Emergency Position Indicating Radio Beacon (EPIRB)-ETO

Picture Credits: Madhan ETO

Emergency Position Indicating Radio Beacon (EPIRB)

EPIRB is a float free radio transmitter which when activated will emit a distinctive radio signal to satellite to determine its position and its identity.

The purpose of EPIRB is to help determine the position of survivors during SAR (Search and Rescue) operation and also a secondary means of distress alerting.

It indicates one or more persons are in distress, may no longer be on board ship or aircraft and receiving facilities may not be available.

TYPES OF ERIPs

Cospas Sarsat EPIRB, -406.025MHz with 121.5MHz the homing signal which is the most common EPIRB.

VHF EPIRB – (Ch. 70 DSC) – found very rarely and only onboard vessels plying the A 1 area.

L  band EPIRB – 1.6Hz (operates with Inmarsat E system) – not in use now.

Cospas Sarsat EPIRB system consists of Six Polar-orbiting LEOSAR (Low Earth Orbiting Search And  Rescue satellites) situated at a height of 800 to 1200 km.

OPERATION OF COSPAS SARSAT EPIRBs

EPIRB is normally fitted on the bridge with HRU for float free/automatic operation. When the EPIRB sinks 1.5 to 4m below water level. It gets automatically released and floats free and gets activated when it’s two terminals come in contact with water. If necessary EPIRB can be hand-carried to survival craft before abandoning vessel and operated manually.

OPERATION OS COSPAS SARSAT EPIRB

When activated manually or automatically, EPIRB transmits the signal (burst of 0.5 sec repeated every 50 secs with a visual indication by a strobe light). These signals when detected by cospas sarsat satellites are relayed to LUT. LUT process these signals and determines the position of EPIRB by Doppler shift and conveys the information to MRCC and SAR vessels via MCC.

MCC is mission control centre where the EPIRBs are registered and particulars of the vessel to which the EPIRB belongs can be obtained.

MRCC IS Maritime rescue coordination center which coordinates SAR operation.

In India, LUTs are situated in Bangalore and Lucknow.

TWO MODES OF OPERATION OF COSPAS SARSAT EPIRB

Real-time mode – When EPIRB and LUT are in the sight of the satellite the EPIRB signal is relayed on receipt.

Global mode – When LUT is not in sight of the satellite when the EPIRB signal is picked up by satellite, then the information is stored in satellite and transmitted when LUT comes on sight. This is called the global mode.

The time delay in detection and relaying of EPIRB transmission in Global mode can be up to 1 hour.

With the recent addition of 5 GEOSAR Geo stationary revolving at a height of 36000km into the COSPAS SARSAT the system, instantaneous detection of EPIRB signal is possible now if the EPIRB is fitted with built-in GPS.

As per SOLAS, every vessel is required to carry at least one EPIRB. But as per DGS requirements Indian flag vessels need to carry two EPIRBs.

The battery used for EPIRB is 18v Lithium battery & have a very long self-life of 5 years or more (very less self-discharge).

The capacity of lithium battery should be enough to lost for 48 hours when activated.

EPIRB battery should be replaced before its expiry date or within three years of installation.

EPIRB is to be tested every month for operation and condition. Test the operation of EPIRB by moving the spring-loaded operating lever switch to test mode and if look for the visual indication (LED and flashing strobe light)