Page 84 - Electronic Navigation Cyber Book

The modified specification for the S-VDR recognizes the difficulties in
interfacing to the existing analog sensors on older ships. The VDR or S-
VDR is designed to record and store, in a secure and retrievable form,
information concerning the ship’s position, movement, physical status
and command and control for the period leading up to and following an
incident. The data must be stored automatically in an approved protective
capsule. In this booklet, we will explain the carriage requirements,
performance standards, interfacing requirements and certification
procedures for VDRs and S-VDRs.

Detailed performance standards for VDRs and S-VDRs are contained in
IEC 61996, published by the International Electrotechnical Commission.
The performance standards state that the VDR or S-VDR should
continuously maintain sequential records of preselected data items
relating to the status and output of the ship’s equipment and command
and control of the ship. The specification for S-VDR differs from that for
the VDR in two areas:
• The requirements for monitoring certain sensors are reduced when the
data is not provided in IEC 61162 format.
• The requirements for the protective S-VDR capsule are different from
the VDR capsule, both for the fixed and float-free versions. Both the VDR
and S-VDR are required to record date and time, ship’s position, speed
and heading, bridge and VHF audio and radar playback. In the case of
the S-VDR, AIS output may be an acceptable substitute for the radar
picture under certain circumstances. Additional data sources are required
with the full VDR.The final recording medium for a VDR or S-VDR should
be installed in a protective capsule 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 secure against
tampering
• Maintain the recorded data for a period of at least 2 years following
termination of recording
• Be fitted with an appropriate device to aid location

The VDR or S-VDR equipment must be designed so that, as far as is
practical, it is not possible to tamper with the selection of data being input
to the equipment, the data itself nor that which has already been
recorded. Any attempt to interfere with the integrity of the data or the
recording should be recorded. 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 recorded. To ensure that the VDR or S-VDR
continues to record events during an incident, it should be capable of
operating from the ship’s emergency source of electrical power. If the
ship’s emergency power fails, the VDR or S-VDR should continue to
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