A classic mechanical stopwatch from Seiko from the late Shōwa era, as used for decades at sporting events, in school lessons or in technical laboratories. Seiko had been one of the world's leading manufacturers of timekeeping instruments since the 1960s, developing not only professional timekeeping systems for international competitions but also robust mechanical stopwatches for daily use.

The example offered here is a typical example of these instruments: functionally designed, very easy to read and mechanically extremely reliable.

Model and Dating

The following information is engraved on the case back:

SEIKO
210412
ACRP
88-5051

The reference 88-5051 belongs to the classic mechanical Seiko stopwatches produced in the second half of the Shōwa era.

The serial number 210412 can be interpreted according to the usual Seiko system as follows:

• 1st digit: year within the decade

• 2nd digit: month

Thus, 21xxxx clearly stands for January of a year ending in 2.

In conjunction with the model type and production period, manufacturing in February 1982 is most plausible.

Movement

The stopwatch is powered by a mechanical hand-wound movement, specially designed for precise timekeeping.

These Seiko stopwatches typically use the Seiko Calibre 8800, a robust mechanical chronograph movement that was used in professional timekeeping instruments for decades.

Typical characteristics:

• mechanical hand-wound movement
• central stop-second
• 60-second scale
• integrated minute totalizer
• precise mechanical reset to zero
• Start / Stop / Reset via crown press

The design is deliberately robust and easy to service – one reason why many of these instruments still function reliably decades later.

Design

The dial follows the classic design of professional timekeeping instruments:

• large 60-second scale
• fine subdivisions for precise measurements
• black central stop hand
• small totalizer for minute measurement
• excellent legibility

This clear instrument look is typical for Seiko stopwatches from the 1960s to 1980s.

Operation (see video)

Operation is via the large crown:

1. Start: first press of the crown
2. Stop: press again
3. Reset: another press resets the hand to zero

This simple and robust system was used in mechanical stopwatches for decades.

Technical Data

Brand: Seiko
Model: 88-5051

Movement: mechanical hand-wound movement (Seiko Calibre 8800)

Manufacture: probably January 1982

Case: metal case with chrome-plated surface
Code on case back: ACRP

Diameter: 57 mm
Total height incl. ring: 80 mm
Case thickness: 18.8 mm

Weight: 164 g

Glass: plastic

Condition

The stopwatch is in good technical and optical condition.

• Function fully tested
• Start, stop and reset work perfectly
• very well preserved dial
• age-related signs of wear on the case

On the back there are superficial rust marks (see video), which are probably due to moisture exposure. These only affect the surface of the case and have no influence on the function of the watch.

Accessories

The watch comes with a lanyard, which is very likely original or at least contemporary.

Such straps were typically used by timekeepers at sporting events so that the stopwatch could be comfortably worn around the neck.

Warranty (used)
This is a used item. The limitation period for claims for defects (statutory warranty) is 12 months from delivery.

Note
As this is a used timepiece, no water resistance can be guaranteed. To protect the movement, the watch should not come into contact with water or moisture.