Marine Device : GYROCOMPASS, REPEATER
Manufacturer : C-PLATH
Type / Model : 4881-AB
C.Plath / Sperry Marine Gyrocompass Repeater 4881-AB
Overview
The C.Plath 4881-AB is a precision bearing/heading repeater designed to display the vessel’s heading data remotely from the master gyrocompass. It accepts serial heading input (e.g., RS-422 or NMEA formats) from a master gyro system (such as the Navigat X MK1/MK2) and drives a mechanical display card (360° scale, or 360° + 10° for steering repeater version) to replicate the heading in a remote location such as on the bridge wing, passageway or control console.
Key Features
-
Remote heading display: Accepts serial heading data (C.Plath format, NMEA 0183 or Lehmkuhl) and drives step-motor mechanism to turn the compass card.
-
Multiple display formats: Standard 360° card version, and variants with additional 10° card for steering monitoring.
-
Self-synchronising: On power-on the unit seeks alignment with master heading; synchronization switch allows manual re-sync if needed.
-
Robust marine build: Designed for installation in bridge consoles, bulkhead mounting or dedicated bearing stands.
-
Address & mode configuration: DIP‐switch panel allows setting of repeater address and display mode (heading, rate of turn, roll etc) to match system requirements.
-
Serial interface options: Supports C.Plath proprietary format, NMEA 0183, Lehmkuhl format; baud rates selectable.
Typical Specifications & Technical Notes
-
Power Supply: Commonly 24 V DC (card illumination and step‐motor drive) plus heading interface supply.
-
Display Card: 360° graduated, some versions include 10° inner dial for fine steering.
-
Synchronisation Indication: LED/switch labelled “Sync.” indicates fault or alignment issues.
-
Interface: RS-422 serial input, support for multiple formats (C.Plath, NMEA, Lehmkuhl) with configured delay compensation.
-
Installation: Suitable for bulkhead, console or pedestal mounting as part of full gyro system network.
Applications & Why It’s Important
-
Provides redundant remote heading indication in critical navigation areas like bridge wings, steering stations, fuelling stations or accommodation corridors.
-
Ensures shipboard personnel always have visual heading data even if main gyro-display fails or is remote.
-
Enhances situational awareness and supports bridge team’s safety of navigation duties.
-
When servicing or replacing, ensures compatibility with C.Plath Navigat X gyro systems and their serial heading outputs.
