Unit 2 Distress,Urgency and Safety Services

Unit 2 Distress,Urgency and Safety Services
Distress,Urgengcy and Safety Services Produced by FYT

Produced by FYT

2.1 GMDSS General Provisions
Global Maritime Distress and Safety System (GMDSS) was set up to provide an international communications network to assist vessels in distress. All distress communications in the maritime mobile service by radiotelephony, digital selective calling and satellite whether and/or direct printing telegraphy (telex), must be conducted strictly in accordance with the correct procedures. Produced by FYT

This ensures that vessels in distress obtain help without delay
This ensures that vessels in distress obtain help without delay. Ships equipped for and operating under GMDSS conditions are obliged to comply with chapter New (IX) of the ITU Radio Regulations. Some provisions of this chapter also apply to the aeronautical mobile service except in the case of special arrangements between the governments concerned. However, stations of the maritime mobile service when equipped to conform to chapter IX of the ITU Radio Regulations, shall comply with the provisions of that chapter. Produced by FYT

The procedures specified in chapter New (IX) of the ITU Radio Regulations are obligatory in the maritime mobile satellite service and for communications between stations on board aircraft and stations of the maritime mobile satellite service, wherever this service or stations of this service are specifically mentioned. Produced by FYT

The International Convention for the Safety of Life at Sea (SOLAS) , 1974, prescribes which ships and which of their survival craft shall be provided with radio equipment, and which ships shall carry portable radio equipment for use in survival craft. Although the procedures are obligatory for all stations using communications in the maritime mobile and maritime mobile satellite service, they do allow: Produced by FYT

(a) Mobile Earth Stations (MESs) in distress to use any means at their disposal to attract attention, make known their position and obtain help; (b) Any stations whether mobile (ship/aircraft) or land stations or coast stations involved in search and rescue duties to use, in exceptional circumstances, any means at their disposal to assist a mobile station or a mobile earth station in distress; Produced by FYT

(c) Any land (or coast station) or LES may use, in exceptional circumstances, any means at their disposal to assist a mobile station or MES in distress. When transmitting distress, urgency or safety messages by radiotelephony, transmissions should be made slowly and distinctly with clear pronunciation. The use of the International Code of Signals is recommended, including the use of abbreviations and the phonetic alphabet, particularly in situations where language difficulties exist. Produced by FYT

For instance: I have a male aged 40 years, patient has been ill for 6 hours, patient is in pain of whole chest, temperature is falling, the pulse is weak, patient appears to be in a state of shock. MAJ40 MAN6 MDF91 MBW MCB MCW ( karte-four nada-zero soxi-six nove-nine una-one) Fan Yaotian: Foxtrot Alfa November Yankee Alfa Oscar Tango India Alfa November Produced by FYT

(a) class J3E emissions on carrier frequencies 2182kHz and 4125 kHz;
Mobile stations may communicate with aircraft for safety purposes, but they must use the approved frequencies and observe the correct procedures. Aircraft which are required by national or international regulations to communicate with maritime mobile stations for safety purposes must comply with GMDSS provisions. Therefore until the full implementation of GMDSS, they must be able to transmit and receive: (a) class J3E emissions on carrier frequencies 2182kHz and 4125 kHz; (b) class G3E emissions on Channel 16 VHF and optionally Channel 6 VHF. Produced by FYT

Within GMDSS a number of frequencies are specifically allocated for distress communication purposes depending on the communication medium being used. These frequencies should be used by ships, aircraft or survival craft when seeking assistance in the maritime mobile service. They should be used for the distress call and distress traffic and for calls preceded by either the urgency signal or the safety signal. DSC, radiotelephone and telex distress and safety frequencies are listed below. Distress Frequencies Produced by FYT

Table 2-1 Band RT Telex MF 2 187.5 kHz 2 182 kHz 2 174. 5 kHz.
DSC RT Telex MF kHz 2 182 kHz kHz. HF 4 MHz kHz 4 125 kHz kHz HF 6 MHz 6 312 kHz 6 215 kHz 6 268 kHz HF 8 MHz kHz 8 291 kHz kHz HF 12 MHz kHz kHz kHz HF 16 MHz kHz kHz kHz VHF Channel 70 Channel 16 Produced by FYT

The frequency 4125 kHz may be used by aircraft engaged in search and rescue (SAR) operations for distress/safety communications to stations in the maritime mobile service. 2182 kHz is used as the international distress and safety frequency and also for international call and reply at the present time. However with the full implementation of GMDSS 2182 kHz is likely to be used exclusively for distress and safety purposes. The aeronautical frequencies 3023kHz and 5680kHz are used for intercommunication purposes between mobile stations and to participating land stations during coordinated SAR operations. Produced by FYT

2.1.2 Aeronautical Frequencies
In the aeronautical VHF radiotelephony service ( MHz~137MHz) the emergency frequency is MHz. Survival craft can also use this frequency for distress and urgency communications. Additionally this frequency may be used in the COSPAS-SARSAT emergency location system by emergency position-indicating radio beacons (EPIRBs) for distress alert transmissions to the satellite. Produced by FYT

The auxiliary aeronautical frequency of 123
The auxiliary aeronautical frequency of MHz is used by the service and by other mobile and land stations engaged in coordinated SAR operations. Maritime mobile stations may communicate with aeronautical stations on MHz and 243MHz for distress and urgency purposes only and on 123.1MHz for coordinated SAR operations. Class A3E emissions are used on these frequencies. Produced by FYT

2.1.3 GMDSS VHF Channel Usage
Channel 6 VHF Used for communication between ships and aircraft for coordinated SAR operations. May also be used by aircraft to communicate to ships for safety purposes. Channel 13 VHF Used for ship to ship communication relating to safety of navigation. Digital Selective Calling Radio Produced by FYT

Channel 16 VHF Used for distress and safety traffic on RT, may also be used by aircraft for safety purposes. Channel 70 VHF Used as a DSC distress and safety calling channel in the maritime mobile service. Produced by FYT

Satellite Service A number of bands are allocated exclusively to particular services in the satellite service; such bands must also be protected to avoid harmful interference. Produced by FYT

Band Use 406MHz~406.1MHz Earth to space EPIRB transmissions.
1530MHz~1545MHz Maritime mobile service. Routine communications and also for distress and safety communications (space to earth). Produced by FYT

Produced by FYT

1626.5MHz—1645.5MHz Maritime mobile service.
Band Use 1626.5MHz—1645.5MHz Maritime mobile service. Routine communications and also for distress and safety communications (earth to space). 1645.5MHz—1646.5MHz Earth to space distress/safety communications (IMARSAT EPIRB) Produced by FYT

2.1.5 Survival craft stations
Equipment for radiotelephony use in Survival craft stations shall, if capable of operating on any frequency in the bands between 156 MHz and 174 MHz, be able to transmit and receive on MHz and at least one other frequency in these bands. Equipment for transmitting locating signals from survival craft stations shall be capable of operating in the MHz band. Produced by FYT

a) in the bands between 1605 kHz and 2850 kHz, be able to transmit on
Equipment with DSC facilities for use in survival craft shall, if capable of operating: a) in the bands between 1605 kHz and 2850 kHz, be able to transmit on kHz; (MF) b) in the bands between 4000 kHz and 27500kHz, be able to transmit on kHz; (HF) c) in the bands between 156 MHz and 174 MHz, be able to transmit on MHz. (VHF) Produced by FYT

2.1.6 Protection of Distress frequencies
It is imperative that distress and safety communications maintain the best possible integrity and the distress and safety frequencies are protected from harmful interference, harmful interference being interference which puts at risk the operation of safety services or radio navigation services or seriously degrades, obstructs, or repeatedly interrupts any radio communication services. Produced by FYT

Therefore to protect distress integrity and to prevent harmful interference, it is absolutely forbidden to broadcast or cause harmful interference by any emissions on any frequency especially those allocated to distress working. Produced by FYT

To further protect distress and safety communications, all other transmissions within particular bands are forbidden, apart from transmissions on specific frequencies. For example in the band kHz~2190.5kHz, transmissions are permitted on 2182 kHz, kHz, 2177kHz, kHz and kHz. All other transmissions in this band are prohibited. All emissions in the frequency band MHz~ MHz are forbidden which might cause interference to VHF Channel 16 (156.8 MHz). Produced by FYT

Transmitter Tests Test transmissions should only be made when absolutely necessary and be kept to a minimum to avoid harmful interference especially on the distress and safety frequencies. Whenever practicable , artificial aerials should be used but where aerials do have to be used tests should be conducted on low power and coordinated with competent authorities. Produced by FYT

Testing on distress and safety calling frequencies should be avoided
Testing on distress and safety calling frequencies should be avoided. Testing stations must always identify themselves and make it clear they are sending a test transmission. Before making a test operators should listen on the frequency to be used to ensure that no distress or safety communications are in progress. Produced by FYT

2.1.8 GMDSS Watchkeeping Arrangements
Coast stations Those coast stations assuming a watch-keeping responsibility in the GMDSS shall maintain an automatic DSC watch on frequencies and for periods of time as indicated in the information published in the List of Coast Stations. Produced by FYT

Coast earth stations (satellite communication)
Those coast earth stations assuming a watch-keeping responsibility in the GMDSS shall maintain a continuous automatic watch for appropriate distress alerts relayed by space stations. Produced by FYT

Ship stations Ship stations, where so equipped, shall, while at sea, maintain an automatic DSC watch on the appropriate distress and safety calling frequencies in the frequency bands in which they are operating. Ship stations, where so equipped, shall also maintain watch on the appropriate frequencies for the automatic reception of transmissions of meteorological and navigational warnings and other urgent information to ships. However, ship stations shall also continue to apply the appropriate watch-keeping provisions of the appropriate Radio Regulations, (see Resolution 331 (Rev.WRC-97)). Produced by FYT

Listening watches on 2182 kHz are no longer mandatory.
In 1998, the Maritime Safety Committee of the International Maritime Organization resolved that, from the coming into force of the GMDSS, until 1st February 2005 every ship while at sea shall maintain, when practicable, a continuous listening watch on VHF Ch 16; such a watch shall be kept at the position from which the ship is normally navigated. Produced by FYT

Ship stations complying with the provisions of the Radio Regulations should, where practicable, maintain a watch on the frequency MHz (VHF Ch 13) for communications related to the safety of navigation. Produced by FYT

Ship earth stations (satellite communication)
Ship earth stations complying with the provisions of the Radio Regulations shall, while at sea, maintain watch except when communicating on a working channel. Produced by FYT

2. 1. 9 Watchkeeping: Alert Calls
Some HF coast stations offer a watch facility on the HF DSC safety frequencies for GMDSS sea areas A3 and A4. As per Regulation 12 of Chapter IV of the Amendments to the 1974 SOLAS Convention (concerning radio communications for GMDSS), every ship, while at sea, shall maintain a continuous watch: Produced by FYT

(a) on DSC Channel 70 VHF, if the ship, in accordance with the requirements of regulation (of the amendments to the 1974 SOLAS Convention), is fitted with a VHF radio installation; (b) on the distress and safety DSC frequency of kHz, if the ship, in accordance with the requirements of regulation or (of the amendments to the 1974 SOLAS Convention), is fitted with an MF radio installation; Produced by FYT

(c) on the distress and safety DSC frequencies of kHz and kHz and at least one of the other HF DSC frequencies ( kHz, 6312 kHz, kHz or kHz), the frequency chosen will be appropriate to the ship's position and time of day, if the ship, in accordance with the requirements of regulation or 11.1 (of the amendments to the 1974 SOLAS Convention), is fitted with an MF/HF radio installation. This watch may be kept by means of a scanning receiver; Produced by FYT

2.1. 10 Dedicated DSC Watchkeeping Receiver
This is a scanning type of receiver which sequentially switches between kHz and kHz. The receiver is able to detect a special "dot pattern" at a particular speed (100 baud) which is sent at the beginning of every DSC call. Should a distress alert be intercepted on any band the call will be processed and an audible alarm will sound. When the receiver is connected to an associated DSC controller the incoming call will be displayed. Produced by FYT

Some types of equipment may have an automatic printer fitted to give a hard copy of any incoming calls. The equipment can be manually programmed to scan any of the other four remaining HF maritime DSC distress and safety calling frequencies as well as the two frequencies mentioned above. It performs this scanning operation within two seconds before repeating the operation. Produced by FYT

DISTRESS SERVICES Distress & Safety Operational Procedures Services available for distress and safety communications are terrestrial radiocommunication in the MF, HF and VHF bands and satellite communication. Distress alerts are transmitted either: Produced by FYT

(a) via satellite with absolute priority using
the general communication channels; or (b) via satellite using exclusive distress and safety frequencies; or (c) using DSC on the appropriate distress and safety frequencies in the MF, HF or VHF bands. Produced by FYT

The authority of the master or person responsible for the ship, aircraft or other vehicle is required before a distress alert can be transmitted. All stations receiving a DSC distress alert must immediately cease any transmission which may interfere with distress traffic. Stations must continue the watch until the distress alert has been acknowledged. Produced by FYT

(a) In the terrestrial radiocommunication bands:
Distress Alerting A distress alert transmission implies that a mobile unit (ship, aircraft or other vehicle) or a person is in distress or imminent danger and requires immediate assistance. A distress alert may be defined as: (a) In the terrestrial radiocommunication bands: a digital selective call (DSC) using the distress call format; or (b) In the satellite service: a message using the distress format for relay through space stations. Produced by FYT

The distress alert must include the identification of the station in distress and its position. Other information such as the nature of the distress and type of assistance required or anything else which may facilitate rescue may be included in the alert. Produced by FYT

Ship to shore distress alerts are used to warn Rescue Coordination Centres (RCC) that a vessel is in distress. This alerting is routed via LES using satellite transmissions from MES or EPIRB. Alternatively, using the terrestrial service, alerts from ship stations or EPIRBs are made to coast stations. Ship to ship alerts warn other vessels in the vicinity of the distressed vessel of the distress situation using DSC techniques in the MF and VHF terrestrial bands. The HF band may also be used. Produced by FYT

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2. 2. 3 Shore to Ship Distress Alert Relay
A coast station or an RCC which receives a distress alert shall initiate the transmission of a shore to ship distress alert relay. This distress alert relay will be addressed to all ships, to selected ships or to an individual ship using the satellite or terrestrial service. Such alert relay messages must contain the identification of the mobile unit in distress, its position and any additional information which facilitates rescue operations. Produced by FYT

2. 2. 4 Distress Alert by a Station not Itself in Distress
Where a station in the mobile or mobile satellite service learns another mobile unit is in distress it must transmit a distress alert when: (a) the mobile unit in distress is not in a position to transmit the distress alert itself; or (b) the master or person responsible for the mobile not in distress or the person responsible for the land station considers further help is required. A station transmitting a distress alert relay must make it very clear that it is not itself in distress. Produced by FYT

2. 2. 5 Acknowledgement of Receipt of Distress Alerts
Satellite service Acknowledgement of receipt of an alert from a MES must be sent immediately. Terrestrial service Acknowledgement of receipt of a distress alert by DSC on terrestrial bands must be in accordance with relevant recommendations. Produced by FYT

Coastal radio/earth station
Public communications network RCC Ship in distress Ship in vicinity Distress alert Distress alert relay Distress alert by a station not itself in distress acknowledgement Produced by FYT

• the distress signal MAYDAY;
Radiotelephony Acknowledgements from a ship or MES are given after the distress message has been received and must take the standard RT form: • the distress signal MAYDAY; • the call sign or other identification of the station sending the distress message, spoken three times; • the words THIS IS (or DE spoken as DELTA ECHO in the case of language difficulties) ; • the call sign or other identification of the station acknowledging receipt, spoken three times; • the word RECEIVED (or RRR spoken as ROMEO ROMEO ROME in the case of language difficulties) ; • the distress signal MAYDAY. Produced by FYT

Example: MAYDAY NONSUCH NONSUCH NONSUCH THIS IS
SEASTAR SEASTAR SEASTAR RECEIVED MAYDAY Produced by FYT

Acknowledgements must be given in the form:
Radiotelex Acknowledgements must be given in the form: • the distress signal MAYDAY; • the call sign or other identification of the station sending the distress alert; • the word DE (meaning "this is" or "from"); •the call sign or other identification of the station acknowledging receipt of the distress alert; • the signal RRR; • the distress signal MAYDAY. Produced by FYT

Example : MAYDAY BXXX DE BAAA RRR MAYDAY Produced by FYT

Acknowledging receipt of the distress alert from an MES using directing telegraphy is given by a LES receiving the alert by re-transmitting the ship station identity of the MES sending the alert. Produced by FYT

2. 2. 6 Acknowledging Receipt of Distress Alerts by Coast Stations, LESs or RCCs
Coast stations or a land earth stations, on reception of the initial distress alert must forward the alert to the appropriate RCC as soon as possible. The alert must be acknowledged as soon as possible by a coast station or RCC via a coast station or appropriate LES. Methods: Coast station: DSC LES: RT or telex Produced by FYT

Where a coast station uses DSC to acknowledge a distress alert, the acknowledgement must be made on the same distress calling frequency used for the original alert and be addressed to all ships. Details of the identity of the ship in distress must be included in the acknowledgement message. Produced by FYT

2. 2. 7 Acknowledging Receipt of Distress Alerts by Ship Stations
A ship receiving a distress alert must inform the master or person responsible for the ship of the contents of the alert as soon as possible. Produced by FYT

In those areas where reliable communications with a coast station is possible, ships should delay acknowledgement for a short period to permit coast stations to acknowledge first. Ships may be trading in areas where reliable communication with a coast station is not practicable. In these circumstances if they receive a distress alert from a ship station, which is beyond doubt, in their vicinity, they must acknowledge receipt as soon as possible. They must also, if so equipped, inform a RCC of the alert via a coast station or LES. Produced by FYT

Ships receiving a HF distress alert do not acknowledge it but should set watch on the RT frequency indicated in the distress alert, they may also set watch on the telex (NBDP) frequency associated with the distress alert frequency. If however the alert is not acknowledged by a coast station within three minutes then the receiving ship station must relay the distress alert. Ships acknowledging receipt of a distress alert under the circumstances outlined above should: Produced by FYT

(a) acknowledge receipt of the alert using RT on
the distress and safety frequency on the band used for the alert; or (b) acknowledge the alert using DSC on the appropriate frequency, if acknowledgment by RT of an alert received on the MF or VHF distress alerting frequency is unsuccessful. Ships which have received a shore to ship distress alert should establish communication as directed by the shore station and render assistance as required. Produced by FYT

2. 2. 8 Preparations for Handling Distress Traffic
On receipt of a transmitted DSC distress alert, ship and coast stations must set a watch on the radiotelephone distress and safety frequency associated with the frequency on which the distress alert was received. Distress alert # distress traffic Produced by FYT

For example, if the DSC distress alert was transmitted on 6312 kHz then a listening watch must be set on the RT distress frequency of 6215 kHz. Similarly ship and coast stations with NBDP equipment must set watch in the NBDP distress frequency if the distress alert message indicates that NBDP is to be used for subsequent communications. If practicable, stations should set watch on the appropriate RT frequency associated with the distress alert frequency. Produced by FYT

Distress Traffic The distress traffic is defined as all messages relating to the immediate assistance required by the ship in distress. It also includes search and rescue (SAR) communications and on-scene communications. All distress traffic should take place as far as possible on the frequencies set aside in band for this purpose. (distress, urgency and safety frequencies or channels) Produced by FYT

When using radiotelex for distress traffic, error correction techniques must be used. All messages must be preceded by at least one carriage return, a line feed signal, a letter shift signal and the distress signal MAYDAY. Distress communication should be established by the ship in distress and should be made in the broadcast forward error correction mode (FEC). ARQ (automatic repetition request) mode may subsequently be used where it is advantageous to do so. When using radiotelephony for distress traffic, simplex mode is recommend. The purpose is to allow other parties participating in SAR listen to the distress traffic. Produced by FYT

2. 2. 10 Imposing Silence Shut up!!!
The RCC responsible for controlling SAR operations also coordinates the distress traffic relating to the incident, it may however appoint another station to do this. Controlling stations may impose silence on stations which interfere with distress or SAR traffic; this may be addressed to all stations or to an individual station. The procedure used is : Shut up!!! Produced by FYT

(a) in radiotelephony, the signal SEELONCE MAYDAY, pronounced
as in the French expression "silence, m'aider"; (b) in NBDP telex normally using FEC mode the signal SILENCE MAYDAY. However the ARQ mode may be used when it is advantageous to do so. Produced by FYT

All stations, which are aware of distress traffic but are not taking part in, forbidden to transmit on the frequencies being used for distress until they receive a signal indicating normal working may be resumed. A station in the mobile service which is able to continue its normal while following distress traffic may do so. This is when the distress is well established and provided the mobile station does not interfere with distress traffic as previously indicated. Produced by FYT

2.2.11 Resumption of Normal Working
When distress traffic has ceased on frequencies which have been used for distress traffic, the RCC or station controlling SAR operations must initiate a message for transmission on those frequencies indicating the distress traffic has finished. Produced by FYT

On radiotelephony this message consists of:
• the distress signal MAYDAY; • the call 'Hello all stations' or CQ (spoken as CHARLIE QUEBEC spoken three times) ; • the words THIS IS (or DE spoken as DELTA ECHO in the case language difficulties) ; • the call sign or other identification of the station sending the message; • the time of handing in the message; • the name and call sign of the mobile station which was in distress; • the words SEELONCE FEENEE pronounced as the French word "silence fini". Produced by FYT

Example MAYDAY HELLO ALL STATIONS, ALL STATIONS, ALL STATIONS THIS IS
SEASTAR SEASTAR SEASTAR, 0920 NONSUCH/BXXX SEELONCE FEENEE Produced by FYT

When using radiotelex, the message consists of:
• the distress signal MAYDAY; • the call CQ; • the word DE; • the call sign or other identification of the station sending the message; • the time of handing in the message; • the name and call sign of the mobile station which was in distress; • the words SILENCE FINI. Produced by FYT

Example: MAYDAY CQ DE BAAA 0920 NONSUCH/BXXX SILENCE FINI
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2. 2. 12 On-scene communications
On-scene communications are those between the mobile unit in distress and assisting mobile units, and between the mobile units and the unit coordinating search and rescue operations. Control of on-scene communications is the responsibility of the unit coordinating search and rescue operations. Simplex communications shall be used so that all on-scene mobile stations may share relevant information concerning the distress incident. If direct-printing telegraphy is used, it shall be in the forward error-correcting mode. Produced by FYT

The preferred frequencies in radiotelephony for on-scene communications are 156.8MHz and 2182kHz. The frequency kHz may also be used for ship-to-ship on-scene communications using, narrow-band direct-printing telegraphy in the forward error correcting mode. In addition to 156.8MHz and 2182kHz. the frequencies 3023kHz, 4125 kHz, 5680kHz, MHz and 156.3MHz may be used for ship-to-aircraft on-scene communications. Produced by FYT

The selection or designation of on-scene frequencies is the responsibility of the unit coordinating search and rescue operations. Normally, once an on-scene frequency is established, a continuous aural or teleprinter watch is maintained by all participating on-scene mobile units on the selected frequency. Produced by FYT

2.2.13 Locating and homing signals
Locating signals are radio transmissions intended to facilitate the finding of a mobile unit in distress or the location of survivors. These signals include those transmitted by searching units, and those transmitted by the mobile unit in distress, by survival craft, by float-free EPIRBS, by satellite EPIRBs and by search and rescue radar transponders (SART) to assist the searching units. Produced by FYT

Locating signals may be transmitted in the following frequency bands:
Homing signals are those locating signals which are transmitted by mobile units 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 transmitting stations. Locating signals may be transmitted in the following frequency bands: Produced by FYT

406-406.1 MHz: COSPAS-SARSAT EPIRB
MHz: VHF EPIRB (70CH) MHz: COSPAS-SARSAT EPIRB MHz: INMARSAT EPIRB and MHz: 9GHz Radar and SART. Locating signals shall be in accordance with the relevant ITU-R Recommendations Produced by FYT

2. 2. 14 Search and Rescue Transponders (SARTs)
In GMDSS, SARTs are mandatory requirements and are used as homing devices to assist rescue craft locate the position of the distress incident. Produced by FYT

2. 2. 15 Charging for Distress Communication
The INMARSAT council defined what constituted distress and safety calls, and confirmed that calls conforming to these definitions would not be charged for the use of satellites. This took effect from 1 January 1992, a month before GMDSS was introduced. The definition of ship to shore distress and safety traffic is: Produced by FYT

(b) SAR coordination communications including
(a) distress alerts; (b) SAR coordination communications including communication subsequent to the initial distress alerts, by voice or telex, relating to the immediate assistance required by a ship which is in distress and in grave and imminent danger, provided that they are made to associated rescue coordination centres via code 39; (c) urgent navigational/meteorological danger reports by telecommunications via code 42; Produced by FYT

(d) medical assistance for grave and
imminent danger, by voice or telex via code 38 to an agency recognised by national maritime administrations. Equivalent waiver arrangements cover ship to shore traffic. It was also agreed that reduced charges will apply for ship to shore medical advice communications via code 32, Produced by FYT

2.2.16 Distress Communications by DSC
I. By ship station Transmission of DSC Distress Alert A distress alert should be transmitted if, in the opinion of the Master, the ship or a person or persons on it is in distress and requires immediate assistance. Produced by FYT

* If time permits, key in or select on the DSC equipment keyboard:
A DSC distress alert should as far as possible include the ship's last known position and the time (in UTC: Universal Time Coordinated) when it was valid. The position and the time may be included automatically by the ship's navigational equipment or may be inserted manually. The DSC distress alert is transmitted as follows: * Tune the transmitter to the DSC distress channel (2187.5kHz on MF, Channel 70 on VHF) * If time permits, key in or select on the DSC equipment keyboard: - the nature of distress; - the ship's last known position (latitude and longitude); - the time (in UTC) the position was valid; - type of subsequent distress communication (telephony); in accordance with the DSC equipment manufacturer's instructions. * Transmit the DSC distress alert. * Prepare for the subsequent distress traffic by tuning the transmitter and the radiotelephony receiver to the distress traffic channel in the same band, i.e kHz on MF, Channel 16 on VHF, while waiting for the DSC distress acknowledgement. Produced by FYT

2.2.16.2 Actions on receipt of a Distress Alert
Ships receiving a DSC distress alert from another ship should normally not acknowledge the alert by DSC since acknowledgement of a DSC distress alert by use of DSC is normally made by coast stations only. Produced by FYT

HF: relay instead of acknowledgement in the above circumstance.
Only if no other station seems to have received the DSC distress alert, and the transmission of the DSC distress alert continues, the ship should acknowledge the DSC distress alert by use of DSC to terminate the call. The ship should then, in addition, inform a coast station or a Coast Earth Station by any practicable means. (MF and VHF) HF: relay instead of acknowledgement in the above circumstance. Produced by FYT

A ship receiving a DSC distress alert from another ship shall:
Ships receiving a DSC distress alert from another ship should also defer the acknowledgement of the distress alert by radiotelephony for a short interval, if the ship is within an area covered by one or more coast stations, in order to give the coast station time to acknowledge the DSC distress alert first. A ship receiving a DSC distress alert from another ship shall: Produced by FYT

* Watch for the reception of a distress acknowledgement on the distress channel (2187.5kHz on MF, Channel 70 on VHF); from coastal radio station * Prepare for receiving the subsequent distress communication by tuning the radiotelephony receiver to the distress traffic frequency in the same band in which the DSC distress alert was received, i.e kHz on MF, channel 16 on VHF; Acknowledge the receipt of the distress alert by transmitting the following, by radiotelephony on the distress traffic frequency in the same band in which the DSC distress alert was received, i.e kHz on MF, Channel 16 on VHF: Produced by FYT

- the 9-digit identity of the ship in distress, repeated 3 times;
- "MAYDAY"; - the 9-digit identity of the ship in distress, repeated 3 times; - "this is"; - the 9-digit identity or the call sign or other identification of own ship, repeated 3 times; - "RECEIVED MAYDAY". Ships out of range of a distress event or not able to assist should only acknowledge if no other station appears to acknowledge the receipt of the DSC distress alert. Produced by FYT

Distress Traffic On receipt of a DSC distress acknowledgement, the ship in distress should commence the distress traffic by radiotelephony on the distress traffic frequency (2182 kHz on MF, Channel 16 on VHF) as follows: - "MAYDAY"; - "this is"; - the 9-digit identity and the call sign or other identification of the ship; - the ship's position in latitude and longitude or other reference to a known geographical location; - the nature of distress and assistance wanted; - any other information which might facilitate the rescue. Produced by FYT

2.2.16.4 Transmission of a DSC Distress Relay Alert
A ship knowing that another ship is in distress shall transmit a DSC distress relay alert if: - the ship in distress is not itself able to transmit the distress alert; - the master of the ship considers that further help is necessary. Produced by FYT

The DSC distress relay alert is transmitted as follows:
* Tune the transmitter to the DSC distress channel ( kHz on MF, Channel 70 on VHF); * Select the distress relay call format on the DSC equipment; * Key in or select on the DSC equipment keyboard: - all Stations Call or the 9-digit identity of the appropriate coast station; - the 9-digit identity, of the ship in distress, if known; - the nature of distress; - the latest position of the ship in distress, if known; - the time (in UTC) the position was valid (if known); - type of subsequent distress communication (telephony); - transmit the DSC distress relay call. Produced by FYT

2.2.16.5 Acknowledgement of a DSC Distress Relay Alert received from a Coast Station
Coast stations, after having received and acknowledged a DSC distress alert, may if necessary, re-transmit the information received as a DSC distress relay call, addressed to all ships, all ships in a specific geographical area, a group of ships or a specific ship. Produced by FYT

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Ships receiving a distress relay call transmitted by a coast station shall not use DSC to acknowledge the call, but should acknowledge the receipt of the call by radiotelephony on the distress traffic channel in the same band in which the relay call was received, i.e kHz on MF, Channel 16 on VHF. Acknowledge the receipt of the distress alert by transmitting the following, by radiotelephony on the distress traffic frequency in the same band in which the DSC distress relay alert was received: Produced by FYT

- "MAYDAY"; - the 9-digit identity or the call sign or other identification of the calling coast station; - ''this is"; - the 9-digit identity or call sign or other identification of own ship; - "RECEIVED MAYDAY". Produced by FYT

2.2.16.6 Acknowledgement of a DSC Distress Relay Alert received from another Ship
Ships receiving a distress relay alert from another ship shall follow the same procedure as for acknowledgement of a distress alert, i.e. the procedure given in section above. Produced by FYT

2.2.16.7 Cancellation of an inadvertent Distress Alert (Distress Call)
A station transmitting an inadvertent distress alert shall cancel the distress alert using the following procedure: - Immediately transmit a DSC "distress cancellation" with own ship's MMSI inserted as identification of ship in distress. In addition cancel the distress alert aurally over the telephony distress traffic channel associated with each DSC channel on which the "distress call" was transmitted. - Monitor the telephony distress traffic channel associated with the DSC channel on which the distress was transmitted, and respond to any communications concerning that distress alert as appropriate. Produced by FYT

II. BY COAST STATION 2.2.16.8 Reception of a DSC Distress Alert (Distress Call)
The transmission of a distress alert indicates that a mobile unit (a ship, aircraft or other vehicle ) or a person is in distress and requires immediate assistance. The distress alert may be a digital selective call using a distress call format (distress call). Coast stations in receipt of a distress call shall ensure that it is routed as soon as possible to an RCC. The receipt of a distress call is to be acknowledged as soon as possible by the appropriate coast station. Produced by FYT

2.2.16.9 Acknowledgement of a DSC Distress Alert (Distress call)
The coast station shall transmit the acknowledgement on the distress calling frequency on which the call was received and should address it to all ships. The acknowledgement shall include the identification of the ship whose distress call is being acknowledged. Produced by FYT

The acknowledgement of a DSC distress call is transmitted as follows:
* Use a transmitter which is tuned to the frequency on which the distress call was received. * In accordance with the DSC equipment manufacturer's instructions, key in or select on the DSC equipment keyboard: - distress call acknowledgement; - 9-digit identity of the ship in distress; - nature of distress; - distress coordinates; - the time (in UTC) when the position was valid. * Transmit the acknowledgement Produced by FYT

2.2.16.10 Transmission of a DSC Distress Relay Alert (Distress Relay call)
Coast stations shall initiate and transmit a distress relay call in any of the following cases: a) when the distress of the mobile unit has been notified to the coast station by other means and a broadcast alert to shipping is required by the RCC; and b) when the person responsible for the coast station considers that further help is necessary (Close cooperation with the appropriate RCC is recommended under such conditions). In the cases mentioned above, the coast station shall transmit a shore-to-ship distress relay call addressed, as appropriate, to all ships, to a selected group of ships, to a geographical area or to a specific ship. Produced by FYT

The distress relay call is transmitted as follows:
The distress relay call shall contain the identification of the mobile unit in distress, its position and other information which might facilitate rescue. The distress relay call is transmitted as follows: * Use a transmitter which is tuned to the frequency for DSC distress calls ( kHz on MF, MHz/Channel 70 on VHF). * In accordance with the DSC equipment manufacturer's instructions, key in or select on the DSC equipment keyboard. - distress relay call; - the format specifier (all ships, group of ships, geographical area or individual station); - if appropriate, the address of the ship, group of ships or geographical area (not required if the format specifier is "all ships"); - 9-digit identity of the ship in distress, if known - nature of distress; - distress coordinates; - time (in UTC) when the position was valid. * Transmit the distress relay call. Produced by FYT

2.2.16.11 Reception of a Distress Relay Alert (Distress Relay Call)
If the distress relay call is received from a ship station, coast stations on receipt of the distress relay call shall ensure that the call is routed as soon as possible to an RCC. The receipt of the distress relay call is to be acknowledged as soon as possible by the appropriate coast station using a DSC distress relay acknowledgement addressed to the ship station. If the distress relay call is received from a coast station, other coast stations will normally not have to take further action. Produced by FYT

2. 2. 17 Satcom Distress Procedure
The following procedures are general procedures using INMARSAT-A; for specific equipment refer to manufacturer's instructions. Similarly for INMARSAT-C (telex only), the procedures are of a general nature and again users should refer to manufacturer's instructions. Telex communication is the preferred mode of operation since it provides a written record of distress traffic. There are four levels of priority: 0 - Routine traffic 1 - Safely traffic 2 - Urgency traffic 3 - Distress traffic Produced by FYT

(1) Lift off the handset. 2. 2. 17. 1 By telephone
(2) Remove protective cover and select EMERGENCY (priority 3). (3) Dial correct digits to select required LES (usually the one nearest to ship). 01 Southbury 01 Santa Paula 02 Goonhilly 03 Yamaguchi 04 Eik Produced by FYT

(4) After making contact with RCC: (5) Begin message:
(4) After making contact with RCC: (5) Begin message: MAYDAY MAYDAY MAYDAY followed by name or other identification of the ship in distress; particulars of position; the nature of the distress and the kind of assistance required; any other information which might facilitate the rescue. (6) Before reverting to routine traffic ensure priority 0 is restored. Produced by FYT

2.2.17.2 By telex (1) Switch telex on-line.
(2) Remove protective cover and select EMERGENCY (priority 3). (3) Type correct digits followed by + to select LES 01 Southbury 01 Santa Paula 02 Goonhilly 03 Yamaguchi 04 Eik Produced by FYT

(4) Upon receipt of answerback from RCC: (5) Type the following:
SOS SOS SOS followed by name or other identification of the ship in distress; particulars of its position; the nature of the distress and the kind of assistance required; any other information which might facilitate the rescue. (6) Before reverting to routine traffic ensure priority 0 is restored. Produced by FYT

2.2.17.3 Sending distress alerts on an Inmarsat-C terminal
There are two methods of sending distress alerts: (1) by keying the information into the MES terminal using the edit facilities; or (2) by using the remote distress alert button (s). Produced by FYT

2.2.17.4 Using the edit facilities on the MES terminal
This is the preferred method as it enables the operator to key in up-to-date information. Method (1) Select the distress alert menus according to the manufacturer's operating instructions. (2) when requested, complete following message: MES ID entered automatically by MES. LES required - select nearest LES within the ocean region to own ship's position. Position latitude and longitude entered manually via keyboard, or automatically from electronic navigator such as GPS. Date & time of last - enter time manually or automatically from position update electronic navigator (all times to be quoted in UTC). Position status should read satisfactorily. Produced by FYT

Nature of distress - One of the following: Unspecified Listing
Fire/explosion Sinking Flooding Disabled and adrift Collision Abandoning ship Grounding Assistance required Produced by FYT

(3) Press the appropriate key(s) to send the alert.
Ship's course(00~3590) - Entered manually or automatically from gyro compass. Ship's speed (Knots) - Entered manually or automatically from speed log. (3) Press the appropriate key(s) to send the alert. (4) If an acknowledgement is not received from both the LES and RCC, within five minutes repeat the distress alert. INMARSAT C Produced by FYT

2. 2. 17. 5 Using the remote distress button(s) on the MES
If distress alert buttons are fitted to the MES and there is insufficient time to use the MES keyboard, an alert may be initiated in this manner. However, the information stored may be out of date unless recently updated positional information has been inserted, or it is continuously updated by an electronic navigator. In the interests of safety of life at sea, operators are advised to keep the MES logged on with up to date positional information in the store at all times. Produced by FYT

Method (1) Press the remote distress alert button until an indication that the MES is in the distress alert mode. This condition should remain until an acknowledgement is received from the LES and then the nearest RCC. (2) If no acknowledgement is received from both the LES and RCC, within five minutes repeat the distress alert. (3) It possible send updated information about your distress situation using the same format. Produced by FYT

2. 2. 18 GMDSS Distress Alert Procedure
It is apparent that mobile stations in distress have a number of options available to them to alert shore-based authorities (or other ships) that they require assistance. The communication medium used will, to a large extent, depend on the area the vessel is in and on the propagation conditions at the time. For example: Produced by FYT

(i) the equipment fitted;
• Ships in Al areas would transmit a ship/shore and ship/ship alert on Channel 70 VHF using DSC. • Ships in A2 areas would transmit their ship/shore and ship/ship alert on kHz using DSC and indicating whether RT or telex (NBDP) is to be used to transmit the distress message, 70CH for ship/ship distress alert. For ships in areas A3 and A4 ship to ship alerts must be transmitted on kHz using DSC and 70CH using DSC. However for ship to shore alerts a choice is available once again depending on: (i) the equipment fitted; (ii) this equipment's operational availability; (iii) the existing propagation conditions. For example: (a) An INMARSAT'S Land Earth Station could be alerted. (b) A coast station could be alerted by using HF RT communications with DSC. (c) A satellite EPIRB could be activated. Produced by FYT

Such arrangements are designed to offer a high probability of a successful alert irrespective of the sea area involved, thus enabling a rapid response to the alert by rescue team. It should be noted that ships in all areas are required to be fitted with EPIRBs under GMDSS carriage requirements. Thus in the event of abandoning ship without sending a distress alert the EPIRB provides a secondary method of distress alerting. Produced by FYT

Any alert (Non-EPIRB) should contain the following information:
(a) ship's identification; (b) its position; (c) the nature of the distress; (d) information which can assist rescuers locate the distress ship and assist in its rescue. Produced by FYT

When alerts are received by one of INMARSAT's Land Earth Stations they are then passed to a Rescue Coordination Centre (RCC). The RCC will relay the alert to search and rescue units and to other ships in the area and will control and coordinate rescue procedures. Relaying of alerts to other vessels in the area is carried out using satellite communications or by terrestrial communications on appropriate frequencies. Use is made of " area call" facilities to notify only those ships in the immediate vicinity of the distress. Ships which have been alerted in this way then establish communications with the RCC via an appropriate medium (satellite or terrestrial communications). Produced by FYT

False Alerts False alerts caused by the inadvertent of incorrect operation of GMDSS equipment can put a significant burden on Search and Rescue Centres. The chances of false alerts coinciding with a real life distress situation are very real and as a consequence, search and rescue forces could be delayed in responding to a real distress. Most false alerts are caused as a result of human error. Produced by FYT

URGENCY SERVICES Urgency and safety communications are defined as those relating to: (a) navigational and meteorological warnings and urgent information; (b) ship to ship safety of navigation communications; (c) ship reporting communications; (d) support communications for SAR operations; (e) other urgency or safety messages; (f) communications relating to the navigation, movements and needs of ships and weather observation messages destined for an official meteorological service. Produced by FYT

2. 3.1 Urgency Communications
The use of the urgency call format implies that the station making the call has a very urgent message to transmit concerning the safety of the mobile unit or a person. The urgency signal or urgency call format must only be sent on the authority of the master or person responsible for the mobile unit or by a land earth station or coast station with approval of the responsible authority. The urgency signal and message must be transmitted on one or more of the authorised distress and safety frequencies or the maritime mobile satellite service. Produced by FYT

In the terrestrial service, the announcement of the urgency message must be made on one or more of the authorised distress and calling frequencies using DSC and the urgency call format. If the maritime mobile telex service is to be used, a separate urgency announcement is not required, as selection of URGENT PRIORITY gains priority access to the system. The urgency signal in radiotelephony consists of the words PAN PAN, each word being pronounced as in the French word "panne" , In radiotelephony the urgency message must be preceded by the urgency signal repeated three times together with the identification of the transmitting station. Produced by FYT

Example: PAN PAN, PAN PAN, PAN PAN
ALL STATIONS, ALL STATIONS, ALL STATIONS THIS IS SEASTAR SEASTAR SEASTAR Produced by FYT

In NBDP (telex) the urgency message must be preceded by the urgency signal and the identification of the transmitting station. Example: PAN PAN DE BACD Produced by FYT

Urgency communication using NBDP telex should be established in the broadcast FEC mode. ARQ mode may subsequently be used where it is advantageous to do so. All messages must be preceded by at least one carriage return (CR), a line feed signal (LF), and the urgency signal (PAN PAN). Produced by FYT

2.3.2 Urgency Messages and DSC I. BY SHIP STATIONS
Transmission of Urgency Messages Transmission of urgency messages shall be carried out in two steps: * Announcement of the urgency message, * Transmission of the urgency message. Produced by FYT

The announcement is carried out by transmission of a DSC urgency call on the DSC distress calling channel ( kHz on MF, Channel 70 on VHF). The urgency message is transmitted on the distress traffic channel(2182 kHz on MF, Channel 16 on VHF). The DSC urgency call may be addressed to all stations or to a specific station. The frequency on which the urgency message will be transmitted shall be included in the DSC urgency call. Produced by FYT

The transmission of an urgency message is thus carried out as follows:
Announcement: * Tune the transmitter to the DSC distress calling channel ( kHz on MF, Channel 70 on VHF); * Key in or select on the DSC equipment keyboard: - All Ships Call or the 9-digit identity of the specific station; - the category of the call (urgency): - the frequency or channel on which the urgency message will be transmitted; - the type of communication in which the urgency message will be given (radiotelephony); in accordance with the DSC equipment manufacturer's instructions. * Transmit the DSC urgency call. Produced by FYT

Transmission of the urgency message:
* Tune the transmitter to the frequency or channel indicated in the DSC urgency call; * Transmit the urgent message as follows: - "PAN PAN", repeated 3 times; - "ALL STATIONS" or called station, repeated 3 times; - "this is"; - the 9-digit identity and the call sign or other identification of own ship; - the text of the urgency message. Produced by FYT

2.3.2.2 Reception of an Urgency Message
Ships receiving a DSC urgency call announcing an urgency message addressed to all ships shall NOT acknowledge the receipt of the DSC call, but should tune the radiotelephony receiver to the frequency indicated in the call and listen to the urgency message. Produced by FYT

II. BY COAST STATIONS 2.3.2.3 Transmission of a DSC Announcement by coast stations
The announcement of the urgency message shall be made on one or more of the distress and safety calling frequencies using DSC and the urgency call format. The DSC urgency call may be addressed to all ships, to a selected group of ships, to a geographical area or to a specific ship. The frequency on which the urgency message will be transmitted after the announcement shall be included in the DSC urgency call. The DSC urgency call is transmitted as follows: Produced by FYT

- the category of the call (urgency);
* Use a transmitter which is tuned to the frequency for DSC distress calls ( kHz on MF, MHz /Channel 70 on VHF). * In accordance with the DSC equipment manufacturer's instructions, key in or select on the DSC equipment keyboard: - the format specifier (all ships call, group of ships, geographical area or individual station); - if appropriate, the address of the ship, group of ships or geographical area (not required if the format specifier is "all ships"); - the category of the call (urgency); - the frequency or channel on which the urgency message will be transmitted; - the type of communication in which the urgency message will be transmitted (radiotelephony). * Transmit the DSC urgency call. After the DSC announcement, the urgency message will be transmitted on the frequency indicated in the DSC call. Produced by FYT

2. 4 SAFETY SERVICES 2. 4.1 Safety Communications
The safety call format implies that the station making the call has an important navigational or meteorological warning to transmit. In the terrestrial service the announcement of the safety message must be made on one or more of the authorised distress and calling frequencies using DSC. If the maritime mobile satellite service is to be used, a separate safety announcement is not required. The safety signal and message must be transmitted on one or more authorised distress and safety frequencies or via the maritime satellite service. The safety signal in radiotelephony consists of the SECURITE pronounced (SAY-CUREE-TAY) as in French. Produced by FYT

SECURITE, SECURITE, SECURITE THIS IS SEASTAR SEASTAR SEASTAR
Example: SECURITE, SECURITE, SECURITE ALL STATIONS, ALL STATIONS, ALL STATIONS THIS IS SEASTAR SEASTAR SEASTAR In NBDP telex, the safety message must be preceded by the safety signal and the identification of the transmitting station. SECURITE DE BACD Produced by FYT

Safety communication using NBDP telex should be established in the broadcast (forward error correction) mode. ARQ mode may subsequently be used where it is advantageous to do so. All messages must be precede by at least one carriage return, a line feed signal, a letter shift signal and the safety signal (SECURITE). Produced by FYT

Messages containing information concerning the presence of serious ice, dangerous wrecks, or any other imminent danger to navigation, must be transmitted as soon as possible to other ship s in the vicinity, and to the appropriate authorities at the first point coast with which contact can be established. These transmissions are preceded by the safety signal. Produced by FYT

2. 4. 2 Intership Navigation Safety Communication
Intership navigation safety communications are VHF RT communications between ships for the purpose of contributing to the safe movement of ships, Channel 13 VHF is used. Produced by FYT

2. 4. 3 Safety Messages and DSC by ship station 2. 4. 3
Safety Messages and DSC by ship station Transmission of safety messages shall be carried out in two steps * Announcement of the safety message, * Transmission of the safety message. The announcement is carried out by transmission of a DSC safety call on the DSC distress calling channel ( kHz on MF, Channel 70 on VHF). Produced by FYT

The transmission of a safety message is thus carried out as follows:
The safety message is normally transmitted on the distress and safety traffic channel in the same band in which the DSC call was sent. i.e kHz on MF, channel 16 on VHF. The DSC safety call may be addressed to all ships, all ships in a specific geographical area or to a specific station. The frequency on which the safety message will be transmitted shall be included in the DSC call. The transmission of a safety message is thus carried out as follows: Produced by FYT

* Key in or select on the DSC equipment keyboard:
Announcement: * Tune the transmitter to the DSC distress calling channel ( kHz on MF, Channel 70 on VHF); * Select the appropriate calling format on the DSC equipment (all ships, area call or individual call); * Key in or select on the DSC equipment keyboard: - specific area or 9-digit identity of specific station, if appropriate; - the category of the call (safety); - the frequency or channel on which the safety message will be transmitted; - the type of communication in which the safety message will be given (radiotelephony); in accordance with the DSC equipment manufacturer's instructions. * Transmit the DSC safety call. Produced by FYT

Transmission of the safety message:
* Tune the transmitter to the frequency or channel indicated in the DSC safety call. * Transmit the safety message as follows: - "SECURITE", repeated 3 times; - "ALL STATIONS" or called station, repeated 3 times; - "this is"; - the 9-digit identity and the call sign or other identification of own ship; - the text of the safety message. Produced by FYT

2.4.3.2 Reception of a Safety Message
Ships receiving a DSC safety call announcing a safety message addressed to all ships shall NOT acknowledge the receipt of the DSC safety call, but should tune the radiotelephony receiver to the frequency indicated in the call and listen to the safety message. Produced by FYT

2.4.4 Transmission of a DSC Announcement by Coast stations
The announcement of the safety message shall be made on one or more of the distress and safety calling frequencies using DSC and the safety call format. The DSC safety call may be addressed to all ships, to a group of ships, to a geographical area or to a specific ship. The frequency on which the safety message will be transmitted after the announcement shall be included in the DSC safety call. Produced by FYT

The DSC safety call is transmitted as follows:
* Use a transmitter which is tuned to the frequency for DSC distress calls ( kHz on MF, MHz/Channel 70 on VHF). * In accordance with the DSC equipment manufacturer's instructions, key in or select on the DSC equipment keyboard : - the format specifier (all ships call, group of ships, geographical area or individual station); - if appropriate, the address of the ship, group of ships or geographical area (not required if the format specifier is "all ships"); - the category of the call (safety); - the frequency or channel on which the safety message will be transmitted; - the type of communication in which the safety message will be transmitted (radiotelephony). * Transmit the DSC safety call. After the DSC announcement, the safety message will be transmitted on the frequency indicated in the DSC call. Produced by FYT

2.5 SPECIAL CONDITIONS AND PROCEDURES FOR DSC COMMUNICATION ON HF BY SHIP STATION
DISTRESS Transmission of DSC Distress Alert DSC distress alert should be sent to coast stations – e.g. in A3 and A4 sea areas on HF - and on MF and/or VHF to other ships in the vicinity. The DSC distress alert should as far as possible include the ship's last known position and the time (in UTC) it was valid. If the position and time is not inserted automatically from the ship's navigational equipment, it should be inserted manually. Produced by FYT

Ship-to-shore Distress Alert Choice of HF band
Propagation characteristics of HF radio waves for the actual season and time of the day should be taken into account when choosing HF bands for transmission of DSC distress alert. As a general rule the DSC distress channel in the 8 MHz maritime band ( kHz) may in many cases be an appropriate first choice. Transmission of the DSC distress alert in more than one HF band will normally increase the probability of successful reception of the alert by coast stations. Produced by FYT

DSC distress alert may be sent on a number of HF bands in two different ways:
a) either by transmitting the DSC distress alert on one HF band, and waiting a few minutes for receiving acknowledgement by a coast station; if no acknowledgement is received within 3 minutes, the process is repeated by transmitting the DSC distress alert on another appropriate HF band etc; b) or by transmitting the DSC distress alert at a number of HF bands with no or only very short pauses between the calls, without waiting for acknowledgement between the calls. It is recommended to follow procedure a) in all cases, where time permits to do so; this will make it easier to choose the appropriate HF band for commencement of the subsequent communication with the coast station on the corresponding distress traffic channel. Produced by FYT

Transmitting the DSC alert
* Tune the transmitter to the chosen HF DSC distress channel (4207.5, 6312, , 12577, kHz) * Follow the instructions for keying in or selection of relevant information on the DSC equipment keyboard as described in Section * Transmit the DSC distress alert. Produced by FYT

2.5.1.2 Preparation for the subsequent Distress Traffic
After having transmitted the DSC distress alert on appropriate DSC distress channels (HF, MF and/or VHF), prepare for the subsequent distress traffic by tuning the radiocommunication set(s) (HF, MF and/or VHF as appropriate) to the corresponding distress traffic channel(s). The distress traffic frequencies are: HF: Telephony kHz kHz kHz kHz kHz Telex kHz kHz kHz kHz kHz MF: Telephony kHz Telex kHz VHF: Telephony (only) Channel 16 ( MHz) Produced by FYT

Distress traffic The procedures described in section are used when the distress traffic on MF/HF is carried out by radiotelephony. The following procedures shall be used in cases where the distress traffic on MF/HF is carried out by radiotelex: Produced by FYT

* All messages shall be preceded by - at least one carriage return
* The Forward Error Correcting (FEC) mode shall be used unless specifically requested to do otherwise. * All messages shall be preceded by - at least one carriage return - line feed - one letter shift - the distress signal MAYDAY. Produced by FYT

- carriage return, line feed, letter shift;
* The ship in distress should commence the distress telex traffic on the appropriate distress telex traffic channel as follows: - carriage return, line feed, letter shift; - the distress signal "MAYDAY"; - the words "this is"; - the 9-digit identity and call sign or other identification of the ship; - the ship's position if not included in the DSC distress alert; - the nature of distress; - any other information which might facilitate the rescue. Produced by FYT

2.5.1.4 Actions on Reception of a DSC Distress Alert on HF from another Ship
Ships receiving a DSC distress alert on HF from another ship shall not acknowledge the alert, but should: * Watch for reception of a DSC distress acknowledgement from a coast station. * While waiting for reception of a DSC distress acknowledgement from a coast station: Prepare for reception of the subsequent distress communication by tuning the HF radiocommunication set (transmitter and receiver) to the relevant distress traffic channel in the same HF band in which the DSC distress alert was received * If no distress traffic is received on the HF channel within 1 to 2 minutes, tune the HF radiocornmunication set to the relevant distress traffic channel in another HF band deemed appropriate in the actual case. * If no DSC distress acknowledgement is received from a coast station within 3 minutes, and no distress communication is observed going on between a coast station and the ship in distress: - Transmit a DSC distress relay alert; - Inform a Rescue Coordination Centre via appropriate radiocornmunications means. Produced by FYT

2.5.1.6 Acknowledgement of a HF DSC Distress Relay Alert received from a Coast Station
Ships receiving a DSC distress relay alert from a coast station on HF. addressed to all ships within a specified area, should NOT acknowledge the receipt of the relay alert by DSC. but by radiotelephony on the telephony distress traffic channel in the same band(s) in which the DSC distress relay alert was received. Produced by FYT

URGENCY Transmission of urgency messages on HF should normally be addressed - either to all ships within a specified geographical area - or to a specific coast station. Produced by FYT

Announcement of the urgency message is carried out by transmission of a DSC call with category urgency, on the appropriate DSC distress channel. The transmission of the urgency message itself on HF is carried out by radiotelephony or radiotelex on the appropriate distress traffic channel in the same band in which the DSC announcement was transmitted. Produced by FYT

2.5.2.1 Transmission of DSC Announcement of an Urgency Message on HF
* Choose the HF band considered to be the most appropriate, taking into account propagation characteristics for HF radio waves at the actual season and time of the day; the 8 MHz band may in many cases be an appropriate first choice; Produced by FYT

* Tune the HF transmitter to the DSC distress channel in the chosen HF band;
* Key in or select call format for either geographical area call or individual call on the DSC equipment, as appropriate; * In case of area call, key in specification of the relevant geographical area; Produced by FYT

* Transmit the DSC call;
* Follow the instructions for keying in or selection of relevant information on the DSC equipment keyboard as described in section , including type of communication in which the urgency message will be transmitted (radiotelephony or radiotelex); * Transmit the DSC call; * If the DSC call is addressed to a specific coast station, wait for DSC acknowledgement from the coast station. If acknowledgement is not received within a few minutes, repeat the DSC call on another HF frequency deemed appropriate. Produced by FYT

2.5.2.2 Transmission of the Urgency Message and subsequent Action
* Tune the HF transmitter to the distress traffic channel (telephony or telex) indicated in the DSC announcement; * If the urgency message is to be transmitted using radiotelephony, follow the procedure described in section ; Produced by FYT

- Use the Forward Error Correcting (FEC)
* If the urgency message is to be transmitted by radiotelex, the following procedure shall be used: - Use the Forward Error Correcting (FEC) mode unless the message is addressed to a single station whose radiotelex identity number is known; - commence the telex message by: * at least one carriage return, line feed, one letter shift Produced by FYT

* the urgency signal "PAN PAN" * "this is";
* the 9-digit identity of the ship and the call sign or other identification of the ship * the text of the urgency message Announcement and transmission of urgency messages addressed to all HF equipped ships within a specified area may be repeated on a number of HF bands as deemed appropriate in the actual situation. Produced by FYT

2.5.2.3 Reception of an Urgency Message
Ships receiving a DSC urgency call announcing an urgency message shall NOT acknowledge the receipt of the DSC call, but should tune the radiocommunication receiver to the frequency and communication mode indicated in the DSC call for receiving the message. Produced by FYT

SAFETY The procedures for transmission of DSC safety announcement and for transmission of the safety message are the same as for frequency messages, described in section 2.5.2, except that: - in the DSC announcement, the category SAFETY shall be used - in the safety message, the safety signal "SECURITE" shall be used instead of the urgency signal "PAN PAN". Produced by FYT

2.5.4 PUBLIC CORRESPONDENCE ON HF
The procedures for DSC communication for public correspondence on HF are the same as for MF. Propagation characteristics should be taken into account when making DSC communication on HF. Produced by FYT

International and national HF DSC channels different from those used for DSC for distress and safety purposes are used for DSC for public correspondence. Ships calling a HF coast station by DSC for public correspondence should preferably use the coast station's national DSC calling channel. Produced by FYT

2.5.5 TESTING THE EQUIPMENT USED FOR DISTRESS AND SAFETY ON HF
The procedure for testing the ship's equipment used for DSC distress, urgency and safety calls on HF by transmitting DSC test calls on HF DSC distress channels is the same as for testing on the MF DSC distress frequency kHz. Produced by FYT

2.6 SPECIAL CONDITIONS AND PROCEDURES FOR DSC COMMUNICATION ON HF BY COAST STATION
DISTRESS Reception and Acknowledgement of a DSC Distress Alert on HF Ships in distress may in some cases transmit the DSC distress alert on a number of HF bands with only short intervals between the individual calls. The coast station shall transmit DSC acknowledgement on all HF DSC distress channels on which the DSC alert was received in order to ensure as far as possible that the acknowledgement is received by the ship in distress and by all ships which received the DSC alert. Produced by FYT

Distress Traffic The distress traffic should, as a general rule, be initiated on the appropriate distress traffic channel (radiotelephony or narrow band direct printing) in the same band in which the DSC alert was received. For distress traffic by NBDP the following rules apply: Produced by FYT

- All messages shall be preceded by at least
one carriage return, line feed, one letter shift and the distress signal MAYDAY; - Forward Error Correcting (FEC) broadcast mode should normally be used ARQ mode should be used only when considered advantageous to do so in the actual situation and provided that the radiotelex number of the ship is known. Produced by FYT

2.6.1.3 Transmission of DSC Distress Relay Alert on HF
HF propagation characteristics should be taken into account when choosing HF band(s) for transmission of DSC distress relay alert. IMO Convention ships equipped with HF DSC for distress and safety purposes are required to keep continuous automatic DSC watch on the DSC distress channel in the 8 MHz band and on at least one of the other HF DSC distress channels. Produced by FYT

In order to avoid creating on board ships uncertainty regarding on which band the subsequent establishment of contact and distress traffic should be initiated, the HF DSC distress relay alert should be transmitted on one HF band at a time and the subsequent communication with responding ships be established before eventually repeating the DSC distress relay alert on another HF band. Produced by FYT

2.6.2 URGENCY 2.6.2.1 Transmission of Urgency Announcement and Message on HF
For urgency messages by NBDP the following apply: Produced by FYT

- The urgency message shall be preceded
by at least one carriage return, line feed, one letter shift, the urgency signal PAN PAN and the identification of the coast station; - Forward Error Correcting (FEC) broadcast mode should normally be used. ARQ mode should be used only when considered advantageous to do so in the actual situation and provided that the radiotelex number of the ship is known. Produced by FYT

2.6.3 SAFETY 2.6.3.1 Transmission of Safety Announcements and Messages on HF
For safety messages by NBDP the following apply: Produced by FYT

- The safety message shall be preceded by
at least one carriage return, line feed, one letter shift, the safety signal SECURITE and the identification of the coast station; - Forward Error Correcting (FEC) broadcast mode should normally be used. ARQ mode should be used only when considered advantageous to do so in the actual situation and provided that the radiotelex number of the ship is known. Produced by FYT

2.6.4 TESTING THE EQUIPMENT USED FOR DISTRESS AND SAFETY
The procedures for ships testing their equipment used for DSC distress, urgent and safety calls on HF DSC distress channels and the acknowledgement of the test call by the coast station are the same as for testing on the MF DSC distress frequency kHz. Produced by FYT

2.7 SEARCH AND RESCUE RADAR TRANSPONDER 2.7.1 INTRODUCTION
At least one Radar Transponder to be carried on every ship of 300 GRT and above and two Radar Transponders on ships of 500 GRT and above. Radar Transponders may be carried in Survival Craft and may be incorporated in a VHF DSC EPIRB. The purpose of a search and rescue transponder (SART) is to indicate the position of persons or vessels in distress. A SART is an easily portable device which should be taken into the lifeboat or life raft when abandoning ship. After switch on, the SART remains in Standby mode (for up to 96 hours) until activated by a 9 GHz radar emission which then causes the SART to transmit a signal appearing as a straight line of 'blips' on the radar display. When switched on it will transmit signals only when triggered by signals from an external marine or aircraft radar operating in the 9 GHz (3 cm) band, it should respond to interrogation from ships at five nautical miles range. Produced by FYT

An audible alarm or small light is incorporated into the device in order that persons in distress will be aware that a rescue ship or aircraft is within close range. Battery capacity should allow 96 hours of standby operation and the SART should be able to respond to interrogating signals even in heavy swell. When a SART is activated it generates a swept frequency signal which shows up on the rescue craft's radar screen. This is a distinctive line of about 12 equally spaced blips extending outwards from the SART's position along its line of bearing. The total length of this line of blips is eight nautical miles. This assists rescue craft locate and approach the scene of the incident. Produced by FYT

2.7.2 SART Signals at Close Range
As a rescue ship nears the SART (usually around one nautical mile) radar antenna sidelobe transmissions cause the dots on the radar screen to change into concentric arcs. At even closer ranges concentric circles appear, which indicates to rescue vessels that the SART is now at very close range. The SART dotted line can be recovered by reducing the radar receiver gain. The exact location of the SART is just inside the first narrow dot (i. e. the one closest to the radar observer). Produced by FYT

Produced by FYT

2.7.3 OPERATIONAL AND TECHNICAL CHARACTERISTICS
The SART can be activated manually or automatically when placed into the water so that it will thereafter respond when interrogated. When activated in a distress situation, a SART responds to radar interrogation by transmitting a swept frequency signal which generates as a line of 12 blip code on a radar screen outward from the SART's position along its line of bearing. Displayed on the Plain Position Indicator (PPI), the spacing between each pair of dots will be 0.6 nautical miles. Produced by FYT

Produced by FYT

In order to distinguish the SART from other responses, it is preferable to use a radar scale between 6 and 12 n miles, this will assist in differentiating between the SART and other responses. As the search craft approaches to within about 1 n mile of the SART, the blip dots will change into wide arcs, and even become complete circles as the SART is closed and becomes continually triggered. This is a useful warning to the search craft to slow down! This distinctive and unique radar signal is easily recognized and is therefore much easier to spot than a single echo such as from a radar reflector. Moreover, the fact that the SART is actually a transmitter means that the return pulses can be as strong as echoes received from much larger objects. Any radar bandwidth of less than 5 MHz will attenuate the SART signal slightly, so it is preferable to use a medium bandwidth to ensure optimum detection of the SART. The specific Radar Operating Manual should be consulted about the particular radar parameters and bandwidth selection. Produced by FYT

The SART also provides a visual or audible indication of its correct operation and will also inform survivors when it is interrogated by a radar. The SART should have sufficient battery capacity to operate in the stand-by condition for 96 hours followed by a minimum 8 hours of transmission while being interrogated by a radar. It should also be able to operate under ambient temperatures of -20°C to + 55°C. Produced by FYT

A SART built to the latest specifications will have excellent receiver sensitivity, and will detect the high power pulses from a search radar at a much greater range then it's relatively weak return pulses will be detected by the radar. The limiting range is therefore determined by the return path. Four main factors will affect the range at which a SART will be detected on a ship's radar screen: Produced by FYT

1) THE TYPE OF RADAR USED, AND HOW IT IS OPERATED
Clearly, some radars are better than others. Larger vessels will have higher gain antennas, set higher above sea level. The radar receiver performance is also very important and should be optimised. 2) THE WEATHER CONDITIONS A flat calm will affect performance due to 'multi-path' propagation - radar pulses being reflected from the surface of the sea. High waves may result in reception at greater distances, due to occasional elevation of both radar and SART; however, detection will be sporadic, due to masking of the signal in the troughs. Elimination of sea and rain clutter will depend on the radar used, and the skill of the operator, as for normal radar operations. Produced by FYT

3) THE MOUNTING OF THE SART ON THE SURVIVAL CRAFT
The mounting of the SART is the one factor over which the SART user has some control. For maximum range an unobstructed mounting as high as possible is required. The IMO Recommended Performance Standard for the SART calls for a range of "up to at least 5 nautical miles", for a SART mounted 1 m above sea level. This assumes a search radar complying with IMO requirements, with its antenna 15m above sea level. Tests have shown the importance of maintaining the SART antenna height of at least 1 m above sea level; Produced by FYT

the following results which give some indication on the degrading of the detection range, were obtained with a SART in a survival craft: a. SART lying flat on the floor range 1.8 n miles b. SART standing upright on the floor range 2.5 n miles c. SART floating in the water range 2.0 n miles Produced by FYT

Survivors are advised not to deploy a SART and a radar reflector on the same survival craft because the reflector may obscure the SART. A well mounted SART in moderate weather conditions is capable of giving a detection range of over 10n miles to a large ship radar. A poorly mounted SART, perhaps operated inside a liferaft or floating in the sea, may provide little better than visual search range to a small fishing boat radar. Line-of-sight problems are much less of a problem for airborne detection of SARTs. With the increased sensitivity of the latest SARTs, compatible radars should have no problem in picking up SARTs at ranges up to 40n miles, given an initial search height of 3000 ft. Produced by FYT

4) The search craft radar controls should be as follows:
(a) receiver gain at MAXIMUM; (b) fast time constant (FTC) or anti-clutter rain (A/C rain) should be OFF; (c) radar range should be selected, giving a receiver bandwidth which is WIDE; (d) receiver should be DE-TUNED in order to reduce unwanted targets such as sea clutter; (e) on approaching the SART, the receiver gain can be reduced to eliminate the concentric arcs or circles previously described and radar range can be reduced in order to locate the exact position of the SART. Produced by FYT

2.7.4 OPERATION OF MARINE RADAR FOR SART DETECTION (Safety of Navigation Circular 197)
WARNING: A SART will only respond to an X-Band (3 cm) radar. It will not be seen on an S-Band (10 cm) radar. Produced by FYT

Introduction A Search and Rescue Transponder (SART) may be triggered by any X-Band (3 cm) radar within a range of approximately 8 n mile. Each radar pulse received causes it to transmit a response which is swept repetitively across the complete radar frequency band. When interrogated, it first sweeps rapidly (0.4 µsec) through the band before beginning a relatively slow sweep (7.5 µsec) through the band back to the starting frequency. Produced by FYT

This process is repeated for a total of twelve complete cycles
This process is repeated for a total of twelve complete cycles. At some point in each sweep, the SART frequency will match that of the interrogating radar and be within the pass band of the radar receiver. If the SART is within range, the frequency match during each of the 12 slow sweeps will produce a response on the radar display, thus a line of 12 dots equally spaced by about 0.64 n miles will be shown. Produced by FYT

When the range to the SART is reduced to about 1 n mile, the radar display may show also the 12 responses generated during the fast sweeps. These additional dot responses, which also are equally spaced by 0.64 n miles, will be interspersed with the original line of 12 dots. They will appear slightly weaker and smaller than the original dots. Produced by FYT

Radar Range Scale When looking for a SART it is preferable to use either the 6 or 12 n mile range scale. This is because the total displayed length of the SART response of 12 (or 24) dots may extend approximately 9.5 n miles beyond the position of the SART and it is necessary to see a number of response dots to distinguish the SART from other responses. Produced by FYT

SART Range Errors When responses from only the 12 low frequency sweeps are visible (when the SART is at a range greater than about 1 n mile), the position at which the first dot is displayed may be as much as 0.64 n mile beyond the true position of the SART. When the range closes so that the fast sweep responses are seen also, the first of these will be no more than 150 metres beyond the true position. Produced by FYT

Radar Bandwidth This is normally matched to the radar pulse length and is usually switched with the range scale and the associated pulse length. Narrow bandwidths of 3--5 MHz are used with long pulses on long range scales and wide bandwidths of MHz with short pulses or short ranges. Produced by FYT

A radar bandwidth of less than 5 MHz will attenuate the SART signal slightly, so it is preferable to use a medium bandwidth to ensure optimum detection of the SART. The Radar Operating Manual should be consulted about the particular radar parameters and bandwidth selection. Produced by FYT

Radar Side Lobes As the SART is approached, side lobes from the radar antenna may show the SART responses as a series of arcs or concentric rings. These can be removed by the use of the anti-clutter sea control although it may be operationally useful to observe the side lobes as they may be easier to detect in clutter conditions and also they will confirm that the SART is near to own ship. Produced by FYT

Detuning the Radar To increase the visibility of the SART in clutter conditions, the radar may be detuned to reduce the clutter without reducing the SART response. Radars with automatic frequency control may not permit manual detune of the equipment. Care should be taken in operating the radar in the detuned condition as other wanted navigational and anti-collision information may be removed. The tuning should be returned to normal operation as soon as possible. Produced by FYT

Gain For maximum range SART detection the normal gain setting for long range detection should be used i.e., with a light background noise speckle visible. Produced by FYT

Anti-clutter Sea Control
For optimum range SART detection this control should be set to the minimum. Care should be exercised as wanted targets in sea clutter may be obscured. Note also that in clutter conditions the first few dots of the SART response may not be detectable, irrespective of the setting of the anti-clutter sea control. In this case, the position of the SART may be estimated by measuring 9.5 n miles from the furthest dot back towards own ship. Produced by FYT

Some sets have automatic/manual anti-clutter sea control facilities. Because the way in which the automatic sea control functions may vary from one radar manufacturer to another, the operator is advised to use manual control initially until the SART has been detected. The effect of auto sea control on the SART response can then be compared with manual control. Produced by FYT

Anti-clutter Rain Control
This should be used normally (i.e. to break up areas of rain) when trying to detect a SART response which, being a series of dots, is not affected by the action of the anti-clutter rain circuitry. Note that Racon responses, which are often in the form of a long flash, will be affected by the use of this control. Produced by FYT

Some sets have automatic/manual anti-clutter rain control facilities. Because the way in which the automatic rain control functions may vary from one radar manufacturer to another, the operator is advised to use manual initially until the SART has been detected. The effect of the auto rain control on the SART response can then be compared with manual control. Produced by FYT

Note: The automatic rain and sea clutter controls may be combined in a single "auto-clutter" control, in which case the operator is advised to use the manual controls initially until the SART has been detected, before assessing the effect of auto. Produced by FYT

Thank you. Thank you for your time. Produced by FYT

Unit 2 Distress,Urgency and Safety Services

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Unit 2 Distress,Urgency and Safety Services

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