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The Black Box


Voyage Data Recorder or VGR is marine equipment serving the purpose of the black box. The equipment collects every data of the ship during the voyage for purpose of study, enhance safety or to investigate an accident.






In the olden days, record keeping was done manually onboard. In the time of emergencies, making data was a ridiculous task as everyone onboard would be trying to secure the ship. Voyage Data Recorder or VDR are considered to be the black box for ships. International Maritime Organisation defines VDR as a complete system that includes an input interface, processing and encoding, final recording medium, the playback equipment, the power supply and dedicated power reserve. According to SOLAS regulation, any passenger vessel or any other ship above 3000gt needs VDR as a compulsory installation. A Voyage Data Recorder is used for reconstruction of the voyage details and vital information during an accident investigation.


VDR is largely a two-part system consisting of a data collecting unit and a storage unit that stores the collected data. The main component is placed inside the ship and is connected to a high capacity memory block inside a capsule. The capsule is designed to withstand fire, deep-sea pressure, shock and penetration.


The memory block can record 12 hours of onboard data that includes date and time, ship position, speed, heading, bridge audio, VHF communication data, radar information, depth under keel, rudder angle, engine order, hull opening status, watertight and fire doors status, stress monitoring and wind speed and direction. This information is collected during any safety investigation to identify the cause of the incident. Apart from accident investigation, data can be used to take preventive measures, enhance performance and improve the safety of the vessel in a cost-effective way. The data records covering the last 12 hours are continuously overwritten by the latest data. The International Maritime Organisation approved the mandatory requirement for the S-VDR system at MSC 79.


VDR has the ability to continuously maintain sequential records of pre-selected data items relating to status and output of the ship’s equipment, command, and control of the ship. To investigate an incident, the method of the recording should ensure that the various data items can be correlated with date and time on a suitable output interface. The system should have the ability to retrieve data at any time. This test may be conducted using the playback equipment and should ensure that all the required data items are being correctly recorded.




Checking and maintenance of all navigational equipment are essential. The process allows the proper operation of any electronic system. Expert engineers need to work inside the equipment. Maritronics, leading maritime service company offers some of the best engineers to fix any navigational equipment problems.


For routine checks, engineers check for broken cables or damage and also check that all connections are firm and rigid. The battery needs to be replaced every four years and new ones should be connected only with the help of a qualified service engineer. A certificate stating that all check-up tests were satisfactory is to be retained on board.


Underwater Acoustic Beacon


Beacon is covered inside the capsule on the monkey island ( Monkey Island is the deck that holds all the important navigational equipment). This is used for locating the ship in case of any disaster. The beacon is attached to a bracket on the capsule which is triggered when immersed in water. The system produces an ultrasonic pulse which can be detected by the airborne or shipborne unit.


Simplified Voyage Data Recorder (S-VDR)


A simplified VDR is known as S-VDR that records information that is only essential and does not record information as extensive as VDR. S-VDR is, therefore, more cost-effective and thus been used in almost every merchant ship. The concept of SVDR can be understood by comparing the data received between a VDR and SVDR. SVDR standards introduced the possibility of float-free capsules leading to the development of advanced S-VDR.


Sea and ocean are a vastness of unknown and unexpectedness. No seafarer thinks that the ocean or sea is completely safe and so it is imperative to know the importance of a VDR in such a situation.