Wristwatch restoration, servicing and repair

Posts Tagged ‘Longines’

Longines Admiral Ref. 8557 (Longines Cal. 508)…

This Longines Admiral diver is certainly a colourful start to the new year.

(Click pictures to enlarge)

Much of the vintage output from Longines had a very classical feel but for brief period between 1968-75 a range of colourful divers and chronographs crept into the model line up, this Admiral diver being one of them. The blue dial and bright orange bezel certainly make a statement but given how few of them are around these days compared with other models in the range, I wonder if the large oval case and contrasting design may have been a step too far, even for the early 1970’s.

Before becoming part of the Swatch group and switching to ETA based calibres, Longines produced some excellent quality in-house calibres. Like the 30L and Ultra-Chron models I’ve written about in the past, the movement in this Admiral diver is another fine example of their work, the cal. 508 – a 21 jewel, bi-directional winding automatic with a beat rate of 21,600 bph and a micrometer regulator. The watch also has a quickset for the date activated by depressing the crown.

As you can see from the pictures above, the case was in decent shape but pretty scruffy and the mineral crystal had picked up a few scratches from daily use. The movement inside was running and relatively clean but looking at the condition of the oils under the microscope I could see that it hadn’t had a full service for quite some time.

The case was fully disassembled and cleaned in the ultrasonic tank and a new crystal and gaskets were ordered to replace the tired originals – it’s worth noting that care should always be taken when levering off the friction fit bezels on all these colourful diver’s watches as the bezel insert is made from acrylic (or bakelite maybe?) and can crack if flexed too much.

The movement service was straight forward with no hidden surprises so the only thing left to do was refresh the tired lume in the hands with a vintage cream lume before the watch could be rebuilt.

With a case size of 44 x 49mm and a lug width of 24mm, strap choices are limited but the Rodania strap found by the owner was a good match and is a similar design to the Longines strap that would have been originally fitted. The watch was also available originally with a full stainless steel bracelet which is near impossible to find these days.

To finish off this post, here is the watch with a couple of the other colourful stable mates from the same period.

On the left is an early 1970’s Ultronic diver (ref. 8484), powered by a pre-quartz, electronic tuning fork or ‘hummer’ calibre, the cal. 6312, and on the right is another popular vintage diver, the Ultra-Chron “Super Compressor” (ref. 8221-2) powered by Longines’ high beat cal. 431 . It may be of interest to any fans of this watch that Longines re-issued a modern version of this model (along with its chronograph sibling) in 2014, albeit with red rather than orange accents.

Rich.

** Many thanks to Chris Harrison for letting me feature his watch on the blog. **


Longines Admiral (Longines Cal. 503)…

The Admiral has been a long standing model in the Longines range and is still in production today, this one is from 1967.

(Click pictures to enlarge)

Turning the watch over reveals a completely smooth caseback and no obvious method of gaining access to the movement – the only clue is the text “Remove bezel – to use 1260 wrench”.

This watch has a one-piece case (or monocoque) case, and as the name suggests, it is machined from a single piece of metal. One-piece cases are used in an effort to improve water resistance – no caseback means there’s one less gasket to fail.

As there is no case back, the watch must be removed from the case through the front, and when tackling these cases there are two considerations; 1. How is the crystal removed?  and 2. How is the crown/stem released?

In the majority of one-piece cases an acrylic ‘tension ring’ crystal is used, and that’s the case with this Longines. Removing tension ring crystals can be tricky at the best of times, and very difficult without the right tools. I don’t have the Longines 1260 wrench mentioned on the back of this case, but in the war against one-piece cases, there are many weapons…

1. A crystal claw: The claw is opened until the teeth fit around the crystal (inset left). The knurled handle is then screwed down, tightening the teeth around the crystal and compressing it from all directions until it is smaller than the inner diameter of the case. The crystal can then be lifted out.

2. A crystal wrench: The aluminium ring in the centre of the wrench is interchangeable and a number are supplied in step sizes of 0.5mm.  The ring is selected that just fits over the crystal (inset centre), and the basic principle is the same as the claw; the wrench is squeezed, the crystal is compressed, and can then be lifted out.

3. Bergeon case pump: In cases where the crystal sits low in the case and there isn’t enough profile showing to grip with the claw or wrench, a case pump comes to the rescue. The pump is supplied with a number of interchangeable nozzles and with the crown and stem removed, the nozzle is selected that fits snugly over the case tube (inset right). The pump is then held tight against the case and compressed, building up internal pressure inside the case until – pop! – the crystal blows out.

Once the crystal has been removed, it’s on to the crown and stem. Watches with one-piece cases are usually fitted with a two-piece (or split) stem.

Before the watch can be released from the case, the stem has to be separated. However, it is always worth checking before pulling out the crown as some watches are fitted with a regular one-piece stem and have a release lever that is accessed once the crystal has been removed. (I’ve even had some models which had neither a split stem or a release lever, just a regular stem and crown – getting those watches out of the case was a real headache!)

With the crown/stem and crystal removed, the movement can finally be revealed – a very nice Longines cal. 503.

This watch arrived with no sign of life at all from the movement, but the cause of the problem was immediately obvious. One of the dial securing screws had worked loose and was jammed in the teeth of the mainspring barrel.

As the watch had spent many years unused, the oils had completely dried out, so the movement was given a full service. After that I cleaned the dial and case, re-lumed the hands, and polished the crystal before re-assembling the watch.


Rich.

** Many thanks to Oscar Zuniga for letting me feature his watch on the blog. **


Longines (Longines Cal. 30L)…

There have been plenty of tool watches on the blog, so this time it’s something with a little more finesse, a 1960’s gents dress watch from Longines.

(Click pictures to enlarge)

Longines is a well respected company in Swiss watchmaking with over a 175 year history. The company started in 1832 assembling watches from parts made by artisans working independently (a common practice at that time) and in 1866, Ernest Francillon the nephew of the founder, opened a factory at “Les Longines” (the long meadows) in St. Imier bringing several artisans under one roof, and pioneered the development of machine tools to increase productivity.

In 1867 at the Universal Exhibition in Paris, Francillon presented the first calibre designed and produced completely in-house, the 20A – a mechanical movement with pendant winding. In 1873 they won the first of many gold medals for precision and reliability at the Universal Exposition of Vienna, and in 1878 produced their first chronograph calibre, the 20H.

The company grew steadily and by the 1920’s employed 2500 workers producing 122,000 watches per year.  During this decade aircraft were starting to be used for military and exploration purposes, and Longines established a link with many aviation pioneers, produced what are arguably their two most famous watches, the Weems and Lindbergh (Hour Angle) models.

The watch in this post dates to 1962 and contains a well respected Longines calibre, the 30L., which was available in a number of different grades, this one being the ‘plain’ version. The higher grade versions had more elaborate decoration on both sides of the calibre and larger balance wheels. The highest grade was the cal. 30Z which was used successfully in Observatory Chronometer testing, competing against other renowned calibres such as the Omega 302 and the Zenith 135.

Like many of Longines’ in-house calibres, the quality and care taken in the manufacturing process shines through and though it is a relatively simple calibre, I’ll take the opportunity to point out a few highlights.

The first thing to notice is that the jewels for all the train wheels are mounted in “chatons”. A chaton is a ring of soft metal (usually gold) which forms a barrier between the brittle jewel and the hard steel plate. Chatons were used to minimise breakages during installation in the days before jewels could be manufactured to extremely tight tolerances. The continued use of chatons  in modern watches is mainly aesthetic as the gold enhances the brilliance and colour of the jewel inside.

There are several other aesthetic enhancements found mainly on higher quality calibres. The edges of the bridges have all been bevelled to remove the sharp edges, then polished, and under the balance wheel is a section of perlage decoration. The arms on all the wheels have been rounded, and the underside of the ratchet wheel has been radially brushed too, which is a nice touch as this isn’t even visible when the part is in place.

The balance wheel in this calibre is typical of many vintage watches from this period as it is fitted with rim mounted screws, and a flat Nivarox hairspring.

The screws are used for poising and to make minor timing adjustments. All balance wheels need to be poised, which means that the centre of gravity must be as close to the centre of the balance staff as possible. If the balance wheel rim has a heavy point then the centre of gravity moves away from the staff when the wheel is rotating, affecting the timing in different positions.  To compensate for this the screws can be moved in or out as required (or their weight changed) to ensure that the balance wheel is perfectly poised.

While screwed balances are still found in some high-grade watches these days, most modern watches have balances made from a single piece of beryllium bronze (Glucydur) which is laser poised by machine. The benefits being that they are more aerodynamic and are unaffected by magnetism or temperature changes.

Though the watch in this post arrived in a non-running condition, it only needed a service to get it up and running again, and the 9ct gold case looked great after a light buff.

Rich.

** Many thanks to Claire Bateman for letting me feature her watch on the blog. **


Longines Ultra-Chron Ref. 7979-1 (Longines Cal. 431)…

Something strange has happened… I’ve bought a watch that works! It’s something I’ve been intrigued by for quite a while, a Longines Ultra-Chron Ref. 7979-1 from 1967 fitted with a Longines Cal. 431 “high beat” movement…

(Click pictures to enlarge)

The term “high beat” refers to the rate at which the movement runs. For a limited time in the late 1960’s and early 70’s a small range of calibres were produced which had a rate of 36,000bph, or 10 beats per second, which claimed to increase accuracy by releasing the mainspring power in smaller, more controllable increments.

High beat calibres were one of the developments to reach the market just before the quartz revolution and are seen by many as the pinnacle of mechanical timekeeping for the masses. Longines were one of only 12 manufacturers to successfully develop a high beat calibre and the only one still in production today is the Zenith Cal. 3019 “El Primero” Chronograph.

Without seeing a high beat movement in action, it’s hard to appreciate just how fast 36,000bph really is, so it’s time to break new ground here at The Watch Spot and include some video clips (with sound!). The first clip is the escapement from a Valjoux Cal. 92 which runs at 18,000bph, the industry standard rate for many years…

 

Now compare that with the Cal. 431 which runs at 36,000bph…

 

So what else is different? To achieve those speeds several changes were necessary; the number of teeth on the escape wheel was increased from the 15 in traditional calibres to 21, which changes the gearing of the rest of the wheels in the going train. Extra speed at the escapement means that more power is also needed from the mainspring, so high beat calibres have a thicker mainspring than regular calibres which results in a larger mainspring barrel if a power reserve of around 40 hours is still to be achieved.

However, increased accuracy comes at a price as correct lubrication of the movement becomes crucial, especially in the escapement. At such high speeds traditional lubricants can literally be thrown off the escape wheel teeth. To prevent this happening Longines recommends that the escape wheel teeth and pallet stones are not lubricated in the traditional manner, but coated with a film of dry lubricant called “molybdenum bi-sulphide”.

Although not all officially certified as chronometers, it is thought that the term Ultra-Chron means “Ultra-Chronometer” and the advertising of the day claimed that the Ultra-Chron was “The world’s most accurate watch… guaranteed accurate to within a minute a month”. That equates to +/-2 secs per day which is certainly well inside the current C.O.S.C. chronometer specifications of -4 to +6 secs per day…

That’s quite a claim, but I can well believe it, as after regulating my Ultra-Chron it runs consistently at -1 sec/day which is very impressive.

Rich.