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The Encyclopedia of Horology

Wristwatch · Chronograph wristwatch

Zenith Horological School of Porrentruy Ref. 01.0500.400 Chronograph

Partially verified

This Zenith gentleman's wristwatch is identified as a school piece (Pièce Ecole) associated with the Horological School of Porrentruy. It is a self-winding, tonneau-shaped chronograph crafted in stainless steel. The watch is powered by the Zenith Caliber 400 Z movement. The silver-colored dial features subsidiary seconds at the 9 o'clock position, a 30-minute recorder at 3 o'clock, a 12-hour recorder at 6 o'clock, and a date aperture between 4 and 5 o'clock. A tachometer scale is graduated on the dial for 400 units per hour. The case measures 37.4 mm in diameter at the bezel, with a height of 45.6 mm and a width of 38.5 mm. It includes a sapphire-crystal snap-on case-back, providing visibility to the movement. The watch is presented on a brown leather Zenith strap with a stainless steel Zenith buckle. The piece is attributed to Laurent F., Master Watchmaker.

Front view of the Zenith Horological School of Porrentruy Ref. 01.0500.400 wristwatch.
Front view of the Zenith Horological School of Porrentruy Ref. 01.0500.400 wristwatch. — Antiquorum. Rights pending — permission not yet requested. Original source

Catalogue identity

Source
catalog.antiquorum.swiss
Category
Wristwatch · Chronograph wristwatch
Maker / attribution
Zenith
Reference
01.0500.400
Catalogue / lot identifier
162
Source-reported date
circa 1990-2000
Source-reported place
Switzerland
Source-reported serial
127 955

Source-reported attribution and specifications are not independent authentication. A listing does not establish present ownership, current display, availability or permission to reproduce.

Object description

Case and Dial

The watch features a tonneau-shaped case constructed from stainless steel. It is water-resistant and includes a snap-on case-back fitted with a sapphire crystal. The case is equipped with two rectangular push-pieces located on the case-band to operate the chronograph functions.

The dial is finished in silver and includes subsidiary dials for the horological complications. The subsidiary seconds are placed at 9 o'clock, the 30-minute recorder at 3 o'clock, and the 12-hour recorder at 6 o'clock. A half-instantaneous date aperture is located between 4 and 5 o'clock. A tachometer scale is graduated on the dial, calibrated for 400 units per hour.

Evidence for this section
  • “Stainless steel, self-winding, “tonneau”-shaped, gentleman’s wristwatch, water-resistant with sapphire-crystal snap-on case-back”
  • “silver colour dial with subsidiary seconds at 9 and four horological complications”
  • “tachometer scale graduated on the dial for 400 units per hour”

Movement

The watch is powered by the self-winding Zenith Caliber 400 Z. This movement is a chronograph with minute and hour counters. The movement is visible through the sapphire-crystal case-back.

The watch is designated as a Pièce Ecole or school piece, linked to the Horological School of Porrentruy and noted in relation to Master Watchmaker Laurent F.

Evidence for this section
  • “Caliber 400 Z”
  • “The Pièce Ecole (school piece) of Laurent F…, Master Watchmaker”

Provenance and Identification

The timepiece is documented as a Zenith El Primero model, specifically produced as a school piece for the Ecole d’Horlogerie in Porrentruy. The watch carries the reference number 01.0500.400 and is assigned movement number 127 955.

The watch is fitted with a brown leather strap and a stainless steel buckle, both signed by Zenith. The auction description notes the piece as a gentleman's wristwatch from the 1990-2000 period.

Evidence for this section
  • “Zenith – Horological School of Porrentruy Ref. 01.0500.400”
  • “Year circa 1990-2000”
  • “Movement No. 127 955”

Open research questions

  • What is the nature of the Pièce Ecole program at the Horological School of Porrentruy?
  • Does the movement serial number correlate to specific Zenith production records outside of this school association?

Source evidence

Recorded claims and source quotations for Zenith Horological School of Porrentruy Ref. 01.0500.400 Chronograph
FieldSource-reported valueSource quotation
MakerZenith – Horological School of Porrentruy“Zenith – Horological School of Porrentruy”
Reference number01.0500.400“01.0500.400”
Movement caliber400 Z“Caliber 400 Z”
Movement serial127 955“Movement No. 127 955”
Case materialStainless steel“stainless steel”
FunctionsChronograph, date, sub-seconds“self-winding, chronograph, minute and hour counters, date”
Case dimensions37.4 mm x 45.6 mm x 38.5 mm“Diameter 37.4 mm. (bezel) Height 45.6 mm. Width 38.5 mm.”

Visible details

  • Rectangular-shaped chronograph push-pieces
  • Visible El Primero caliber through sapphire case-back
  • Tachometer scale printed on the outer dial periphery
  • Date aperture positioned between 4 and 5 o'clock

Research qualifications

  • The exact provenance of the association with 'Laurent F.' is not detailed beyond the auction report
  • Specific production year is given as an estimate rather than a confirmed date

Photograph identity and source facts were screened before import; rights clearance remains pending.

Consulted source

Zenith – Horological School of Porrentruy Ref. 01.0500.400, self-winding, chronograph, minute and hour counters, date; “El Primero”, “Ecole d’Horlogerie, Porrentruy”; stainless steel -- The Pièce Ecole (school piece) of Laurent F…, Master Watchmaker --

Reviewed 2026-10-26 · Record 64231f8ee0

Terms in this record

Glossary explanations for terms named in this object’s record.

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