In part 1, we met the subject of this latest project and learned a little bit about its history and what makes it such a special watch.  This second part of the series will focus on the deconstruction of the movement, taking in as we do, some of the aspects of this project that will make it such a challenge.

This bird’s eye view of the rear of the movement reveals the very close familial relationship to the 5719 on which it is based.  The main difference relates to the separation of the start/stop and reset functions from a single pusher to two pushers, the first dealing with the former and the second with the latter.  You should be able to pick out the main points of difference from the comparison photo below.

Back to the 5718, and there is not a great deal from this perspective to cause alarm but I am anticipating a battle to extract the movement because the case back gasket is rock hard and there appears to be lashings of rust around the casing ring.

My anticipation is rewarded, first by the supreme resistance to extraction offered up by the gasket.  I suspect it may have regretted going into battle with me.

But with the gasket removed, we get a better idea of the extent of the corrosion affecting the interface between the case ring and the case.  That corrosion is mirrored on the gasket mating surface of the case back.  Note also the stress fracture mentioned earlier, this time viewed from the other side.  As I’ve noted on numerous occasions in the past, the embossed crane motif indicates that this watch (or at least the case) was made in the Daini Seikosha factory in Tokyo, in spite of the fact that the 57-series was a Suwa product line.

Extracting the ring and then the movement requires somewhere from which to gain purchase and so this is the point at which it is prudent first to remove the balance.

Following an extended process of gentle teasing, levering and cajoling I was finally able to persuade the casing ring to give up its resistance.

Before we remove the movement from the case, now might be a good time to take a closer look at the design of the brake lever that is actuated by the upper pusher and which comes into play when stopping the chronograph.  In the 5719, the function of this lever is to prevent the centre chronograph wheel from rotating when the chronograph is stopped but in the 5718, it also has to prevent rotation of the elapsed minute wheel, located on the other side of the movement.  This requires the presence of a second arm that extends to the edge of the movement where it coordinates with the minute wheel braking lever on the dial side of the movement.  Notice also that the castle wheel on this movement has three more turrets than the wheel fitted to the 5719.

There is no impediment now to the movement dropping out upon inverting the case.  Doing so and setting the movement into a holder provides an unobscured view of the dial and hands.

Superficially, this looks fairly presentable but there are some problems – serious problems.  I mentioned earlier that the interior of the watch had been contaminated/spritzed with a film of oil, with the oil having gathered most conspicuously as droplets on some of the polished surfaces on the dial, such as the polished hour markers, and in congealed clumps elsewhere (we shall discover these as we delve further into the layers beneath the dial).  For the moment though, let’s allow our gaze to wonder over the dial and pick out some of the obvious flaws.  The first of these, to my eye, was the condition of the centre chronograph hand and the elapsed minute hand.  These would originally have been a pale cream colour, chosen to contrast with the shiny silver colour of the hour/minute and running seconds hand (the hand sitting co-axially with the elapsed minute hand in the sub-dial).  Both have discoloured to a darker cream colour with the elapsed minute hand closer to brown.  The paint on both hands is crumbling, some of it already lost. 

The second gentle chime on the alarm bell was the slightly cock-eyed upward slant of the left-hand counter disk.  You may notice that the 5 (two photos up) and the 7 (in the close-up photo below) is sitting higher than the neighbouring 2 (above) or 4 (below) within the window.  The two numerals should be perfectly in line with one another.  We will see the reason for this in due course (and it’s got nothing to do with the transition that occurs once every two revolutions of the hour hand) as well as the operational consequence.

Of equal, possibly greater, concern, was the state of the lacquer protecting the dial print.  In many areas around the dial, the lacquer had been penetrated and lifted by the oil film, and this has affected the integrity of some of the print.  Some of these areas are highlighted in the photo below.

I did not realise at the time I took this photo just how fragile the print was, particularly around the sub-dial.  You will see the consequence of that a little later.  I would also draw your attention to the plated 5 marker, also indicated above.  In common with most of the hour markers, this one was contaminated with oil droplets but more so than any of the other markers.  A closer view of the marker reveals the green colour of the oil droplets.

The green is from oxidation of the copper in the brass substrate beneath the plating and is a sign that the plating itself has been compromised.  As with much of the other havoc that has been wrought by the oil contamination, the true consequence will not be realised until the clean-up operation is under way.

It is time to remove the dial and get our first look at the dial side of the movement.

Our view is dominated by the two counter disks, peering at us wide-eyed, the hour wheel and cannon pinion playing the role of the nose and the sub-dial pinions as a puckered mouth.  At this stage, the controlling mechanisms are hidden from view behind what in the 6138 or 4006 calibres would be referred to as a calendar plate.  I suppose we can call it that here too as the count graph disks also play the role of date disks. 

While we gird our loins in preparation for the challenges to come, the most dispiriting observation to make is that the widespread oil/grease contamination persists at least as badly at this level.  As with the tachymeter ring and the dial itself, the oil has caused significant damage to the print on the two counter dials, the 10-counter being the more seriously affected (the one on the left, above).  From this initial view, we can see the numeral 9 on the left-hand disk is damaged and the 6 on the right-hand disk.  What you cannot necessarily recognise just yet is that the oil covers most of the surface area of both disks and the print transfer has lifted in places, rendering the print extremely vulnerable.  One of the most frustrating (not to mention stressful) aspects of this project will be the impossible dilemma presented by the need on the one hand to eliminate as much of the filthy, congealed grease as possible whilst at the same time avoiding compromising the print.  As we shall see, those two drivers will prove to align at 180 degrees to each other.

Let’s see what forensic conclusions we can draw from the condition of the rear of the dial.

The most striking feature is the two circular reliefs that have been machined to accommodate the two counter disks.  As might be expected, there is plenty of congealed oil here too.

In fact, if we look more closely at the two circular depressions, we can see the text fragment missing from the 6 on the unit counter disk, adhered to the dial rear by a goodly clump of grease.  You can also see some transfer from the 10-lap counter disk, but with most of the damage on that disk being to the blank region between the 1 and the 9, the missing fragment from the 9 is a little trickier to spot.  At risk of flogging this point to death, here’s a closer look at the slick of oil on the calendar plate.

I’ve not addressed this question yet, although it is there in the sub-text, but what can possibly have motivated someone to carry out this act of vandalism.  This amount of oil can’t just be the result of over-oiling by a trigger-happy watchmaker, can it?  A plausible alternative theory is that it is the result of someone thinking it would be a good idea to give the watch a good squirt of aerosol grease, just as you might to a sticky bicycle derailleur.  Let’s press on.  As I was following my nose, curiosity taking a front seat over logic at this stage, I thought the next step should be to remove the calendar plate.

Our reward is our first proper look at the mechanisms that control the lap counter disks and the operation of the minute sub-register.  And yes, let’s not overlook the puddles of oil.  A close-up of the two disks shows a little better the extent of the damage, in particular, to the 10-counter disk on the left.

What you may not be able to see is that in addition to the lost fragments of text, affecting the 9, 1 and 2 numerals, the lacquer across the whole surface of this disk is lifting.  Turning our attention to the lower part of the main plate, it becomes clear that I’ve got ahead of myself in prematurely removing the calendar plate before the gear train.  To the right of the minute register wheel, we can see the unconstrained lower pinion of the third wheel.  The arrow in the inset is highlighting a clump of grot, stuck to one of the teeth of the pinion.

Incidentally, the tension spring design of the minute wheel calls to mind the minute register wheel in the later 7018 fly-back chronograph.  As in that case, the friction exerted by the spring is designed to be sufficient to allow rotation of the minute recording wheel and its axle in concert when the chronograph is running but when stopped, the friction is small enough to allow the wheel to continue to rotate whilst the axle remains stationary.

One step back then, requiring the temporary reinstallation of the calendar plate while I deal with the chronograph and gear train deconstruction.  We join the action in familiar(ish) territory, having recently re-encountered the 5719 (here) with which the 5718 shares the essentials in terms of the chronograph layout.  The tetratypch below charts, from top left to bottom left, clockwise: all present and correct, hovering above the dual-action brake lever; the brake lever and its spring have departed (top right); a shift in location, viewing the coupling clutch, the spring serving it and the hammer having been removed (bottom right); and finally, the coupling clutch removed (bottom left).

If we focus our attention for a moment on the castle wheel and hammer, we note the almost inevitable stress fracture compromising the c-clip whose job is to secure the hammer.

Removing that c-clip, allows the hammer to be extracted at which point we get a less obstructed view of the operating lever (the lever sitting beneath the triple-slotted screw), the castle wheel and its jumper and finally the reset lever to the right of the pillar wheel.

In the 5719, the single pusher at the 2 o’clock position performs all three stop-watch functions: start, stop and reset from sequential pushes but in the 5718, there is a second dedicated pusher at the 4 o’clock position to perform the reset operation and this therefore requires an additional lever.  You will also have deduced that with a minute sub-register, the reset button must also reset the elapsed minute hand:  if you look at the end of the reset lever in the image above, you will see that its action is actually secondary to the lever serving the elapsed minute hand – the end of the pusher comes into contact first with the vertical end of the elapsed minute reset lever, which we shall meet shortly – and it is this part that transfers the motion to the seconds reset lever.

Moving on, having now removed all of the chronograph mechanism from this side of the movement, we can take a breath and note that the chronograph bridge, and indeed (almost) all of the gear train components beneath are shared with the 5719.  I would also note, because this will crop up later, that one of the three screws securing the barrel and train wheel bridge is missing.

The chronograph bridge provides the lower pivot points for the fourth wheel and the centre chronograph wheel.  Note (surprise, surprise) the presence of random bits of detritus on the chronograph wheel and teetering on the edge of the hole above the escape wheel Diafix setting.

From here to the exposed gear train is but a few short steps.

As with the 5719, the fourth wheel and pinion has two wheels: the lower and larger of the two serves the conventional role of driving the escape wheel while the upper, smaller wheel plays the role of chronograph fourth wheel, driving the chronograph wheel via the coupling wheel.  This wheel also serves as the platform for the running seconds pinion which is absent in the 5719.  Thus this double-stacked fourth wheel is unique to the 5718.

The crown wheel and click are hidden away in this movement beneath the barrel and train wheel bridge with the click interfacing directly with the crown wheel rather than the ratchet wheel.

In examining the bridge, I noticed that the upper third wheel jewel was chipped (see inset, top right in the close-up photo below).

This part is common to the 5719 as well as other calibres and securing a replacement was straightforward.  Pressing a new jewel into place solved this particular little niggle.

With the escape, fourth, third wheels and the mainspring barrel removed, we meet the centre wheel bridge.  In the 5719, this bridge is equipped with two jewels, one to support the centre wheel and a second, off-centre and pressed into a hole in the bridge, to provide the lower bearing for the fourth wheel pinion.  In the 5718, the bridge also features two jewels but the second jewel, rather than being pressed into a machined hole in the bridge, sits in a separate plate that screws into a recess in the bridge.  The jewel itself is charged with two jobs:  the first is to support the much broader base of the fourth wheel pinion (not having the short pinion of the 5719 fourth wheel), and the second to support the elapsed minute register wheel mounted on the dial side.  The larger inner diameter of the jewel also provides passage for the long fourth wheel centre pinion upon which the running seconds hand will be mounted.  The jewel is highlighted in the photo below.

We can now return to where we had found ourselves, before realising the miss-step, and resume our exploration of the considerably complexities of the dial-side of the movement.  We begin by re-removing the calendar plate, noting the absence now of the third wheel pinion, and cautiously extract the minute register wheel.

This wheel needs disassembling to clean it properly, an undertaking not for the faint of heart if one were to contemplate the consequences of say, breaking (or losing) that spring.

The reverse of the wheel (above, left) is equipped with both a reset heart cam, similar to that on the top of the centre chronograph wheel, and a finely-toothed disk against which the braking lever will sit when the chronograph is in its stopped condition.  In case you were wondering, I did manage to execute this sequence without calamity but I am most emphatically not looking forward to refitting that spring.

Rather than bundling the next steps into groups, I thought I’d walk you through, step-by-step in the slow and steady way that the process actually occurred.  I think what follows is probably close to the sequence of how this should actually be accomplished.  We start by removing the 10-counter quickset lever (for want of a better term) and the two screws that secure the two lap-counter disks.  Note that the screw securing the 10-counter disk is left-threaded.

I am going to work clockwise around the main plate from here but as the next components that I need access to are partially obscured by the two disks, these need to come next.  The disks themselves are a little reluctant to part company with their posts and their removal requires simultaneous leverage from opposite sides.  For no logical reason, I remove the unit-counter disk first, exposing its sprung-loaded jumper beneath.

You may have noticed that I have also removed the unit-counter lever spring and its screw in preparation for removal of the lever itself, but first the 10-lap-counter disk departs using the same technique as on the first disk.

Are you keeping tabs on all these left-threaded screws?  One securing the 10-lap counter disk and a further five on display in the photo above.  There was one also on the balance side of the movement and so that makes seven in total.  Comfortably more than I have seen on any movement I’ve worked on previously.  It’s worth bearing in mind that perhaps all but one of these may be dedicated to this movement and so to lose just one does not bear thinking about.  Removing the unit-lap-counter disk advance lever (maybe that’s a better term than quickset) requires removal first of the left-threaded screw and the plate beneath, just to the right of the stem in the lower right quadrant of the photo above.  Slowly but surely, the clutter reduces.

Let’s pause to take in some of the detail:  upper-most, we see the two opposing sprung lap counter jumpers, there to coordinate with the stars mounted on the rear of each disk.  The wheel sitting beneath and between them is effectively a date driving wheel, there to advance the unit-lap counter disk at midnight, and therefore providing the option of using the counters as a calendar.  Both jumpers are secured with left-threaded screws and so righty-loosey for both to free them (and their spring) from their confinements.

The long lever to the right, above, is the transmission brake lever for the minute-register wheel.  Rather than acting directly on the minute register wheel, its role is to transmit the instruction to the minute register brake lever whose default resting state is in the brake-on condition.  Contact from the transmission lever moves the second lever against the opposing force of its spring, releasing its contact with the fine-toothed wheel on the rear-side of the minute register wheel.  More on this later.  Removal of the transmission lever is accomplished by removing its left-threaded screw and this provides us with access to the reset hammer whose job it is to reset the elapsed minute hand back to zero when the reset pusher is pushed.

Here’s that minute register brake lever, removed, exposing a mini slick of oil, the release of the surface tension of which producing a little squelch of protest.  The inner diameter of the cut-out of the lever is what comes into contact with the minute register wheel.

With all of those parts removed, we arrive at the much more familiar territory of the setting parts, already partially dismantled in the photo below.

With the main plate having shed the last stragglers, the final call is the mainspring which, hidden away in the safe confines of the barrel, has escaped the abuse that pretty much everything else above decks has been subject to.

The state of the movement parts meant that the cleaning process was a very lengthy and time-consuming process that spanned: manual cleaning in L&R watch rinse solution; pegging of all bearings and pivot points; application of considerable amounts of elbow grease in removing stubborn clumps of grot from plates and from in between pinion splines; and then the usual four-stage process of ultrasonic bath, one cycle of agitative cleaning, two rinse cycles and the drying stage.   The result was a very clean collection of parts but with some cosmetic issues related to the loss of plating that resulted from the aggressive effects of the oil contamination.  This marks the end of the rendering of a whole into a very large collection of fragments.  In part 3, we will attempt to rebuild the movement and discover the full extent of the damage caused by the oil contamination.