This little Cyma Navystar came in for a bit of TLC recently. The Navystar range was introduced in the 1950’s and encompassed many different designs and movements, the common theme being it was a rugged waterproof watch in a slim case. There were over 20 patented technological innovations introduced to allow these timepieces to function under particularly demanding circumstances. The Cymaflex logo at the botttom of the dial refers to the patented anti shock system used on the balance staff.
A shot of the undecorated caseback.
This had one of the tightest backs I’ve undone in a long time due to the fibre and alloy caseback seal that had welded itself to the surfaces. Eventually I freed it and the beautiful calibre R.459 movement was revealed. The R.459 is a 17 jewel 18,000bph, manual wind movement with an indirect centre seconds pinion. Interestingly the ratchet wheel is branded ” + Tavannes Switzerland”, Tavannes was a watch manufacturer based in the Swiss village of the same name who sold a lot of their calibers to many other Swiss brands.
A closer shot of the indirect seconds drive.
With the movement uncased the dial is revealed, black is an unusual colour for a Navystar but it looks very striking with its gold accents and handset. It’s obviously degraded a little over the years but thankfully the finish was still solid and hadn’t started to flake.
With the dial removed you can see the patented shock protection on the balance and escape wheel. There are four shock protection points on this calibre and each one is different to the rest – lean manufacturing was the preserve of bacon production in those days!
The dial side stripped completely.
The motion work coming apart in this picture….
….until all that’s left is a bare plate.
The parts were then cleaned and inspected.
Whilst the components were cleaning the case was stripped and ultrasonically cleaned ready for a new crystal to be fitted.
Here it is with it’s new crystal squeezed into position.
A couple of issues were found on inspection, the third wheels pinion was bent…
…and the bridle had broken off the end of the mainspring.
The third wheel responded well to straightening, this isn’t always the case with pinions and all to often they’ll snap just when you’re giving them that final tweak!
A new mainspring was ordered and fitted, the bridle is the tang on a manual wind mainspring that latches onto a cutout in the barrel wall to deliver the power to the train, obviously with a broken one the spring will just slip.
The rebuild started with the barrel and centre wheel.
Here you can see the centre wheel, third wheel, fourth wheel and escape wheel in position ready for the bridge to be fitted.
Here the motion work is almost complete, you can see the unusual Cymaflex patented design of the balance staffs shock protection. The spring is move to one side to allow the freshly cleaned and lubricated balance jewel and end cap to be fitted.
The chaton and end cap are dropped in place as a unit.
Then the spring is moved back over to hold it all in place and offer shock protection. What a gorgeous little movement the R.459 is.
The keyless work, wheels and jewels are refitted to the dial side.
And the cleaned dial and handset are fitted. I’d much rather see an vintage watch like this with it’s original dial as opposed to a refinished one, however it wouldn’t take too much more corrosion on this one for there to be no choice but to refinish it. As it is it looks just right!
The movement was then recased and a new caseback seal fitted, there are a couple of service marks on the back from the late sixties and early seventies which is good to see. There’s also an extra one in there now!
Have I mentioned how good this movement looks? It’s almost a shame to cover it up.
And she’s finished, a lovely little survivor from the fifties running beautifully once more.