OK I’m just going to say it. The Patek Philippe 5370 split second chronograph is potentially one of the best Patek Philippe chronographs of all time. Why? To me it’s the combination of aesthetics and technical innovation. From the aesthetics side it reminds me of my two favorite Patek Philippe split second chronographs, the 1436 which is the split-second version of the hallowed reference 130 and the 1563, which is the split second version of the transcendent 1463 or Tasti Tondi.
From the perspective of the square pushers it is more in alignment with the 1436 but from the viewpoint of the case its robustness and especially its size at 41 mm in diameter it is borrows spiritually from the 1563 which was considered large for its time.
But then there is the dial which is an absolute masterpiece. First it is an applied Breguet numeral dial, which from the perspective of all the dial variations for vintage Patek Philippe chronographs is by far the most collectable.
Second the dial is crafted from “Grand Feu” enamel which are the most beautiful hand fired dials in Christendom. And third the dials are a dark background, in the case of the platinum watch with a black dial, and here with a blue dial which means the sub dials, chemin de fer and tachymeter are all printed in white.
This color combination is not only extremely rare from a Patek Philippe’s perspective it is also much more legible than a light dial with these same elements printed in black. Finally, the leaf shape hands are luminous, something that many people overlook because it is so subtly executed. But I can tell you for a fact that any luminous hand, Breguet numeral Patek Philippe chronograph comprises the Holy Grail of collectability, add to this the split seconds function and this is without a doubt the most sought-after triumvirate of Patek Philippe features in the world.
But that is just on the dial side. The other reason I love the 5370 so much is that the movement the CH 29-535 is the single best and brilliantly designed manual wind laterally coupled rattrapante in existence. To be honest it is really the only modern rattrapante around that is deeply rooted in the grand rattrapante movements from the 1940s or earlier. I will exclude the vertical clutch split second movements from this because they are to me a totally different category of caliber.
Why is the CH 29-535 so reliable and brilliantly conceived? Well to begin with it was designed from the ground up to accommodate a split-seconds function. Says Thierry Stern, “The Lemania movement was never really created to have a split-seconds function so to get the movement to work in the context of the 5004 split seconds perpetual calendar it was really very challenging.” One of the solutions Patek Philippe came up with for the 5004 was to add an isolator to the split-second function. An isolator is essentially a wheel with a finger that lifts the spring-loaded return lever off the reset heartcam on the chronograph wheel. This helps to eliminate rattrapante drag.
But in the CH 27 the device operating this wheel, a beautifully shaped element dubbed “The Octopus” could only turn in one direction as such its isolator wheel spring had to overcome the force of the spring exerting pressure on the split-second brake. In the case of the CH 29 the isolator is able to move back and forth in both directions, so it no longer has to overcome this spring force which is much better for long term reliability.
Second in the CH 27 you had a spring integrated into the isolator wheel to get it to return back to its original position (this is the afore mentioned isolator wheel spring) when released. In the new movement a long incredibly designed and engineered spring that is integrated into the cap of the split seconds column wheel does this with far less force also helping with long term reliability. Finally the CH 29’s frequency of 28,800 vph also allows it greater stability.
Note that throughout the lifespan of the CH 27 there was never a split-seconds chronograph only version of this watch. There were of course references such as the 5959 but that watch was based on an ancient Victorin Piguet ebauche. The CH 29 based 5370 is unique in that it is the only modern split seconds chronograph, designed from the ground up with this feature with a fully contemporary movement and excellent reliability in existence. Add to this the host of aesthetic flourishes and it is definitely the one current collection Patek Philippe watches I don’t own, that I would love to have. Finally, this new watch marks the very first time that platinum has been used in the 5370, which pairs beautifully with the stunning blue “Grande Feu” enamel dial.
Caliber CHR 29-535 PS; Manually wound mechanical movement, split-seconds chronograph with two column wheels, wheel clutch (horizontal), and instantaneous 30-minute counter, sweep chronograph and split-seconds hands, subsidiary seconds
950 platinum, Sapphire-crystal case back and interchangeable solid platinum back, Flawless rare white Top Wesselton diamond between the lugs at 6 o’clock, Water resistant to 30 meters (3 bar)
Blue Grand Feu enamel on white gold, glossy finish, Applied Breguet numerals in 18K white gold, Scales for tachymeter and chronograph counter printed white, Leaf-shaped hour and minute hands in 18K white gold with luminous coating, Leaf-shaped subsidiary seconds hand in 18K white gold, Chronograph and split-seconds hands in steel, sandblasted and rhodiumed, Leaf-shaped hand for the 30-minute counter in 18K white gold
Hand-stitched alligator leather with large square scales, shiny night blue, fold-over clasp in 950 platinum