IEC 61996-2:2006

INTERNATIONAL IEC
STANDARD 61996-2
First edition
2006-03
Maritime navigation and radiocommunication
equipment and systems –
Shipborne voyage data recorder (VDR) –
Part 2:
Simplified voyage data recorder (S-VDR) –
Performance requirements, methods of
testing and required test results

Reference number
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INTERNATIONAL IEC
STANDARD 61996-2
First edition
2006-03
Maritime navigation and radiocommunication
equipment and systems –
Shipborne voyage data recorder (VDR) –
Part 2:
Simplified voyage data recorder (S-VDR) –
Performance requirements, methods of
testing and required test results

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– 2 – 61996-2  IEC:2006(E)
CONTENTS
FOREWORD.4

INTRODUCTION.6

1 Scope.7

2 Normative references .7

3 Terms, definitions and abbreviations .8

4 Performance requirements .10

4.1 General .10
4.2 Purpose .11
4.3 Operational requirements .11
4.4 Data selection and security .13
4.5 Continuity of operation .14
4.6 Data items to be recorded .15
5 Technical characteristics .18
5.1 Co-relation in date and time .18
5.2 Particular design requirements for the protective capsule.18
5.3 Location beacon(s) for the protective capsule.19
5.4 Survivability of recorded data .20
5.5 Information to be included in the manufacturer’s documentation.20
5.6 Bridge audio specifications.21
5.7 Communications audio .22
5.8 Radar data – post-display selection.23
6 Methods of testing and required test results .24
6.1 General .24
6.2 Data items to be recorded .31

Annex A (informative) IEC 61162 sentence formats .47
Annex B (informative) Cross-references between VDR and S-VDR .48
Annex C (informative)  SN/Circ.246 Recommended means for extracting stored data
from voyage data recorders (VDRs) and simplified voyage data recorders (S-VDRs) for

investigation authorities .49
Annex D (informative) Mandatory alarms .50

Annex E (informative) Requirement/test – cross-references .52

Bibliography.54

Figure 1 – Test set-up block diagram .39
Figure 2 – Comparison of images .42

Table 1 – Bridge audio, signal to noise measurements .33
Table 2 – Bridge audio, signal to noise and distortion (SINAD) measurements.34
Table 3 – Communications audio, signal to no-signal measurements .36
Table 4 – Communications audio, signal to noise and distortion (SINAD) measurements .37
Table 5 – Intersection colours of test images 1 and 2.41

61996-2  IEC:2006(E) – 3 –
Table A.1 – References in this standard .47

Table B.1 – Subject list and clauses .48

Table D.1 – IMO instrument: SOLAS Chapter II-1 .50

Table D.2 – IMO instrument: SOLAS Chapter II-2 .51

Table D.3 – IMO instrument: Resolution A.481.51

Table E.1 – Subject list and clauses .52

– 4 – 61996-2  IEC:2006(E)
INTERNATIONAL ELECTROTECHNICAL COMMISSION

____________
MARITIME NAVIGATION AND RADIOCOMMUNICATION

EQUIPMENT AND SYSTEMS –
SHIPBORNE VOYAGE DATA RECORDER (VDR) –

Part 2: Simplified voyage data recorder (S-VDR) –

Performance requirements,
methods of testing and required test results

FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
this end and in addition to other activities, IEC publishes International Standards, Technical Specifications,
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Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested
in the subject dealt with may participate in this preparatory work. International, governmental and non-
governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely
with the International Organization for Standardization (ISO) in accordance with conditions determined by
agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
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4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence
between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
the latter.
5) IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for any
equipment declared to be in conformity with an IEC Publication.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
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expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.

9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 61996-2 has been prepared by IEC technical committee 80:
Maritime navigation and radiocommunication equipment and systems.
This standard cancels and replaces IEC PAS 61996-2 published in 2005. This first edition
constitutes a technical revision and additionally incorporates new IMO recommendations on
means for extracting data from the S-VDR.

61996-2  IEC:2006(E) – 5 –
The text of this standard is based on the following documents:

FDIS Report on voting
80/430/FDIS 80/439/RVD
Full information on the voting for the approval of this standard can be found in the report on

voting indicated in the above table.

This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.

IEC 61996 consists of the following parts under the general title Maritime navigation and
radiocommunication equipment and systems – Shipborne voyage data recorder (VDR):
Part 1: Performance requirements, methods of testing and required test results
Part 2: Simplified voyage data recorder (S-VDR) – Performance requirements, methods of
testing and required test results.
The committee has decided that the contents of this publication will remain unchanged until
the maintenance result date indicated on the IEC web site under "http://webstore.iec.ch" in
the data related to the specific publication. At this date, the publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
A bilingual version of this publication may be issued at a later date.

– 6 – 61996-2  IEC:2006(E)
INTRODUCTION
The S-VDR has been introduced by IMO for fitting to existing ships as a simplified alternative

to the voyage data recorder (VDR) which is required for all new ships.

This part of IEC 61996 provides information on the testing requirements for S-VDR as defined

in IMO performance standard MSC.163(78).

The specification for S-VDR differs significantly from that for VDR in two areas:

a) the requirements for monitoring certain sensors are reduced when the data is not

provided in IEC 61162 format, and
b) the requirements for the protective S-VDR capsule are different from the VDR capsule,
both for the fixed and float-free versions.
Annex B provides a cross-reference between this standard and IEC 61996-1 to aid test
houses who may already have test results for VDRs which are being submitted as S-VDRs.
Subsequent to publishing the performance standard for S-VDR, MSC.163(78), in 2004, the
IMO sub-committee on Safety of Navigation (NAV) at its fifty-first session in June 2005,
discussed the issue of download and playback of information. Recognising that after an
accident there is a need for investigators to be able to download the stored data and playback
the information from VDRs/S-VDRs without delay, the sub-committee agreed on
recommended means for extracting stored data for investigation authorities as SN/Circ.246.
This Circular is reproduced as Annex C and its recommendations are referenced in this
standard.
61996-2  IEC:2006(E) – 7 –
MARITIME NAVIGATION AND RADIOCOMMUNICATION

EQUIPMENT AND SYSTEMS –
SHIPBORNE VOYAGE DATA RECORDER (VDR) –

Part 2: Simplified voyage data recorder (S-VDR) –

Performance requirements,
methods of testing and required test results

1 Scope
This part of IEC 61996 specifies the minimum performance requirements, technical
characteristics and methods of testing, and required test results, for simplified shipborne
voyage data recorders (S-VDRs) as required by IMO MSC.163(78). It takes into account IMO
resolution A.694(17) and is associated with IEC 60945. When a requirement in this standard
is different from IEC 60945, the requirement in this standard takes precedence.
NOTE All text of this standard, whose wording is identical to that of IMO MSC.163(78) or A.861(20) is printed in
italics, and the Resolution and associated performance standard paragraph numbers are indicated in brackets.
2 Normative references
The following referenced documents are indispensable for the application of this document.
For dated references, only the edition cited applies. For undated references, the latest edition
of the referenced document (including any amendments) applies.
IEC 60068-2-27:1987, Environmental testing – Part 2: Tests – Test Ea and guidance: Shock
IEC 60268-16:2003, Sound system equipment – Part 16: Objective rating of speech
intelligibility by speech transmission index
IEC 61672-1:2002, Electroacoustics – Sound level meters – Part 1: Specifications
IEC 60945:2002, Maritime navigation and radiocommunication equipment and systems –
General requirements – Methods of testing and required test results
IEC 61097-2:2002, Global maritime distress and safety system (GMDSS) – Part 2: COSPAS
SARSAT EPIRB – Satellite emergency position-indicating radio beacon operating on 406 MHz

– Operational and performance requirements, methods of testing and required test results
IEC 61097-7:1996, Global maritime distress and safety system (GMDSS) – Part 7: Shipborne
VHF radiotelephone transmitter and receiver – Operational and performance requirements,
methods of testing and required test results
IEC 61162-1, Maritime navigation and radiocommunication equipment and systems – Digital
interfaces – Part 1: Single talker and multiple listeners
IEC 61162-2, Maritime navigation and radiocommunication equipment and systems – Digital
interfaces – Part 2: Single talker and multiple listeners, high-speed transmission
IEC 61260:1995, Electroacoustics – Octave-band and fractional-octave-band filters

– 8 – 61996-2  IEC:2006(E)
IMO A.658(16): Use and fitting of retro-reflective materials on life-saving appliances

IMO A.662(16): Performance standards for float-free release and activation arrangements for
emergency radio equipment
IMO A.694(17): General requirements for shipborne radio equipment forming part of the
Global maritime distress and safety system (GMDSS) and for electronic navigational aids

IMO A.810(19): Performance standards for float-free satellite emergency position-indicating
radio beacons (EPIRBs) operating on 406 MHz

IMO A.830(19): Code on alarms and indicators
IMO A.861(20): Performance standards for shipborne voyage data recorders (VDRs)
IMO MSC.81(70): Testing of life saving appliances
IMO MSC.163(78): Performance standards for shipborne simplified voyage data recorders
(S-VDR).
IMO:1974, International Convention for the Safety of Life at Sea (SOLAS), as amended
ITU-R M.633-3:2004, Transmission characteristics of a satellite emergency position-indicating
radiobeacon (satellite EPIRB) system operating through a low polar-orbiting satellite system
in the 406 MHz band
Eurocae: ED56A Amendment 1 – Minimum operational performance specification (MOPS) for
cockpit voice recorder system
VESA:1996, Video electronics standards association – Discrete monitor timings standard 1.0,
Revision 0.7 (DMT)
SAE AS 8045:1988, Engineering Society for advancing mobility land sea air and space –
Minimum performance standard for underwater locating devices – acoustic-self-powered
3 Terms, definitions and abbreviations
For the purposes of this document, the following terms, definitions and abbreviations apply.

3.1 Definitions
3.1.1
activation of a suitable alarm
mutable audible alarm and persistent visual indication, given according to the requirements of
IMO A.830(19) but with an audible level in the range of 55 dBA to 65 dBA
3.1.2
combined EPIRB/S-VDR capsule
a single unit which meets all the requirements of a satellite EPIRB (as required by the
carriage requirements of SOLAS IV) and all the requirements of a S-VDR (as required by the
carriage requirements of SOLAS V)

61996-2  IEC:2006(E) – 9 –
3.1.3
bridge work station
position at which a person is expected to be when performing one of the normal bridge duties

at, for example, the following work stations:

• centre line conning
• bridge wing(s)
• main radar
• chart table
• helms
• communication
3.1.4
data
any item of information received by the S-VDR for recording, including numerical values, text
and audio or radar signals, except where specifically stated or the context dictates otherwise
3.1.5
dedicated reserve power source (MSC.163(78) 4.5)
secondary battery, with suitable automatic charging arrangements, dedicated solely to the S-
VDR, of sufficient capacity to operate it as required by 4.5.3
3.1.6
final recording medium (MSC.163(78) 4.3)
any item of hardware on which the data is recorded such that access to it would enable the
data to be recovered and played back by use of suitable equipment
3.1.7
playback equipment (MSC.163(78) 4.4)
any equipment, compatible with the recording medium and the format used during recording,
employed for recovering the data. It includes also the display or presentation hardware and
software that is appropriate to the original data source equipment
3.1.8
recorder (S-VDR) (MSC.163(78) 4.1)
complete system, including any items required to interface with the sources of input data, for
processing and encoding the data, the final recording medium in its capsule, the power supply
and dedicated reserve power source
3.1.9
resolution
smallest detectable increment between two values
3.1.10
sensor (MSC.163(78) 4.2)
any unit external to the S-VDR to which the S-VDR is connected and from which it obtains
data to be recorded
3.2 Abbreviations
AIS Automatic identification system
ALR IEC 61162 sentence: Set alarm state
DPT IEC 61162 sentence: Depth relative to the transducer
DTM IEC 61162 sentence: Geodetic datum reference
EPFS Electronic position fixing system
EPIRB Emergency position-indicating radio beacon

– 10 – 61996-2  IEC:2006(E)
EUT Equipment under test
GMDSS Global maritime distress and safety system

GNS IEC 61162 sentence: GNSS fix data

GNSS Global navigation satellite system

HDG IEC 61162 sentence: Magnetic compass heading

HDT IEC 61162 sentence: True heading

HTC IEC 61162 sentence: Heading/track control command

HTD IEC 61162 sentence: Heading/track control data

IMO International Maritime Organization
INS Integrated navigation system
ITU International Telecommunication Union
MWV IEC 61162 sentence: Wind speed and angle
OOW Officer of the watch
ROV Remotely operated vehicle
RPM IEC 61162 sentence: Revolutions per minute
RSA IEC 61162 sentence: Rudder sense angle
SAR Search and rescue
SENC System electronic navigation chart
SINAD Signal to noise and distortion
STI Sound transmission index
TXT IEC 61162 sentence: Text message
UTC Coordinated universal time
VDM IEC 61162 sentence: AIS – VHF data link message
VDO IEC 61162 sentence: AIS – VHF data link own-vessel message
VHF Very high frequency
VBW IEC 61162 sentence: Dual ground water speed
XDR IEC 61162 sentence: Transducer measurements
ZDA IEC 61162 sentence: Time and date
NOTE For IEC 61162 sentences, see Annex A.
4 Performance requirements
Performance requirements described in the following clauses are specified, where relevant,
by reference to the numbered paragraphs of IMO MSC.163(78), if not otherwise indicated.
4.1 General
Requirements specified in this standard are only relevant to equipment designated as an
S-VDR and required to meet IMO MSC.163(78).
For equipment designated as a VDR to IMO Performance standards defined in resolution
A.861(20) refer to IEC 61996-1.
A table of cross-references between this standard and IEC 61996-1 is included in Annex B.

61996-2  IEC:2006(E) – 11 –
4.2 Purpose
(MSC.163(78) 1)
The purpose of a simplified voyage data recorder (S-VDR) is to maintain a store, in a secure

and retrievable form, of information concerning the position, movement, physical status,

command and control of a vessel over the period leading up to, and following, an incident

having an impact thereon. Information contained in a S-VDR shall be made available to both

the Administration and the shipowner. This information is for use during any subsequent

investigation to identify the cause(s) of the incident.

4.3 Operational requirements
(MSC.163(78) 5)
4.3.1 Design and construction
(MSC.163(78) 5.1.4)
The design and construction, which shall be in accordance with the requirements of resolution
A.694(17) and international standards acceptable to the Organization , shall take special
account of the requirements for data security and continuity of operation as detailed in
IMO MSC.163(78) 5.2 and 5.3 and in this standard 4.3, 4.4 and 4.5.
4.3.2 Maintenance of sequential records
(MSC.163(78) 5.1.1)
The S-VDR shall continuously maintain sequential records of pre-selected data items relating
to the status and output of the ship's equipment, and command and control of the ship,
referred to in 4. 6.
4.3.3 Co-relation in date and time
(MSC.163(78) 5.1.2, 5.4.1)
To permit subsequent analysis of factors surrounding an incident, the method of recording
shall ensure that the various data items can be co-related in date and time during playback on
suitable equipment.
The recording method shall be such that the timing of all other recorded data items can be
derived on playback with a resolution sufficient to reconstruct the history of an incident in
detail (see 4.6.1).
4.3.4 Protective capsule
4.3.4.1 Final recording medium

(MSC.163(78) 5.1.3)
The final recording medium shall be installed in a protective capsule. The capsule may be
designed to remain fixed to the ship in all circumstances. Alternatively, it may be designed to
float free automatically if the ship sinks (see 5.2). The fixed capsule may also comply with the
requirements of IEC 61996-1.
4.3.4.1.1 Fixed capsule
(MSC.163(78) 5.1.3.2)
The fixed type protective capsule shall comply with the requirements set out in resolution
A.861(20) and this standard with the exception of the resulting requirements for withstanding
penetration.
———————
Refer to IEC 60945: Maritime navigation and radiocommunication equipment and systems – General
requirements, methods of testing and required test results.

– 12 – 61996-2  IEC:2006(E)
4.3.4.1.2 Float-free capsule
(MSC.163(78) 5.1.3.3)
In addition to meeting the requirements of this standard, the float-free type protective capsule

shall:
a) be so constructed as to comply with the requirements specified in resolutions A.810(19)
and A.662(16);
b) be fitted with means to facilitate grappling and recovery and be designed with due regard to

preventing it from being fouled during release;

c) be so constructed as to minimise the risk of loss or damage to the final recording medium

during recovery operations; and
d) be capable of transmitting an initial locating signal and a further locating and homing
signal for at least 48 hours over a period of not less than 7 days/168 hours.
4.3.4.2 Access to capsule
(MSC.163(78) 5.1.3.1.1) (See also 5.2)
The capsule shall be capable of being accessed following an incident but secure against
tampering.
The capsule shall enclose the final recording medium. The final recording medium shall not
be accessible by standard operating procedures during normal ship operations.
A means shall be provided to retrieve stored information via an external device without
opening the protective capsule.
4.3.4.3 Location and identification
(See also 5.2)
4.3.4.3.1 Location
(MSC.163(78) 5.1.3.1.4) (See also 5.3)
The capsule shall be fitted with an appropriate device to aid location.
4.3.4.3.2 Visibility and marking
(MSC.163(78) 5.1.3.1)
The capsule, together with any outermost shell, shall be of a highly visible colour, marked
with retro-reflective materials that comply with the relevant requirements of IMO A.658(16)
and marked with the legend:
“VOYAGE DATA RECORDER – DO NOT OPEN –
REPORT TO AUTHORITIES”
4.3.5 Assessment of recording medium
Where the storage medium cannot be readily and reliably inspected after an incident, means
shall be provided to enable an accident investigator to determine, prior to an attempted
replay, whether the storage medium has been subjected to an excessive level of heat, where
the survival of the stored data may be in doubt.

61996-2  IEC:2006(E) – 13 –
4.3.6 Interfaces
(MSC.163(78) 7)
Interfacing to the various sensors required shall be in accordance with the relevant

international interface standard, IEC 61162 series, where possible (see Annex A).

The interfaces for bridge audio, communications audio and radar are defined in 5.6.1, 5.7.1

and 5.8.1 respectively.
Any interface units which may be required to convert non-IEC 61162 signals, shall conform to

the requirements of IEC 60945.

In all cases, any connection to any item of the ship's equipment shall be such that the
operation of that equipment suffers no deterioration, even if the S-VDR system develops
faults.
NOTE No loss of steering or propulsion is allowed.
4.4 Data selection and security
(MSC.163(78) 5.2)
4.4.1 Selection of data items
(MSC.163(78) 5.2.1)
The minimum selections of operational data items to be recorded by the S-VDR are specified
in 4.6. Optionally, additional items may be recorded provided that the requirements for the
recording and storage of the specified selections are not compromised.
In addition to the operational data referred to in the preceding paragraph, a data block
defining the configuration of the S-VDR and the sensors to which it is connected shall be
written into the final recording medium during commissioning of the S-VDR. This configuration
data shall be permanently retained in the final recording medium and protected from
modification other than by a duly authorised person following any change to the configuration.
Any change to the configuration of this data block shall not affect the recording of the
mandatory items.
The following system configuration information and data source identity shall be included in
this data block:
a) type approval authority and reference;
b) IMO vessel identification number;

c) software version(s) used;
d) microphone locations and recording port allocation;
NOTE This does not imply channelisation.
e) VHF communications – which VHF radio installation is recorded;
f) date and time – from which source obtained;
g) ship’s position – from which EPFS obtained and relative position on the vessel;
h) other data inputs – identification of which equipment is supplying recorded data; sign
conventions and identity of all alarm/door inputs; and
i) automatic insertion of date and time of last amendment.

– 14 – 61996-2  IEC:2006(E)
4.4.2 Resistance to tampering
(MSC.163(78) 5.2.2)
The equipment shall be so designed 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

shall be recorded.
4.4.3 Recording integrity
(MSC.163(78) 5.2.3)
The recording method shall be such that each item of the recorded data is checked for
integrity, for example, it is identical to the data being received, and an alarm given if a non-
correctable error is detected.
The S-VDR shall automatically continuously monitor the following (see 6.1.10):
a) power supply;
b) record function;
c) bit error rate;
d) microphone functionality.
Malfunction of any of the above shall generate an alarm (see 3.1.1) in accordance with the
relevant requirements of IMO A.830(19) at the position from which the vessel is normally
navigated. It shall be possible to mute the alarm but a visual indication shall remain until the
equipment is serviceable. It shall also indicate its alarm status by means of contacts of a relay
(or equivalent) which is held energised in the no-alarm condition.
4.5 Continuity of operation
4.5.1 Operation
(MSC.163(78) 6)
The unit shall be entirely automatic in normal operation. Means shall be provided to ensure
that the recorded data can be saved by an appropriate method following an incident, with
minimal interruption to the recording process and without requiring opening of the protective
capsule. Controls for use during the saving process shall be simple to use.
a) The recording process to the final recording medium shall not be interrupted for more than
10 min during the saving process. The data recorded in the final recording medium shall
not be erased.
b) The data saved shall be automatically checked to ensure that it is identical to the recorded
data on the final recording medium. Any failure shall be indicated.
c) When the saving process is completed, means shall be provided to enable copies to be
made of this or of data relating to subsequent incidents.
NOTE “Saving process” – means – preserving a copy of the data contained in the final recording medium.
d) The S-VDR shall be provided with an output port providing data in an internationally
recognised format (see Annex C) .
———————
The Sub-Committee on Safety of Navigation (NAV), at its fifty-first session (6 to 10 June 2005), recognising
that, after an accident, there is a need for the investigators to be able to download the stored data and
playback the information from VDRs/S-VDRs without delay, agreed on recommended means for extracting
stored data from voyage data recorders (VDRs) and simplified voyage data recorders (S-VDRs) for
investigation authorities as SN/Circ.246 which is reproduced as Annex C.

61996-2  IEC:2006(E) – 15 –
4.5.2 Power source
(MSC.163(78) 5.3.1)
To ensure that the S-VDR continues to record events during an incident, it shall be capable of

operating from the ship's emergency source of electrical power. Whenever electrical power is

available the S-VDR shall operate, except as permitted in 4.5.4 (see 6.1.15).

4.5.3 Dedicated reserve power source

(MSC.163(78) 5.3.2)
If the ship's emergency source of electrical power supply fails, the S-VDR shall continue to

record bridge audio (see 4.6.5) from its dedicated reserve source of power for a period of
2 h. At the end of this 2 h period all recording shall cease automatically (see 3.1.5).
4.5.4 Recording period and duration
(MSC.163(78) 5.3.3)
Recording shall be continuous unless interrupted briefly in accordance with 4. 5 . 1 or
terminated in accordance with 4.5.3. The time for which all stored data items are retained
shall be at least 12 h. Data items which are older than this may be overwritten with new data.
Recording may also be terminated, by means of a key or other secure method.
NOTE This may occur under the following circumstances:
a) during essential maintenance purposes whilst the vessel is in port;
b) when the vessel is laid up;
c) when the vessel has a marine incident.
4.6 Data items to be recorded
(MSC.163(78) 5.4)
4.6.1 Date and time
(MSC.163(78) 5.4.1)
Date and time referenced to UTC, shall be obtained from a source external to the ship (for
example, an EPFS or radio time signal if available), or from an internal clock at least once
per hour. The recording shall indicate which source is in use. The recording method shall be
such that the timing of all other recorded data items can be derived on playback with a
resolution sufficient to reconstruct the history of the incident in detail, not worse than 1 s.
4.6.2 Ship’s position
(MSC.163(78) 5.4.2)
Latitude and longitude, and the datum used, shall be derived from a designated EPFS or INS
if available. The recording shall ensure that the identity and status of the source can always
be determined on playback. The ship’s position shall be recorded, as available on the ship, up
to a resolution of 0,0001 min of arc.
4.6.3 Speed
(MSC.163(78) 5.4.3)
Speed through the water, or speed over the ground (transverse as well as longitudinal in
either case, as available on the ship), including an indication from which it is, derived from the
ship’s designated speed and distance measuring equipment, shall be recorded, as available
on the ship, up to a resolution of 0,1 kn.

– 16 – 61996-2  IEC:2006(E)
4.6.4 Heading
(MSC.163(78) 5.4.4)
As indicated by a designated ship's compass. The ship’s heading shall be recorded, as

available on the ship, up to a resolution of 0,1°.

4.6.5 Bridge audio
(MSC.163(78) 5.4.5)
One or more microphones positioned on the bridge shall be placed, such that conversation at

or near the conning stations, radar displays, chart tables etc., (for example at work stations as

defined in 3.1.9) may be adequately recorded. As far as is practicable, the positioning of
microphones shall also capture the input and output of intercom, public address systems and
the audible alarms on the bridge (bridge mounted equipment).
The audio signals at all work stations shall be recorded continuously. Optionally, means may
be provided so that the originating work station can be identified with the audio signal being
analysed during playback of the recorded information (see 5.6 for technical characteristics).
4.6.6 Communications audio
(MSC.163(78) 5.4.6)
VHF communications relating to ship operations shall be recorded, independently of the
bridge audio. The recording shall include both transmitted and received audio signals and
shall be continuous from a directly connected fixed VHF radio to be designated at installation
of the S-VDR (see 5.7 for technical characteristics).
4.6.7 Radar data – post-display selection
(MSC.163(78) 5.4.7)
This shall include electronic signal information from within one of the ship's radar installations
which records all the information which was actually being presented on the master display of
that radar at the time of recording. This shall include any range rings or markers, bearing
markers, electronic plotting symbols, radar maps, whatever parts of the SENC or other
electronic chart or map that were selected, the voyage plan, navigational data, navigational
alarms and the radar status data that were visible on the display. The recording method shall
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 S-VDR (see 5.8).
4.6.8 AIS
(MSC.163(78) 5.4.8)
Where there is no commercial off-the-shelf interface available to obtain radar data then AIS
target data shall be recorded as a source of information regarding other ships; otherwise AIS
information may be recorded additionally as a beneficial secondary source of information on
both other and own ship.
The VDM message shall be recorded in such a way, that all target data available from the
onboard AIS are acquired.
If the VDO message is recorded, this shall be additional to the recording of individual sensor
data as per 4.6.1 to 4.6.4.
61996-2  IEC:2006(E) – 17 –
4.6.9 Other items
(MSC.163(78) 5.4.9)
Any additional data items listed by IMO with the requirements set out in resolution A.861(20)

(4.6.10 to 4.6.17 below) shall be recorded where the data is available in accordance with the

international digital interface standards using approved sentence formatters.

4.6.10 Echo sounder
(A.861(20) 5.4.8)
This shall include depth under keel,up to a resolution of 0,1 m as available on the ship. The

depth scale currently being displayed and other status information shall be recorded where

available.
4.6.11 Main alarms
(A.861(20) 5.4.9)
This shall include the status of all IMO mandatory alarms on the bridge.
The status of all IMO mandatory alarms shall be recorded by the bridge audio and as a data
parameter where practicable (see Annex D).
4.6.12 Rudder order and response
(A.861(20) 5.4.10)
Both rudder order and response angles shall be recorded up to a resolution of 1º as available
and permitted on the ship. Status and settings of heading or track controller, if fitted, shall
also be recorded.
4.6.13 Engine order and response
(A.861(20) 5.4.11)
This shall include the positions of any engine telegraphs or direct engine/propeller controls,
including shaft(s) (revolutions or equivalent), and feedback indications, if fitted, including
ahead/astern indicators. This shall also include status of bow and stern thrusters if fitted.
Revolutions shall be recorded up to a resolution of 1 rpm and pitch shall be recorded up to a
o
resolution of 1 .
4.6.14 Hull openings (doors) status
(A.861(20) 5.4.12)
This shall include all IMO mandatory status information required to be displayed on the
bridge.
4.6.15 Watertight and fire door status
(A.861(20) 5.4.13)
This shall include all IMO mandatory status information required to be displayed on the
bridge.
4.6.16 Accelerations and hull stresses
(A.861(20) 5.4.14)
Where a ship is fitted with IMO mandated hull stress and response monitoring equipment, all
the data items that have been pre-selected within that equipment and are available shall be
recorded.
———————
Refer to publication IEC 61162.

– 18 – 61996-2  IEC:2006(E)
4.6.17 Wind speed and direction

(A.861(20) 5.4.15)
This shall be applicable where a ship is fitted with a suitable sensor. Either relative or true

wind speed and direction may be recorded, but an indication of which it is shall be recorded.

5 Technical characteristics
5.1 Co-relation in date and time

To ensure that relative timings can be determined within a resolution of 0,1 s, all data items

shall, when sampled by the S-VDR, be recorded with a time index derived from a S-VDR
system clock with a resolution of 0,05 s. The drift of this system clock shall be not more than
1 s in 1 h.
5.2 Particular design requirements for the protective capsule
(MSC.163(78) 5.1.3)
The final recording medium shall be installed in a protective capsule of either a fixed or float-
free type, which shall meet all of the following requirements:
a) maintain the recorded data for a period of at least 2 years following termination of
recording;
b) be of a highly visible colour and marked with retro-reflective materials.
5.2.1 Fixed protective capsule
5.2.1.1 Design of the fixed capsule
The capsule containing the final recording medium shall be designed to be installed on the
external deck of the vessel.
The capsule shall be designed to protect the stored data against the following (see 5.4.2.1):
– shock;
– fire;
– deep-sea pressure and immersion.
5.2.1.2 Release mechanism
The fixed capsule shall have a release mechanism to facilitate recovery under water by a
diver or a remotely operated vehicle (ROV). Possible items to be considered are:
a) the use of break-away bolts;
b) release levers; or
c) twist lock.
To ensure that the capsule may be retrieved safely after release, suitable large pad eyes or
handles shall be incorporated.
NOTE It should be borne in mind that the manipulator jaws of typical underwater recovery machines have a
maximum opening of only 300 mm, a gripping force limit of about 1 kN, and a pulling force limit of about
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