105
1 INTRODUCTION
Worldwideshippingindustryisapproachingtheend
of ECDIS implementation process on board ships.
Unlike the other aspects of vessels operation
proceduresinstructionsrelatedtoECDISarenotfully
established what often creates uncertainty especially
when the vessel is about to undergo vetting
inspection.
Inadditiontoother
inspectionsandauditstanker
vessels are subjected to be assessed by OCIMF Ship
InspectionReportingProgramme.TheOilCompanies
International Marine Forum (OCIMF) is a voluntary
associationofoilcompanieshavinganinterestinthe
shipmentoftankers[9].OCIMFformationcommence
in 1970 when major oil companies bond together
to
attain stronger influence in the international rules
formingprocess.Asfortoday(2016)94membersare
part of OCIMF. Wide experience in hydrocarbons
transport is an excellent foundation for professional
guidelines published by OCIMF. Even though those
guidelines are only recommendations not the
international rules they tend to set worldwide
standards for tanker shipping industry. Besides
extensive list of publications OCIMF has built a
database of worldwide tanker fleet which consist
detailed reports with regards to safety management
systems.ShipInspection Report Programme (SIRE)
was established in 1993 and more than 180000
inspection reports have been prepared since then.
SIRE
database is a great tool for ship operators in
process of selecting particular tanker for charter.
PositiveresultofSIREinspectionisaclearindication
thatvessel iswellmaintainedinaccordancetosafety
international standards. SIRE examiners use the
specificguidelinesforcarryingoutinspections.Those
guidelines named Vessel Particulars
Questionnaire
(VPQ)andVesselInspectionQuestionnaire(VIQ)are
set of questions to be answered during inspection.
Each question has a background in commonly
recognized rules; for instance SOLAS, IGC Code,
Bridge Procedures Guide, FSS Code, LSA Code,
MARPOL, IMDG Code.Direct references leave
Position Cross-Checking on ECDIS in View of
International Regulations Requirements and OCIMF
Recommendations
W.Legieć
GdyniaMaritimeUniversity,Gdynia,Poland
ABSTRACT:Inthispaperauthorsuggestmethodsforpositioncross checkingonmodernbridgeequippedwith
ECDIS. Terrestrial navigation techniques in relation to newly implemented technology are adopted to fulfil
internationalrequirementsandrecommendations.Authorproposesvoyagerecordingproceduresconforming
to IMO requirements ready to be
used as navigational procedures in Safety Management System. Vessel
InspectionQuestionnaireofShipInspectionReportProgramme isusedtosystematizetheneeds.Differencesin
approachbetweenpaperchartsandECDISnavigationareexposedandclarifiedservingasa guideforships
liable to undergo vetting inspection. Author shows both, advantages
and weak points of various ECDIS
featuresusingasanexampleECDISmanufacturedbyJapanRadioCompany.
http://www.transnav.eu
the International Journal
on Marine Navigation
and Safety of Sea Transportation
Volume 10
Number 1
March 2016
DOI:10.12716/1001.10.01.12
106
almost no room for individual often subjective
inspector interpretation. At present ECDIS related
procedures are not completely settled what causes
frequentconfusionsaboutitsusage.Itisaninterestof
all parties involved to agree on international
standardsandproceduresforECDISservice.
2 POSITIONFIXANDPOSITIONCROSSCHECK
ECDIS introduction changed the view at position
fixingon boardmodernships.Besideother benefits,
unlikewithpaper charts navigationOOW canfocus
onthenavigationalsituationwithoutinterruptionfor
continuous position plotting. GNSS derived position
(usually GPS) is unceasingly plotted on the ECDIS
screenandthe wholesystem is
basedonnumber of
sensorswhichmustbecrosscheckedbyothermeans
tokeepthe shipon the safeside [7].ECDISused in
conjunctionwith traditionalnavigation methodslike
visual, radar, and celestial observations gives an
overallperceptionofthecurrentsituation[11].
It is an imperative to understand
the difference
between position fixing and position crosschecking
definitions. When paper charts were in use position
fixing term apply as it was plotted on the chart
manually by OOW. Position coordinates were
obtained from GPS, radar or by visual observations
and then plotted on the paper chart by
navigating
officer. Situation was pretty straightforward: fix
position and plot it on the chart. Nowadays when
working with ECDIS ship’s position is fixed and
plotted on the chart continuously and OOW is
responsible for crosschecking of position derived
fromGNSSreceiver.
2.1 Positioncrosscheckintervals
Whenusingpaper
chartstermpositionfixing interval
meanthowoften positionshouldhave to be plotted
manually on the paper chart by OOW. Additionally
therewasarequirementforconfirmingGPSderived
position accuracy by use of other position fixing
methodsatintervalsfrequentenoughnotrunintothe
danger in the
time between fixes. At present, while
usingECDISpositionfixintervaldefinitiondoesnot
applyasfixing isalreadydoneandpositionisplotted
unceasingly. Today we can say only about position
crosscheckinginterval.
Table1.Positionfixingandcrosscheckingintervals
_______________________________________________
GPSderivedVisual,radar,
positioncelestial,position
_______________________________________________
Plotting  Required Plotting Required
method intervalmethodinterval
_______________________________________________
Paper Plotted Vesselcannot
charts manually runintoPlotted
byOOW dangerduring manuallyNot
ECDIS Plotted theinterval byspecified
Automaticallybetweenfixes OOW
byECDIS
_______________________________________________
Evaluating question no. 4.26 in OCIMF Vessel
Inspection Questionnaire itcanbe seen that interval
forGPSposition crosscheckingbyother methods is
not precisely identified. It says that “At least two
methods of position fixing should be charted, where
possible.Visualandradarpositionfixingandmonitoring
techniques should be used whenever possible. GPS
derivedpositionsshouldalwaysbeverifiedbyalternative
methods” [8]. It is essential to specify position cross
checkingintervalswithinNavigationalProceduresin
Safety Management System [13]. Let’s study an
exampleextractedfromoneofthemajoroilshipping
companies’navigationalprocedures.Whilstthevessel
wasontheopenoceanthepositionfixingintervalset
by company policy was
one hour. This interval
decreased gradually as the vessel approaches the
land.Whennavigatinginconfinedwaterswithpilot
onboardtheintervalforpositionfixingwasseton3
minutes. Asaresultnavigating officer was required
toplotthe positionmanually(using mixed methods
GPS,visualorradar)
atveryshortintervalsinorder
tonavigatesafelyandconformtoSafetyManagement
System procedures.Situation becomes unsafe
especiallyduringnighttimewhenofficerwasforced
to be a multitasker and focus in the same time on
collision avoidance, monitoring the helmsman
responseonpilot’s orders, reportingtoVTS stations
and other duties. OOW was constantly shifting
betweenthechartroomandconningpositiontesting
his rapid eye accommodation skills. In order to
supportbridgeteamitwasquitecommontoengage
anotherofficerjustforpositionplottingbutitleadsto
work/rest hour’s issues when arriving in port. SIRE
inspectors are very sensitive about hours of rest
regulationsandstudying VIQquestionno.4.9itcan
be noted that bridge manning is underlined there
Inspectorsmusttakeintoaccounttheimpactofadditional
bridgemanningupontheworkloadofanyindividualand
impact of hours of rest regulations”
[8]. ECDIS
introduction changed this ridiculous situation and
improved safety of navigation significantly. OOW
finallycanfocusonthenavigationalsituationhaving
advantage of real time position plotting on ECDIS
display. What remains to be specified is a position
crosscheckinterval.Itisquitecommonthatposition
crosschecking intervals
are simply copied from
previous position fixing interval requirements
applicable for paper chart navigation. Lack of
understanding of ECDIS system and advantages
which comes with it leads to dangerous situation
whennavigatingofficerisrequiredtocrosscheckhis
GPSpositionatabsurdintervals.Onceagain,position
fixintervaland
position crosscheck intervalarenot
thesamethings.MaingoalofECDISintroductionon
board the vessels was to lessen the workload and
improve navigation safety. GNSS derived position
must be checked‐no question about it, but cross
checking it every 3 minutes is like moving back to
papercharts
age.Itisfutiletokeepcontinuousdouble
positonmonitoring.IfGNSSisnottobetrustedfora
fewminutesthenwhatisthepointofusingECDIS.
Asaconclusion,thelastsentenceinVIQquestion
no.4.26The frequency of positionfixing should be such
thatthe
vesselcannotrunintodangerduringtheinterval
between fixes [8] is always satisfied while working
withECDISasthepositionisfixedcontinuouslyand
the distance passed between fixes is always lesser
thanthedistancetotheclosestdanger.
107
3 VOYAGEPLANSTAGES
Question no. 4.25 in SIRE Vessel Inspection
Questionnaireisa bittricky.Itstates“Thefollowing
shouldbemarkedonthechart,where itenhancessafe
navigation: (…) Methods and frequency of position
fixing; (…) In the event that ECDIS is the primary
meansofnavigation,
theaboveshouldbetakeninto
account”[8].
ForECDISuserstermshouldbeisdegradedbythe
expression should be taken into account. It means that
elementsofpassageplanrequiredonthepapercharts
arenotexactlythesameasthoserequiredforpassage
plan prepared on ECDIS.
For instance methods and
frequencyofpositionfixingmarkingscannotbedone
inthesamewayonelectronicandpapercharts.While
usingpaperchartspositionfixingmarkingprocedure
is well known to everyone and does not require
furtherexplanation.OnECDISwheredisplayedchart
scale is often changed sentence
should be repeated
endlesstimesinoneareainordertobevisibleatall
times.Constantlyrepeatedinformationaboutposition
crosscheckfrequencyanditsmethodscanresultwith
cluttered chart picture therefore it is necessary to
solvethisissueinadifferentway.Oneofthemethods
is to
split the route into the segments (Open Sea
Navigation, Coastal Navigation and Confined
Waters) and assign them with clear instructions in
regardstofrequency andmethodsofpositioncross
checking[5].
3.1 OpenSeaNavigation‐definitionandmethodsfor
shippositionchecks
OpenSeaNavigationcouldbedefinedaspart
ofthe
shipsvoyageplanwherenolandisinvicinity[5].At
thisstageshipspositionisobtainedwithuseofGPS
andcouldbeconfirmedeitherbyCelestialFixesorby
comparisonbetweenGPSreceivers.ECDISuserswill
takeanadvantageofhavingtwoGPSreceiverswhat
is required
by IMO on every vessel equipped with
twoindependentECDISstations[3].
3.2 CoastalNavigation‐definitionandmethodsofship
positionchecks
Coastal Navigation definition apply for the areas
where vessel is closer to shore and radar or visual
objects are available for GPS position crosscheck.
When navigating in coastal waters OOW duty is to
employ Radar Overlay feature and terrestrial
navigation
position fixing methods to confirm
accuracy of positions derived from GNSS plotted
automaticallyonECDIS[11].Inaddition,comparison
betweentwoGPSreceiversshouldbeperformedwith
useofthesamemethodsasforOpenSeaNavigation;
that means secondary position symbol or secondary
trackdisplayshouldbeenabledas
wellasdifference
betweenpositionsalarm.
3.3 ConfinedWaters‐definitionandmethodsofship
positionchecks
Confined Waters or Pilotage Waters is a part of
voyage pla n where ship is in the area of shallow
watershavinglimitedroomtonavigate.
Confinedwatersexamples:
Canals
Locksystems
Rivers
leadingtoport
Confinedareasamongislandsandreefs
Waterways
TrafficSeparationSchemes
Bays
Harbors
Portapproaches
There is no rigid distinction between coastal and
confinedwatersandthelimitsofthosearetobesetby
NavigatingOfficerwhilepreparingthePassagePlan.
Since the utmost accuracy is essential throughout
Confined Waters navigation, position crosscheck
frequencyshouldbegraduallyincreased[10].
3.4 Voyageplanstages‐methodsofship’spositionchecks
‐summary
Table2.Positioncrosscheckingsummary
_______________________________________________
Voyage VisualCalculated GPSposition GPSposition
Plan comparison comparison accuracy accuracy
stage between betweenconfirmedby confirmedby
twoGPS twoGPS Visual/Radar RadarOverlay
receivers receivers observation
_______________________________________________
Ocean YES YES NONO
Navigation
Coastal YES YES YESYES
Navigation
Confined YES YES YESYES
Waters
_______________________________________________
4 POSITIONCROSSCHECKMETHODS
4.1 Visualcomparisonbetweentwogpsreceivers
GPS positions could be compared visually or by
calculating the difference between indicated co
ordinates.Secondarypositionsourcesymbolmustbe
displayedontheJRCECDISscreeninordertocheck
visually that positions derived from two GPS
receiversmatcheachother.Othermanufacturers(i.e.
Furuno) provide the function of displaying primary
andsecondarypasttracks.WithbothsystemsOOWis
abletoseeatglancethatGPSpositionscorrelatesby
confirmingthateither symbolsor tracksseenonthe
displayoverlapeachother.