SART: Search and Rescue Transponder

Posted by author on June 30th, 2010

What is SART?

SART is a small, buoyant battery powered, omnidirectional radar receiver and transmitter, capable of registering radar waves from a radar onboard a ship or an aircraft.

The most essential purpose of the SART is to provide the main means of locating a survival craft, or life boats, after sea damage, or sea wreck. A SART will automatically respond only when interrogated/activated by all maritime 3 cm radar installations operating on 9 GHZ.

A SART can be activated into stand by condition by:

Breaking the seal
Removing the locking pin or switch block.
Check that the switch is in the – ON – position.
An audible – BEEP – will be heard, and the led indicator starts flashing.
Place (hold) the start in a vertical position as high as possible. (In survival craft, sarts are to be mounted 1 meter above sea level)When the radar transponder receives a radar signal i.e. when a signal from an aircraft or ship is received it sweeps through the whole 9GHZ radar band 12 times and emits 12 characteristic dashes which on the radar screen indicates that this is a SART signal, and at the same time gives position of the ship in distress. These characteristics signal transmitted from the SART are called homing signals.
This homing signals wil be seen on the radar screen of the ship, or aircraft as a line of 12 blips extending approximately 5NM outwards from the SART’s position, along its bearing, clearly identifying the survival craft.

Homing Signals:

Homing signals are those locating signals whoch are transmitted by mobile units (ships) in distress, or by survival craft, for the purpose of providing searching units with a signal that can be used to determine the bearing to the transmitted stations.
if electronic unit is separated from the battery unit, the battery unit must be placed in such a way, that light or audio signals may be observed.
When the SART is within the range of RADAR station the light and audio sensors will be activated.

To Stop the Activation of the SART:

Move the switch to position – OFF -
Replace the locking pin

The battery capacity should allow the SART in a standby mode for approximately 96 hours. When in use for approximately 8 hours. A SART weighs about 700 grams.

Whenever a change of battery is required the complete lower part of the SART is to be replaced. The upper unit of the TRON SART consists of the microwave receiver transmitter and antenna (the electronic unit), the lower unit contains batteries and activation control, as well as the optical and audio indicators (Battery Unit).

The SART operates in the frequency band of 9200 – 9500 MHz.

Range Performance:

The SART operates correctly when interrogated by:

by Navigational (SHIPS) radars with an antenna height of 15 meters, at a distance from approx. 5NM.
by Airborne (AIRCRAFT) radars with peak power of at least 5 to 10KW at a height of 3000ft. at a distance from 30NM to 40NM.
On the survival craft the survivors will receive an audibly and visually indication from the SART signals indicating that the signals have been received by an approaching ship or aircraft.

SARTS are grouped in 3 categories:

SART for fix installation in lifeboat, or raft
portable SART
SART mounted in release mechanism and / or combined with float free EPIRB.

Test Procedures of the SART

Set radar range to 12NM.
the radar screen
activate the SART, by processing the switch to – test – position.
Check the radar display that 12 or 24 rings are observed.
The SART responds with a continuous sound, and the LED indicator is on continuously.

General: The SART should:

Be capable of being easily activated by unskilled personnel.
Be fitted with means to prevent inadvertent activation.
Be capable of withstanding without damage, drops from height of 20 Meters into the water
Be watertight at a depth of 10 meters for 5 minutes.
The height of the installed SART antenna should be at least 1 meter above sea level
Be able to operate under temperatures -20 degree Celsius to +55 degree celsius
Not be unduly affected by sea water and oil.
Be water resistant, marked with make, type, and serial number.
It must have operating instructions, and battery expiry date, and ship ID.