VDR is a marine recording device that functions like an aircraft's black box, recording critical ship data and communications to help investigators determine the cause of accidents. A VDR continuously records data from navigational equipment, alarms, and communications for at least 12 hours. This data is stored in a protective capsule that can withstand fire and deep water immersion. Accessing and analyzing VDR data after an incident allows for faster, more accurate investigations that help improve safety. VDR recordings have also assisted ship owners in assessing bridge team performance and identifying areas for improvement.

1. 1 | P a g e W h a t i s V D R ( V o y a g e D a t a R e c o r d e r ) ?
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Microphone
Units
(Optional)
(Fixed or
Float-free Type)
(Main, Emergency and Reserve)
Simplified VDR diagram Captain Yashpal Singh
VDR (VOYAGE DATA RECORDER):
VDR is a marine counterpart of black box used in aviation industry. It is used for
recording and storing critical parameters pertaining to ship’s operation and progress. The
record is retrievable and helps accident investigators in reconstructing the sequence of
events culminating in the incident. Thus rather than making assumptions and relying on
skills of speculation, the situation can be analyzed in a systematic and logical manner and
the cause(s) of accident can be ascertained with greater and assured accuracy. Not only
that, the investigations can be concluded faster and with optimum use of time, human and
material resources.
There is recording facility in ECDIS as well, where data is recorded minute by minute for
a period of 12 hours. However this record comprises only the ECDIS picture and does not
contain all the critical data.
The recorded data should be capable of being downloaded to a PC so that it can be played
back for analysis and investigation. Additionally navigator can use this for self analysis, as
lessons-learning tool and thus improvement of procedures in the future.
VDR should have high level of technical flexibility so that it can be interfaced with
existing equipment.
VDR consists of following parts:
VDR
Main Unit
Input Data from
Radar, Echo
Sounder, Log,
Gyro, Wind
Meter, GPS etc.
Power
Supply
Voyage
Data
Capsule
Remote
Display
and
Replay

2. 2 | P a g e W h a t i s V D R ( V o y a g e D a t a R e c o r d e r ) ?
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Power Supply Unit:
The VDR is supplied with electrical energy via this unit. In addition to the supply from
main source, VDR is also powered with emergency supply and also provided with reserve
power for specific task.
VDR Main Unit:
The unit receives the variety of data from different sensors via interface. It processes all
the data and stores them in compatible format. It is directly connected to power supply
unit.
Microphone Units:
It consists of microphone units strategically located to record voices and onboard
communications. The microphones placed in wheel/house, bridge wings, E/R and other
critical places.
VDR Capsule:
This may be fixed type or float-free type and is usually located in place free from
obstructions, such as Monkey Island. It is designed to meet stringent requirements of
withstanding shock, pressure tightness, easy detection, fire resistance, impact etc.
Alarm Unit:
This is part of the Main data Unit and warns the OOW of any malfunction and equipment
errors.
Replay Station (optional): This unit is not compulsory. Where fitted, it can be used to
download and replay the recorded data. This way the unit can be put to use for self-
analysis, meeting training needs and improving the operation practices and procedures.
Operation:
The VDR will continuously maintain a sequential record:
 Of pre-selected data items related to ship status,
 Output of the ship’s equipment and
 Command and control of the ship.
The VDR shall record and store the following:
Status and Alarms:
Bridge alarms, Status of hull openings, water tight doors, fire doors, hull stresses and
accelerations.
Navigational equipment outputs:
Heading, ROT, speed, position, time, date, radar picture, echo sounder output and wind
direction/speed.
Command and Control: Rudder order/response, Engine order/response, onboard
communication, communication with other ships/stations.
VDR Capsule:
The voyage data capsule shall be entirely automatic and record data without human
intervention. It shall continuously record 12 hours of data from the VDR system. The

3. 3 | P a g e W h a t i s V D R ( V o y a g e D a t a R e c o r d e r ) ?
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subsequent data will keep overwriting the previous data. The capsule will be installed in a
protective casing that is brightly coloured and fitted with an appropriate device to aid
location. Further:
 It will be designed to allow copies of incident data to be made.
 It may be fixed or float free capsule
 It should be able to withstand impact equivalent to 250kg pin dropped from height
of 3m.
 It should withstand fire at 260 degree Celsius for 10hrs
 It should withstand pressure at depths of up to 6000m
 It should be fitted with acoustic beacon
Fixed type or Float-free type:
The choice is left to the ship owner. Each type has its own advantages and requirements.
Fixed: Initial capital cost is more. The recovery is expensive and tedious. The
underwater beacon required to operate for 28 days following immersion. This gives time
for an accurate position fix to be obtained during a one month period. The decision or
necessity to recover the capsule can be postponed for up to two years post incident.
Float-free: Initial cost is less. The recovery is cheaper, faster and simpler. The beacon is
designed to operate for 7 days following release from the vessel. The capsule must be
located within this time frame, irrespective of priorities or sea conditions.
Advantages of VDR:
1. Accident investigation and enquiry is simpler, cheaper and faster.
2. Causal factors in an accident can be pinpointed with greater certainty.
3. It can be used for enhancing safety by addressing shortcomings becoming apparent
by self-analysis.
4. Eventually as the performance improves, claims and subsequently insurance
premium will come down.
5. Generation and study of data is easier, which will have multi-faceted use for the
industry.
Annual Performance Test:
VDR will be subjected to an annual performance test carried out by a suitably Competent
Person. The annual testing and checks must be carried in conjunction with the relevant
Statutory Survey (e.g. Passenger Ship Safety Certificate (PC), Cargo Ship Safety
Certificate (CSC) or Cargo Ship Safety Equipment Certificate (SEC)).The VDR check
must also be carried out within the survey period permitted by the Harmonized System of
Survey and Certification. The Survey Window allowed is up to 3 months before the due
date for PC; and -/+ 3 months of due date for CSC and SEC. (Thus the Maximum period
between subsequent checks of the VDR is 15 months for Passenger vessels and 18 months
for Cargo vessels).

4. 4 | P a g e W h a t i s V D R ( V o y a g e D a t a R e c o r d e r ) ?
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Where vessels are on a partial continuous survey regime the VDR annual performance
testing can be scheduled into the continuous survey cycle.
The Competent Person shall check among other things, mainly: accuracy of data recorded,
duration for which data is recorded and recoverability of data recorded.
Data Ownership and Recovery:
Non-catastrophic accident:
In such cases the data recovery is obviously simple and straightforward. This simply
means an initiative in the direction of preserving the evidence soon after the accident, for
use by both the investigator and the ship owner. This usually will be carried out by ship
staff under the orders of Master, who in turn will be implementing the ship owners’
standing orders.
Abandon ship:
In the case of abandonment of a vessel during an emergency, master should exercise due
diligence, without compromising the safety of life, in recovering the stored data. The
master should further remove it to a place of safety and to preserve it until it can be passed
to the investigator.
Catastrophic accident:
In the case a vessel has sunk and the data has not been retrieved prior to abandonment, a
decision will need to be taken by the Flag State in consultation with any other
substantially interested states. The decision will depend on the viability of recovering the
protective capsule against the potential use of the information. If decision is to recover the
capsule, the investigator will be entrusted with responsibility. The assistance and co-
operation of the owners, insurers and the manufacturers of the VDR and those of the
protective capsule may be required. Expert assistance may also have to be hired to
maximize the recovery and preservation of the data.
Custody of VDR data:
The way investigators are allowed all access to bell books, log books, charts, course
recorders and other sources of evidence, the investigator, in all circumstances, during the
course of an investigation, should have custody of the original VDR data.
Although the investigator will have custody of the original VDR data, a copy of the data
must be provided to the ship owner in all circumstances.
Further access to the data will be governed by the applicable domestic legislation of the
flat state, coastal state and the lead investigating state as appropriate.
Ownership of VDR/data:
The ship owner will, in all circumstances and at all times, own the VDR and its data.
In all circumstances the responsibility to arrange down loading and read-out of the data
from the recovered memory in whatever form should, in the first instance, be undertaken
by the investigator who should keep the ship owner fully informed. Additionally,
especially in the case of a catastrophic accident where the memory may have sustained

5. 5 | P a g e W h a t i s V D R ( V o y a g e D a t a R e c o r d e r ) ?
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damage, the assistance of specialist expertise may be required to ensure the best chance of
success.
VDR and S-VDR:
Both VDR and S-VDR are required to maintain sequential records of:
 Pre-selected data
 Output of ship’s equipment and
 Command and control of ship.
However, specifications of VDR and S-VDR differ in two respects:
1. Number of sensors providing data are lesser in S-VDR
2. Requirements for the S-VDR protective capsule are different from that of VDR.
NOTE: The concept of S-VDR was introduced to take into account the difficulties being
encountered in interfacing the existing analog sensors on older ships.
VDR has already started doing its job helping judgments being delivered swiftly, justly
and without quibbling. Some examples are:
1. RO-RO ferry in collision with fishing vessel:
Radar information gained from the ferry’s VDR proved incontrovertibly that the fishing
vessel had made a large alteration of course across the ferry’s bow moments before the
collision, contrary to the Collision Regulations. Unfortunately bridge audio data which
might have given insight to the human factors that lay behind the accident was lost to the
investigators due to background noise from a radio which had been playing in the
wheelhouse for entertainment.
2. Vessel dragged anchor in high winds and touched another ship anchored to
leeward:
Evidence from the VDR allowed the Management to review action by the OOW and
provided the P&I club with the evidence they required to settle the claim
VDR has been a boon in helping ship owners and managers in identifying weak links,
shortcomings in their vessels’ onboard procedures and ship management. For example:
1. Near collision between passenger ferry and general cargo:
VDR information enabled the investigators to establish the true course of events which
was contrary to both the masters’ accounts. Shortfalls in bridge team management were
uncovered to the benefit of the individuals involved, the owners and training
establishments.
2. Passenger vessel lost power on a lee shore in gale force winds:
VDR information enabled a detailed analysis of the bridge team’s actions in an emergency
situation to be carried out. Many shortfalls in performance were uncovered to the benefit
of the bridge team, the owners and training establishments.
3. Vessel rounding Ushant was in close quarters situation whilst overtaking
another vessel:

6. 6 | P a g e W h a t i s V D R ( V o y a g e D a t a R e c o r d e r ) ?
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Evidence from the VDR enabled management to review the OOW’s actions and take
necessary remedial action
Following example shows that ship owners’/ship managers’ initial reluctance to VDR was
not well-founded and though VDR is mandatory, it is a worthy investment:
1. Vessel berthing at builder's yard for guarantee dry docking hit jetty whilst
under pilotage sustaining $150,000 steel damage:
When the yard was made aware that Pilot’s actions had been recorded, they paid for
repairs without question.
Prior to VDR times it was not uncommon to attribute marine accidents to incompetence,
inexperience, misjudgments and poor seamanship of seafarers. Many officers have had
their careers ruined or borne the hard hand of the law. Officers indeed stand to benefit
more from fitting of VDR. Following examples should allay the fears of the officers who
dub VDR a spy-camera:
1. Vessel entering continental port was in collision with yacht:
Evidence from the VDR absolved the Master of all blame.
2. Vessel entering port in narrow channel struck an underwater object:
The VDR showed the ship to be right on track in the dredged channel, thus absolving the
Master from blame or criticism.
3. High speed close quarters incident with warship:
The VDR provided evidence that clearly confirmed that the HSC Master had taken the
correct action when the warship failed to give way as required by Collision regulations.
4. Engine room fire:
A review of the evidence from the VDR confirmed that in general terms, the personnel
concerned had taken the correct action, but some areas for improvement and training
needs were also identified.
(Source for examples of incidents/accidents: MAIB)