SART and EPIRB

  • Vignesh 
  • 7 min read

Safety is must always a seafarer should be concerned of before his/her voyage. One should must know how to face emergency situations in case of any distress condition to safe himself. Safety Equipments such as SART and EPIRB, Compass, Life Jackets, Flares & etc. A Search and Rescue Transponder (SART) is an electronic device that automatically reacts to the emission of a radar.  EPIRB is used to alert search and rescue services in the event of an emergency.

Table of Contents

SART

SART and EPIRB

Search and rescue transponder abbreviated as SART. A SART operates in a 9GHz frequency band used by marine radar transmits response signal and interrogates with ship borne or air borne radar. It is designed to be self-reliant, water proof with a bright color for easy detection in blue water. It is important under SOLAS and manufacturer’s requirement for installation, maintenance and testing. It is embedded with an omnidirectional (So it can be detected at any direction) transmitter along with a receiver which transmits and receives signal.

It may be permanently fitted in survival craft or mounted in easy location i.e. wheel house ready for use to take into the life raft. SART used in a life raft is often mounted on a telescopic hole rigged through the antenna opening in the canopy. Mounting should be 1m above the sea level, to ensure maximum detection and SART transmission by search and rescue radar. If radar reflectors provided in a life raft it should not be used with the SART. It causes a large radar shadow sector’s thus preventing the detection of survival craft.

SART and EPIRB

SART receives radar signal and it response with its own transmission. The radar displays the transmission as a series of dots along the line of bearing with first echo as target. As the distance between the rescue boat and SART decreases, the signal become more prominent.

Below 1 mile the radar displays arcs of circles shown above in the picture.

Undoubtedly best results are found that using Radar at 12 miles scale (Initially) and then changing to 6 miles gives optimum performance. As the range decreases below a mile the signal begin to form arcs and continue to comtrentic circles.

Typical detection range of SART transmission is around 5 to 7 miles depending on the radar scanner and height of the vessel. From air craft the detection range will be much greater i.e. of 50 miles of about 3000 feet in altitude. SART should be tested and maintained as per the manufacturers instruction maintenance is simple that batteries must be retained if expired.

Undoubtedly best results are found that using Radar at 12 miles scale (Initially) and then changing to 6 miles gives optimum performance. As the range decreases below a mile the signal begin to form arcs and continue to comtrentic circles.

Typical detection range of SART transmission is around 5 to 7 miles depending on the radar scanner and height of the vessel. From air craft the detection range will be much greater. In of 50 miles of about 3000 feet in altitude. SART should be tested and maintained as per the manufacturers instruction maintenance is simple that batteries must be retained if expired.

For testing the push switch should be switched to test position the blinking of light shows the device works.

EPIRB

Emergency position indicating radio beacon abbreviated as EPIRB. An EPIRB is a float free device which operates on 406MHZ and normally uses 121.5MHZ transmission to facilitate local homing search and rescue craft. Some EPIRB uses INMARSAT satellite system which operates on 1.6GHZ but greater majority uses 406MHZ. It is important as these devices installed and maintained according to the manufacturer’s instruction. Special cases should be taken to ensure that the EPIRB is mounted on the superstructure such that the way they are capable to float free from the vessel if it sinks.

Every EPIRB should be checked as the manufacturer’s recommended interval to ensure that the use of battery and hydrostatic release unit are valid. A self-test of that the unit should be made to ensure the EPIRB doesn’t transmit live signals during the test and the EPIRB is armed and fixed in its mounting.

Specialized equipment is available in which it test the signal transmitted by EPIRB and ensures that the vessel identity is correctly being programmed. The specialized equipment shows the frequency and country code with ID & serial no etc.

A line is provided to attach in a life raft after floating free, onto a survivor in water. It should not be secured to the ship’s rail or any other structure to prevent the release of EPIRB from the vessel.

406Mhz EPIRB use the polar orbiting satellite to communicate the distress information on activation of the EPIRB transmit the distress message containing the identity code for the vessel this maybe serial number or code sign or maritime mobile service identity of the vessel.

Every EPIRB should be registered provided by the details of the vessel of maritime authority, whether the vessel is registered. It should not be transferred to another vessel, unless the identity code and registration details first being changed that of the new vessel. Incorrectly registered information of EPIRB could cause unnecessary confusion or delay in rescue operation.

After being relay by the satellite the distress signal is received by the earth station known as local user terminal this signal is decoded and used to calculate the position of vessel in distress and send to appropriate control mission center. Some EPIRB are capable of transmitting the position of vessel as they built in navigation receivers. In (UK) the data is sent to UK mission control center for them to take appropriate action. In this case they pass the data to the (MRCC) maritime rescue coordination center who will alert the sub center for launching appropriate rescue craft for rescue operation. When the rescue vessel nears the survivor’s position homing signal should be heard from the EPIRB on the VHF direction finder using 121.5 MHZ. The EPIRB transmission from sea level of 121.5 is limited in range and detection will depend on highest of direction finding area of rescue boat, but from Air the detection is much greater.

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