161.EPIRB

An EPIRB is a compact, buoyant, self-contained radio transmitter.  Activated, it continuously emits a distinctive radio signal for a minimum of 48 hours.

An Emergency Position Indicating Radio Beacon is used to alert search and rescue services in the event of an emergency. t does this by transmitting a coded message on the 406 MHz distress frequency via satellite and earth stations to the nearest rescue co-ordination centre.

Some EPIRBs also have built-in GPS which enables the rescue services to accurately locate you to +/- 50 metres.

How does an EPIRB work?

406 MHz EPIRBs work with the Cospas-Sarsat polar orbiting satellite system, giving true global coverage. 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

Hydrostatic Release Unit

A hydrostatic release unit allows a liferaft to launch automatically if there isn’t time for crew to launch it manually.

How it works:

The strong white rope is secured to the deck or liferaft cradle and attached to the liferaft lashing with a sliphook. If the ship sinks, the water pressure will (within 4 metres) activate the sharp knife which cuts the white rope and the liferaft will float free. As the ship sinks, the liferaft painter line will be stretched and the liferaft starts to inflate. The Red Weak Link breaks and survivors can board the floating liferaft.

Breaking strength of white rope sling: min 15kN.

Breaking strength of red weak link: 2.2 +/- 0.4 kN.