Tuesday 12 March 2013

IMO PERFORMANCE STANDARDS FOR VDR


IMO PERFORMANCE STANDARDS FOR VDR
IMO PERFORMANCE STANDARDS FOR SHIPBORNEVOYAGE DATA RECORDERS (VDRs)

The purpose of a voyage data recorder (VDR) is to maintain a store, in a secure and retrievable form, of information concerning the position, movement, physical status, command and control of a vessel over the period leading up to and following an incident having an impact thereon. Information contained in a VDR should be made available to both the Administration and the ship-owner. This information is for use during any subsequent investigation to identify the cause(s) of the incident.

A VDR with capabilities not inferior to those defined in these performance standards is required to be fitted to ships of classes defined in SOLAS chapter V, as amended.

DEFINITIONS
Voyage data recorder (VDR) means a complete system, including any items required to interface with the sources of input data, for processing and encoding the data, the final recording medium in its capsule, the power supply and dedicated reserve power source.
Sensor means any unit external to the VDR, to which the VDR is connected and from which it obtains data to be recorded.
Final recording medium means the item of hardware on which the data is recorded such that access to it would enable the data to be recovered and played back by use of suitable equipment.
Playback equipment means the equipment, compatible with the recording medium and the format used during recording, employed for recovering the data. It includes also the display or presentation hardware and software that is appropriate to the original data source equipment.
Dedicated reserve power source means a secondary battery, with suitable automatic charging arrangements, dedicated solely to the VDR, of sufficient capacity to operate it.

OPERATIONAL REQUIREMENTS

The VDR should continuously maintain sequential records of preselected data items relating to the status and output of the ship's equipment, and command and control of the ship.
To permit subsequent analysis of factors surrounding an incident, the method of recording should ensure that the various data items can be co-related in date and time during playback on suitable equipment.
The final recording medium should be installed in a protective capsule which should meet all of the following requirements:
• Be capable of being accessed following an incident but secure against tampering.
• Maximize the probability of survival and recovery of the final recorded data after any incident.
• Be of a highly visible color and marked with retro-reflective materials; and
• Be fitted with an appropriate device to aid location.
• Playback equipment is not normally installed on a ship and is not regarded as part of a VDR for the purposes of these performance standards.

Data selection and security

The equipment should be so designed that, as far as is practical, it is not possible to tamper with the selection of data being input to the equipment, the data itself nor that which has already been recorded. Any attempt to interfere with the integrity of the data or the recording should be recorded.
The recording method should be such that each item of the recorded data is checked for integrity and an alarm given if a non-correctable error is detected.

Continuity of operation

1. To ensure that the VDR continues to record events during an incident, it should be capable of operating from the ship's emergency source of electrical power.
2. If the ship's emergency source of electrical power supply fails, the VDR should continue to record Bridge Audio from a dedicated reserve source of power for a period of 2 h. At the end of this 2 h period all recording should cease automatically.
3. The time for which all stored data items are retained should be at least 12 h. Data items which are older than this may be overwritten with new data.

OPERATION

The unit should be entirely automatic in normal operation. Means should be provided whereby recorded data may be saved by an appropriate method following an incident, with minimal interruption to the recording process.

INTERFACING

Interfacing to the various sensors required should be in accordance with the relevant international interface standard, where possible. Any connection to any item of the ship's equipment should be such that the operation of that equipment suffers no deterioration, even if the VDR system develops faults

Following Data items to be recorded:

Date and time
Date and time, referenced to UTC, should be obtained from a source external to the ship or from an internal clock. The recording should indicate which source is in use. The recording method should be such that the timing of all other recorded data items can be derived on playback with a resolution sufficient to reconstruct the history of the incident in detail.
Ship's position
Latitude and longitude, and the datum used, should be derived from an electronic position-fixing system (EPFS). The recording should ensure that the identity and status of the EPFS can always be determined on playback.
Speed
Speed through the water or speed over the ground, including an indication of which it is, derived from the ship's speed and distance measuring equipment.
Heading
As indicated by the ship's compass.
Bridge Audio
One or more microphones positioned on the bridge should be placed so that conversation at or near the conning stations, radar displays, chart tables, etc., are adequately recorded. As far as practicable, the positioning of microphones should also capture intercom, public address systems and audible alarms on the bridge.
Communications Audio
VHF communications relating to ship operations should be recorded.
Radar data, post-display selection
This should include electronic signal information from within one of the ship's radar installations which records all the information which was actually being presented on the master display of that radar at the time of recording. This should include any range rings or markers, bearing markers, electronic plotting symbols, radar maps, whatever parts of the SENC or other electronic chart or map that were selected, the voyage plan, navigational data, navigational alarms and the radar status data that were visible on the display. The recording method should be such that, on playback, it is possible to present a faithful replica of the entire radar display that was on view at the time of recording, albeit within the limitations of any bandwidth compression techniques that are essential to the working of the VDR.
Echo sounder
This should include depth under keel, the depth scale currently being displayed and other status information where available.
Main alarms
This should include the status of all mandatory alarms on the bridge.
Rudder order and response
This should include status and settings of auto-pilot if fitted.
Engine order and response
This should include the positions of any engine telegraphs or direct engine/propeller controls and feedback indications, if fitted, including ahead/astern indicators. This should also include status of bow thrusters if fitted.
Hull openings status
This should include all mandatory status information required to be displayed on the bridge.
Watertight and fire door status
This should include all mandatory status information required to be displayed on the bridge.
Accelerations and hull stresses
Where a ship is fitted with hull stress and response monitoring equipment, all the data items that have been pre-selected within that equipment should be recorded.
Wind speed and direction
This should be applicable where a ship is fitted with a suitable sensor. Either relative wind speed or true wind speed; and direction may be recorded, but an indication of which it is should be recorded.
.

IMO PERFORMANCE STANDARDS FOR S - VDR IMO PERFORMANCE STANDARDS FOR SHIPBORNE SIMPLIFIEDVOYAGE DATA RECORDERS (S-VDRs)


IMO PERFORMANCE STANDARDS FOR S - VDR
IMO PERFORMANCE STANDARDS FOR SHIPBORNE SIMPLIFIEDVOYAGE DATA RECORDERS (S-VDRs)The purpose of a simplified voyage data recorder (S-VDR) is tomaintain a store, in a secure and retrievable form, of informationconcerning the position, movement, physical status, command andcontrol of a vessel over the period leading up to and following anincident having an impact thereon. Information contained in an S-VDR should be made available to both the Administration and theship-owner. This information is for use during any subsequentinvestigation to identify the cause(s) of the incident.An S-VDR with capabilities not inferior to those defined in theseperformance standards is required to be fitted to ships of classesdefined in SOLAS chapter V, as amended.DEFINITIONSSimplified Voyage data recorder (S-VDR) means a complete system,including any items required to interface with the sources of inputdata, for processing and encoding the data, the final recordingmedium, the power supply and dedicated reserve power source.Sensor means any unit external to the S-VDR, to which the S-VDR isconnected and from which it obtains data to be recorded.Final recording medium means the item of hardware on which thedata is recorded such that access to it would enable the data to berecovered and played back by use of suitable equipment.Playback equipment means the equipment, compatible with therecording medium and the format used during recording, employedfor recovering the data. It includes also the display or presentationhardware and software that is appropriate to the original datasource equipment.Dedicated reserve power source means a secondary battery, withsuitable automatic charging arrangements, dedicated solely to theS-VDR, of sufficient capacity to operate it.

OPERATIONAL REQUIREMENTS1. The S-VDR should continuously maintain sequential records of preselected data items relating to the status and output of theship’s equipment, and command and control of the ship.2. To permit subsequent analysis of factors surrounding an incident,the method of recording should ensure that the various data itemscan be co-related in date and time during playback on suitableequipment.3. The final recording medium should be installed in a protectivecapsule of either a fixed or float-free type, which should meet all of the following requirements:• Be capable of being accessed following an incident but secureagainst tampering;• Playback equipment is not normally installed on a ship and is notregarded as part of a S-VDR for the purposes of these performancestandards.• Maintain the recorded data for a period of at least 2 yearsfollowing termination of recording;• Be of a highly visible color and marked with retro-reflectivematerials; and• Be fitted with an appropriate device to aid location.• The fixed type protective capsule should comply with therequirements set out in resolution A.861 (20) with the exception of the resulting requirements for withstanding penetration.4. The float-free type protective capsule should:• be fitted with means to facilitate grappling and recovery;• be so constructed as to minimize risk of damage during recoveryoperations; and• the device should be capable of transmitting an initial locatingsignal and further locating homing signal for at least 48 hours over aperiod of not less than 7 days/168 hours.Data selection and securityThe equipment should be so designed that, as far as is practical, it isnot possible to tamper with the selection of data being input to theequipment, the data itself nor that which has already beenrecorded. Any attempt to interfere with the integrity of the data orthe recording should be recorded.The recording method should be such that each item of therecorded data is checked for integrity and an alarm given if a non-correctable error is detected.Continuity of operationTo ensure that the S-VDR continues to record events during anincident, it should be capable of operating from the ship’semergency source of electrical power.
If the ship’s emergency source of electrical power supply fails, theS-VDR should continue to record Bridge Audio from a dedicatedreserve source of power for a period of 2 h. At the end of this 2 hperiod all recording should cease automatically.The time for which all stored data items are retained should be atleast 12 h. Data items which are older than this may be overwrittenwith new data.OPERATIONThe unit should be entirely automatic in normal operation. Meansshould be provided whereby recorded data may be saved by anappropriate method following an incident, with minimal interruptionto the recording process.INTERFACINGInterfacing to the various sensors required should be in accordancewith the relevant international interface standards, where possible.Any connection to any item of the ship’s equipment should be suchthat the operation of that equipment suffers no deterioration, evenif the S-VDR system develops faultData items to be recordedDate and timeDate and time, referenced to UTC, should be obtained from a sourceexternal to the ship or from an internal clock. The recording shouldindicate which source is in use. The recording method should besuch that the timing of all other recorded data items can be derivedon playback with a resolution sufficient to reconstruct the history of the incident in detail.Ship’s positionLatitude and longitude, and the datum used, should be derived froman electronic position-fixing system (EPFS). The recording shouldensure that the identity and status of the EPFS can always bedetermined on playback.SpeedSpeed through the water or speed over the ground, including anindication of which it is, derived from the ship’s speed and distancemeasuring equipment.HeadingAs indicated by the ship’s compass.Bridge AudioOne or more microphones positioned on the bridge should be placedso that conversation at or near the conning stations, radar displays,chart tables, etc., are adequately recorded. As far as practicable,the positioning of microphones should also capture intercom, publicaddress systems and audible alarms on the bridge.Communications AudioVHF communications relating to ship operations should be recorded.Radar data, post-display selection

This should include electronic signal information from within one of the ship’s radar installations which records all the information whichwas actually being presented on the master display of that radar atthe time of recording. This should include any range rings ormarkers, bearing markers, electronic plotting symbols, radar maps,whatever parts of the SENC or other electronic chart or map thatwere selected, the voyage plan, navigational data, navigationalalarms and the radar status data that were visible on the display.The recording method should be such that, on playback, it ispossible to present a faithful replica of the entire radar display thatwas on view at the time of recording, albeit within the limitations of any bandwidth compression techniques that are essential to theworking of the S-VDR.AIS DataIf it is impossible to obtain radar data3 then AIS target data shouldbe recorded as a source of information regarding other ships. If radar data is recorded, AIS information may be recorded additionallyas a beneficial secondary source of information on both other andown ship.

IMO PERFORMANCE STANDARDS FOR SPEED AND DISTANCEMEASURING EQUIPMENT (SDME)


IMO PERFORMANCE STANDARDS FOR SPEED AND DISTANCEMEASURING EQUIPMENT (SDME)
IMO PERFORMANCE STANDARDS FOR DEVICES TO INDICATE SPEED

AND DISTANCE (SDME)Devices to indicate speed and distance are intended for generalnavigational and ship maneuvering use. Although the minimumrequirement is to provide information on the distance run and theforward speed of the ship through the water or over the ground,additional information on ship's motions other than in the forwardaxis may be provided. The equipment should comply fully with itsperformance standard at forward speeds up to the maximum speedof the ship and in water of depth greater than 3 m beneath the keel.Devices to indicate speed and distance should comply with thefollowing minimum performance requirements.1. Speed information may be presented in either analogue or digitalform. Where a digital display is used, its incremental steps shouldnot exceed 0.1 knots. Analogue displays should be graduated atleast every 0.5 knots and be marked with figures at least every 5knots. If the display can present the speed of the ship in other thanthe forward direction, the direction of movement should beindicated unambiguously.2. Distance run information should be presented in digital form. Thedisplay should cover the range from 0 to not less than 9999.9nautical miles and the incremental steps should not exceed 0.1nautical miles. Where practicable, means should be provided forresetting readout to zero. The display should be easily readable byday and by night.3. Means should be provided for feeding distance run information toother equipment fitted on board.4. If equipment is capable of being operated in either the "speedthrough the water" or "speed over the ground" mode, modeselection and mode indication should be provided.5. If the equipment has provision for indicating speeds other than ona single fore and aft axis, then the forward and athwart speedthrough the water must be provided, and the forward and athwartspeed over the ground may be provided as an additional option.Resultant speed and course information may be provided as aswitchable option. All such information should clearly indicate thedirection, mode and validity status of the displayed information.6. Errors in the indicated speed, when the ship is operating freefrom shallow water effect and from the effects of wind, current andtide, should not exceed 2% of the speed of the ship, or 0.2 knots,whichever is greater.7. Errors in the indicated distance run, when the ship is operatingfree from shallow water effect and from the effects of wind, currentand tide, should not exceed 2% of the distance run by the ship in 1h or 0.2 nautical miles in each hour, whichever is greater.8. If the accuracy of devices to indicate speed and distance run canbe affected by certain conditions (e.g. sea state and its effects,water temperature, salinity, sound velocity in water, depth of waterunder the keel, heel and trim of ship), details of possible effects
should be included in the equipment handbook.9. The performance of the equipment should be such that it willmeet the requirements of these standards when the ship is rollingup to + 10
°
and pitching up to + 5
°
.10. The system should be so designed that neither the method of attachment of parts of the equipment to the ship nor damageoccurring to any part of the equipment which penetrates the hullcould result in the ingress of water to the ship.11. Where any part of the system is designed to extend from andretract into the hull of the ship, the design should ensure that it canbe extended, operated normally and retracted at all speeds up tothe maximum speed of the ship. Its extended and retractedpositions should be clearly indicated at the display position.

IMO PERFORMANCE STANDARDS FOR ROTI


IMO PERFORMANCE STANDARDS FOR ROTI
IMO PERFORMANCE STANDARDS FOR ROTI1. The Rate-of-Turn Indicator (ROTI) shall be capable of indicating rates of turn to starboard and toport of the ship to which it is fitted.2. The ROTI may be self-contained; alternatively it may form part of, or derive information from, anyother appropriate equipment.3. The indication required shall be provided by a centre-zero analogue type indicator (preferablycircular). Where a circular scale indicator is used, the zero shall be uppermost.4. A turn of ship to port shall be indicated on the left of the zero point and a starboard turn to the rightof the zero point. If the actual rate of turn exceeds full scale deflection, this shall be clearly indicatedon the display.5. In addition, an alphanumeric display may be provided. Positive indication of port and starboard shallbe provided on such displays.6. The length of scale in either direction from zero shall not be less than 120 mm. The sensitivity of thesystem shall ensure that a change in the rate of turn of one degree per minute is represented by adistance of not less than 4 mm on its scale.7. A linear range scale of not less than ± 30 degrees per minute shall be provided. This scale shall bemarked in intervals of one degree per minute on both sides of zero. The scale shall be marked withfigures every 10 degrees per minute. Every 10 degree mark shall be significantly longer than the 5degree mark which in turn shall be significantly longer than the one degree mark. The marks andfigures shall preferably be red or a light color on a dark background.8. Additional linear range scales may be provided.9. Damping of the ROTI shall be provided with a time constant which may be varied during operationin the range zero to at least 10 seconds.10. The indicated rate of turn shall not deviate from the actual rate of turn of the ship by more than 0.5degrees per minute plus 5 per cent of the indicated rate of turn of the ship. These values include theinfluence of earth rate.11. Periodic rolling motion of the ship with an amplitude of ± 5 degrees and period of up to 25 secondsand periodic pitching motion with an amplitude of ± 1 degree and period of up to 20 seconds shall notchange the mean value of the indicated rate of turn by more than 0.5 degrees per minute.12. The ROTI shall meet these accuracy requirements at all ship speeds up to 10 knots.13. The ROTI shall be ready for operation and comply with these standards within 4 minutes of beingswitched on.14. The design shall be such that whether operating or not, the ROTI will not degrade the performance

of any other equipment to which it is connected.15. The ROTI shall include a means of enabling the operator to verify that it is operating.

IMO Performance Standards for IBS PERFORMANCE STANDARDS FOR INTEGRATED BRIDGE SYSTEMS


IMO Performance Standards for IBS
PERFORMANCE STANDARDS FOR INTEGRATED BRIDGE SYSTEMS (IBS)IBS: An integrated bridge system (IBS) is defined as a combination of systems which areinterconnected in order to allow centralized access to sensor information or command/control fromworkstations, with the aim or increasing safe and efficient ship's management by suitably qualifiedpersonnel.IBS, in addition to meeting the functional requirements contained in applicable IMO instruments,should comply with the followingperformance standards.SYSTEM REQUIREMENT:The IBS should support systems performing two or more of the following operations:.1 passage execution.2 communications.3 machinery control.4 loading, discharging and cargo control.5 and safety and securityGENERAL REQUIREMENTS1 The IBS should comply with all applicable IMO requirements and recommendations. Parts executingmultiple operations should meet the requirements specified for each individual function they control,monitor or perform.

2 Each "part" of an IBS should meet the relevant requirements andtheir associated technical testing standards. In consequence, the IBS is in compliance with theserequirements without further environmental testing.Note: "part" is meant to be - for example - an individual module, equipment or subsystem.3 A failure of one part should not affect the functionality of other parts except for those functionsdirectly dependent upon the information from the defective part.INTEGRATION:The IBS should provide functional integration meeting the following requirements:1 The functionality of the IBS should ensure that its operation is at least as effective as for stand-aloneequipment.2 The continuously displayed information should be reduced to the minimum necessary for safeoperation of the ship. Supplementary information should be readily accessible.3 Where multifunction displays and controls are used to perform functions necessary for safe operationof the ship they should be duplicated and interchangeable.4 It should be possible to display the complete system configuration, the available configuration andthe configuration in use.5 Each part to be integrated should provide details of its operational status and validity of essentialinformation. Means should be provided with the IBS to make use of this information.6 An alternative means of operation should be provided for essential functions.7 An alternative source of essential information should be provided. The IBS should identify loss of either source.8 The source of information (sensor, result of calculation or manual input) should be displayedcontinuously or upon request.DATA EXCHANGE:1. Interfacing to an IBS should comply with the relevant international marine interface standards.2. The integrity of data flowing on the network should be ensured.3/ A failure in the connectivity should not affect independent functionalityOPERATIONAL REQUIREMENTS1/The IBS should be capable of being operated by personnel holding appropriate certificates.2. The Man Machine Interface (MMI) should be designed to be easily understood.TECHNICAL REQUIREMENTS1. In order to ensure an adequate system functionality the sensors employed should ensurecommunication compatibility in accordance with the relevant international marine interface standard.2. The IBS alarm management, as a minimum, should comply with the requirements of the Code onAlarms and Indicators,3. The number of alarm types and their release should be kept as low as possible by providingindications for information of lower importance.4 Alarms should be displayed so that the alarm reason and the resulting functional restrictions can beeasily understood. Indications should be self-explanatory.5. If subjected to an orderly shut-down, the IBS should, upon tum-on, come to an initial default state.6. After a power interruption full functionality of the IBS should be available after recovery of allsubsystems. The IBS should not increase the recovery time of individual subsystem functions afterpower restoration.7. If subject to a power interruption the IBS should, upon restoration of power, maintain theconfiguration in use and continue automated operation, as far as practicable. Safety related automaticfunctions should only be restored upon confirmation by the operator.8. The IBS should be supplied:i) from the main and emergency sources of electrical power with automated changeover through a localdistribution board with provision to preclude inadvertent shut-down;.ii) from a transitional source of electrical power for a duration of not less than 1 min; andiii) where required, parts of the IBS should also be supplied from a reserve source of electrical power.

IMO PERFORMANCE STANDARDS FOR GPS


IMO PERFORMANCE STANDARDS FOR GPS

IMO PERFORMANCE STANDARDS FOR GPS
IMO PERFORMANCE STANDARDS FOR MARINE GLOBAL POSITIONING SYSTEM (GPS) RECEIVER EQUIPMENT

The Global Positioning System (GPS) is a space-based positioning, velocity and time system that has three major segments: space, control and user. The GPS space segment will normally be composed of 24 satellites in six orbits. The satellites operate in circular 20,200 km orbits at an inclination angle of 55° with a 12-hour period. The spacing of satellites in orbit will be arranged so that a minimum of four satellites will be in view to users world-wide, with a position dilution of precision (PDOP) of = 6. Each satellite transmits on two "L" band frequencies, L1 (1575, 42 MHz) and L2 (1227, 60 MHz). L1 carries a precise (P) code and coarse/acquisition (C/A) code. L2 carries the P code. A navigation data message is superimposed on these codes. The same navigation data message is carried on both frequencies. Receiver equipment for the GPS intended for navigational purposes on ships with maximum speeds not exceeding 70 knots should comply with the following minimum performance requirements.

The words "GPS receiver equipment" as used in these performance standards includes all the components and units necessary for the system properly to perform its intended functions. The equipment should include the following minimum facilities:
• antennas capable of receiving GPS signals
• GPS receiver and processor
• means of accessing the computed latitude/longitude position
• data control and interface
• and position display and, if required, other forms of output
• The antenna design should be suitable for fitting at a position on the ship which ensures a clear view of the satellite constellation.

PERFORMANCE STANDARDS FOR GPS RECEIVER EQUIPMENT

The GPS receiver equipment should:

1. be capable of receiving and processing the Standard Positioning Service (SPS) signals as modified by Selective Availability (SA) and provide position information in latitude and longitude World Geodetic System (WGS)-84 co-ordinates in degrees, minutes and thousandths of minutes and time of solution referenced to UTC. Means may be provided for transforming the computed position based upon WGS-84 into data compatible with the datum of the navigational chart in use. Where this facility exists, the display should indicate that co-ordinate conversion is being performed, and should identify the co-ordinate system in which the position is expressed.
2. operate on the L1 signal and C/A code.
3. be provided with at least one output from which position information can be supplied to other equipment. The output of position information based upon WGS-84 should be in accordance with international standards.
4. have static accuracy such that the position of the antenna is determined to within 100 m (95%) with horizontal dilution of precision(HDOP) = 4 (or PDOP = 6).
5. have dynamic accuracy such that the position of the ship is determined to within 100m (95%) with HDOP = 4 (or PDOP = 6) under the conditions of sea states and ship's motion likely to be experienced in ships.
6. be capable of selecting automatically the appropriate satellite-transmitted signals for determining the ship's position with the required accuracy and update rate.
7. be capable of acquiring satellite signals with input signals having carrier levels in the range of -130 dBm to -120 dBm. Once the satellite signals have been acquired, the equipment should continue to operate satisfactorily with satellite signals having carrier levels down to -133 dBm.
8. be capable of acquiring position to the required accuracy, within 30 min, when there is no valid almanac data.
9. be capable of acquiring position to the required accuracy, within 5 min, when there is valid almanac data.
10. be capable of re-acquiring position to the required accuracy, within 5 min, when the GPS signals are interrupted for a period of at least 24 h but there is no loss of power.
11. be capable of re-acquiring position to the required accuracy, within 2 min, when subjected to a power interruption of 60 s.
12. generate and output to a display and digital interface a new position solution at least once every 1 s.
13. have a minimum resolution of position, i.e. latitude and longitude, of 0.001 minutes.
14. generate and output to the digital interface course over the ground (COG), speed over the ground (SOG) and universal time co-ordinated (UTC). The accuracy requirement for COG and SOG should not be inferior to the relevant Performance Standards for Heading and SDME;
15. have the facilities to process differential GPS (DGPS) data fed to it. When a GPS receiver is equipped with a differential receiver, static and dynamic accuracies should be 10 m (95%).
16. Precautions should be taken to ensure that no permanent damage can result from an accidental short circuit or grounding of the antenna or any of its input or output connections or any of the GPS receiver equipment inputs or outputs for duration of 5 min.
17. The equipment should provide an indication of whether the position calculated is likely to be outside the requirements of these performance standards.
 
18. The GPS receiver equipment should provide as a minimum:
 
• an indication within 5 s if the specified HDOP has been exceeded.
• a new position has not been calculated for more than 1 s. Under such conditions the last known position and the time of the last valid fix, with explicit indication of this state, so that no ambiguity can exist, should be output until normal operation is resumed.
• a warning of loss of position.
• differential GPS status indication of.
• the receipt of DGPS signals; and
• whether DGPS corrections are being applied to the indicated ship’s position.
• DGPS integrity status and alarm; and
• DGPS text message display.

IMO PERFORMANCE STANDARDS FOR ECHO SOUNDER


IMO PERFORMANCE STANDARDS FOR ECHO SOUNDER


IMO PERFORMANCE STANDARDS FOR ECHO-SOUNDING EQUIPMENT
(FOR PHASE-II MMD EXAMINATION PURPOSE)The purpose of echo sounding equipment is to provide reliable information on the depth of water under a ship to aid navigation in particular in shallow water. Echo sounding equipmentshould comply with the following performance requirements. These Performance Standards areapplicable for ship speeds from 0 up to 30 knots. Sound speed in water for the purpose of this standard is set at 1500 m/s:

1.Under normal propagation and sea bed reflectibility conditions the equipmentshould be capable of measuring any clearance under the transducer between 2 mand 200 m.
2.The equipment should provide a minimum of two range scales one of which, theshallow range, should cover a range of 20 m, and the other, the deep range, shouldcover a range of 200 m.

3.The function of range scale selection should be directly accessible. The settings forthe following functions should be recognizable in all light conditions:a.

---- range scale , andb.

---- preset depth alarm.4.

The scale of display should not be smaller than 5.0 mm per meter depth on theshallow range scale and 0.5 mm per meter depth on the deep range scale. .5.

The primary presentation should be a suitable graphical display which provides theimmediate depth and a visible record of soundings. The displayed record should,show at least 15 min of soundings. Other forms of display may be added but theseshould not affect the normal operation of the main display.6.

It should be possible to record on paper recording or other means the informationabout:i.

the depth(s), andii.

the associated time for 12 h.There should be means to retrieve the recorded information.

7.

The graphical display should be capable of showing:i.

depth marks at intervals not larger than one-tenth of the range/scale inuse; andii.

time marks at intervals not exceeding 5 min.

8.

If paper is used for recording either by marks on the recording paper, or by othermeans, there should be a clear indication when the paper remaining is less than 1 m.

9.The pulse repetition rate should not be slower than 12 pulses per minute on thedeep range and 36 pulses per minute on the shallow range.10.

Output(s) should be available from which depth information may be supplied toother equipment such as remote digital displays, voyage data recorder and a trackcontrol system. These outputs should be digital, serial communication, facilitieswhich should comply with the relevant international standards.11.

More than one transducer and associated transmitter-receiver may be fitted. If more than one transducer is used:i.

means should be available to display the depths from the differenttransducers separately.ii.

a clear indication of the transducer(s) in use should be provided.12.

The performance of the equipment should be such that it will meet therequirements of these performance standards when the ship is rolling + 10° and/orpitching + 5°.13.

Based on a sound speed in water of 1,500 m/s, the tolerance of the indicated depthshould be either: - + 0.5 m on the 20 m range scale, respectively + 5 m on the 200 mrange scale; or - + 2.5% of the indicated depth, whichever is greater. (error)14.

An alarm signal - both visual and audible with mute function - should be providedwhen the water depth is below a preset value.15.

Alarm signals, both visual and audible (with mute function) to the navigator on thewatch should be provided to indicate failure or a reduction in the power supply tothe echo sounder which would affect the safe operation of the equipment.