====== PP 315 ======

Calibre **PP 315** (and the similar **PP 330**) is an [[automatic]] watch movement from [[Patek Philippe]].

This is Patek Philippe's mainstream central rotor automatic movement from [[1984]] through [[2005]], when [[PP 324|Cal. 324]] was introduced.

===== Info =====
Calibre 315 was an innovative movement on its introduction around [[1984]], replacing the ill-conceived [[PP 335|Cal. 335 and 310]]. Although sharing its basic architecture with the 335, Cal. 315 was improved in almost every way. The most critical improvement was reduction in frequency to 21,600 A/h and more durable uni-directional automatic winding gears, addressing a critical issue in the 28,800 A/h Cal. 310. Later, 100 "Advanced Research" Cal. 315 movements were presented in [[2005]] with a silicon escape wheel and ceramic bearings. Although most watch models use the newer [[PP 324|Cal. 324]], a few continue with the now-venerable 315.

There is some controversy about the number of jewels in Cal. 315. Patek Philippe initially said the movement had 29 jewels, but later revised this to 30. Still later the company went back to saying it had 29 jewels. It is not clear what caused this discrepancy.

===== Cal. 330 =====
Calibre 330 is virtually identical to Calibre 315 apart from the location of the date Cal. 330 includes four extra parts so the date could be narrower and recessed into the movement, although the date aperture is still located at 3 00. This gives Cal. 330 an overall height of 3.5 mm, rather than the 3.22 mm of Cal. 315.

===== Complications =====
Patek paired the slim Cal. 315 with various complication modules:

^Calibre      ^Dimensions (mm) ^Jewels ^Parts ^Usage ^Features ^
|[[PP 315|315 S C]] |Ø 27.5, H ?|29 | |[[Patek Philippe Calatrava 3820|Calatrava 3820]], [[Patek Philippe Calatrava 5127|Calatrava 5127]] |[[Center seconds]], [[date]] |
|[[PP 315|315 S QR]] |Ø 27.5, H ?|29 | |[[Patek Philippe Perpetual Calendar 5050|Perpetual Calendar 5050]] |[[Perpetual calendar]]: Date, day, leap year, month, [[moon phase]]|
|[[PP 315|315 S IRM QA LU]] |Ø 27.5, H ?|36 | | |[[Annual calendar]], [[moon phase]], [[power reserve indicator]]|
|[[PP 315|315 S IRM QA LU Si]] |Ø 27.5, H ?| | | |[[Patek Philippe Advanced Research|Advanced Research]] silicon escape wheel, [[annual calendar]], [[moon phase]], [[power reserve indicator]]|
|[[PP 315|315/136]] |Ø ?, H ?| | | |[[Perpetual calendar]], [[retrograde]] date, month [[moon phase]], [[power reserve indicator]]|
|[[PP 315|315/290]] |Ø ?, H ?|29 | |[[Patek Philippe Calatrava 5127|Calatrava 5127]] |[[Calendar]] module|
|[[PP 315|315/299]] |Ø ?, H ?| | | |[[Annual calendar]] module|

===== Advanced Research =====
Patek Philippe began an [[Patek Philippe Advanced Research|Advanced Research]] program in [[2000]] to invent new watch components and approaches. One of the first fruits of this labor was the development of a [[silicon]] escape wheel. They found that this wheel, paired with traditional ruby escapement pallets, had the same friction characteristics as lubricated steel but needed no lubrication. This was paired with lubrication-free ceramic ball bearings for the winding rotor and produced in limited numbers as calibre **PP 315 S IRM QA LU SI**. 100 special [[Patek Philippe Advanced Research|Advanced Research watches, Ref. 5250]] were produced with this movement, and these included a special "loupe" on the rear sapphire crystal so the silicon escapement can be viewed.

===== See also =====
  * [[PP 335|PP 335 and PP 310]], the predecessor
  * [[PP 324]], the successor

<WRAP ud ud_mov>
**Description:**
  * [[Automatic]] movement

**Functions:**
  * Hour/minute/second hands
  * Chronograph with hour counter, 30-minute counter, and 1/4 second markers
  * [[Second time-zone]]
  * Date

**Data:**
  * 21,600 A/h

**Production period:**
  * [[1984]]-current
</WRAP>

{{tag>Movements Automatic_movements Dual_timezone_movements Patek_Philippe_calibres}}