Ship Clocks

Summary:

Ship clocks—also known as marine clocks or ship’s bell clocks—were designed for use aboard vessels where reliability, ruggedness, and clear audible signals were essential. Their thick brass cases, secure bezels, and precision balance-wheel movements made them resistant to vibration, humidity, and motion at sea. Many include the traditional Ship’s Bell strike system, which marks the sailor’s watch schedule rather than the standard 12-hour strike.

Key Identifiers:

Heavy Brass or Bronze Case

Ship’s clocks are typically built with:

  • Thick solid brass or bronze housings

  • Front-opening hinged bezels with gasketed seals

  • Screw-back or flange-mounted backs for wall or bulkhead mounting

The case is designed to resist corrosion and secure the movement from vibration.

Balance-Wheel Movement

Most models use:

  • A platform escapement with a balance wheel

  • No pendulum (essential for shipboard use)

  • Spring-driven 8-day mechanisms

This allows the clock to operate accurately in motion or uneven conditions.

Ship’s Bell Strike System (Common)

The traditional ship’s bell strike marks eight bells per watch, not standard hour counts:

  • 1 bell = first half-hour

  • 2 bells = first full hour

  • Continues to 8 bells, then repeats
    This corresponds to the four-hour watch rotation used at sea.

Some ship’s clocks may be time-only, but the bell strike system is a signature feature.

Bold, High-Contrast Dials

Common dial features include:

  • Black numerals on white enamel or painted metal

  • Luminous hands on some later models

  • Maker names such as Chelsea, Seth Thomas, Schatz, Wempe, or Smiths

  • Heavy brass bezels with thick glass

Operational Guide:

Mounting & Placement

Ship’s clocks are designed to be wall-mounted, but can operate on shelves.

  • Mount on a solid wall or wooden panel for best sound

  • Ensure screws or mounting plate are secure

  • Keep away from direct sunlight or damp environments in home settings

The case should sit firmly to prevent vibration noise.

Step 1:

Winding the Clock

Ship’s clocks are typically spring-driven with two winding arbors:

To wind:

  • Insert the key fully

  • Turn slowly, evenly, and stop when resistance increases

  • Do not overwind

Most require winding every 7–8 days.

Step 2:

Setting the Time

  • Move the minute hand forward only

  • Allow the strike to complete before passing each half hour

  • Never move the hour hand independently; it follows the minute hand

  • For clocks with ship’s bells, the strike sequence may take up to one full cycle (4 hours) to self-correct if previously stopped

If your clock has a strike-silent switch, use it during setup if desired.

Step 3:

Ship’s Bell Strike Operation

If equipped:

  • Half-hours: 1, 3, 5, 7 bells

  • Hours: 2, 4, 6, 8 bells

  • Pattern restarts every four hours

Ship’s bell clocks use a hammer striking a bell mounted inside the case, producing a sharp, nautical tone.

Step 4:

Regulating the Time

Ship’s clocks use balance-wheel regulators:

  • Look for a small F / S lever on the platform escapement

  • Move slightly toward F to speed the clock

  • Move toward S to slow it

  • Adjust in small increments and wait 24 hours to evaluate

Some models may have a micrometer-style adjusting screw.

Step 5:

Routine Maintenance

Case Care

  • Clean brass cases with a non-abrasive polish or microfiber cloth

  • Avoid ammonia-based cleaners on plated or lacquered finishes

  • Keep the bezel glass free of fingerprints and salt residue (if used near the ocean)

Movement Care

  • Service every 5–10 years by a qualified clockmaker

  • Platform escapements are delicate—avoid oiling or adjusting them yourself

  • Keep the rear plate sealed to prevent dust intrusion

Handling & Transport

  • Transport upright when possible

  • Avoid shaking the clock; the platform escapement is precision-built

If mounted, remove the clock from the wall before winding or moving to prevent strain on screws