The History Of The Rolex Oyster Case

Rolex’s position at the very top of horology’s hierarchy is no fluke. Neither is it entirely down to some of the most canny marketing in the business—although, that certainly doesn’t hurt.

The brand is actually responsible for two innovations which did more than anything before or since to popularize the wristwatch as a practical, wearable accessory for everyone.

Prior to the convenience of their Perpetual self-winding movements and the safety and reliability of their Oyster cases, a wristwatch was most often seen as an item of lady’s jewelry, and a fragile one at that. Men wore pocket watches; or at least, men who didn’t want to be laughed at in the street.

But wartime, and particularly the horrors of WWI, exposed the usefulness of a timepiece worn on the wrist in terms of speed and expediency. Soldiers returning home from the front with their own pocket watches jerry rigged onto straps on their arms turned the tide on the public’s image, and marked the start of a more universal acceptance.

The Forerunners

It was a secure housing, one that could offer robust protection against the elements, which would be perhaps the most important of the two inventions.

However, Rolex and its founder, Hans Wilsdorf were not the first to come up with the notion of a waterproof case. Far from it, in fact.

As early as 1872, a patent for a prototype cover demonstrating how a screw thread arrangement could successfully keep out dirt, debris and moisture was filed in Switzerland. That was subsequently built on by a further development in 1881, when a patent for a pocket watch with a screw down crown was submitted by an American inventor.

And 10-years after that, a Swiss manufacturer named Francois Borgel created a sealed wristwatch which shielded its movement between two threaded case halves.

Rolex itself had some initial success with their own ‘Hermetic’ model, otherwise known as the Submarine. This small, officers-style watch secured not only the movement but also the winding crown inside the case, with a cap which screwed down on top. Although relatively practicable, the wearer still had to open up the watch completely in order to set the time or wind it which, in the absence of an automatic movement as of yet, was a daily task.

But all of these small steps paved the way for what was to follow.

The Rolex Oyster Case

Wilsdorf knew that for the wristwatch to have any chance of sustained marketability to a male audience, it was going to have to offer as dependable a safeguard to the external environment as the pocket watch. These were protected not only by their own case, usually with a hinged lid across the dial, but also by the fact they were kept safely tucked away in a vest pocket for most of the time.

It was his decree that for Rolex’s wristwatches to compete, they should be able to withstand the sort of punishments even the pocket watch could not. For him, the obvious answer was to ensure they were completely waterproof.

Wilsdorf took to scouring the entries in the Swiss patent office and in 1925, came across number 114948. This, registered to two men from La Chaux-de-Fonds (now the spiritual home of Swiss watchmaking), Paul Perregaux and Georges Peret, laid out the workings for a new system which saw the watch’s winding crown screw into a threaded tube fixed to the inside of the case.

Simple, effective and most of all, commercially viable, it was the last part of the puzzle for Rolex. Wilsdorf, who’s watchmaking skills were surpassed only by his shrewd business acumen, did not acquire the patent himself. Instead, he had it transferred to Charles Rodolphe Spillman, the owner of one of Rolex’s Geneva-based case makers. Spillman passed the license over to Wilsdorf five days later, on the 24^th July 1926, and a further five days after that, the word ‘Oyster’ was registered as a Rolex trademark.

The Oyster Case Develops

However, there was still some fine-tuning needed.

The initial Oyster cases were produced by longtime Rolex cohort, Aegler and it was their early mock-ups which highlighted a problem. As these were still manually-winding watches, the crown would stop turning when the mainspring was fully tightened. That, of course, prevented the wearer from being able to screw the crown down completely into the case.

Wilsdorf found the answer in another patent, again from 1881, called the crown clutch. This allowed for the crown to tighten fully, irrespective of the tension on the mainspring.

The basic underpinnings of the winding crown arrangement are more or less the same today as they were in the 1920s. Rolex introduced the Twinlock system in the 1950s with the Submariner, using a pair of O-rings to create two sealed zones inside the watch, and beefed it up in the 1960s with the Sea-Dweller’s Triplock and its three zones for even greater water resistance.

But the Oyster case itself has progressed more significantly.

Aegler’s original efforts attached the internal caliber, along with the dial and hands, to a metal ring fitted to the case of the watch rather than directly onto the case itself. The crown, winding stem and the threaded tube which secured them were all then fixed in place, and the entire unit was sealed by screwing the bezel and case back down on either side.

The gaskets were made from soft lead, which would distort as the various parts were attached and fill in any of the minute spaces left by imperfections in manufacturing.

Rolex’s Debut Oysters

Rolex’s first four Oyster watches went on general sale in 1926. Aimed at both men and women, they measured 28mm or 32mm, and could be had with either octagonal or cushion-shaped cases. The bezels were coin-edged in design, the precursor to the current fluted type, and served to give the watchmaker a way to grip the surround as they screwed it down.

The styling took its cues from the Art Deco movement, in full swing at the time, and the watches started to focus attention on Rolex as a brand. That turned into international fame the following year when Wilsdorf, in another marketing masterstroke, persuaded a young British woman called Mercedes Gleitze to wear one of his Oyster models as she attempted to swim across the English Channel. Although the bitterly cold waters forced her to abandon the effort 21 miles into the 22-mile crossing, the watch emerged working perfectly after being immersed for more than 10-hours.

The ‘Wonder Watch That Defies The Elements’ trumpeted the full front page ad Wilsdorf commissioned in recognition of the event in the Daily Mail the following month.

Rolex Synergy

So the Oyster, and Rolex, had arrived. Yet there was still one drawback.

With the crown now being used to both wind the watch every day and keep the case watertight, the constant opening and closing quickly wore out the screw threads. It would take until 1933 before Rolex found their own answer to their own problem and virtually eliminated the need to use the crown at all.

The Perpetual self-winding movement meant the watch stayed wound merely by the motion of the wearer’s arm and, just as importantly, made it so the crown could stay secured for the vast majority of the time.

It seems fitting that both breakthroughs should come from the same company, working in tandem to create the perfect whole.

Over the nearly nine decades since the first of the newly-christened Oyster Perpetuals arrived on the scene, the case has continued to be updated.

Thanks to the Twinlock crown system, every Rolex watch bar the Cellini collection is waterproof to at least 100m, including the likes of the Datejust and Day-Date—not two models you would think of as diving companions.

The three in the portfolio you most definitely would consider for your next underwater adventure—the Submariner, Sea-Dweller and Deepsea—take the Oyster’s basic concept to far greater extremes. The former pair, rated to 300m and 1,220m respectively, can rely on the traditional case’s engineering, albeit thicker and tougher.

The Deepsea, on the other hand, may look simply like a more robust version of the standard design, but does in fact have highly evolved architecture underneath.

Centering around what is known as the Ringlock system, in some ways you can think of it as a cutting-edge reworking of those very first Oyster case attempts. The ring in question sits at the heart of the watch, forged from BioDur 108, a nitrogen-alloyed metal three times stronger than traditional steel. On to that are fixed the 5.5mm sapphire crystal and the specially devised, two-piece case back; the inner part made from Grade 5 titanium, with an Oystersteel outer covering.

As the Deepsea is built to withstand pressures down to its stated depth of an insane 3,900m (more than 5,600psi) the case back is designed to flex, absorbing the crushing forces before it can break or crack. The result is an internal movement safeguarded from the weight of two-and-a-half miles of seawater pushing down on it.

The Rolex Oyster Legacy

It is nearly impossible to overstate the importance of Rolex’s Oyster case. We take for granted now that watches, even the dressiest, least tool-like examples, are able to withstand the sort of punishment which would have destroyed them at the turn of the 20^th century.

It was Hans Wilsdorf’s revolutionary thinking which transformed the perception of the wristwatch and has left the brand at the very pinnacle of the industry.

Virtually every other brand has adopted at least some of the Oyster’s basic DNA into their own engineering, but the original continues to be modernized to stay as the undisputed leader.

Even for a manufacturer with a litany of innovations as long as Rolex, we can look to their elegantly simple, deceptively ingenious waterproof housing as the reason for the horology industry we have today.

— Featured Photo: BeckerTime’s Archive.