PAM 21 Special Editions from 1997 are equipped with vintage Rolex 618 movements. Where did these movements come from and why do they have completely different engravings than all Cal. 618 used before? A closer look reveals more differences…
The PAM 21 was Richemont Panerai’s first special edition in 1997. The story goes that Angelo Bonati found 60 brand new Rolex movements in stock after the take over of Vendome.
Angelo Bonati said back then:
In the stock, I found 60 brand new Rolex movements, and immediately, I replicated the Radomir using that mechanism. We sold it for 20,000 euros, which in 1998 was a lot, but it was sold out in 2 weeks.
Mr. Ferretti ‘s version of the story is slightly different. In his opinion these movements were handed over to Vendome by Mrs. Maria Abetti Panerai, the widow of Giuseppe Panerai. He also said these movements were ment as replacement units during the late 1950’s to 1960’s.
The engravings on these “replacement” units are totally different than all 618 movements before although they are technically almost the same like Rolex 618 Type 4 used in Ref. 6152/1. The caliber stamp “Cal. 618” has its first ever appearance on an Cal. 618.
Similar engravings (17 Rubis Swiss, Geneve) were found on the movement shown below. It’s based on Cortebert Cal. 624 and the case back markings suggest 1953 as production year.
There is no caliber stamp! None of the 16 ligne movements used by Rolex for their pocket watches or Vintage Panerai watches ever had caliber stamps. Only Cortebert used to stamp caliber numbers on their movements.
Another interesting observation is that these 60 movements consist of two different types.
Pallet fork bridge
The main difference between these two types is the pallet fork bridge underneath the balance wheel. The first type (a) has the conventional bridge used in all Cal. 618 before. The second type (b) has a L shaped bridge. These kind of bridges were used in the last 3 series of Cortebert 616 movements.
618 stamp on the base plates
The second to last series had the L shaped bridge with a visible “Cort” stamp. The last two series also had the L shaped bridge but the cort stamp was hidden underneath the balance cock and not visible without taking apart the movement.
The finish of the base plates is slightly different as well.
The first type (a) has the usual “Cort” stamp and added on top “618” while the second type (b) only has “618” stamped. These markings on the base plate were never used by Cortebert and must have been apllied by someone else.
We can conclusively say that this group of movements are a compilation of different production dates.
Cover plate for Cortebert holes
These “replacement” units also don’t have the usual cover plate to hide the holes for the Cortebert 616 escapement bridge. Cal. 616 and 618 share the very same base plates, only the bridges are different.
The following picture shows the cover plate in detail. Underneath the plate the “Cortebert” escapement bridge holes are clearly visible.
The next picture shows a Rolex 618 Type 4 movement with the escapement bridge of a Cortebert 616. This is a good example to show that the main plates of Cal. 616 and cal. 618 are basically the same and able to take both bridge layouts.
Breguet overcoil hairspring vs. flat hairspring
Another obvious difference is the regulator on the balance cock. Its shape is different than those used in 618’s before.
All Cal. 618 before had a Breguet overcoil hairspring (3) and therefore a slightly different regulator (1). PAM 21 movements have a flat hairspring from regular Cortebert 616 units and the very same regulator.
Côtes de Genève
Last but not least, late Cortebert 616 (15 Jewels) of the last 2 series with the L shaped pallet fork bridge had slightly differently positioned Côtes de Genève.
Within the same series Cortebert 616 and Rolex 618 always had the same amount of Côtes de Genève and they were applied on the very same position/direction. Rolex 618 were most certainly completely produced and assembled by Cortebert. This is the reason why the balance cock can be swapped between historically corresponding calibers and the Côtes de Genève will always match.
It is interesting to see that those 618’s with the L shaped bridge have Côtes de Genève which are a mix between the old series and the new.
These “replacement” movements used in PAM 21’s have a lot in common with regular Cortebert 616’s. The engravings are different than anything before, Côtes de Genève don’t match the Cortebert production and the caliber stamp is strange to say the least. Only Cortebert used caliber stamps on these kind of movements. To see another caliber stamp on the base plate is even more peculiar.
Having 2 significantly different types of movements also means different production dates. Years may lie between Type A and Type B.
Rolex 618’s of T1 and T4 were highly elaborated movements with 17 Jewels (1 or 2 capstones for escapement wheel, jeweled centre wheel) and Breguet overcoil hairspring. The latter was also installed on simpler 618’s of T2 and T3.
PAM 21 movements don’t fully match the technical standards which were set with Rolex 618’s of T4.
Also, why were these movements not used for the very first series of Pre-Vendome watches? In “Panerai – Una storia Italiana” it is mentioned that Rolex had been contacted in order to get these very movements.
So far we can only speculate about the provenience of these movements. Perhaps Rolex bought leftovers from Cortebert and finished the mechanisms by themselves. Why they applied a caliber stamp is a riddle.
These movements could also be conversions on the basis of Cortebert 616’s, a similar concept to the Angelus 240 units used in the PAM 203/267 SE from 2005/2008.
There are a couple of Vintage Panerai watches with this kind of movements as well.