MAIN HEAD Simplified VDRs 1189 words ibowles@ruttertech.com DECK HEAD The main difference between standard voyage data recorders and "simplified" voyage data recorders is the cost of the recording medium, but this makes little difference to the total price, argues Ian Bowles of VDR manufacturer Rutter BODY Proposals are circulating for a simplified voyage data recorder, which all ships will be required to fit (not just passenger ships and new ships). The real differences between the fundamentals of the VDR and S-VDR are minimal. The proposed simplified voyage data recorder is supposed to be "significantly" cheaper than the standard voyage data recorder. Looking at the proposed requirements, there are two main areas where changes have been made with a view to reducing costs. The first is with data items to be recorded. Under the proposed S-VDR requirements, if there is no serial signal in the correct format, then those items need not be recorded. IE no extra interface is required. The second is with the relaxing of the Final Recording Medium (data capsule) specifications. With the simplified VDR, the data capsule does not need to withstand such a tough penetration test as the standard VDR; there is an option for a float free version in line with the current GMDSS EPIRB specifications. SUBHEAD Interfaces The big expense of the standard VDR installation that sometimes gets forgotten is the labour involved interfacing the unit to all the shipboard equipment and doors. This should be considered to be in the region of 25% of the overall VDR installation price. However fitting a voyage data recorder system on a new vessel is generally much easier than a retrofit on an existing vessel. For a new building today, most of the equipment that is required to be recorded by the VDR comes as standard with correct serial outputs, and because the installation is taking place during ship construction, the same installation issues do not apply. On existing ships, much of the equipment will be of an era where standard serial outputs were not available, (even as an option from the manufacturer), and require electrical interfaces to convert analogue and contact outputs to the necessary serial format. Most VDR retrofits performed so far have been on passenger ships which are very complicated. The numerous fire doors, watertight doors and hull openings commonly associated with a passenger vessel meant even more interfaces and more importantly, many more labour hours. There is misconception that to retrofit a VDR on an existing cargo vessel will be equally complicated to passenger vessels and in a similar price range. Significant reductions should be easily achievable for the existing cargo vessel owner. Reducing the interface requirements is a cost saving for a ship owner and a commercial advantage for a VDR manufacturer that does not have the expertise and economical interface solutions. SUBHEAD Data to be recorded At a minimum, a S-VDR will be required to record date and time, ship position, ship speed over ground, ship speed through water, heading, bridge audio, communications audio and radar data. The date, time and position can be generated directly by the GPS. The heading will come from gyrocompass, which should already have an interface from the preceding AIS installation requirements. If the primary radar is of an age where no commercial off the shelf interface is available, then the AIS data should be recorded. The AIS will have an output in the correct format. The data sources likely to be missing are engine data, rudder data, depth, wind speed and direction. SUBHEAD Fixed recording medium The most expensive aspect of the fixed recording medium in the normal voyage data recorder is that it must be able to withstand a high penetration force. This requirement is removed for the simplified voyage data recorder. With this requirement removed, the costs of a fixed and float free recording medium are similar. 95 per cent of all ship casualties do not sink immediately, but it is these 5 per cent of casualties where the vessel does sink immediately where it is most important to know what happened to the vessel. The fixed unit is designed to sink with the ship, which means that possible recovery could be very expensive depending on location and depth. The fixed unit will survive fire and submersion to 6,000m so it is a reliable method of saving the data under numerous circumstances. The float free unit will float if the vessel sinks, similar to the GMDSS EPIRB, with the same transmission locating life of an EPIRB: 48 hours. Conceivably this may not be enough for data retrieval as the priority after any casualty will be search and rescue of the victims and by the time that the appropriate authorities can dedicate time to locating and retrieving the data, it may well not be possible. Should the vessel not sink immediately then of course the unit can also be carried off the vessel, however, it is unlikely to be anywhere near as robust as the fixed unit and so will not survive such disasters as fire. If the recording medium meets the same requirements as the GMDSS EPIRB, it may be reasoned and approved that this unit could also act as the GMDSS EPIRB and so allow the ship owner to fit just one EPIRB This may be considered as a definite advantage from a marketing and cost point of view but needs to be looked at closely. If the vessels EPIRB were now to be incorporated in the float free VDR Final recording Medium, then the annual testing of the EPIRB would have to be incorporated in the annual testing and recertification of the VDR. BOX TEXT SUBHEAD Current S-VDR status The current status with simplified voyage data recorder requirements is that the IMO Sub-Committee on Safety of Navigation (NAV) has told the IMO Maritime Safety Committee it thinks that retrofitting existing cargo ships with voyage data recorders is "feasible and desirable." The next MSC meeting is in May 2004. According to the draft regulation, the S-VDR should be fitted to cargo ships above 3,000 gt, with ships over 20,000 gt required to fit them by January 2007 and ships above 3,000 gt required to fit them by January 2008. There would be an exemption for ships with only 2 years of life in them after the implementation date. NAV concluded, on the basis of evidence from flag state administrations, that fitting a VDR on existing vessels would be feasible and cost effective so long as the performance standard for standard voyage data recorders could be simplified in some way, by reducing the amount of data which needs to be recorded and reducing the survivability parameters of the data capsule. NAV decided that the S-VDR would only need to record date, time, position, speed, heading, bridge audio, comms audio and radar data (alternatively AIS data if the radar is impossible to obtain). The final recording capsule can be fixed or float free, with a possibility of combining the float free data capsule with the EPIRB. NAV estimated the costs of fitting such a VDR on $92,000 per ship not including installation labour.