It has been discussed for years why the Reference 7016 & 7021 Submariners were introduced. First seen around 1968 (verfiable) they feature a long list of changes compared to the Reference 7928. First of all there are two of them. 🙂 The 7016 features a non-date layout while the 7021 features a layout with a Date mechanism. If we look at the Rolex world, this co-incides with the realease of the 1680 – the Rolex Submariner with a date. So, this “explains” why the 7021 was introduced. By why add the 7016 ?
The reason is most likely movements. The 7928 featured the cal. 390 automatic movement, bought from Fleurier (FEF). During the 60’s almost all Tudor models disbanded the various movement manufactureres and went pure ETA. (Exception of course being the Tudor Advisor with the proprietary alarm clock movement). The Cal 390. was first seen in early Tudor automatics (most famous the Tudor Oyster 34) from 1951-52 – so realistically the movement has seen at least 16 years of service. And the base is even older. The combination of a pure ETA movement strategy (well, untill the Chronos were introduced 2 years later) and the fact that training and mechanical service would be much easier when the date and non-date Submariners used the same base – resulted in the death of the 7928.
To add to the complexity – both versions came with the choice of dial color. Either blue or black. Case dimensions and overall design was more or less identical to the 7928. Interestingly enough, the very first 7016 featured the same dial layout as the 7928. (Rose dial with the 4 lines on the bottom half of the dial). These (in the examples I have seen) feature a semi-pointed crownguard case. And most likely not produced for very long. Subsequently the dial layout changed to the classic “Snowflake” design with square markers and square hands.
It has not been possible to determine exactly for how long the “transitional” 7016 was produced. But the versions we have seen are all 68-69 dated casebacks. As many collectors certainly have experienced, there was a issue with the 7016 and 7021. The paint/laquer used on the dials – on the early versions – decayed at a rapid rate. In general Tudor dials are often quite bad – usually due to water ingress or bad maintenance. (They were often not “babied” as their Rolex sisters). However the decay of the 7016 & 7021 dials was extreme. The dial rot often showed itself as bubbles under the surface, starting around the centre of the dial. It’s quite easy to see the difference between dial rot and water ingress. The tritium markers themselves are often quite nice on rotted dials – as its only the lacquer that disintegrates.
In the past, collectors have speculated that the black dial versions were “disbanded” and the blue color versions were introduced instead, as they had better dials. This is incorrect. We have seen 7021’s as early as mid 1968 with pale blue dials, with classic dial rot and a nice roulette style date wheel. 100% original, 1 owner piece. So, more than likely, the black and blue dials co-existed – and were both prone to rot.
Technically the 7016 features a ETA Cal. 2483. It’s a 25 jewel movement (as opposed to the 17j cal. 390 in the older Reference 7928). In the Tudor / Rolex technical service manuals it is designated as 2461-2483. In the past this covers an internal and an external reference number.
The 7021 features the cal. 2484. Main difference is of course the date feature.
It should be noted that in Rolex documentation the references are other denoted as 7016 or 7016/0 – and 7021 or 7021/0. The addition of the /0 was a common reference changed, started by Rolex and Tudor in the middle of the 60’s. However, there seems to be no system as to when the different references changed from the classic 4 digits to the 4+/0 digit system. The /0 of course describes the case material as stainless steel (as it does in Rolex models). In my experience all 7016 and 21 series watches have the /0. If anyone has seen one without the /, please email me a scan. 🙂
The 7016 and 7021 ended production circa 1975 when the 9401 and 9411 models were introduced in their place. In our findings it seems that the serial # range for these watches are:
620.000 serial till 780.000 serial. (1968-1975).
* Should be noted that Military issued MN 7016’s have been seen with serials up in the 820.000′ range. Which is nearly a year later than 9401/11 introduction. Most likely due to either Rolex selling old cases off to DOD customers, or more likely a specific order from the MN, requesting 7016.
We are still working on figuring out which Rolex dial produceres were making the dials for the 70xx series Submariners. We have seen dial rot in models up to and including 1975. Since 7016 and 7021’s with GOOD dials have been spotted in the collectors community, it would indicate that they are either service dials, or that some of the dials produced in the 7 year window, actually did not develop dial rot. More details about this at a later point.