NAUTILUS P01 OCTOBER 2010.qxd - Nautilus International

24 | telegraph | nautilusint.org | October 2010 October 2010 | nautilusint.org | telegraph | 25
TECHNOLOGY
TECHNOLOGY
Get ECDIS
to work
for you …
Compulsory carriage of electronic charts is on the way
for shipping. In this special report, chart agents Thomas
Gunn consider the best ways of making the system work
to everyone’s benefit
O
Only a type-approved electronic chart display and
information system (ECDIS) operating with up-todate
electronic navigational charts (ENCs) and with
appropriate back-up may be used to replace all paper charts on
a vessel.
Where ENCs are not yet available, IMO regulations allow flag
states to authorise the use of raster navigational charts (RNCs)
together with an appropriate folio of paper charts. Note that in
all other cases the vessel must carry all paper charts necessary for
its intended voyage.
From the regulatory perspective, the most important statement
about the legal status of ECDIS is contained in the amended
Chapter V of the SOLAS Convention, set into force on 1 July
2002. ECDIS is specifically referred to in Regulation 19 ‘Carriage
requirements for shipborne navigational systems and equipment’.
However, in order to replace paper charts, such systems must
fulfil considerable technical requirements laid down in ECDIS
performance standards:
zthe chart data in use must be official — ENCs where these are
available — and the graphic display on the screen must meet the
equipment-independent specification
zthe equipment must support the full range of navigational
functions that can be performed on the traditional paper
charts.
O
No electronic system is completely failsafe. IMO performance
standards therefore require that the ‘overall
system’ includes both a primary ECDIS and an adequate
independent back-up arrangement that provides:
zindependent facilities enabling a safe takeover of the ECDIS
functions in order to ensure that a system failure does not result
in a critical situation
za means to provide for safe navigation for the remaining part
of the voyage in case of ECDIS failure
However, these rather basic statements allow considerable
leeway and there are various interpretations of the minimum
functional requirements, or what constitutes ‘adequate’ backup
arrangements.
There are two commonly accepted options:
za second ECDIS, connected to an independent power supply
and a separate GPS position input
zan appropriate up-to-date folio of official paper charts for the
intended voyage
Some flag states may permit other options (eg radar-based
systems such as ‘Chart-Radar’). Shipowners should consult
their national maritime administration for specific advice in
Interpreting MSC 232/82 and, in a documented risk assessment,
show that with regards to equipment and SMS procedures compliance
has been achieved, and measures are in place to allow the
mariner and vessels to comply with this.
O
Unlike the paper chart, ECDIS is a highly sophisticated
system which, besides the navigational functions,
includes components of a complex, computer-based
information system. In total, the system includes hardware,
operating system, ECDIS software (kernel and user interface),
sensor input interfacing, electronic chart data, rules for presentation
and display, status and parameters of alarms and indications.
All these items are accessed through an appropriate humanmachine
interface. As such, care must be taken when navigating
with ECDIS to avoid false operation, misinterpretation, malfunction
or — even worse — over-reliance on this highly-automated
navigation system
As with any type of shipboard navigation equipment, it can
only be as good as those who use it and what it is being used for.
In the case of ECDIS and electronic charts, if mariners are well
trained the system provides the information flow that they need
to make good decisions and therefore contributes significantly
to safe and efficient navigation.
The STCW Convention now has specific regulation
and references to ECDIS training
Stated another way, an ECDIS is another tool to enable mariners
to perform their job better. However, just having some
‘knowledge’ about ‘functions’ and ‘operational controls’ is insufficient
to maximise the benefits of ECDIS. Proper training is
absolutely necessary.
O
ECDIS and other electronic charting systems have
become increasingly important to ship navigation
and are already widely used either as a primary navigation
tool or as an aid to navigation.
The systems are increasingly complex, and require adequate
and appropriate training in order to be operated correctly and
safely. Without proper training, these systems will not be used
to their full potential and could, under some circumstances,
increase the hazard to navigation.
The Standards of Training, Certification & Watchkeeping and
International Safety Management codes put the responsibility
firmly on the shipowner to ensure that mariners on their vessels
are competent to carry out the duties they are expected to
perform. If a ship is fitted with ECDIS, the owner has a duty to
ensure that users are properly trained in the operation and use of
electronic charts and are familiar with the shipboard equipment
before using it operationally at sea.
There is now specific regulation and reference to ECDIS
systems in the STCW Convention, following the diplomatic
conference in Manila in July. Additionally, since ECDIS systems
are related to electronic charts, references to them are considered
to be included in the material covered by the word ‘chart’.
To encourage effective ECDIS education, the IMO approved
a standardised model course for training on the operational
use of ECDIS in 1999 (IMO course 1.27). This course is offered by
approved training institutions and maritime academies. Maritime
administrations can provide information on approved
institutions. Some flag states have developed their own ECDIS
training courses in order to be able to recognise the training
certificates.
Type specific ECDIS training is provided by equipment manufacturers.
O
Navigating with ECDIS is fundamentally different
from navigating with paper charts. Important bridge
work processes are significantly affected — in particular,
voyage planning and voyage execution task. These require
careful analysis and consideration.
ECDIS provides a number of additional planning functions
and features such as safety contours, alarms, and click-and-drop
facilities for waypoints and markers. Whilst in many ways ECDIS
makes voyage planning easier, it is still possible to make errors.
However, these are likely to be of a different type from those
encountered when using paper charts.
Even though ENC coverage is increasing rapidly, many vessels
will, to some degree, have to operate a dual — or even triple
— system with ENCs, paper and raster charts. Planning and
validation of the route has therefore to consider issues such as
which chart types are available for the various segments of the
voyage.
The format of the voyage plan is likely to differ from the traditional
alphanumeric lists of waypoints used with paper charts
and should include information on the usability of connected
electronic navigational devices such as GPS and AIS and their
actual alarm settings.
It is essential to make use of the in-built automatic check
functions provided by ECDIS when validating and approving
the voyage plan. Thought also needs to be given to ensuring that
a back-up to the voyage plan on the ECDIS is available in case of
equipment failure.
It is important that there is good communication of the voyage
plan to all bridge officers so that they are prepared for the
intended voyage. This should include information on equipment
status and back-up procedures.
At the beginning of the voyage, as well as at any change of
watch, the officers should review the voyage plan and agree the
selected pre-settings of functions, alarms and indicators to be
used on the ECDIS.
Where vessels carry paper charts as well as an ECDIS, the role
Don’t place too much reliance on electronic displays,
Thomas Gunn warns, and don’t forget to look out of
the window to cross-check information
of the ECDIS and the charts should be considered. If the ECDIS
is used for real-time navigation, the statutory requirements
regarding monitoring of the progress of the voyage and marking
of positions will need to be considered:
zare positions marked in paper charts solely for record-keeping
purposes
zwhat steps are taken to ensure that intended tracks marked
on the paper charts correspond with the ECDIS information
zhave the bridge procedures set in place by the shipping company
been adapted for the use of ECDIS and are all persons concerned
with the navigation familiar with these adaptations
O
There is a tendency to put too much trust in computerbased
systems and believe whatever is on the display.
It is essential that officers do not become complacent,
understand the limitations of the equipment, and employ the
basic navigational skills to cross-check the information displayed
by all other means available — especially by looking out
the window and watching the radar! Bridge procedures must be
adapted appropriately and ENC training must be carried out to
alleviate these concerns.
Support for
the switch
The British navigational
systems firm Kelvin Hughes
has launched a new product
which claims to offer everything
a vessel needs to comply
with the new electronic chart
requirements in a single
package.
The product, known as ECDIS
Plus, promises users a ‘turnkey
solution’ to the challenges
of installing, updating and
maintaining licences for ECDIS
hardware and ENC charts. The
idea is for each user to tailor the
package to their own needs,
taking up the elements required
for a particular vessel.
So, for example, if a ship
already has ECDIS hardware
but needs chart updates and
maintenance support, the
owners can buy a version of
the ECDIS Plus package which
reflects this — with the cost
adjusted accordingly. For those
installing electronic charts for
the first time, the full package
consists of the following
elements:
zECDIS hardware supply
zECDIS backup provision
zchart folio definition
zinitial chart supply
zChartCo update system
zlicence and permit
management
zIMO approved training
zglobal installation and
service packages
Kelvin Hughes CEO Russell
Hughes welcomed the move
towards mandatory ECDIS,
adding: ‘Through ECDIS Plus,
Kelvin Hughes can provide
every component needed to
make ECDIS easy and compliant
and help customers make the
journey from paper to electronic
navigation.’
Practices can
make perfect
Things happen very quickly at 28 knots. A cable is covered
cin 13 seconds and a mile in only 2 minutes 9 seconds. It
feels even faster at night, close to shore, navigating with only a
chart, the log and a stopwatch whilst under pressure to deliver
three consorts into a coordinated anchorage on time. At least
during the day you get the use of a sextant!
This is what it is like to undertake the Specialist Navigator’s
course, or SPEC N for short, the Royal Navy’s (RN) premier
navigation course. Designed to test the student’s mental maths,
quick thinking, initiative and raw navigational ability under
intense pressure, it is seen as the ultimate test for any navigator.
What makes the SPEC N course so challenging is the
requirement to accurately fix the position of the ship and predict
future position at high speed without the use of modern fixing
aids such as radar and GPS.
Instead, the student is forced to harness all available
navigation techniques — in particular those contained within the
Admiralty Manual of Navigation. These include fixing by a line of
soundings, running fixes, sextant angles, doubling the angle on
the bow and use of bearing pairs to calculate distance off an
object.
It is quite common on course to conduct an anchorage with a
sextant in either hand, taking a vertical sextant angle with one
and a horizontal angle with the other.
Now, imagine plotting fixes in this manner on a paper chart.
Would you know how to do it When was the last time you picked
up a sextant or station pointer Now imagine planning and
executing it with ECDIS as your primary means of navigation.
Again, would you know how to do it and is your ECDIS capable of
processing such information (At the moment the reader is
probably thinking, who cares Who actually needs to do this in
real life anyway...)
Notwithstanding the questions above, you may be asking why
one would need to go to such lengths when radar and GPS are
available. The Royal Navy needs to be able to navigate in a
sensor-deprived situation because operational areas could
preclude the use of radar to avoid detection and where GPS
jamming and other sensor denial is prevalent.
The RN must train its navigators to acquire such skills. This
necessitates pushing the ECDIS system to the limits of its
capabilities and is why the warfare equivalent of ECDIS (WECDIS)
gives access to increased functionality to facilitate underwater
navigation, waterspace management and the input of position
information from a variety of traditional sources.
So that’s the RN, but realistically with today’s reliability of GPS
and radar, are such advanced ECDIS techniques really relevant in
the Merchant Navy
The ability to perform some of the techniques mentioned
above may be deemed unnecessary and old fashioned for
commercial operation. However, the skill of manually fixing
independent of radar and GPS and the ability to clearly display
where your ship can and cannot go on the chart are techniques
relevant to any mariner.
Firstly, manual fixing independent of radar and GPS may be
the only means of cross-checking the GPS or in the extreme, but
not uncommon, navigating in an area of an unreliable datum or
sensor input failure.
Let’s not forget all the work conducted by Trinity House with
regards to the very present danger of GPS jamming and the
importance of being able to identify and manage such a
situation. Secondly, calculating the safe water available when
operating to minimal under keel clearance with a safety depth
that falls in between charted contours is vital to safely manage
today’s commercially pressured operations.
It would therefore be prudent to develop procedures and
practice them in case of such an outcome. I therefore advocate
two techniques that should be utilised in ECDIS as common
practice — manual fixing and the ability to implement a Limiting
Danger Line (LDL). We at ECDIS Ltd feel so strongly about the
relevance of these techniques that we teach them as part of our
five-day STCW IMO 1.27 course.
It is not enough to rely solely on GPS or radar to provide fix
information. An ECDIS does not have to have a radar overlay
under performance standards, but if it does have this facility, it is
prudent to utilise it in its entirety.
However, for GPS denial, the mindset you need to be in is not a
case of ‘if you lose GPS’ but very much a case of ‘when you lose
GPS’. The mariner must therefore utilise the ECDIS like any other
navaid and question the accuracy of the data in order to quality
control the information.
The premise here is twofold — that manual fixing should be
used to cross-reference GPS and that loss of GPS does not mean
Traditional skills need to form the foundation for safe
navigation in the digital era, says Malcolm Instone,
ECDIS Ltd’s director of operations and standards…
loss of ECDIS. I therefore recommend that manual fixing is
incorporated by operators to prove the GPS position correct and
good practice in case of ECDIS failure.
Plotting a fix in ECDIS (Lines of Position) is a requirement
under the performance standards and executing this function can
be very quick. However, it does depend on the software and just as
on paper, practice, practice, practice. It can easily be quicker to
plot a fix on an ECDIS than on a paper chart so there should be no
excuse for not doing it if needed.
The importance of being able to perform this task swiftly is
threefold:
zit should not detract from looking out the window and driving
the ship safely using all navaids
zthe task is performed as a quick check at an appropriate time
zoperators should be able to comfortably manage long periods
of relative navigation for areas of the world that require it and in
case of sudden need.
In event of GPS failure, the operator can utilise the DR
cfunction in ECDIS and revert to traditional fixing skills in
order to provide accurate positional data. Note that loss of GPS
may also mean loss of positional information on your radar.
Ten pieces of advice from
the experts at ECDIS Ltd
1. To get the most out of your ECDIS you need to know your
equipment. Ask questions of your equipment, such as Does it
alarm for safety depth
2. Effective use of ECDIS hinges on setting the system up
correctly. There is a lot to remember, so use check-off cards to
aid this process
3. Always navigate on the best scale chart, as this is the
only way you will see all the charted data whilst not being
affected by SCAMIN
4. Always navigate on the correct display setting. Base is
not adequate for navigation and Standard may require
customising
5. Do not rely solely on the radar or GPS — prove ECDIS correct
at every opportunity by visual and all available means
6. Remember that after setting your safety contour value,
it may vary depending on the scale of chart in use (system
dependent)
7. Where possible when route planning, use clearing
bearings, clearing ranges and parallel index lines to enhance
safety when executing a route. Many systems now offer such
tools
8. Improve your knowledge of ECDIS by getting yourself on
the five-day MCA approved ECDIS
course at ECDIS Ltd
9. Improve your knowledge of your ECDIS system
by arranging a type-specific course from ECDIS Ltd
10. ECDIS is a navaid, so treat as such and question what it
is telling you — if you put rubbish into the system, you get
rubbish out!
Furthermore, the environment you find yourself in may preclude
or limit visual fixing to such an extent that the operator may have
to use transferred position lines or fix by a line of soundings.
Some systems can perform beyond the minimum
performance standards in this regard by allowing the operator to
plot visual bearings, radar ranges and other techniques
accordingly. As well as being quick and easy to plot, the operator
also benefits from a system that automatically calculates DR and
EP based upon last known values such as set and drift, COG and
SOG, when in ‘DR mode’.
It can be seen therefore that manually entered positional
information can very quickly establish where you are and where
‘GPS failure need not be an emergency’
you will be to a high degree of accuracy.
GPS failure need not be an emergency, although to maintain
safety of navigation you may be forced to push your system
further than you have ever done before. The prudent operator
should therefore make it their business to know the capabilities
and limitations of their system, how to prove positional
information correct and what to do when GPS is unreliable.
The ability of an ECDIS system to highlight a given safety
contour based on a set Safety Depth is one of the great
advantages of the system. In essence, the system displays clearly
in bold the contour beyond which you do not wish to proceed.
Furthermore, if you have activated your anti-grounding cone
(AGC, also called Safety Frame or Guard Zone) the system will
alarm when in contact with the safety contour, thereby giving
prior warning of the proximity of danger.
However, the lack of contour data currently available within
ENCs means the operator is not able to fully harmonise the safety
contour with the safety depth. If I set my safety depth value to
6.5m, for example, the system will automatically highlight the
next available contour, which is normally the 10m line. It can be
seen therefore, that if the vessel by necessity has to proceed over
soundings of less than 10m but greater than 6.5m, safe areas
cannot be defined and it is therefore dangerous. Furthermore, the
system will continuously alarm, causing alarm fatigue.
This shortfall essentially means that vessels that need to
reduce the safety contour in accordance with their safety depth in
order to get into harbour safely will be faced with two options:
zturn the anti-grounding cone off
zreduce the safety contour value to 5m
Both options are inherently dangerous. Turning the AGC off
means that the system will only alarm when the ship symbol
encounters them, which in most cases will be too late. Reducing
the safety contour value below the value of safety depth is
possible in many systems, although I do not recommend it, as the
majority of systems only alarm crossing the safety contour — not
the safety depth!
A solution to this problem is the drawing of a limiting danger
line or LDL. This is a tried and tested technique that works on RNCs
as well as ENCs. Essentially, it is a manually inserted danger line
that will alarm when the safety frame touches it, replacing the
safety contour in extremis. The value of the LDL is calculated as
follows:
Draught + Safety + Squat — HoT (Time dependent)
When the safety depth value is inserted, all soundings equal to
or less than this value are highlighted in bold. Using the relevant
function on your ECDIS system, draw a danger line around the
soundings to produce the LDL. The safety value is a prime
consideration and must be large enough to take into account the
quality of data. Because the contour is being drawn manually you
must take into account the inaccuracy of the data in use. It is of
note that some systems can draw an LDL automatically. It must be
remembered that a LDL is time dependent because it is based
upon the height of tide and that when no longer required it must
be ensured that the safety contour is reverted back to a value
greater than safety depth. It goes without saying that you really
must know what you are doing before attempting this technique.
It may be seen that an advanced level of knowledge is required
in order to ensure the best use of an ECDIS system on any given
ship. However, what level of knowledge is required to manage
and quality control a fleet of ECDIS systems The answer is that a
level of expertise and understanding is required that goes beyond
being an ECDIS operator at sea. Provision of expert
guidance on managing a fleet with ECDIS
is available from ECDIS Ltd in
the form of the
Quality Controlling
ECDIS course.