IWC Big Pilot's Heritage 55 and 48

IWC: History of the pilot’s watch

Words: Gisbert L. Brunner
Photography: IWC and Gisbert L. Brunner
Graphics: Gisbert L. Brunner

Up, up and away - The history of IWC, it’s pilot’s watches and their calibres
Gisbert Brunner

Gisbert L. Brunner was born in 1947 and has worked with every sort of precision timepiece, though mainly wristwatches, since the 1960s. He has now published more than 15 books on the subject. He is also in demand the world over as a public speaker.

The history of IWC, founded in Schaffhausen in 1868, contains as much high flying as crash landings, such as the one brought about by the two Americans, Florentine Ariosto Jones and Ferdinand F. Seeland. After the second bankruptcy, in 1880 shareholder Johannes Rauschenbach, joined the following year by his son of the same name, took the ailing manufacture under his wing, and the company was cleared for take-off.

Following Johannes Rauschenbach-Schenk’s death, his heirs transferred control of IWC to Ernst Jakob Homberger, who became sole proprietor in 1929. His sons Hans and Rudolf had an insatiable passion for flying. The former gained his sports aircraft pilot’s license in Britain in 1933. Brother Rudolf piloted a Messerschmitt Me-109 in the Swiss Army, with considerable distinction.

From the beginning, then, there was a family dimension to the pilot’s watches at IWC. There was a great demand for watches of this type in the pioneering years of aviation. They had to contend with intense vibrations and extreme temperature fluctuation as well as substantial magnetic fields. On top of that, they had to be quickly, clearly legible in the cockpit. These requirements, safety considerations and the highly demanding business of flying called for a specially constructed timekeeper with a movement as precise as it was reliable. And since 1936, this has brought IWC renown as a pilot’s watch pioneer.

IWC Fliegeruhren Historie


In 1936, IWC introduced the pilot’s watch with black watch face, large luminous figures and striking luminous hands. It included a rotating bezel with indicator arrow for setting the departure time. The 12-line manual winding bridge movement, calibre 83, had an anti-magnetic escapement. The regulation functioned in temperatures in the range of minus to plus 40 degrees. Lead seals prevented moisture or dust from working their way into the stainless steel case with unbreakable glass. In the same year, 1936, IWC supplied one of the first of these “special pilot’s watches” to Novotny/Freund in Prague. By 1941, several hundred pieces had gone out to customers. 

In the late 1930s, IWC developed a professional pilots’ watch for the German Luftwaffe which came in a matt stainless steel case of 55 millimetres’ diameter. This jumbo serves as the model for the new “Big Pilot’s Heritage Watch 55”, reference number IW510401, which can be seen in a revised version at  SIHH 2016. But more on that later.

All the optical and technical specifications were itemised in a specification sheet of the departments and high command. Each copy had to satisfy the testing requirements for “first class” status in precision pocket watches stipulated by the German Naval Observatory. The regulation required six positions in three different temperature states. Other features: handy winding crown, black watch face with luminous numbers and hands, stop second mechanism as well as long leather straps worn over the sleeve. This watch, with its impressive weight of 183 grams, was the first to include magnetic field protection for the 19-line centre-second calibre 52 T. S.C. (tirette seconde centrale). Which meant that the watch face, movement ring and internal base were constructed from soft iron. IWC made a total of 1,200 of these precision calibres, which were used as observation pocket watches. IWC supplied the timekeeper for the German Luftwaffe via an indirect route, through a German specialist dealer called Siegfried Heindorf

History of IWC Pilot's Watches

Like the first pilot’s watch from 1936, IWC equipped the 1945 watch for military usage with the proven hand-winding calibre 83. The “W.W.W. (watch, wrist, waterproof)”, made between 1945 and 1947, ran to around 6,000 units. They bore the case numbers 1,131,001 to 1,137,000. The black watch face with the large luminous numbers were the distinguishing features of “chemin-de-fer minuterie”, or railway minute markers. The versions for the British military feature a “broad arrow” (or “king’s arrow”) beneath the company logo. From 1944 the calibre 83 also included “Incabloc” shock protection. 

The “Mark 11” from 1948 is regarded as a true cult watch. IWC started supplying them to the flying troops of Britain’s Royal Air Force and other Commonwealth member states in November 1949. They continued to serve until 1981. Not just military pilots, but civil aviation captains as well relied on the watch with the soft iron inner case, into whose construction flowed the experience of every pilot’s that came before it. The cage protects the movement against magnetic fields up to 80,000 ampere per metre. The built-in calibre 89 (diameter 26.5 mm, height 4.25 mm) has a patented movement for the centre second hand as well as a stop second mechanism. Before winging their way into the world, every single “Mark 11” underwent a 648-hour test programme for “navigator wrist watches”. The test for movement accuracy was carried out in five positions and in temperatures ranging between -5 and +46 degrees Celsius. 

The pilot’s watch tradition continued in 1988, by which time IWC had been part of the VDO Group for ten years, with the first pilot’s chronograph based on the automatic calibre Valjoux 7750. In 1992 came the split-second hand variant, the “Pilot’s Watch Double Chronograph”

Anyone who missed out on the “Mark 11” could comfort themselves with 1994’s “Mark XII” with the extra-slim automatic calibre 884 (ébauche LeCoultre), four-hertz balance wheel frequency, regulation in five positions, date window. The 36-millimetre case, available in steel or solid gold, contained a soft-iron inner.

In 1998 the “UTC” with practical time zone display as well as the “pilot’s chronograph” with black ceramic case came on the market. The year 2000 was marked by the “Mark XV”, now grown to 38 millimetres, with anti-magnetic inner case and the proven automatic calibre Eta 2892-A2. 

Pilot's Watch Renaissance

In 2002 IWC launched the “Big Pilot” tradition. Inside the 46.millimetre newcomer ticked the opulent 7-day automatic calibre 5011 with date window, power reserve indicator and centre second hand. 

At Geneva’s SIHH, IWC will be presenting a completely revised pilot’s watch collection. I was able to get a preview of the new models back in November. But right now I can only tell you about the two “Big Pilot’s Heritage Watch” models.

The larger, as the suffix 55 indicates, has an almost gigantic 55-millimetre case, comparable with the original from 1940. You need the right kind of wrist to wear this watch. To keep the weight down, the outer case is made of titanium; it houses a soft iron inner and the 37.8 millimetre manufacture hand-winding calibre 98300 with 2.5 hertz balance wheel frequency and 46 hours’ power reserve, waterproof to six bar. This means the whole thing, including calfskin straps, hits the scales at just 150 grams.

The conspicuous centre second hand of the original is replaced by a smaller one at the “6”. It stops when you pull out the crown to accurately set the time. Because the tension spring comes with the dragging bridle on the tension spring which is standard for automatic calibres, the energy reserve can’t break. IWC is restricting the edition to just 100 units.

Big Pilot's Watch

The “Big Pilot’s Heritage Watch 48”, limited to 1,000 units, is more moderate in its dimensions, with a titanium case that is seven millimetres smaller, waterproof to six bar pressure. The narrower diameter also means 30 grams less weight. Naturally there is magnetic field protection for the manufacture hand-winding calibre 59215. Its power reserve is good for 192 hours. A peephole in the base reveals, in this case, a power reserve indicator. Here, too, a friction clutch prevents the owner from over-winding. Balance wheel and balance spring oscillate at four hertz.

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01 2016 The Red Bulletin

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