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.