposure. For example, the concentric circles of the hairspring can come together, thus causing friction. This could ultimately affect the amplitude and accuracy of the escapement. In most cases, once the magnetic field is removed, the watch may resume normal operation, but in the case of a particularly strong magnetic field, it may stop working altogether.

In 1915 Vacheron Constantin created an anti-magnetic pocket watch and in 1930 Tissot produced its first anti-magnetic watches. In both cases palladium was used in the construction of the escapement.

Pilot’s watches like the IWC Mark XI used an antimagnetic soft iron cage.

During World War II, the German Air Force (Luftwaffe) received pilot watches whose movements were enclosed in a soft iron case, known as a Faraday cage, to resist the effects of magnetism at high altitude. Longines supplied the Czech Air Force in the 1930s with watches bearing “antimagnetic” markings on the dial.

In 1949, Jaeger-LeCoultre and IWC produced the Mk11 pilot’s watch for British RAF pilots. These watches were made under the strictest conditions set by the Ministry of Defense and required the movement to be enclosed in a soft iron case. IWC produced the Mk11 from 1949 to the early 80s.

The 1950s was the “tool watch era”, during which a series of watches celebrated man’s spirit of adventure and exploration. These included Universal Geneva’s Polerouter (originally called the Polarouter) designed for pilots and crew of SAS (Scandinavian Air Services) Airlines flights, which flew over the North Pole in an effort to reduce flight times between Europe and New America.

These watches, which had to withstand the strong magnetic fields present around the North Pole, were initially issued only to the SAS crew and were designed by a young Gérald Genta, who would go on to design classics like the Audemars Piguet Royal Oak and the Patek Philippe Nautilus. .

Universal Geneva Polerouter

In 1955, IWC launched the Ingenieur (Ref: 666A), the brand’s first antimagnetic automatic watch. The work of IWC technical director Albert Pellaton, the watch was supposed to be the civilian, automatic version of the famous Mk11.

It was also famous for introducing the first bi-directional rotor in an automatic movement. Early advertisements for the Ingenier (“Engineer” in French) claimed that the watch could withstand magnetism up to 1,000 Oersted (1,000 Gauss). This was at a time when most mechanical watches could only withstand magnetic fields up to 100 Gauss.

IWC Engineer Models

The ISO 764 standard states that, to be considered antimagnetic, a watch must withstand a magnetic field of 4,800 A/m (60 Gauss) and its accuracy must remain within +/- 30 seconds per day.

In 1956, Rolex introduced the Milgauss (Ref: 6541), a watch capable of withstanding a magnetix flux density of 1,000 Gauss and was supplied to CERN scientists and power station technicians. The Milgauss was to become the most famous anti-magnetic watch of our time.

Omega launched the Railmaster (ref CK2914), which was able to withstand magnetic fields, and produced these watches until 1963 before they were discontinued. Omega revived the Railmaster a few years ago, but these are the early models that are collectible now.

In 1958, Jaeger-LeCoultre launched the Geophysic chronometer to commemorate the International Geophysical Year. Geophysics was created for engineers and scientists and was able to withstand the magnetic fields of the North Pole. (More details here.)

The legendary Rolex Milgauss

Patek Philippe also came to the tool watch party in 1958, with its first anti-magnetic wristwatch, the Amagnetic (Ref. 3417 in stainless steel). It was produced for two years and featured a soft iron cage and, in some cases, beryllium components to further counteract magnetism.

Most modern watches use non-ferrous metals in the escapement, so unless they are subjected to very high magnetic fields, they should be able to withstand all the magnetic fields they encounter on a normal day.

In 1989, IWC introduced a rare iteration (Ref. 3508) that was tested to withstand magnetic fields up to a strength of 500,000 A/m (6,250 Gauss), the most antimagnetic watch of its time.

Ulysee Nardin made a significant leap forward in 2001 when it launched the Freak, the first production wristwatch to use a silicon escape wheel. It was the first time silicon parts were used in a wristwatch. Designed by Ludwig Oechslin, the Freak announces the use of silicon in watch movements.

The Ulysse Nardin Freak was the first watch to use silicone parts.

Boutique watchmaker Christophe Claret caused a stir in the watch world with the introduction of the X-TREM-1, a watch that used magnetic fields to display the time, in 2012. The watch featured two balls spherical crystals enclosed in clear sapphire tubes attached to the middle of the watch to display the time. The watch’s bi-retrograde display was unique and revolutionary. You can find out more about the new Christophe Claret X-Trem-1 – Sting HD here.

In 2013, Breguet delivered the first Classique Chronométrie 7727, a high-pulse wristwatch with magnets (yes, magnets) holding the balance wheel. These magnets do not damage the movement because its in-line Swiss lever escapement and its double hairsprings are made of silicon.

This Breguet watch uses magnetic pivots in its movement. With the introduction of silicon into the moving parts of a watch’s movement, the battle against magnetism received a big boost, and in 2013 Omega took another step forward by introducing the Master Co-Axial movement (Caliber 8508) which was able to withstand 15,000 Gauss. This is a far cry from the days when watches resisted 1,000 Gauss in the late 1950s.

The use of silicon and anti-magnetic materials in the movement ensured that the movement did not need a soft iron cage, so the watches could benefit from a transparent sapphire crystal caseback. Omega hopes to deploy this technology on all its movements by 2020.

In 2017, Zenith unveiled the Defy Lab, which used a new oscillator to replace the traditional balance-spring first used in 1657 by Christiaan Huygens. The result is an incredibly accurate mechanical watch (within 0.3 seconds). The movement is insensitive to temperature gradients, gravity and magnetic fields, all of which are insects of current balance-spring assemblies which are subject to deformation and/or dilation, which leads to a reduction in precision.

The new oscillator used on the Zenith Defy Lab

A version of this article first appeared on WatchTime Middle East.

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