EPIRB
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| Last update: | February 2022 |
| Page completeness level: | High |
Contents
Overview
An Emergency Position-Indicating Radio Beacon (EPIRB) is used to alert search and rescue services in the event of a maritime emergency. It does this by transmitting a coded message on the 406 MHz distress frequency via satellite. This distress signal is automatically relayed through an automatic ground station to a control center where it is decoded and the distress and registration details are passed on to the relevant search and rescue authority. Some EPIRBs also have built-in GPS which enables the rescue services to accurately locate you to +/- 50 metres.
Performance standards, testing standard & carriage requirement
Carriage requirement
- In accordance with the GMDSS, cargo and passenger ships are required to carry at least 1 EPIRB.
Performance standards
- EPIRB must comply with MSC.471(101) if installed on or after 1 July 2022
- ECDIS must comply with A.810(19) as amended by resolutions MSC.56(66) and MSC.120(74) if installed before 1 July 2022
Testing standard
- IEC 61097-2:2021 specifies the operational and performance requirements, methods of testing and required test results of EPIRB conforming to MSC.471(101)
- IEC 61097-2:2008 specifies the operational and performance requirements, methods of testing and required test results of EPIRB conforming to A.810(19)
MSC.471(101) EPIRB - technical changes
MSC.471(101) included the following technical changes to EPIRB:
- the addition of an integral GNSS receiver
- the addition of an AIS locating transmitter
- a light visible to night vision devices
- makes provision for Cospas-Sarsat Second Generation 406 MHz beacons.
- the transmitting duty cycle of the 121.5 MHz homing signal was reduced to accommodate these additional features.
These changes are intended to improve the accuracy of the position provided in the distress alerting signal and to enable additional assets at sea to more readily assist in search and rescue efforts.
How it works
406 MHz EPIRBs work with the Cospas-Sarsat satellite system. There is an alert delay of about 45 minutes dependant on when the satellites come into view on the horizon. The satellite can determine the position of your EPIRB to within 5km (3 miles). The coded message identifies the exact vessel to which the EPIRB is registered. This information allows the rescue services to eliminate false alerts and launch an appropriate rescue. GPS-enabled EPIRBs have a built-in transmitter which will typically alert the rescue services within 3 minutes and to a positional accuracy of +/- 50 metres (updated every 20 minutes) given a clear view skywards. Some EPIRBs also have a secondary distress transmitter. This transmits on 121.5 MHz and is used for "homing" purposes. When the rescue services get close, this allows them to direction find on the signal. Some EPIRBs also have a high brightness LED flashing light that aids final visual location.
Activation
An EPIRB can be activated either manually or automatically when the EPIRB comes into contact with water. Manual activation brackets will cover the water sensors, preventing them from activating the EPIRB if, for example, a wave breaks over the boat, and keeping it in a handy location should you need to access it quickly. Auto Float-free housings automatically deploy the EPIRB when submerged to a depth lower than 2 - 4 metres in the sea. They work by means of a Hydrostatic Release Unit which cuts the EPIRB free from its housing, causing it to activate. The EPIRB can also be removed from the auto housing to be activated manually.
Registration
Once purchased an EPIRB must be registered in the appropriate country. Contact information plus information about the vessel it is to be used on must be provided.
