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Der Einsatz-ZeitMesser 1 -
The "Mission Timer 1" & The Lemania 5100
The "Mission Timer 1" & The Lemania 5100
*I do not claim to be author of the entire article.
Portions of text are from April 1998 issue of the German Chronos and translated by Roman Hartmann & George Chow.
Additional info by the great and late Chuck Maddox (Rest in peace well dear friend) - Chuck's blog here
Additional info from the military watch enthusiasts site www.broadarrow.net
History of the Lemania 5100
The chronograph world isn’t what it used to be. Due to escalating manufacturing cost, the Swiss industry has gravitated toward fewer popular calibres. An example of one such basic and functional calibre is the Lemania 5100. Manufactured since 1978, it was once rescued from an untimely demise by the Swatch group and then put to death again by a policy change in the same hands of the rescuer.
In the 1997, Nouvelle Lemania was planning to cease production of the 5100, a particularly rugged but accurate calibre used mostly in military and space applications.
There were two reasons for Lemania’s decision:
(1) Foremost was that the simplistic design of the 5100 no longer fitted the manufacturer’s product line and philosophy.
(2) The tools for the movement, being 25+ years old, were outdated and in need of restoration. However, the needed investment couldn’t be justified by the calibre’s limited sales to its remaining main customers: Fortis, Sinn, and Tutima. (Paul Picot and Alain Silberstein also use the calibre but only in very limited fashion unlike the other three.) At the very least, Lemania would not be able to maintain the calibre’s price.
One intermediate wheel makes a lot of difference
However, Fortis, Sinn, and Tutima insisted on the continuation of production because the 5100 is the only calibre that met their military requirements.
The 5100, due to its construction, is the only chronograph movement that can withstand large shocks without its chronograph seconds hand stopping. This is because its chronograph mechanism is driven directly unlike most other chronographs which use an intermediate wheel. The calibre easily withstands acceleration in excess of 7G without appreciable loss of accuracy. Its ruggedness is legendary; the calibre easily absorbs shocks and blows. The calibre also maintains its accuracy over long periods without servicing. Service intervals from four to seven years have shown to be sufficient.
Everything has a weakness
On the other hand, the 5100’s weakness, at least from a watchmaker’s perspective, is its simple, even anachronistic construction. Like a cheap old mechanical wristwatch or a mechanical alarm clock, it uses a pillar construction. That is, the cock and bridges are attached to the main plate by thin pillars. In a more conventional design, the cock and bridges are terrace-like and mount directly onto the main plate.
Pillar construction reduces manufacturing cost since parts can be stamped as opposed to being milled. But that’s not all. The designers even dared to use some nylon parts in the movement. The choice of nylon not only lowered production costs but was also deemed, at the time, to be progressive. After all, this was during the time of the Tissot Research 2001, a watch with a movement made entirely of nylon and fiberglass. The day and date wheels of the 5100 and their cams are also nylon. On the periphery of the movement are two gray nylon half-moons that support the rotor and absorb shocks from the rotor in case of hard blows. This nylon “ring” around the movement hides much of the pillar construction from the casual viewer.
Fortunately, Lemania did not cease production of the 5100 (in 1997). However, the wholesale price of the movement nearly doubled from 230 SFR to about 400 SFR to reflect the cost of the new machines and tooling's.
A brief glance over the 30 years history of the automatic chronograph shows that the golden age of the chronograph when a large number and variety of calibres flourished is largely over now.......well maybe not, there has been a bit of a renaissance lately but we shall see.
20 years +
Indeed, only a few integrated (as opposed to modular) automatic chronographs remain on the market. Nearly all of these are at least 20 years old.
It started with Zenith’s El Primero in 1969. The El Primero’s strongest rival was the calibre 11/12 from Breitling, Heuer, Hamilton and Buren that was released the same year. However, the El Primero is today, 20 years after the production of the calibre 11/12 ended, still in production.
In 1972, Lemania released the calibre 1340 that lives on today, albeit after a long hiatus, as the 1350.
Today’s ubiquitous ETA-Valjoux 7750 was released in 1973. Five years later, the 5100, the simplified successor to the 1340/1341 was released.
Antiquated but Reliable
The Lemania 5100 demonstrates other unusual constructions. The navette-type chronograph mechanism is fitted not as usually between the base plate and the automatic winding system but between the dial and the base plate instead. The rotor winds in one direction only over the reduction gear and runs in a hard iron bearing instead of jewels.
The ratchet wheel under the rotor transfers the rotation of the rotor to a reduced wheel. The yoke spring on the rotor doubles as a click. The above clearly shows that the Lemania 5100’s antiquated construction, while simple, is nonetheless reliable and functional. The clutch wheel is also made out of nylon, another tribute to rational production.
The large mainspring barrel continues the rugged design philosophy of the movement. The balance is also quite large for a high beat movement running at 28’800A/h. The calibre uses the reliable and space-saving Triovis regulator. Kif-Flector shock absorber was chosen instead of the more usual Incabloc shock absorber seen in ETA calibre. At 8.2mm, the 5100 is 0.3mm taller than the ETA-Valjoux 7750. This makes the 5100 the tallest of today’s chronograph calibre.
Effective, Precise, and Reliable… In short: Unbeatable
Because the Lemania 5100 is built for tool watches with an instrument appearance, the height of the calibre is not very important. Sinn was the first to see the potential of this underdog. Sinn released the Sinn 142 in 1980 (roughly at the same time as Omega’s release of their second edition of the Speedmaster Mark IV). The Sinn 142 is a large tool-watch with a highly functional dial.
Orfina’s Porsche Design chronograph in the early 1980s was another functional (and minimalist design) that used the Lemania 5100.
Tutima’s military chronograph was released in 1985 and was chosen shortly after as the official watch for German air-force pilots.
In 1994, Fortis replaced their unpopular Stratoliner model with the very well-made Official Cosmonaut chronograph. The calibre remained the Lemania 5100. Even Alain Silberstein used the 5100, changing the color of some of the nylon parts in his provocative “Krono Bauhaus”.
Sinn released their EZM1 (Einsatz-Zeitmesser 1), a novel chronograph design using the 5100 that moves the crowns and pushers to the left side of the case (in addition to removing all subdials and the day/date functions).
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