A JELLY FISH 344527460?



I have written about the Patek caliber 27-460, which is nothing less than one of the two or three finest automatic
movements ever to leave the hands of Swiss manufacturers.  It is an exquisite movement, built to the standards of an age when time and cost were of relatively little consequence. 

This wonderful caliber is available in a variety of older Pateks, including the Reference 3445 (right).  It is a beautiful watch in a 1960’s Patek sort of way:  elegant, refined,
simple, modest.  As a friend commented, “Nothing to complain about.”  Oh, the power of faint praise.

But what bothered me most about the 3445 was that it gave no hint of the
much greater beauty inside.  Rita Hayworth in army drabs, albeit custom tailored.  Oh, to reveal the insides!   


No, not the submarine, the Swatch! 

Why not, I thought, do this with something a bit better in the movement department?  Something that
would show the 27-460 front and back in all its glorius craftsmanship?

In examining the Patek 3445 back, it measured only 0.5 millimeters thick throughout the center section.  There would
be no way to put a crystal in that.  I’d need at least one millimeter and even that was cutting it close.


I did a little sketch on a napkin during lunch at The Drunken Boat, and then took it to my friend John, the jewelry maker.  

“What’s this,” he asked.  “A flying saucer?”

knew my ways.  I explained that I actually wanted him to solder an 18K ring to the caseback of the 3445 (right, arrow).  I had calculated the diameter and depth, and this
would give me enough material in the back to install a sapphire. 

“I hate it when you use the p-word [‘It has to be perfect’],” John said.   “But I’ll do it.”


It’s always unnerving to put an irreplacable piece of a Patek in the lathe.  But it’s not going to get any easier, so why dally around?

John had provided me with excess metal in every dimension, so I was able to exactly machine the inside diameter, height, and width of the


After machining the rough dimensions, there  followed several hours of grinding, grinding, grinding, polishing, polishing, polishing, and then a
final brushed finish.  (The original gold back threads, a little the worse for forty years of wear, are visible in the profile,  left.)



I installed the sapphire glass with a tight press fit, and cemented it in place with a wonderful Seiko epoxy made for crystals.


The beautiful dial side of the 27-460 could be revealed simply by removing the dial.  Fortunately the dial side plate for the calendar mechanism
holds the hour wheel in place (it is normally held by the dial).  Fortunately, every detail of the dial side is beautifully finished.




I liked the brushed metal calendar ring laying out the entire month to be seen, but there was a need for some kind of dial markers.  I happened to
have some 18K arrow markers left over from a recent project on another watch.  Waste not, want not.  I cut them in half, drilled 0.20 millimeter holes in the periphery of the ebauche
and installed the markers with one foot each at the four cardinal positions.


Because this was, after all, still a Patek, I placed double markers at 12 o’clock.


It was time to put it all together.  With an increase in case depth of only 1.5 millimeter, the watch had a much beefier, heavy feel, and sat quite
differently on the wrist.  I liked it.  The original 3445 was a bit diminutive.





The dial side was finished.












The back was finished.







a Jelly Fish 344527460.