Designed to aid in accident and incident investigations, Voyage Data Recorders (VDRs), or black boxes for ships as they are commonly referred as, must be carried on all passenger ships and other vessels above 3,000gt which are subject to SOLAS regulations.
In addition to their mandatory carriage on SOLAS vessels as mentioned, some flag states also require that VDRs be carried on certain other vessel types that trade only domestically and are therefore outside the scope of SOLAS.
VDR - A complex piece of kit
A VDR is not a single piece of equipment as the name suggest but is a system for collecting and recording data that involves electronic feeds from navigating equipment and machinery systems on board, sound and video recording devices that capture human involvement and reaction, a central control cabinet and data acquisition unit and a data recording capsule designed to protect the data in the event of any manner of disastrous event including fire, explosion and sinking. In some instances a float free data capsule is part of the system.
To be compliant with the regulations covering their carriage, VDRs need to be connected to the navigating instruments, alarm systems and the majority of controls on the bridge. In addition they must be able to make audio recordings of the bridge environment so that conversations and orders occurring before and during an incident can be accessed as part of any official investigation.
When first introduced, the rules required the recording media of a VDR to be capable of recording at least 12 hours of continuous data after which it could be overwritten. The majority of VDRs were able to record for much longer than the minimum allowed but there are now much more stringent requirements in place. Recording media has improved greatly since VDRs were first introduced with hard disks now often replaced by solid state memory which is much more robust and less prone to damage.
When originally mooted as an item of mandatory equipment around the turn of the century, VDRs were initially considered as an unnecessary surveillance of crew activity but have since become an accepted part of bridge equipment. There was too, some criticism about the data recording capsule not being required to be a float-free device; the argument being that unlike aircraft black boxes, VDRs will almost certainly end up at the bottom of the ocean in worst case scenarios.
Another point of concern was that given the range of equipment that would need to be connected to a VDR, it might not be possible for existing ships to comply with the rules contained in SOLAS and the accompanying performance standards. This was recognised as a valid point by the IMO and eventually a simplified or S-VDR standard was formulated for vessels unable to comply with the full version. It was further permitted for flag administrations to dispense with even the S-VDR and exempt ships, other than ro–ro passenger ships, constructed before 1 July 2002 from being fitted with a VDR where it could be demonstrated that interfacing one with the existing equipment on the ship was unreasonable and impracticable.
The original performance standards for VDRs
These can be found in IMO Resolution A.861(20) from 1997 and those for S-VDRs in MSC 163(78) adopted in May 2004. The latter S-VDR standards introduced the possibility of float free capsules leading to the development of S-VDR SARTs by some manufacturers. IMO Resolution MSC.214(81) adopted two years after the SVDR standards were defined, introduced a requirement for data download capability on both VDRs and S-VDRs.
In May 2012 the standards for VDRs were further refined by Resolution MSC.333(90) which added a requirement for data from more equipment including ECDIS and Inclinometers if fitted for any VDR installed after 1 July 2014.
The new requirements were a catalyst for some makers to withdraw from the market mainly because the anticipated volume of sales for new models is now quite small and because the necessary changes to equipment would make production uneconomic. The withdrawal of manufacturers does not make existing equipment invalid or non-compliant but lack of support may mean that a new compliant replacement will be necessary in the event of failure.
The new standards also make a float-free recording device compulsory and have increased the minimum recording times requirements. The current performance standards including the 2012 revisions are now covered by the annex to Resolution A.861(20). Sections 1 to 4 are concerned more with references and definitions than practical matters which are covered in sections 5 through to 9 and which are:-
**`Operational requirements`** 5.1. General 5.1.1 The VDR should continuously maintain sequential records or preselected data items relating to the status and output of the ship’s equipment, and command and control of the ship, referred to in 5.5.` 5.1.2 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. 5.1.3 The system should include functions to perform a performance test at any time, e.g. annually or following repair or maintenance work to the VDR or any signal source providing data to the VDR. This test may be conducted using the playback equipment and should ensure that all the required data items are being correctly recorded. 5.1.4 The design and construction, which should be in accordance with the requirements of resolution A.694(17) and international standards acceptable to the Organization, should take special account of the requirements for data security and continuity of operation as detailed in 5.3 and 5.4. 5.2 Final recording medium. The final recording medium should consist of the following items: 1. fixed recording medium; 2. float free recording medium; and 3. long-term recording medium. 5.2.1 Fixed recording medium The fixed recording medium should be installed in a fixed protective capsule which should meet all of the following requirements: 1. be capable of being accessed following an incident but secure against a physical or electronically manipulated change or deletion of recorded data; 2. maintain the recorded data for a period of at least two years following termination of recording; 3. maximize the probability of survival against fire, shock, penetration and deep-sea- pressure and recovery of the final recorded data after any incident; 4. be of a highly visible colour and marked with retro-reflective materials; and 5. be fitted with an appropriate device to aid location under water. 5.2.2 Float-free recording medium The float-free recording medium should be installed in a float-free capsule which should meet all of the following requirements: 1. be fitted with means to facilitate grappling and recovery; 2. maintain the recorded data for a period of at least six months following termination of recording; 3. be so constructed as to comply with the requirements specified in resolution A.810(19) and to minimize risk of damage during recovery operations; 4. be capable of transmitting an initial locating signal and further locating homing signal for at least 48 hours over a period of not less than seven days/168 hours; and 5. be capable of being accessed following an incident but secure against a physical or electronically manipulated change or deletion of recorded data. 5.2.3 Long-term recording medium The long-term recording medium should: 1. `be capable of being accessed from an internal, easily accessible area of the ship; and` 2. `provide access to the data held on it but be secured against a physical or electronically manipulated change or deletion of recorded data. 5.3 Data selection and security 5.3.1 The minimum amount of data items to be recorded by the VDR is specified in 5.5. Optionally, additional items may be recorded provided that the requirements for the recording and storage of the specified selections are not compromised. 5.3.2 The equipment should be so designed that, as far as is practical, it is not possible to manipulate the amount of data being recorded by the VDR, the data itself nor the data which has already been recorded. Any attempt to interfere with the integrity of the data or the recording should be recorded. 5.3.3 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. 5.4 Continuity of operation 5.4.1 The VDR should be capable of operating from the ship’s main and emergency source of electrical power.` 5.4.2 If the ship’s source of electrical power supply fails, the VDR should continue to record Bridge Audio (see 5.5.5) from the dedicated reserve power source for a period of 2 hours. At the end of this 2 hour period all recording should cease automatically. 5.4.3 Recording should be continuous unless terminated in accordance with 5.4.2. The time for which all stored data items are retained should be at least 30 days/720 hours on the long-term recording medium and at least 48 hours on the fixed and float-free recording media. Data items which are older than this may be overwritten with new data` 5.4.2 The time for which all stored data items are retained should be at least 30 days/720 hours on the long-term recording medium and at least 48 hours on the fixed and float-free recording media. Data items which are older than this may be overwritten with new data. 5.5 Data items to be recorded 5.5.1 Date and time. Date and time, referenced to UTC, should be obtained from a source external to the ship and an internal clock should be synchronized with valid date and time data. During times of a loss of the external source, the internal clock should be used. 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 and continuity sufficient to reconstruct the history of the incident in detail. 5.5.2 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. 5.5.3 Speed through the water and speed over the ground, including an indication of which it is, derived from the ship’s speed and distance measuring equipment, as required by SOLAS regulations. 5.5.4 Heading as indicated by the ship’s heading source. 5.5.5 Bridge audio. Microphones should be positioned on the bridge covering all work stations as described in MSC/Circ.982 so that conversation is recorded. The recording should be such that, on playback, a normal speaking voice should provide adequate intelligibility while the ship is performing its normal operations. This performance should be maintained at all work stations while there is a single audio alarm anywhere on the bridge or any noise, including noise from faulty equipment or mounting, or wind. This should be achieved through the use of at least two channels of audio recording. Microphones positioned outside on bridge wings, should be recorded on at least one additional separate channel. 5.5.6 Communications. audio VHF communications relating to ship operations should be recorded on an additional separate channel to those referred to in 5.5.5. 5.5.7 Radar. The electronic signals of the main displays of both ship’s radar installations as required by SOLAS regulations. 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. 5.5.8 ECDIS. Where a vessel is fitted with an ECDIS installation, the VDR should record the electronic signals of the ECDIS display in use at the time as the primary means of navigation. The recording method should be such that, on playback, it is possible to present a faithful replica of the entire ECDIS 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 and in addition the source of the chart data and the version used. 5.5.9 Echo sounder depth information. This should include, where available, depth under keel, the depth scale currently being displayed and other status information. 5.5.10 Main alarms. This should include the status of all mandatory alarms on the bridge or as received from the Bridge Alert Management System, if installed, recorded as individually identified alarms. 5.5.11 Rudder order and response This should include status and settings of heading or track controller, if fitted and indicate the control station, mode, and power unit(s) in use. 5.5.12 Engine and thruster order and response. This should include the positions of any engine telegraphs or direct engine/propeller controls and feedback indications on the bridge, if fitted, including ahead/astern indicators and indicate the control station in use. This should also include any thrusters if fitted and indicate the control station in use.` 5.5.13 Hull openings status. This should include all mandatory status information required to be displayed on the bridge. 5.5.14 Watertight and fire door status. This should include all mandatory status information required to be displayed on the bridge. 5.5.15 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. 5.5.16 Wind speed and direction. Where a ship is fitted with a suitable sensor, wind speed and direction should be recorded, including its true or relative status. 5.5.17 AIS. All AIS data should be recorded. 5.5.18 Rolling motion. The VDR should be connected to an electronic inclinometer if installed. The recording method should be such that the rolling motion can be reconstructed during playback. 5.5.19 Configuration data. In addition to the data items specified in 5.5.1 to 5.5.18, a data block defining the configuration of the VDR and the sensors to which it is connected should be written into the final recording medium during commissioning of the VDR. The data block should be maintained up to date with respect to the vessel installation. It should include details on the manufacturer, type and version number of a sensor, the identification and location of the sensor and the interpretation of the sensor data. This configuration data should be permanently retained in the final recording media and protected from modification other than by a duly authorized person following any change to the configuration. 5.5.20 Electronic logbook. Where a ship is fitted with an electronic logbook in accordance with the standards of the Organization the information from this should be recorded. 6 Operation The unit should be entirely automatic in normal operation. 7 Documentation. Information describing the location of the long-term recording medium interface and instructions describing the means of interfacing with it as referred to in 9 should be provided in at least the English language. The equipment documentation should include guidance for the placement of the information and instructions at a prominent position as close to the long-term recording medium interface as practicable. 8 Interfacing. Interfacing to the various signal sources 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. 9 Download and playback equipment for investigation authorities 9.1 Data output interface The VDR should provide an interface for downloading the stored data and play back the information to an external computer. The interface should be compatible with an internationally recognized format, such as Ethernet, USB, FireWire, or equivalent. It should be possible to perform a download of the recorded data for a user- defined period of time. 9.2 Software for data downloading and play back 9.2.1 A copy of the software program providing the capability to download the stored data and play back the information onto a connected external laptop computer and for the playback of the data should be provided for each VDR installation. 9.2.2 The software should be compatible with an operating system available with commercial-off-the-shelf laptop computers and provided on a portable storage device such as a CD-ROM, DVD, USB-memory stick, etc. 9.2.3 Instructions for executing the software and for connecting the external laptop computer to the VDR should be provided. 9.2.4 The portable storage device containing the software, the instructions and any special (not commercial off-the-shelf) parts necessary for the physical connection of the external laptop computer, should be stored within the main unit of the VDR. 9.2.5 Where non-standard or proprietary formats are used for storing the data in the VDR, the software for converting the stored data into open industry standard formats should be provided on the portable storage device or resident in the VDR. <strong>Notes</strong> <em>Refer to publication IEC 60945 – Maritime navigation and radio-communication equipment and systems – General requirements, methods of testing and required test results. Resolution A.1021(26), Code on Alerts and Indicators, 2009, table 10.1.1. Refer to publication IEC 61162 – Maritime navigation and radio-communication equipment and systems – Digital interfaces. Of necessity every VDR on the market should be type approved and capable of meeting the performance standards applying taking into account ship age and type and the date on which the VDR was installed. Beyond that, some makers have added features to their products in an attempt to be more attractive in a competitive field and to meet specific requests from some customers. As a consequence it is possible to find VDRs that have the capability to transmit all recorded data via the ship’s communication system to shore offices.</em>
Information received ashore could be used for internal investigations and for training purposes. Following on from the tragic incident involving the Costa Concordia in January 2012, it is even possible that a future performance standard might make such transmission and monitoring of data a requirement under the ISM Code.
Some VDRs such as those produced by INTERSCHALT, Netwave and Danelec now have the potential to be accessed directly by the shore office allowing remote assistance to be given during emergencies when shore personnel can see exactly what officers on the bridge are experiencing. This feature also permits fault finding to be carried out remotely meaning that shore engineers can have any required replacement parts to hand when they arrive on the vessel.
Some makers such as Furuno have made it possible to access stored data in other ways as well. The introduction of flash memory recording devices can allow authorised persons to transfer data simply and quickly. This can make information readily available to officials and to company staff investigating incidents.