Complications
Halgedahl's detailed inquiry into chronograph minute hand mechanisms, informed by conversations with Richard Habring, offers a deep dive into a rarely discussed technical aspect of watchmaking. This post aims to clarify the distinctions between continuous, semi-instant, and true snap minute hand movements, providing valuable insights for enthusiasts and aspiring database creators. It highlights the importance of understanding these subtle mechanical differences.
Fellow Enthusiasts!
I will attempt here to put into the least number of words the results of my recent, quite delightful, âconversationsâ with Richard Habring regarding chronograph movement design. From the beginning my interest has centered on the movement of the chrono minute hand, for in certain designs the hand moves continuously, while in others it remains stationary until it jumps in a more or less all-at-once motion. Yet, such a significant difference is rarely (if ever) listed by manufacturers, and ignored even in caliber archives such as Ranfftâs. What are we to do who prefer one way over the other? Thus it has been my hope not only to build a database of models and calibers to assist all who are interested in this complication, but to understand the mechanical differences involved, as well as the reasons a watch designer might choose between the two (or three, as it turns out) actions of that hand.
Mr. Habring writes that watchmaker manuals list three distinct types:
1) continuous drive: in which the hand is driven continuously by various wheels
depending on the movementâs design (sub-dial, or center minute hand).
2) semi-instant: in which the handâusually moving ever-so-slightly before it âjumpsâ to
the next minute markerâis triggered by a spring (weâll agree to agree on a difference
between âjumpâ and âsnapâ to keep matters clear here).
3) true snap (the only really instantaneous one): in which the hand, triggered by a snail
or cam, moves in less than a second to its new position.
My first post with information gleaned from Richard included a mechanical drawing of his continuous drive, designed specifically for a center minutes hand.
In this case, the chrono minute hand is driven by the second wheel of the train gear, with an added clutch system of lever and wheels (since that gear turns continuously), and not by the chrono seconds wheel, which is on the opposite side of the movement. Chrono minute hands placed in sub-dial arrangements might require other designs?
But in my initial post, which asked why this difference is rarely delineated, Cazalea was kind enough to rummage around and find a good diagram of the classic, spring-driven, semi-instant design in an old IWC manual.
[For those few readers who are not already aware, Richard worked for IWC early in his career, where he distinguished himself by developing the first affordable rattrapante (split) chronograph built on the venerable Valjoux 7750. Until that date, the split was a really pricy object, as it took great skill (and time) to fashion it from not one, but two column wheels. The advantage of Richardâs solution was a module that added a second cam to the 7750âs far simpler cam lever system. Viola! (allow me a string player joke, here) an affordable split!]
Regarding the third typeâor âtrue snapâas I have chosen to call itâRichard was kind enough to furnish the following video of Lange & Söhneâs solution, found in their Datograph.
And not only Lange's solution, but to call my attention to Eternaâs caliber 39, which also features a snail mechanism that results in essentially the same motion. Hereâs a photo of the snail.
And a bit more on the caliber, as a whole, is available HERE.
Habring points out that
1) Since both of these designs have gathered the energy for the "snap" over (nearly) the entire minute before, the instant of the snap does not cause undue pressure against the drive train.
2) On the other hand, the semi-instant (spring) design requires that all of the energy required to move the spring be gathered and released in that second or so during which we can actually see (at least in my 1863) the chrono minute hand move just slightly before it "jumps" to the next minute marker.
3) Although this design (#2) causes more pressure against the drive train for a moment during each passing minute (enough, actually, to cause the watch to stop if it is near the end of its power reserve), design #1 actually requires more total energy for movement function, due to the additional wheels/cams/levers required.
It was interesting to me to learn that Habring uses both the direct drive and semi-instant designs in his watches, a continuous (from the center) movement in his Doppel 3.1, and what he termed the âclassicalâ semi-instant design in the Doppel-Felix; Doppel 3; and Chrono-Felix models. But wait! Thereâs more!
When Richard heard that I wished to post my findings on the site he pointed out that their new Perpetual-Doppel, a watch that celebrates the brandâs 15thanniversary, hadnât yet been reviewed here. Would I be willing to furnish a link? Well, of courseâparticularly as the watch features my preferred semi-instantaneous âjumpâ of the chrono minute hand!
Specific information on this new piece may be accessed HERE.
***
As cordial as Mr. Habring is, and as important as it was to have the input of a watchmaker on this topic (and quite a watchmaker this!), I must say it has been equally delightful to see how insightful and knowledgeable my colleagues on the Forum have shown themselves to be in their responses to my previous posts. Cazalea started us out with a diagram of the âclassicâ semi-instant design; Dr. No wondered intuitively if the additional hardware necessary for a true âsnapâ might not be a point of power drain; rdenney furnished an informative photo of Eble's caliber 139, and skyeriding, in addition to offering an important perspective on how prominently friction figures into some designs, furnished a concise list of calibers of all three types. And all of this before Richardâs final word! But this can hardly be surprising, considering the passionate following the mechanical watch enjoys on the WatchProSite.
Through this discussion I have been able to add several watches to my list that distinguishes chronographs by chrono minute hand movement. But this will be a work in progress for some time. So keep sending discoveries as you make them. I appreciate greatly the interest and support of my WPS brothers!
Fred Halgedahl
I want to show it to you: This just came into my favorite shop and I couldnât miss the chance to check it out and share some photos with everyone. Cazalea
I'll hope that after you've had the piece a few weeks you'll give us your unvarnished impressions (I love the pincer brake seen through the back.) Wear it in good health! FH
Whatâs your impression concerning readability? Thatâs always a crucial point for me when I think about buying a perpetual. The watch is very tempting, even more as it comes from my home country. Perhaps I will pull the trigger. Best, Thomas
Because the chronograph doesnât clutter up the sundials. Photo from Habring2 site. Cazalea
I will try to see it in flesh. Perhaps I will get a chance soon. For example: I had the luck to try the new Blancpain Villeret Perpetual in 42 mm which had an excellent readability. On the other hand the new IWC Da Vinci Perpetual in steel which I liked so much from pictures couldnât convince me in reality. It was very hard to read. Best, Thomas
Mine is the most visible IWC but still you have to look carefully
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