Reliable and Easy to Use

The NAVITWIN IV Heading Management System displays and monitors a minimum of one and a maximum of four heading sources (3 gyrocompass headings and 1 magnetic heading) from a variety of heading sensors.

The NAVITWIN IV is Northrop Grumman Sperry Marine's central, all-embracing multiple heading reference management system. The NAVITWIN IV can be used as heading source selector for:

  • Heading difference monitor
  • Off heading monitor
  • Magnetic heading
  • Central gyro compass control unit

Key Benefits of the NAVITWIN IV:

  • Current heading from all available heading sources on a colour TFT LCD screen
  • Monitors the difference between any two of the displayed headings, including a Heading Difference Alarm
  • Independent back-up magnetic heading source (TMC) for autopilots, repeaters, radar, etc.
  • Active heading source distribution to subscribers such as Repeaters, Autopilots, Radars, ECDIS
  • Automatic and controlled takeover of the heading from an alternative source when the active heading source fails (DNV Grounding Avoidance System)


The NAVITWIN IV is a central control and display device for multi-compass systems. Depending on the system at hand, it may be configured to perform a number of different functions:

  • Heading source selector – The NAVITWIN IV displays heading data from up to three true heading sources and one magnetic compass heading source. By selecting the active heading source at the NAVITWIN IV, the operator determines which source is to be used as the reference for distribution via the Switch-Over Unit to other equipment, such as compass repeaters, heading control systems, radar, ECDIS etc.
  • Heading difference monitor – NAVITWIN IV can monitor the difference between any two of the connected heading sources. Should this difference exceed a user defined threshold, a “Heading Difference Alarm” is raised.
  • Off heading monitor – In automatic steering modes, NAVITWIN IV can monitor the difference between the actual heading from the active source and the commanded set heading. Should this difference exceed a user-defined threshold, an “Off Heading Alarm” is raised. The set heading may be received automatically from a heading control system or may be entered manually.
  • Magnetic heading – In conjunction with a Northrop Grumman Sperry Marine fluxgate sensor type 4863, fitted to a compatible magnetic compass, NAVITWIN IV senses the vessel‘ s magnetic heading and converts it to the NMEA 0183 (IEC 61162) format, including automatic correction for magnetic variation and sensor calibration values.
  • Central gyro compass control unit

Control and Display

In single, dual and triple gyro compass systems comprising current models from the NAVIGAT gyro compass line, the NAVITWIN IV acts as the system‘s central control and display unit. System-wide alarm messages from the gyro compasses are indicated and may be acknowledged at the NAVITWIN IV.

For more information about Northrop Grumman Sperry Marine’s
NAVITWIN IV Heading Management System, please  do not hesitate contact us.


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