VDR is an equivalent of a ship’s black box on an aeroplane. It documents the events of a maritime incident such as the time and date of an accident, location of the ship at the moment of the incident, its speed, course and more. The data gathered can be used in identifying possible safety risks and improve operations.
According to IMO regulations the standard VDR is required to store an array of information. These include the following: date and time referenced to Coordinated Universal Time (UTC) vessels’ position (latitude longitude, latitude, coordinate reference), speed and heading as well as bridge audio (acquisition of voice messages recorded by a microphone or two installed on the bridge to record conversations and sound alarms), VHF radio communications (VHF) and radar information (a exact representation of the display that was on view at the time of the recording), rudder order and response as well as engine response and order watertight doors as well as their status, and the hull’s accelerations and stresses.
The system is comprised of a concentrator that process and encodes the data stream sensors that supply input to the concentrator and a final recording medium (FRM) designed to withstand accidents and to enable recovery of voyage data. The FRM can be a fixed unit attached to the vessel or a floating unit that is connected to an EPIRB to pinpoint the location of the vessel in the event of an accident.
The most efficient way to ensure the integrity of the vdr system is to make its use an integral element of bridge drills and training sessions for crews. The saved data may also be used as a way to identify areas in need of training and to improve bridge procedures and operational security.