Lars Thrane LT-3100S Iridium GMDSS Satcom System

Iridium GMDSS Distress and Safety Services

The LT-3100S gives the bridge direct access to the core Iridium GMDSS safety functions required for approved maritime operation. Supported services include:

• Distress Alert and Distress Call
• Safety Calling and Safety Messaging
• Maritime Safety Information
• Ship Security Alert System
• Long Range Identification and Tracking

The system is type-approved for SOLAS GMDSS operation in Sea Areas A1, A2, and A3 and carries MED and Wheelmark certification. It also supports Bridge Alert Management, remote alarm panels, and an external GMDSS printer when the appropriate optional interface equipment is installed.

Pole-to-Pole Iridium Coverage

The LT-3100S operates over the Iridium low-Earth-orbit satellite network, providing coverage across the world’s oceans and polar regions. This makes it particularly relevant for commercial vessels, research ships, offshore support vessels, fishing fleets, and operators whose routes extend into high northern or southern latitudes.

Satellite communication still requires the antenna to have a suitable view of the sky. Vessel structures, incorrect antenna placement, and damaged cabling can affect system performance.

Everyday Ship-to-Shore Communication

Alongside its regulated distress and safety functions, the LT-3100S supports standard Iridium voice calls, SMS, modem data, and vessel tracking. This allows the same terminal to support routine bridge and operational communication when it is not being used for GMDSS traffic.

The LT-3100S is intended for essential low-bandwidth communication rather than broadband internet. An active Iridium GMDSS service agreement and any applicable voice or data services are required.

Bridge Control and Operation

The LT-3110S Control Unit uses a 4.3-inch TFT display for calling, message handling, safety functions, system status, and configuration. The display supports clear day and night operation, while the supplied handset uses a noise-canceling microphone to improve voice communication in working marine environments.

A built-in web server supports configuration, service, and maintenance from a connected computer. The system also contains a high-performance GNSS receiver for position-dependent safety services and vessel reporting.

Single-Cable Antenna Installation

The control unit supplies power and communication to the LT-3130 Antenna Unit through one standard coaxial cable. Supported separation between the control unit and antenna can reach up to 500 m when the correct cable type and installation requirements are followed.

This arrangement provides flexibility on larger vessels where the bridge equipment and antenna location may be far apart. The antenna should be positioned with clear sky visibility and adequate separation from interfering transmitters and vessel structures.

Marine Construction and Mounting

The indoor control unit and handset are rated IP32, while the exterior antenna is rated IP67 and operates from -40°C to 55°C. The control unit can be installed with the included bracket or an optional flush mount. Optional antenna pole mounts are available for 38.8 mm and 53.0 mm tubes.

The system is supplied with the principal terminal components and mounting materials. Additional hardware may be required for SSAS, alarm panels, GMDSS printing, power redundancy, or connection to the vessel’s wider bridge systems.