For the past few months I have had a desire to add a complicated wrist watch to my collection. When I have done research about such things in the past I have tended to stalk the current offerings of some of my favorite brands and get dissuaded by the prices of the impressive Swiss offerings. I however am never deterred for that long and always end up marking my way to browse through the endless vintage offerings hoping to spy an overlooked model that represents the kind of price and value that makes me drool at the chance to pounce and grow the collection one bit more. Most of the time I am left in a daze, thirty tabs open, eyeballs fried from blue screen glow, staring at the time in the corner of the screen doing the depressing calculation of how long I’ll get to sleep before I need to get up the next morning. That however is just most of the time. Sometimes (just enough to keep me going in this hobby) I am rewarded with the discovery of something truly cool and at price point that has nothing to do with the purchase price of a new car. The watch I want to talk about today is one of those watches the Dubey & Schaldenbrand Index Mobile.

Dubey & Schaldenbrand (D&S from here on out) is a Swiss firm locaded in La Chaux-de-Fonds. The company was formed in 1946 as a partnership between two watchmakers Georges Dubey and René Schaldenbrand. The manufacture website lists these two men as the inventors of “the split second chronograph” I find this claim to be incredibly fishy as we have seen the complication in pocket watches from the 1880’s and in a Patek wristwatch from 1930. What is clear though is that the two watchmakers had a passion for the complication and a desire to do something interesting with it.

D&S had an idea to make a rattrapante chronograph that would cut down on the huge number of parts required to make the mechanism work in its most traditional from with the idea to make the movement easier to manufacture. For those with little intuition as to the complexity of these movements a modern manufacturer at the top of their game like Lange can produce a perpetual calendar with 211 components and a rattrapante with 206. As a matter of fact alongside tourbillons, and minute repeaters the split second chronograph is considered a grand complication in its own right. Reducing the complexity of such a device is no simple engineering feat especially when your stated goal is to make this wildly complex however very practical piece of engineering cheap enough for the everyman to strap on his wrist.

D&S decided not to start with a split seconds movement and strip it down but to start with a chronograph movement and work up. The main modifications as I can tell are to add another shaft through to the dial side which holds the “split hand” and friction break that can be applied the split hand through the button in the crown. The real brilliance happens on the dial side what looks like a hair spring is attached to connect the split hand and the main chronograph hand so that while the break is applied the spring coils tighter snapping the two hands together when the brake is released. These heavily modified movements can come from a few manufactures I am not a watchmaker or even an expert on these exact watches but I have heard reports of people finding watches that have both Landeron 248 and Venus 175’s as the base movement.

This is not a perfect solution the split hand only remains separate as long as you keep the brake depressed if you want to read the final time and the split time you need to hold the crown down while operating the upper start/stop pusher which might be tricky depending on how you grabbed the watch. The hair spring is obviously visible dial side. Some of these watches have busy dials with tachy scales and telemeter scales on the dial but I think legibility still remains quite high. As we discussed earlier this is a very hard problem so some allowances must be made. Today these watches are available on the vintage market in decent numbers considering their low production numbers. Estimates are that less than 3000 produced a year while they were in production. Prices seem to start at around $1600 and go up to $2200 a wonderful value for a charming and unique complication that provides a useful feature and some good fun to play around with.

 

Thanks for the writeup on this little known complication that never really caught on with the public.