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Rado Watch Co.’s Earliest Chronometers

- By C. Bradley Jacobs (PA) 09/01/20

vintage Rado wristwatch beside a postage stamp depicting a telescope viewing a comet flying in a night sky
Figure 1. A re-cased early 56-H hands, dial, and movement beside a Belgian stamp from 1966, commemorating the 10th anniversary of the discovery of Comet Arend-Roland 1956h. PHOTO BY THE AUTHOR.

Q: What do these three things have in common?

  • the watch-making house Schlup & Co. of Lengnau, Switzerland
  • a pair of astronomers at the Royal Observatory in Uccle, Belgium
  • the first comet visible to the unaided eye in the northern hemisphere since Halley’s passed near the Earth in 19101

A: All were part of a worldwide fascination with space exploration that influenced the production of the first high-grade solid gold wrist chronometer from Rado.

In recent years, Rado Watch Co. has ranked among the top 20 producers of Swiss chronometer watches.2 In the mid-1950s, it was in the early stages of becoming established as the premier brand of Schlup,3 including expansion into the Japanese market.4 Though the Rado name had been used on watches as early as the 1930s,5 innovations and the development of a cohesive style and futuristic vision appear to have taken hold with the brand in the mid-20th century, supplanting their other brands such as Exacto. New case designs, an innovative dial logo (patents then pending), and the international fascination with space and its exploration seem to have galvanized an exciting brand for whom the sky was the limit.

In an international market that had become saturated with Swiss watches during the post-war period of prosperity, a relatively new brand had some difficulty standing out. Many older, established brands were not only better known than Rado, benefitting from decades of customer awareness and expansive marketing campaigns, but they were also introducing exciting models with new features. Some of these are iconic today: divers’ watches (such as the Rolex Submariner and Omega Seamaster), full-rotor automatics with date and/or calendar functions, and movements certified to be accurate by testing centers based in a handful of observatories in Switzerland, later to be consolidated under the COSC.6 The Rolex Day-Date and Omega Constellation are prime examples of this era of wrist chronometers—a class of watches signifying the producer as being among the most accomplished in the industry. Previously, such accuracy signified success in exclusive timing competitions, conferring bragging rights upon the elite watch-making houses. In the 1950s, certified accuracy became readily available for the wrist of luxury watch buyers.

Coincidentally, observatories were also quite busy at the time making astronomical discoveries. Advancements made during wartime in science and technology were being applied for peaceful purposes across many disciplines and industries. There were keen races among developed nations to explore the heavens via land-based observation methods as well as satellites. This space exploration was expected to lead soon to human space travel.

One of the more notable discoveries of the period was the comet C/1956 R1 (Arend–Roland), observed on November 8, 1956, by two astronomers in Belgium.7 It was spotted by Sylvain Arend and Georges Roland on photographic plates, months before it became visible to the naked eye, and so served as the subject of much preparation and observation across the areas where it would be visible from Earth. A distinguishing feature of the comet was its tail, which at the time was described as having three “beams,” or individual, separate portions.8 Period photographs and other visual representations made the tail of this comet stand out from others previously observed (Figure 1).

It was the discovery of this comet, and the growing Rado brand’s desire to compete with exclusive international brands, that led them to release its first chronometer wristwatch, named model 56-H.

Why was it so named? In 2008, I began researching this model, having obtained a nearly New Old Stock example of a 56-H in steel. I contacted Rado directly, but my contact there was unable to provide any insight into the significance of the name. I persevered over the course of the next several years, and my research, ably aided by members of the Rado forum at (EOT), initially focused on space exploration events of the mid-1950s. Factors such as the shape of the hands, the crown logo, and the caliber used in early 56-H watches were clear indicators that the mid- to late-1950s were our target. Coming at the beginning of the space race, it seemed sensible to investigate rocket launches or orbits of 56 hours’ duration. These proved fruitless but suggested ways to expand our criteria. COMET C/1956 R1 (AREND-ROLAND; O.S. 1957 III)9 caught the attention of Tim Callaghan on EOT, helping us turn a critical corner. In December 2017, two facts were exposed that we believe were sufficient to confirm the connection: (1) the designation of the Arend-Roland comet as 1956h (“h” signifying the eighth comet discovered in 1956) and (2) the descriptions of the comet’s three-beam tail. This name and the presence of a shooting star with a ternate tail (Figure 2) on the back of the watch’s case is evidence far too corroborative to be mere coincidence. In November 2019, I corresponded with Rado’s public relations department, and they agreed with my interpretation. They also provided additional information from their archives, some of which is shared in my findings below.


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rado wristwatch with the caseback open revealing an automatic movement inside
Figure 2. The caseback and AS Cal. 1701 movement from the author’s steel 56-H. PHOTO COURTESY RGM WATCH CO.

Series I: Rado’s First Chronometer

The initial 56-H (reference number 11670) was cased in 18-kt. solid gold with a gold or silver dial and powered by a chronometer-certified 25-jewel A. Schild caliber 1361N. The dial featured Rado’s newly introduced swinginganchor (used even today on Rado dials, denoting the presence of an automatic movement) and a signed crown of the oldest type used by Rado, with an italicized sans serif capital R. Some casebacks featured only the Rado name, while others exhibit a version of the shooting star image shown in Figure 2. The existence of these case and dial variations is supported by promotional images; photographic evidence of examples, believed to be original, posted on the EOT Rado Forum10; and by several dial examples owned by the author. I speculate that the early examples used 18-kt. casebacks readily available from a case supplier, while a 56-H–specific caseback was being produced. Corroboration of this is still being sought, though recent communication with Rado has turned up no records to support this contention. Rado did provide me with some images from period product catalogs (1956–61) that supplied additional information—notably, that the hands, dial markers, and the swinging anchor symbol on early 56-H watches were all made of solid gold. It is worth noting that the arrowhead-like dial markers and the night-sky image on the back of the 56-H are very similar in style to the markers and caseback on one of that era’s most iconic wrist chronometers: Omega’s Constellation. It seems clear that Rado had a target market in mind for the 56-H.

Period Rado catalog pages also indicated that a “presentation box made of carefully selected woods” accompanied each 56-H chronometer of that series. Multiple images exist showing such a box, with a medallion on its front replicating the comet-in-flight image from the caseback (Figure 3).

Because the introduction of a fine gold chronometer wristwatch represented a major advancement for Rado as a brand, they published their pride in their product literature. The following text accompanied images of the first generation of the 56-H: “Only half a century’s experience in watch technique could succeed in developing this masterpiece of accuracy.” Hyperbole? Yes, but this progress, arguably, also set the stage for a long period of innovation in case shapes and materials, a hallmark of the brand to this day. It also established a tradition of associating technological advancements with advancements in aerospace and space exploration. In addition to the Comet Arend–Roland connection, Rado released their first mystery dial watch around 1957. Named Satellite, it features a series of layered dial discs that show a Sputnik-like object orbiting Earth. Additionally, an early Rado calendar model was named Jetliner; modern hour-marker shapes and startling dial designs made their debut on mid-1960s Starliner models; Rado’s first scratchproof watch was known as DiaStar (1962); angular cases and crystals combined with battery-powered mechanical (ESA Dynotron) movements defined the Space Flight, Newtronic, and Marstron models (Figure 4). This continued up to the 1970s, with advertising post-Apollo 11 showing Rado watches arranged on a moon-like landscape (Figure 5).

vintage advertisement illustration of a gold-cased Rado wristwatch inside a watchbox
Figure 3. An excerpt from a period Rado product catalog (1956–1961). IMAGE COURTESY RADO WATCH CO.

Series II

The 56-H model was updated in 1962 with a thinner movement (AS 1701, with 25 or 30 jewels) and the addition of a framed date window. Versions in stainless steel and gold plate were added alongside the 18-kt. model, now using the bayonet caseback featured on many Rado watches of that era (Figure 2) and a case with smoothly tapered, not notched, sculpted lugs. The italicized letter R on the crown of the initial series was replaced with a block serif R, representing the change to the new font used on all Rado branding—a departure from the mid-century modern futurism of the R-line dial logo that was widely used prior to the late-1950s’ introduction of the anchor.11 The new model retained its caseback image of the comet passing above Europe, and added the label “56-H,” both of which differentiated it from other Rado models of the period, whose “waterproof” cases (the term was still legal to use then) were predominantly embossed with two or three seahorses on the back. Marketing materials of the time indicate the Series II (or 56-H-B) was still available with leather straps. It was also available with an articulated and sculpted 18-kt. gold bracelet, fitted to the case, which sold at a price roughly equal to that of the watch itself (Figure 6).

Three dial variants have been seen for the Series II watch. The steel-cased model has a dial of silver with silver-tone markers (Figure 4). The solid gold model was available (per the information in Figure 6) with a silver or gold dial (both with gold markers). The gold-plated model has been seen with the silver dial with gold markers. It is unknown whether any 56-H-Bs were made with a gold dial in a gold-plated case. No advertising has been found that announced availability of the 56-H in optional steel or gold-plated cases, and very few non-18-kt. examples have been spotted or obtained by fellow collectors or myself. Suitable to the prestige a chronometer conferred on their brand, the focus of Rado’s promotion of 56-H was always on the pricier 18-kt. models.

six artistically arranged steel-cased Rado wristwatches
Figure 4. A mid-1960s steel 56-H amid various space-themed Rado models of the period. PHOTO BY THE AUTHOR.
black and white space-themeed vintage Rado advertisement
Figure 5. A moon-themed Rado advertisement issued post-Apollo 11. IMAGE COURTESY RADO WATCH CO.

The Series II 56-H was updated around 1968 with the 25-jewel A. Schild caliber 1858 (based on cal. 1903 plates). It is unknown how many 56-H watches were produced. In his book Wristwatch Chronometers, Fritz von Osterhausen asserted that 911 Rado chronometers were produced—including the original and the 1962 and 1968 movement revisions—between 1957 and 1972.12 I believe his numbers include more than just the 56-H, as two other chronometer models were produced with the A. Schild caliber 1858/1903 prior to Rado developing new models, using ETA movements, at the end of the 1960s—more on this below.

Examples of the chronometer certificates accompanying 56-H watches—so far only from 1965–66—have been seen on the Internet and among collectors and show that they were tested and certified at Bienne. A Rado brochure describing the early model claimed “All Rado 56 H chronometers without exception obtain a certificate with the mention <<especially good results>>” (Figure 7). It is hoped that other certificates will surface and provide additional data to corroborate the production dates asserted herein or possibly reveal later dates that 56-Hs were produced/certified.

vintage German advertisement illustration of a gold-cased Rado chronometer
Figure 6. A page from a German Rado brochure showing a 56-H-B, ca. 1965. IMAGE COURTESY RADO WATCH CO.
vintage illustration of a Rado chronometer in a watchbox
Figure 7. A page from a Rado brochure describing the chronometer testing, ca. 1965. IMAGE COURTESY RADO WATCH CO.
Accompanying the Series II watch was a new box—green, rather than wood, with “RADO Chronometer” embossed in gilt letters on the top. Inside, the same label was printed in white silk, with a white ribbon on the lower padding of the box exhibiting the same text plus “56H” and “Officially Certified.” The medallion depicting the comet in flight was not present.

A notable element of the rare steel-cased 56-H is how its AS 1701 movement was marked. Although it is identified as a chronometer on the dial, and it has a movement number (something Rado’s noncertified movements do not have), its movement is marked “unadjusted.” The presence also of the three-letter import code UOR indicates that this was a watch destined for the U.S. market. Rado’s entry into the U.S. market, heralded by the iconic Manhattan model and its TV-screen shape, took place in 1965, so this steel chronometer must have been produced around or shortly after, that time but before Rado began using AS cal. 1858. Sadly, the original chronometer certificate for this watch was lost during prior ownership. In the 1960s, the threat of tariffs on imported complete watches, especially for those with high counts of jewels and/or adjustments, suggests Rado wished to avoid paying extra duty,13 and so marked the A Schild caliber “unadjusted.” No other 56-H movement has been reported that touts any adjustments or the lack thereof.

Other Rado Chronometers of the 1960s and Beyond

During or shortly after 1968, Rado issued reference number 11821 (Figure 8), the first steel-cased chronometer to be issued without the 56-H model name. The new watch featured a large appliqué of the word Chronometer in script (likely familiar to owners of Mido chronometers from that period to today) instead of the 56-H name and a caseback showing the reference number instead of the name and image of the comet. Offered only in stainless steel, the 11821 exhibited a modern style far removed from the shapeliness of the original model, and was available with a model-specific stainless steel bracelet fitted to its squared lugs. The previous stylized “R” on the crown was replaced with the now-standard anchor logo. The hour markers and hands of this new model reflect changing tastes. The pointed hands and thin, unobtrusive markers of 56-H had given way to thick, rectangular hands and blocky raised markers—a scene played out among watch companies worldwide in the 1960s. One notable design element of the original 56-H was retained: the subtle five-point star printed on the dial.

One additional Schild-powered chronometer was introduced in the later years of the 1960s. The DiaStar 1 Chronometer was first produced circa 1969, according to movement dating codes documented on the EOT Rado Forum.14 This was a chronometer-certified version of the iconic scratchproof watch with an ovoid case introduced in 1962. Additional chronometer variants of the DiaStar family were produced into the 21st century: the early 1970s 1/E (the first ETA-powered Rado chronometer, cal. 2783); the mid-1970s DiaStar-based Balboa Chronometer (also ETA); 2002’s 40th Anniversary Chronometer (ETA 2836-2); and the circa 2006 Original Chronometer Rattrapante, Rado’s first split-second chronograph model (base Valjoux 7770).

vintage illustration of a Rado chronometer
Figure 8. An excerpt from a Japanese Rado product catalog showing Ref. 11821, ca. 1969. IMAGE COURTESY RADO WATCH CO.

It is not yet known how enthusiastically Rado dealers advertised the brand’s first chronometer series or subsequent releases. Collections of vintage advertising and product catalog pages owned and shared on the EOT Rado Forum have turned up few references to the Rado chronometers of the 1950s and 1960s. The most frequently seen are a page in the small booklet accompanying the OEM box and guarantee information (circa mid-1960s) and a slot alongside all the other current models in period catalogs, all specific to the 56-HB. Oddly, the advertising generally refers to the watch as 56H or 56 H without the hyphen, while the caseback and the dial of the watch clearly show the presence of one (Figure 2). Apparently, a fair amount of marketing was focused on Japan; various images collected from Japanese-market product catalogs and print advertising show the initial 56-H (hyphenated, Figure 9), the later steel chronometer, Ref. 11821 (Figure 8), and the DiaStar 1 Chronometer.

The earliest pieces of stand-alone chronometer print advertising I have seen are 1970s examples of the DiaStar chronometer known as model 1/E, largely promoted in Japan (Figure 9). It seems likely that the 56-H, being a small edition of specialty timepieces, was promoted at industry trade shows (such as Baselworld), or within favored Rado retail establishments. The 56-H initially served to showcase Schlup & Co.’s growing capabilities and the innovation of the then-new Rado brand, possibly with the expectation that watch distributors would devote more attention to Rado and that designers and industry suppliers would wish to forge partnerships with them.

In contrast, significant press and marketing campaigns touted the 1962 introduction of the DiaStar (the world’s first scratchproof watch, cased in tungsten-carbide with sapphire crystal), which helped define the course of development of Rado’s case architecture, shapes, and materials to this day. This is a subject worthy of other articles, but its mention serves almost as an epitaph for the 56-H and its successors roughly a decade before they reached the end of their production run. Between 1972—the accepted end of the line for Ref 11821, when five-digit reference numbers were phased out—and 2008, all Chronometer models produced by Rado were cased in scratchproof materials. Only the low-production Golden Horse Chronometers—the first of which was a follow-up to the retro-styled 50th Anniversary Golden Horse edition of 2007 (Japan only), and the second, 2012’s HyperChrome Golden Horse chronometer15—were housed in steel or gold-plated cases of the traditional shape also used for the 56-H.

Image description
Figure 9. An excerpt from a Japanese Rado print advertisement showing an early Rado 56-H, ca. 1962. IMAGE COURTESY RADO WATCH CO.

Notes and References

1. Porter J G. The Two Bright Comets of 1957 – I Arend-Roland (1956h) and Mrkos (1957d). Vistas in Astronomy 1960(3):128.
2. Deshpande J. “Top 20 Swiss Chronometer Watch Brands.” Accessed on October 17, 2019.
3. Locatelli D. “The Origins of Rado.” Accessed on November 22, 2019.
4. Per author’s personal correspondence with Rado Watch Co., 2007.
5. Shawkey B. More Information on Rado Watches. Wristwatch News Fall 2003;2(3):7.
6. COSC. “Our History.” Contrôle officiel suisse des chronomètres. Accessed on October 17, 2019.
7. Editors of Encyclopedia Britannica. Comet Arend-Roland. Encyclopedia Britannica. Accessed on October 17, 2019.
8. Larsson-Leander G. Physical Observations of Comet Arend-Roland (1956 h). Arkiv för Astronomi 1959;2:262.
9. Bortle J E. “The Bright-Comet Chronicles.” International Comet Quarterly. Accessed on November 24, 2019.
10. Jacobs C B et al. “A Project Chronometer Arrives.” Accessed on October 17, 2019.
11. Jacobs C B. Vintage Rado Automatics. International Wristwatch July 2003:120–128.12. Von Osterhausen F. Wristwatch Chronometers. Munich: Callwey Verlag, 1996:235.
12. Von Osterhausen F. Wristwatch Chronometers. Munich: Callwey Verlag, 1996:235.
13. U.S. Government Publishing Office. “Tariff Schedules of the United States, Vol. 77a, 1963.” Accessed on November 24, 2019.
14. Callaghan T et al. “A. Schild Cal. 1858/1903 Question.” Accessed on October 17, 2019.
15. Jacobs C B. Rado Golden Horse Chronometer. WristWatch Magazine Winter 2013:64–66.

About the Author

C. Bradley Jacobs is an avid collector and chronicler of vintage Rado watches. He is an administrator at and co-moderator of content on the site’s Rado Forum, where visitors can find more information and images, and engage in discussion on this topic. He may be contacted via his website

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