I asked that question of an old watchmaker once. You know, those red reversing wheels, ventilated rotor, multiple plates and bridges, even the balance bridge – none look like your typical equivalent ETA 2824, 2836, or 2892.
Some are design considerations (the rotor, and the balance bridge with its associated balance guard). Some are the result of production surface treatments (those red reversing gears are coated with Teflon). And some are seemingly simply the result of what some might call over-engineering (the multiple bridges which add thickness as well as robustness to the assembly).
As for the old watchmaker’s answer to my question? He offered a sly smile and said, “Rolex just does things a bit differently.”
Watchmakers and watch geeks alike will tell you there are movements which are the equal of Rolex’s calibres. Many hold up the ETA 2892-A2 for example. And from an accuracy point of view, it may be true. Or from a reliability standpoint. Or from that of durability/toughness. But all three? Give me a Rolex calibre every time.
Those multiple bridges – the parts that constrain the wheels and provide mounting points for other components. Here’s a list of bridges for the 3135: barrel bridge, train wheel bridge, pallet bridge, minute pinion bridge, winding bridge, automatic device lower bridge, automatic device upper bridge, and balance bridge (this works in tandem with a balance guard). All these bridges fit and work together like pieces of a three dimensional puzzle. They form a structure that represents an abundance of engineering that other movements simply don’t match.
Rolex 3135 Movement
By contrast, the ETA 2892-A2 bridges consist of the barrel bridge, train wheel bridge, balance bridge (which really isn’t a bridge at all, as it’s only screwed down on one end), the pallet bridge, and the automatic device lower bridge. Five bridges to the 3135’s eight (nine if you count the balance guard).
Some would call it over-engineering, but really Rolex’s design intent is for the movement to handle just about anything the wearer can throw its way. And do so while remaining as accurate as ever.
The downside of this robust engineering? Those bridges take up volume. The movement is often nearly twice as thick as a competitor’s counterpart. The 3135 is 6mm thick while ETA’s 2892-A2 is only 3.6mm thick.
Rolex Caliber 3135 Parts
Now, if you claim that the modern cubicle spelunker or corporate ladder alpinist doesn’t need all that robustness, I’m not going to argue.
Instead, I’d suggest those corporate adventurers are traversing a pitch every bit as perilous as those of the cavers and climbers they admire so much. Why shouldn’t they wear a watch that can withstand either environment?