Wristwatch restoration, servicing and repair

Minerva Chronograph Ref:1335 (Minerva Cal. 13-20)…

Another quality vintage chronograph on the blog, this time from Minerva.

(Click pictures to enlarge)

Minerva was founded in 1858 as “H. & C. Robert” in Villeret in the Bernese Jura by two brothers, Charles-Ivan and Hyppolite Robert. Like many other companies, they started by producing pocket watches built around calibres from other manufacturers until they could establish their own place in the market.

Hyppolite retired in 1880 and as the company continued to grow, Charles’ brother Yvan and sons Charles-Auguste and George-Louis joined the company and the name was changed around 1889 to “Robert Frères Villeret” along with the introduction of a new RFV trademark.

From 1902 onward RFV began producing their own in-house calibres and cases, with their first chronograph and stopwatch calibres being introduced in 1908. The Minerva brand name as we know it today was first introduced in 1923 and the company was renamed to the now familiar “Minerva SA, Villeret” in 1929.

In 1934 Minerva SA was taken over by Charles Haussener and Jacques Pelot and run by Pelot’s nephew Andre Frey. The Frey family retained ownership of the company and production continued uninterrupted up until 2000 when there were big changes at Minerva, but more on that later…

The movement inside the watch in this post is one of Minerva’s longest serving column-wheel chronograph calibres, the cal. 13-20.

The cal. 13-20 was one of the earliest wristwatch chronograph calibres available and was developed in collaboration with chronograph specialists Dubois-Depraz. First produced in 1923 it was originally designed as a mono-pusher chronograph before being changed to a two pusher design around 1940 after which it was available in both 30 and 45 minute variants.

Even at a glance it’s easy to spot the quality in this calibre; the plates and bridges are richly plated, most of the components have polished bevels and it has solid steel return springs throughout. Typical of calibres from this period it has a screwed balance wheel, a Breguet hairspring and it pre-dates any shock mechanism for the balance staff.

Under the dial, with no hour register the calibre is pared down to a minimum, with the set lever spring and minute wheel bridge being combined into one component.

As well as the Minerva ‘arrow in a circle’ on the train side of the movement (pictured inset), the RFV trademark with the arrow is clearly visible here along with a serial number. Under the RFV trademark is the word ‘Depose’ which is short for Modèle Déposé, the Swiss/French for “Registered Design”.

Arriving already in excellent condition both mechanically and cosmetically, the movement needed no more than a routine service and a new mainspring this time.

At 36mm it’s quite a small chronograph by modern standards but the design has certainly aged well. There’s no denying that with its blued cathedral hands and minimal dial markings, this is a handsome watch.

A testament to the quality of the cal. 13-20 is the fact that is was produced almost unchanged from the 1940’s and was still being manufactured on the original production machinery until 2000. At that time the Frey family sold the company to an Italian investor, Emilio Gnutti, who radically changed the working practices and the future for the whole Minerva brand.

It was decided at that time that the current Minerva calibres could not be reproduced using modern machinery so they were re-engineered in CAD for CNC machining. The 13-20 was effectively retired at that point and the redesigned calibre was named the cal. 13-21 to reflect the updates. As you can see below, using modern production methods and hand finishing techniques the quality of the resulting calibre is clear to see.

Interestingly, the calibre was returned to the original mono-pusher design before the subsequent development of a two pusher version, the cal. 13-22.

Powered by updated calibres the Minerva brand was effectively relaunched into the Haute Horlogerie segment with a range of new models. Sadly their rebirth was relatively short lived as Minerva was bought by the Swiss luxury goods company Richemont in October 2006 and was assigned to the Montblanc brand where it remains today.

Minerva branded watches are no longer available and Minerva’s technical team are now responsible for producing the hand crafted calibres found in other Richemont brands, predominantly the Montblanc 1858 Villeret collection and more recently in a small number of Panerai chronographs.


** Many thanks to Daniel Spiegel for letting me feature his watch on the blog. **

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