False alerts in the GMDSS

Anyone who has studied the GMDSS system knows that it is based on a small number of specific functions that a ship must be able to perform when trading in any Sea Area. The GMDSS is fully automatic, eliminating the need for manual watchkeeping, and is used for distress communications as well as for general communication.

It is important that every single distress transmission initiated at sea be heard and taken care of, primarily by shore based facilities (MRCC, RCC).

The GMDSS system has been in operation for several years already, and it has been proven that all distress calls are heard ashore at MRCC and RCC.

Statistics show that, depending on what kind of communications are employed, between 75 and 100 per cent of these distress calls are false alarms or inadvertent transmissions.

The rate of false alerts and inadvertent GMDSS Distress and Safety Communicationsdistress calls has become a major problem in the GMDSS system and could, if nothing is done to stem the flow, develop into a catastrophe for the GMDSS. The key to the eradication of false alarms lies in the hands of GMDSS radio operators.

All experts that have examined the problem of false or inadvertent alarms agree that factors outside the mariners control contribute towards escalating the problem.

These factors are primarily naive equipment design and a lack of proper training among radio operators. Most false alarms are due to inadvertent misuse of Ship’s Antennas Systems and Radio Wave Propagationradio equipment. Below you will find examples of some major areas of concern.

INMARSAT-C

When operating an INMARSAT–C terminal it is very easy to send a distress alert by means of the software resident on some terminals.

Activating the “DISTRESS MENU” for such an elementary task as to familiarize oneself with the equipment/software, can actually activate an inadvertent distress alert if the operator does not exit this particular menu in the correct manner. The alarm will then be sent automatically.

Another cause of false alarms may occur when an operator is distracted or called away during a PVT (Performance Verification Test). Towards the end of the PVT, the operator is asked by the CES to manually “Activate distress as part of PVT test”. This alert, activated during a PVT, is recognized by the CES as a test call and not passed through to the MRCC/RCC.

In such cases, the operator must send the distress signal within a certain period of time, if not, the equipment itself will automatically send this distress alert and finish the test.

When the operator returns to the terminal he will find a message on the printer asking him to press the distress alert as part of the PVT test. If he does this, a real distress alert will then be transmitted and the CES will pass the message through to the MRCC/RCC, whereupon the appropriate distress alert action will be initiated by the shore based facilities.

EPIRB

The simple fact that an EPIRB needs cleaning from time to time can cause a false or inadvertent distress alert. The mariner removes the EPIRB from the housing to clean it with soapy water, holding the EPIRB with the “heavy” end down. A distress alert will now be generated as the seawater contacts are armed.

The alarm will be passed through the appropriate Exploring the Future of Satellitessatellite system and finally acted upon by the MRCC/RCC.

DSC

In one incident, a DSC call located in the North Sea, generated over 100 subsequent DSC calls from other ships. Most of these subsequent DSC transmissions came from ships relaying the received Digital Selective Calling-DSC During Disasters or EmergenciesDSC distress message. The ship that transmitted the original DSC alert message ended up relaying its own message a few minutes later. Incredible! According to standard procedure, only coast stations shall give acknowledgements by DSC (main rule).

Ships shall prepare for subsequent communication on the appropriate communication channel/frequency assigned for distress and safety purposes, and give acknowledgement of receipt of the distress alert on these frequencies.

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The maritime establishment is now fighting this problem by means of several different strategies. One of these concerns the design of GMDSS equipment; a second, the proper education and training of users; and a third, measures to enhance the MRCC/RCC’s ability to identify distress alerts and thereby ascertain whether they are genuine or not.

A GMDSS radio operator must be made aware of the fact that he can trigger off a false or inadvertent distress alert. GMDSS instructors are urged to obtain case studies on procedures to be followed by mariners if they do trigger off a false alarm. IMO has begun work on reducing the level of false alarms from GMDSS equipment. In May 1995, the Maritime Safety Committee (MSC) approved a draft assembly recommendation on guidelines for avoiding false alerts. The contents of this recommendation are presented in IMO COM/Circ. 127 – “Guidelines for avoiding false distress alerts”. Extracts from IMO COM/Circ. are presented on the following pages.

Guidelines for avoiding false distress alerts

Administrations should:

1 inform shipowners and seafarers about the implications of the rising number of false distress alerts;

2 make important provisions for ships to properly register all GMDSS equipment, and ensure that this registration data is readily available to RCCs;

3 consider establishing and using national violation enforcement measures to prosecute those who:

• inadvertently transmit a false distress alert without proper cancellation, or who fail to respond to a distress alert due to misuse or negligence;
• repeatedly transmit false distress alerts; and
• deliberately transmit false distress alerts;

4 use the International Telecommunication Union violation re porting process for false distress alerts, or for failure to respond to distress alerts relayed from shore-to-ship;

5 ensure that all relevant ship personnel know how GMDSS equipment operates, the importance of avoiding false distress alerts, the necessary steps to be taken to prevent transmitting false distress alerts and the procedures to be followed when a false distress alert has been transmitted;

6 inform type-approval authorities of false distress alert problems in order to draw their attention to the testing and alerting functions of radio equipment during type approval process;

7 urge companies installing radio equipment to train relevant ship personnel to ensure that they are familiar with the operation of the installed equipment;

8 investigate the cause when a specific model of GMDSS equipment repeatedly transmits unwanted distress alerts and inform appropriate organizations accordingly;

9 ensure that surveyors and inspectors are informed about GMDSS equipment, and particularly how to operate and test it without transmitting a false distress alert; and

10 require that GMDSS radio operators be appropriately certificated.

Manufacturers, suppliers and installers should:

1 design equipment for distress alerting so that:

• it will not be possible to transmit a distress alert unintentionally;
• the panel for emergency operation is separated from the one for normal operation and is partially fitted with a cover, and switches on the panel are clearly classified by colouring; and
• there are standardized arrangements of operation panels and operational procedures;

2 design test features so that the testing of GMDSS equipment will not result in the transmission of false distress alerts;

3 ensure that any distress alert activation is indicated visually or acoustically, or both and shows that the equipment is transmitting a distress alert, until manually deactivated;

4 ensure that the satellite EPIRB position on board, installations (including release and activation mechanisms) and handling procedures preclude unwanted activation (designing the EPIRB so that when it is out of its bracket it must also be immersed in water to activate automatically. When operated manually a two-step activation action is required);

5 provide clear and precise operational instructions that are easy to understand (maintenance and operational instructions should be separated, and should be delivered in English and any other language deemed necessary);

6 ensure that when any GMDSS equipment has been installed, necessary instructions are given to appropriate ship personnel, specifically pointing out the operational procedures (a record should be kept that such instructions have been given); and

7 ensure that supplier and installation personnel understand how the GMDSS works, and the consequences of transmit ting a false distress alert.

Trainers and educators should:

1. ensure that maritime education centres are informed about and teach students the problems concerning false distress alerts, the implications these have on SAR, the GMDSS, etc., and the procedures to be followed if a false distress alert is transmitted;
2. obtain and use actual case histories as examples when teaching;
3. emphasize the need to avoid false distress alerts in all maritime training and education; and
4. ensure that no inadvertent transmission of false distress alert occurs when training on GMDSS equipment.

Companies, Masters and seafarers should, as appropriate:

1. ensure that all GMDSSS certificated personnel responsible for sending a distress alert have been instructed and are competent to operate the particular radio equipment of the ship;
2. ensure that the person or persons responsible for communications during distress incidents give necessary instructions and information to all crew members who should know how to use GMDSS equipment to send a distress alert;
3. ensure that during each abandon ship drill, instruction is given on how emergency equipment should be used to provide GMDSS functions;
4. ensure that GMDSS equipment testing is only undertaken under the supervision of the person responsible for communications during distress incidents;
5. ensure that GMDSS equipment testing or drills are never allowed to cause false distress alerts;
6. ensure that encoded identities of satellite EPIRBs, which are used by SAR personnel responding to emergencies, are properly registered in a database accessible 24 hours a day or automatically provided to SAR authorities (masters should confirm that their EPIRBs have been registered with such a database to help SAR services identify the ship in the event of distress and rapidly obtain other information to help them respond appropriately);
7. ensure that EPIRB, INMARSAT and DSC registration data is immediately updated in the event of the ship’s owner, name, flag or similar information being changed; and that necessary action is taken to reprogram the ship’s new data on the GMDSS equipment in question;
8. ensure that, for new ships, positions for installing EPIRBs are considered at the earliest stage of ship design and construction;
9. ensure that satellite EPIRBs are carefully installed in accordance with manufacturers’ instructions and using qualified personnel (sometimes satellite EPIRBs are damaged or broken due to improper handling or installation. They must be installed in a proper location to float free and automatically activate if the ship sinks. Care must be taken that they are not tampered with or accidentally activated. If the coding must be changed or the batteries serviced, the manufacturers’ requirements must be strictly followed. We have seen cases where EPIRB lanyards have been attached to the ship so that the EPIRB cannot float free; the lanyards are only to be used by survivors for securing the EPIRB to a survival craft or person in the water.);
10. ensure that the EPIRBs are not activated if assistance is already immediately available (EPIRBs are intended to call for assistance if the ship is unable to obtain help by other means, and to provide position information and homing signals to SAR units);
11. ensure that if a distress alert has been accidentally transmit ted, the ship makes every reasonable attempt to communicate with RCC by any means to cancel the false distress alert using the procedures given in the appendix;
12. ensure that, if possible, after emergency use, the EPIRB is retrieved and deactivated; and
13. ensure that when an EPIRB is damaged and needs to be disposed of, or if a ship is sold for scrap or for any other reason a satellite EPIRB is no longer to be used, that the satellite EPIRB is made inoperable by either removing its battery and if possible returning it to the manufacturer, or by demolishing it.

Instructions for mariners and others for cancelling a false distress alert

DSC VHF

• switch off transmitter immediately (1);
• switch equipment on and set to channel 16;
• make a broadcast to “All Stations” giving name of vessel, call sign and DSC number, and cancel the false distress alert.

DSC MF

• switch off equipment immediately (1) This applies when the false alert is detected during transmission.x;
• switch equipment on and tune for Transmission of Urgency and Safety Signals from a Vesselradiotelephony transmission on 2 182 kHz;
• make a broadcast to “All Stations” giving the vessels name, call sign and DSC number, and cancel the false distress alert, (as shown in example above).

DSC HF

Procedure as with MF, except that the alert must be cancelled on all the frequency bands on which it was transmitted. Hence, in stage 2.2 the transmitter should be tuned consecutively to the radio telephony distress frequencies (4125/6215/8291/12290/16420) on the bands as necessary.

INMARSAT-C

Notify the appropriate RCC to cancel the alert by sending a distress priority message via the same CES through which the false alert was sent.

EPIRB

If, for any reason, an EPIRB is activated accidentally, the ship should contact the nearest coast station or an appropriate coast earth station or RCC and cancel the distress alert.

General information

1. Notwithstanding the above, a ship may use any means avail­ able to them to inform the appropriate authorities that a false distress alert has been transmitted and should be cancelled.
2. No action will normally be taken against any ship or mariner for reporting and cancelling a false distress alert. However, in view of the serious consequences of false alerts, and the strict ban on their transmission, governments may prosecute in cases of repeated violations.

Author

Olga Nesvetailova

Freelancer

Literature

1. Global Maritime Distress and Safety System: IMO 1987.
2. Manual for use by The Maritime Mobile and Maritime Mobile- Satellite Services: ITU 1992.
3. Radio Regulations 1-2-3: ITU 1990.
4. Manual for Norwegian Mobile Radiotelephone Stations: The Norwegian Telecom 1992.
5. Modem Electronic Communication: Gary M. Miller 1978.
6. Brochures and data sheets from manufacturers of GMDSS Equipment.
7. Inmarsat: Inmarsat-A User’s Manual, Inmarsat-C User’s Manual.
8. Nodposisjonering: Bjomar Augdal, 1992.
9. Skipsantenner: Bjomar Augdal 1991.
10. COSPAS-SARSAT Secretariat: COSPAS-SARSAT System Data Documents.
11. Admiralty List of Radio Signals.