LSA Part 4: Carriage requirements for radios, SARTs and alarm systems
Relevant documents and M-notices: SOLAS Chapter III and IV, MSC 246 (AIS SARTs), MSC 510 (Radar SARTs), MSC 149 (VHF radios), IMO Circular 322 (AIS SART symbols)
This article was updated in September 2024 to reflect the 2024 SOLAS amendments.
SOLAS Chapter IV Regulation 7 requires that the following are carried.
For cargo ships of 300GT and up but less than 500GT:
At least two two-way VHF radios
At least one search and rescue locating device
For passenger vessels and cargo ships of 500GT and up:
At least three two-way VHF radios
At least two search and rescue locating devices (one on each side of the bridge)
There are other requirements, too; SOLAS Chapter IV, Regulation 7 states that:
Every ship shall be provided with…a search and rescue locating device capable of operating either in the 9GHz frequency or on frequencies dedicated for AIS…(this) may be one of those required by regulation III/6.2.2 for a survival craft.
I’ve never seen a search and rescue locating device of any sort other than SARTs and AIS-SARTs; it’s possible that this regulation anticipates such a device coming to the market, or perhaps there are some devices that are very rare.
On ships equipped with two or more search and rescue locating devices and equipped with free-fall lifeboats, one of the search and rescue locating devices is to be stored in the free-fall lifeboat and the other on the bridge.
Performance standards and testing of SARTs and VHF radios is covered further on in this article.
On-board communication and alarm systems
All ships must have an emergency means, either portable or fixed, of two-way communication between emergency control stations, muster and embarkation stations and strategic positions on board.
Ships normally meet this requirement by some combination of the following:
VHF radios (and spare batteries). These are often kept at muster stations and can then be taken to embarkation stations for lifeboats, liferafts etc. in the event of an abandon ship order being given.
A sound-powered telephone system. This generally links the bridge, the engine main control room, the steering flat, the emergency generator room, the citadel etc. It works even if the ship loses all power.
Ships fitted with a Marine Evacuation System (MES) must also ensure communication between the embarkation station and the platform or the survival craft.
General emergency alarm system
A general emergency alarm system complying with the requirements of paragraph 7.2.1 of the Code shall be provided and shall be used for summoning passengers and crew to muster stations and to initiate the actions included in the muster list. The system shall be supplemented by either a public address system complying with the requirements of paragraph 7.2.2 of the Code or other suitable means of communication.
The general emergency alarm system shall be audible throughout all the accommodation and normal crew working spaces. On passenger ships, the system shall also be audible on all open decks.
From the LSA Code 7.2.2
The general emergency alarm system shall be capable of sounding the general emergency alarm signal consisting of seven or more short blasts followed by one long blast on the ship's whistle or siren and additionally on an electrically operated bell or klaxon or other equivalent warning system, which shall be powered from the ship's main supply and the emergency source of electrical power required by regulation II-1/42 or II-1/43, as appropriate. The system shall be capable of operation from the navigating bridge and, except for the ship's whistle, also from other strategic points. The alarm shall continue to function after it has been triggered until it is manually turned off or is temporarily interrupted by a message on the public address system.
Public address system on passenger ships
All passenger ships must be fitted with a public address system. It must be clearly audible above the ambient noise in every space on the ship. It must be possible to override every speaker from the bridge, regardless of whether they have been switched off, turned down etc. or if the PA is already in use from another location. It must be connected to both normal and emergency power sources.
What is a search and rescue locating device?
These come in two forms, as described in the excerpt from Chapter IV: 9GHz radar SARTs and AIS-SARTs. The performance standards for these are laid out in MSC 510 and MSC 246 respectively. SART stands for Search And Rescue Transponder when referring to a radar SART and Search and Rescue Transmitter when referring to an AIS (Automatic Information System) SART.
Radar SARTs must:
be capable of indicating the location of a unit in distress on the assisting units' radars by means of a series of 12 equally spaced dots
be capable of being easily activated by unskilled personnel
be fitted with means to prevent inadvertent activation
be equipped with a means which is either visual or audible, or both visual
and audible, to indicate correct operation and to alert survivors to the fact
that a radar has triggered the radar SART
be capable of manual activation and deactivation; provision for automatic
activation may be included
be provided with an indication of the standby condition
be capable of withstanding without damage drops from a height of 20 m into
water
be watertight at a depth of 10 m for at least 5 min
maintain watertightness when subjected to a thermal shock of 45 degrees C under
specified conditions of immersion
be capable of floating if it is not an integral part of the survival craft
be of a highly visible yellow/orange colour on all surfaces where this will
assist detection
have a smooth external construction to avoid damaging the survival craft;
and
be provided with a pole or other arrangement compatible with the antenna
pocket in a survival craft
be equipped with a buoyant lanyard, suitable for use as a tether; if it is
capable of floating;
not be unduly affected by seawater or oil
be resistant to deterioration in prolonged exposure to sunlight
It should have sufficient battery to operate, once activated, in standby for 96 hours and to transmit for 8 hours.
The range of a radar SART does depend on both the height of the unit and the height of the interrogating radar transceiver, but at least five miles is the figure for the standard heights.
AIS-SARTs must:
be capable of transmitting messages that indicate the position, static and safety information of a unit in distress. The transmitted messages should be compatible with existing AIS installations. The transmitted messages should be recognized and displayed by assisting units in the reception range of AIS-SART, and clearly distinguish the AIS-SART from an AIS installation.
be capable of being easily activated by unskilled personnel
be fitted with means to prevent inadvertent activation
be equipped with a means which is either visual or audible, or both visual and
audible, to indicate correct operation
be capable of manual activation and deactivation; provision for automatic
activation may be included
be capable of withstanding without damage drops from a height of 20 m into
water
be watertight at a depth of 10 m for at least 5 min
maintain water tightness when subjected to a thermal shock of 45°C under
specified conditions of immersion
be capable of floating (not necessarily in an operating position) if it is not an
integral part of the survival craft
be equipped with buoyant lanyard, suitable for use as a tether, if it is capable of
floating
not be unduly affected by seawater or oil
be resistant to deterioration in prolonged exposure to sunlight
be of a highly visible yellow/orange colour on all surfaces where this will assist
detection
have a smooth external construction to avoid damaging the survival craft
be provided with an arrangement to bring the AIS-SART antenna to a level of at
least 1 metre above sea level, together with illustrated instructions
be capable of transmitting with a reporting interval of 1 minute or less
be equipped with an internal position source and be capable of transmitting its
current position in each message
be capable of being tested for all functionalities using specific test information.
I have made bold in the second list the differences between the performance standards for the radar SART and the AIS-SART.
The AIS-SART must have sufficient battery to operate for 96 hours and to provide for testing of the functions. It must have a unique identifier to ensure the integrity of the VHF data link.
The AIS-SART should be detectable at a range of 5 miles; note that they can be detected from up to 130 miles by aircraft. It should continue transmitting even if the position and time synchronisation from the position system fails. It should transmit within 1 minute of activation.
Both SART types should be clearly marked with brief operating and test instructions, and the expiry date of their batteries.
How does a radar SART show up on a radar display?
An activated SART will show up on an x-band radar display as a series of twelve dots radiating away from the transceiver, with the SART located at the dot nearest to the transceiver; this makes it very easy to take a bearing. As the vessel approaches the SART these dots become arcs, which then become concentric circles once the SART is within one mile.
How does an AIS SART show up on an AIS/ECDIS displays?
An old-style AIS display may show a SART as a triangle.
A new-style AIS display should show a SART as a circle with a cross
Both should show associated text; the MMSI number and either SART ACTIVE or SART TEST.
An ECDIS should show a SART symbol similar to the circle with a cross shown on new-style AIS displays, but coloured red. The MMSI and status of the SART should be visible, with the self-reported COG and SOG of the unit available on interrogation.
Testing radar SARTs
Radar SARTs can be tested with our own x-band radars. Ideally this should be done well away from other traffic. First, make a Sécurité announcement to ships in the vicinity, warning them that you are about to test your SART. Have someone take the SART either forward or aft on the vessel to ensure that they are in the line of transmission of the radar. Switch the SART to ‘test’ mode and check that the light on the unit is flashing or that it is making a sound (see unit instructions). Check the x-band display; it should show concentric circles. Switch the SART off and make a Sécurité announcement informing vessels in the vicinity that you have finished testing your SART.
Testing AIS-SARTs requires specialist equipment to measure the strength of their signal. The IMO recommend that this is done sparingly, to preserve battery life. Port authorities should be informed; they can confirm that the signal has been received.
VHF radios
VHF radios must:
be capable of being operated by unskilled personnel
be capable of being operated by personnel wearing gloves as specified for immersion suits
be capable of single-handed operation except for channel selection
withstand drops on to a hard surface from a height of 1 m
be watertight to a depth of 1 m for at least 5 min
maintain watertightness when subjected to a thermal shock of 45 °C under conditions of immersion
not be unduly affected by seawater, or oil, or both
have no sharp projections which could damage survival craft
be of small size and light weight
be capable of operating in the ambient noise level likely to be encountered on board ships or in survival craft
have provisions for its attachment to the clothing of the user
be resistant to deterioration by prolonged exposure to sunlight
be either of a highly visible yellow/orange colour or marked with a surrounding yellow/orange marking strip
be capable of operation on the frequency 156.800 MHz (VHF channel 16) and on at least one additional channel
be operational within 5 s of switching on
be labelled with brief operating instructions and expiry date of primary battery
MCAQs
What VHF radios and SARTs are required on;
A 310GT passenger vessel?
A 2500GT passenger vessel?
A 550GT cargo ship?
A 330GT cargo ship?
Explain the two types of SART and how you would test them.
Would you test a radar SART in the English channel?
What alarms are required on a ship? (Note, you’d be expected to talk about the general alarm and the fire alarm; the fire alarm will be covered by another article)
Tell me about the public address system on a passenger ship, what are the requirements?
What are the performance requirements for a radar SART? How do the requirements differ for an AIS-SART?
How would you test a radar SART/an AIS SART?
How many VHF radios are required on a 350GT cargo vessel? How about a 350GT passenger vessel?
What are the performance requirements for these radios?
Could the radios be black, or green?
What is the general emergency alarm signal?
Where must the general emergency alarm system be operable from?
How do the requirements for the PA system on a cargo ship differ from the requirements for the PA system on a passenger vessel?