Lars Thrane LT-3100S Iridium GMDSS Terminal (plus voice, data, tracking; SSAS & LRIT Options)

Lars Thrane

Contact Mackay for all questions & assistance for Iridium GMDSS

Circa December 2020, Iridium’s Global GMDSS Service is LIVE and fully functional.

The Lars Thrane LT-3100S Iridium GMDSS system is designed for all vessel class & sizes.  This enhanced solution is the first IMO-approved alternative system to Inmarsat-C since GMDSS became operational in 1999.   The LT-3100S GMDSS system meets all standards and certification requirements for worldwide marine satcom equipment (MED, Wheelmark).

The LT-3100S GMDSS compact integrated system has voice, data & SMS capabilities with 100% global coverage.  The package consists of a control unit, handset, and compact antenna, connected to the below-decks unit with a single cable. Installing with a standard single LMR400 coaxial cable (up to 500 meters @ 24VDC) enables the antenna(s) to be mounted in an optimal location, with free line-of-sight to the satellites

The FREE Global Iridium GMDSS Service also enables access to Marine Safety Information (MSI) and Medical Assistance, which may be critical in times of distress

Although the LT-3100S GMDSS system is designed for the Iridium GMDSS Safety Services, it can be used as the primary satellite communication system on vessels, providing  basic connectivity between the ship and shore including voice, SMS, data, vessel tracking, and other Iridium services with competitive airtime rates.

The LT-3100S capabilities continue to evolve. An external interface module is now available to support additional features, including the IMO / ISPS regulatory requirements for SSAS (10/2021) and LRIT (Q1 2022); both approved and available.

Iridium GMDSS Advantage 

  • Wheelmark Certified SOLAS GMDSS Approved (Sea Areas: A1-2-3)
    • 50+ Flag States approved for Global GMDSS Coverage
  • Integrated voice, data and tracking
  • High Performance GNSS/GPS Receiver
  • Compact 1-piece system
  • Distress Alert directed to an in-person call  (Safety Voice), followed by Relayed Alert
  • GLOBAL Distress Coverage & Alert Functionality (incl. the poles)
  • Options:
    • SSAS-enabled (10-21) – requires adding LT-3140 Interface Unit
    • LRIT (Q1 ’22) functionality (contact ASP – CLS or Pole Star to enable & receive test compliance certification)

Note: The LT-3100S must be installed by a certified provider, such as Mackay, to maintain the system warranty and ensure safety protocol.


Launch & Certification Details:  In 2018, the IMO’s Maritime Safety Committee (MSC) recognized Iridium as a provider of GMDSS satellite services.  Throughout the intervening period, Iridium has run 13k + service tests and onboard terminal assurance via the LT-3100S GMDSS system, a integrated terminal developed by Lars Thrane A/S.  This was a ground-breaking event, given Iridium GMDSS is the first system approved by the IMO as a GMDSS- Inmarsat C alternative, since first operational in 1999

Contact Mackay for Iridium GMDSS details:
Mackay Marine Global Locations
or Satellite Services Department
Phone:    919 850 3100 (worldwide)

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