GMDSS: Operational Requirement

General

The GMDSS enables a ship in distress to send an alert using various radio systems. These systems are designed such that the alert has a very high probability of being received by either shore rescue authorities and/or other vessels in the area.

Equipment performing GMDSS functions must be simple to operate and (wherever appropriate) be designed for unattended operation.

Distress Alerts must be able to be initiated from the position from which the ship is normally navigated (ie; the bridge).

EPIRBs are required to be installed close to, or capable of remote activation from the position from which the ship is normally navigated.

The SOLAS GMDSS regulations are structured such that all GMDSS ships are required to carry a minimum set of equipment, with basically more equipment being required the further the ship travels from land.

The SOLAS GMDSS regulations do not make particularly easy reading - a simplified version of the equipment required to be carried for each sea area is detailed below.

Minimum GMDSS Carriage Requirement

Equipment	Area A1	Area A2	Area A3	Area A4
VHF with DSC	2 Nos	2 Nos	2 Nos	2 Nos
MF/HF DSC with Transceiver	----	1 No	1 No	2 Nos
Inmarsat A or B with EGC or SAT-A	----	1 No	1 No	---
EPIRB	2 Nos	2 Nos	2 Nos	2 Nos
SART	2 Nos	2 Nos	2 Nos	2 Nos
SURVIVAL CRAFT HAND HELD VHF        Up to 500 GRT        Above 500 GRT (With Spare Primary Battery with Seal Intact)	2 Nos 3 Nos	2 Nos 3 Nos	2 Nos 3 Nos	2 Nos 3 Nos
Navtex	1 No	1 No	1 No	1 No
Shore Based Maintenance	---	Yes	Yes	Yes

Duplication Of Equipments: (Primary Means)

Area	Primary Means	Secondary Means
Area A1	VHF with DSC	VHF with DSC
Area A2	MF/HF DSC with Transceiver with NBDP	SAT C With EGC
Area A3	SAT C With EGC	SAT C With EGC
Area A4	MF/HF DSC with Transceiver with NBDP	MF/HF DSC with Transceiver with NBDP

Secondary Means: 2 Nos EPIRB

Power supply requirements

GMDSS equipment is required to be powered from three sources of supply:

ship's normal alternators/generators;

ship's emergency alternator/generator (if fitted); and

a dedicated radio battery supply.

The batteries are required to have a capacity to power the equipment for 1 hour on ships with an emergency generator, and 6 hours on ships not fitted with an emergency generator.

The batteries must be charged by an automatic charger, which is also required to be powered from the main and emergency generators.

Changeover from AC to battery supply must be automatic, and effected in such a way that any any data held by the equipment is not corrupted (ie: "no break").

Operator qualifications

There are a number of different types of GMDSS qualifications, as follows:

First Class Radio-Electronic Certificate;

Second Class Radio-Electronic Certificate; and

GMDSS General Operator's Certificate

The First and Second Radio-Electronic Certificates are diploma and associate diploma level technical qualifications. They are designed for Ship's Radio-Electronic Officers, who sail on GMDSS ships which use the option of at-sea electronic maintenance.

The GMDSS General Operator's Certificate is a non-technical operator qualification, designed for Navigating Officers.

The GMDSS General Operator's Certificate is normally awarded after a ten day course and examination.