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1Global Maritime
DP SEMINARDP SEMINAR
The Principles, Practices and The Principles, Practices and Problems of Safe DP OperationsProblems of Safe DP Operations
2Global Maritime
INTRODUCTION TO GMINTRODUCTION TO GM• Jose Vera Vega
• Chris Jenman
• Walter Rodriguez
• Doug Phillips
• Jack Mercier
• Kees van Beveren
3Global Maritime
MORNING SESSIONMORNING SESSIONINTRODUCTION TO GMDP HISTORYBASIC PHILOSOPHYSCOPE OF DPDP EQUIPMENT CHARACTERISTICS ADVANTAGES AND DISADVANTAGES OF DPDP CAPABILITYFMEAOPERATIONS, TRAINING AND DOCUMENTATIONWEATHER PRECAUTIONSINTERNATIONAL, GOVERNMENT AND REGULATIONASSESSMENT TOOLS
4Global Maritime
AFTERNOON SESSIONSAFTERNOON SESSIONS• FOUR GROUPS --- DP PROBLEMSFOUR GROUPS --- DP PROBLEMS
(KNOWLEDGE TRANSFER)(KNOWLEDGE TRANSFER)• PIPE LAY• ACCOMMODATION• HEAVY LIFT• DIVING
• Closing combined session on the way forward• DP incidents
5Global Maritime
Global Maritimethe leading marine, offshore & engineering consultant
Global Maritimethe leading marine, offshore & engineering consultant
Established 1979
6Global Maritime
Global Maritime GroupGlobal Maritime Group
Eagle Lyon PopeLimited(7 Staff)
HalifaxCanada
(Branch office)
S ingaporeFar East
(Branch office)
BakuAzerbaijan
(Branch office)
G lobal MaritimeConsultancy Limited
(34 Staff)
G lobal MaritimeScotland Limited
(20 Staff)
Ciudad del CarmenMexico
(Branch office)
AmericanG lobal Maritime Inc
(18 Staff)
G lobal Maritime A/SStavanger(32 Staff)
G LO BAL MARITIMEHOLDINGS LIMITED
7Global Maritime
Mariners18%
Naval Architects
26%Administration
8%
Marine Engineers
11%Civil/Strucural
Engineers21%
Others16%
8Global Maritime
Global Maritime and DPGlobal Maritime and DP• 1980 Investigating DP incidents• 1981 design review and FMEA of 3 new DP vessels• 1994 UK Government contract• 1985-1990 DP Incident publication for UK DoE• 1990 Formation of DPVOA (GM Secretariat) • 1990-91 “Guidelines for the design and operation of DP
vessels”• 1992-3 IMO working group for MSC 645• 1994 IMO MSC 645 in force• 1995 Petrobras DPPS Group• 1995-6 IMO MCS 738 “Training and Experience of key DP
Personnel”• 1996 DPVOA + AODC = IMCA• 1996-present Technical Advisors and Committee Members
to IMCA
9Global Maritime
the leading marine, offshore & engineering consultant
Current DP Work
• Original Design: New semi, new heavy lift vessel
• Design Advice: Three new DP drilling semi-subs, One new Accommodation semi, One new special semi
• Upgrades: One DP DSV, One DP drilling Semi,
• FMEA and Trials, Three DP tankers, One Drillship, two DP DSVs
• Analysis: 2003 DP Incidents, 10 years of DP incident data, Update of safety of tanker offtake, Data base for DP drilling units running WSOG
• Surveys: various
10Global Maritime
ELECTRICALFAULT
POWERGENERATION
FAULT
THRUSTERFAULT
ENVIRONMENTALFORCE
SOFTWAREFAULT
or
POWER ORTHRUSTFAULT
INSUFFICIENTPOWER OR
THRUST
or
OPERATORERROR
and
LOSS OFPOSITION
HARDWAREFAULT
REFERENCEFAULT
or
DPEQUIPMENT
FAULT
OPERATORERROR
and
LOSS OFPOSITION
or
EMERGENCYDISCONNECT
OPERATORERROR
NEWFAILURE
MODE
NORECOVERY
LIKELY
0.0870.087
0.1740.174
0.0650.065
0.1520.152
0.0220.022
0.2610.261
0.1090.109
0.1300.130
ELECTRICALFAULT
POWERGENERATION
FAULT
THRUSTERFAULT
ENVIRONMENTALFORCE
SOFTWAREFAULT
or
POWER ORTHRUSTFAULT
INSUFFICIENTPOWER OR
THRUST
or
OPERATORERROR
and
LOSS OFPOSITION
HARDWAREFAULT
REFERENCEFAULT
or
DPEQUIPMENT
FAULT
OPERATORERROR
and
LOSS OFPOSITION
or
EMERGENCYDISCONNECT
OPERATORERROR
NEWFAILURE
MODE
NORECOVERY
LIKELY
0.0870.087
0.1740.174
0.0650.065
0.1520.152
0.0220.022
0.2610.261
0.1090.109
0.1300.130
11Global Maritime
Courtesy of Fugro GEOS
DP HISTORYDP HISTORYDP HISTORYDP HISTORY
12Global Maritime
DP HISTORYDP HISTORY• 1961 Mohole Project• Mohorovici discontinuity• Cuss 1 La Jolla California (manual)• Eureka for drilled in 500 ft for Shell
(automatic)• 1968 Glomar Challenger – drill in 5000 m
13Global Maritime
14Global Maritime
15Global Maritime
Courtesy of Fugro GEOS
What is the Mohorovicic Discontinuity?
The surface of the earth is called the crust, which is the uppermost part of the Lithosphere (which includes the upper portions of the mantle). The "Moho" is the boundary between the crust and upper mantle.
16Global Maritime
DP DEVELOPMENTDP DEVELOPMENT• 1970s – Drilling then Diving• 1980s – More Diving then ROV Vessels• 1990 – More Construction, Accommodation, 5th Gen
Drilling Vessels and many other applications - • Pipe lay, heavy lift, mine hunt, buoy tender, rock
dump, dredge, well stim, offtake tankers, FPSO, cruise liners, cable layers, offshore supply, seismic, diamond mining, treasure hunting, etc.
17Global Maritime
SUPPLIERSSUPPLIERS• Early 1970s – Honeywell then1990s Nautronix• Mid to Late 1970s – GEC and Kongsberg –
Cegelec and Simrad, Alstom and Kongsberg, • Acoustics – Honeywell and Simrad, Later
Sonardyne and then Nautronix• DGPS – Racal, John E Chance, Fugro now
Thales
18Global Maritime
19Global Maritime
Basic PhilosophyBasic Philosophy
DynamicDynamicPositioning??Positioning??
DynamicDynamicPositioning??Positioning??
20Global Maritime
DP DefinitionDP Definition
May be defined as a system which automatically maintains the position and heading exclusively by means of active thrust
21Global Maritime
DP DefinitionDP Definition
A dynamically positioned vessel (DP-vessel) means a unit or a vessel which automatically maintains its position (fixed location or predetermined track) exclusively by means of thruster force.
22Global Maritime
Wind
Waves
Current Forces
Courtesy of Fugro GEOS
UNLIKELY IDEA?UNLIKELY IDEA?
23Global Maritime
Rotational about the Vertical Axis
Linear along the Vertical Axis
Linear along theAthwartship Axis
Rotational aboutthe LongitudinalAxis
Rotational about theAthwartship Axis
Linear alongthe Longitudinal Axis
Courtesy of Petroleum Extension Service, U at Austin
24Global Maritime
What DP DoesWhat DP Does• External forces (wind,waves,current move
the vessel away from desired position.• DP system controls vessel motion in the
Surge, Sway and Yaw axis.• Commands are sent to the thrusters such
that the vessel returns to the desired set point.
• It all revolves around knowing where you were, where you want to be, (how fast you are getting there) and where you are now.
25Global Maritime
Basic PhilosophyBasic Philosophy• A fully operational DP system shall
Reliably keep a vessel in position.Have a max. excursion = or < than 1/2 the
critical excursion for work carried out.All necessary equipment is working.Provide adequate information to operators.Have a permanently manned DP & ECR.
26Global Maritime
Basic PhilosophyBasic Philosophy• Safe working limits be determined forSafe working limits be determined forLocationType of task to be performedKnown failure modesTime to restore the DP system and/or
move to a safe situation.
27Global Maritime
Basic PhilosophyBasic Philosophy• 'safe situation''safe situation' where the work could immediately cease
and there are no serious consequences from position loss. • 'safe working limits''safe working limits' are the environmental limits that
would make a critical excursion from a single fault very unlikely, because – adequate control and power remaining,– environmental loads are small– the time to reach a safe situation is short in comparison to the
speed of position loss– because in the existing circumstances and conditions position loss
does not have any serious consequences.
28Global Maritime
DP EQUIPMENT CLASSESDP EQUIPMENT CLASSES
29Global Maritime
DP ClassDP Class• 4 Classes (levels) of redundancy
• Class 0 – No redundancy• Class 1 – Limited redundancy (a back up joystick
control)• Class 2 – Redundant – No single failure, hidden
failure, or act of mal-operation• Class 3 – As with class 2, plus redundancy in event
of loss of compartment due to fire or flooding.
30Global Maritime
DP Class 2DP Class 2• Additional requirements
• DP system must have full Failure Modes and Effects Analysis (FMEA)
• Automatic bump less changeover
• Consequence analysis.
31Global Maritime
DP Class 3 DP Class 3 • All of Class 2 plus:• Able to maintain position in the event of the
loss of ANY one compartment. • Separate engine rooms (fuel supplies, air,
cooling)• Separate switchboard rooms• Separate cable runs for all DP systems• Back up DP control system and necessary
equipment in separate room with A60 bulkhead
32Global Maritime
DP Class DP Class
• . BodyBody Class 2Class 2 Class 3Class 3
IMO Class 2 Class 3
ABS DPS-2 DPS-3
LRS AA AAA
DNV AUTR AUTRO
BV MAR MARS
IMCA Class 2 Class 3
33Global Maritime
Some DifferencesSome Differences
• IMO and Lloyds require 3 gyrocompasses for class 2 certification
• ABS require 2 gyrocompasses• DNV now include hidden failures• GL and BV do not have many DP vessels• Class relies on local surveyors• Notation is not weather related
34Global Maritime
IMO DP Class IMO DP Class • IMO in MSC Circular 645 (Ref. 1),
recommends that DP vessels built after 1st July 1994 be assigned an Equipment Class.
Class 1.Class 2.Class 3.
35Global Maritime
IMO DP Class 1 IMO DP Class 1
• Loss of position may occur in the event of a single fault.
36Global Maritime
IMO DP Class 2 IMO DP Class 2 • Loss of position should not occur from a single
fault of an active component or system such as generators, thruster, switchboards remote controlled valves etc. A loss of position is possible from a fire of water ingress or after failure of a static component such as cables, pipes, manual valves etc.
• .
& & & &
37Global Maritime
IMO DP Class IMO DP Class • Class 3 - Loss of position should not occur
from any single failure including a completely burnt fire sub division or flooded watertight compartment.
• NOTE - A single fault includes a single inadvertent act by any person on board the DP Vessel.
38Global Maritime
The boundaries are uncertainThe boundaries are uncertain
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SCOPESCOPEOF AOF A
DYNAMIC POSITIONING DYNAMIC POSITIONING SYSTEMSYSTEM
46Global Maritime
Scope of Dynamic Positioning Scope of Dynamic Positioning • A Dynamic Positioning system comprises• All equipment that directly or indirectly effects the
position keeping ability• The DP comprise three main areasthree main areas:-
– Power generationPower generation, distribution & consumptiondistribution & consumption (by thrusters)-
– ControlControl - power management and position control
– ReferencesReferences - sensors for position, environmental and vessel attitude
47Global Maritime
““DP SYSTEM”DP SYSTEM”
48Global Maritime
49Global Maritime
DPController
DPController
ThrusterAllocate
ThrusterAllocate
Wind Comp
Wind Comp
ThrusterCurves
ThrusterCurves
ThrustersThrusters VesselVessel
Position Measure Position Measure
WindWavesCurrent
WindWavesCurrent
Wind SensorWind Sensor
CurrentEstimator
CurrentEstimator
Per Axis:– Surge – Sway - YawPer Axis:– Surge – Sway - Yaw
BarredZones
BarredZones
Power System
Power System
VRSGyro
VRSGyro
50Global Maritime
Scope of Dynamic Positioning Scope of Dynamic Positioning • Equipment that provides redundancy has
to be on line or immediately availableSuch thatSuch that • sudden failure of one item will not cause
an unexpected position excursion• transfer of control between redundant
equipment should be smooth.• So no unwanted thruster activity occurs.
51Global Maritime
Deepwater HorizonDeepwater Horizon
52Global Maritime
DP EquipmentDP Equipment
53Global Maritime
FUEL
PRIME MOVER
GENERATOR
DISTRIBUTION
DRIVE
PROPELLER
OPPOSE WEATHER
ENERGY ENERGY TRANSLATIONTRANSLATION
54Global Maritime
COFFEE BREAK!!!!COFFEE BREAK!!!!
55Global Maritime
DP Equipment DP Equipment
• Power GenerationPower Generation – prime movers, generators, fuel, sea water cooling, fresh water cooling, lube oil, compressed air, ventilation.
• Power DistributionPower Distribution – high voltage, medium voltage, low voltage, control voltage, DC voltage, UPS
• ThrustersThrusters – drives, azimuth control, thrust control, cooling, ventilation, feedbacks, emergency stops, direct manual controls.
56Global Maritime
DP Equipment DP Equipment • Power ManagementPower Management – Redundancy, Auto Start and
Stop, Start Blocking, Load Sharing – kW, Load Sharing kVAR, Black Out Recovery, Load Shed, Phase Back, DP Power Limiting
• Position ControlPosition Control – Arrangement, Networks (number, topography), Operator Stations, Outstations, Power Supplies (diodes), Control Modes, Thruster Modes, features (consequence analysis, fast current update), DP Interruptible Power Supplies, distribution (batteries, duration, distribution)
57Global Maritime
DP Equipment DP Equipment
• Position Reference SystemsPosition Reference Systems – DGPS, Acoustics, Taut Wire, Artemis, Fan Beam, Gangway, - Pos Ref Processing (weighting, voting, median test)
• SensorsSensors Gyro compasses, Vertical Reference Sensors, Wind Sensors, - Voting
•
58Global Maritime
DP Equipment DP Equipment
• For Class 3For Class 3
• Cabling and Physical Separation
59Global Maritime
DP Equipment Human FactorsDP Equipment Human FactorsControl Position - view of work area, radar, Manual
Control nearby, e stops, CCTV monitors, cameras, layouts, night, sun
Communications DP alerts, VHF, SPT, telephone, talk back
Operations Manual, Standing Orders, Emergency Procedures, Check Lists DP, ECR,
Qualifications, Shift Pattern and DP watch, ECR manning when on DP.
•
60Global Maritime
Consequence AnalysisConsequence Analysis• Real-time station keeping monitoring
program• Predicts if vessel would be able to
maintain current position if single worst failure occurs– Thruster failure– Generator failure– Switchboard failure– Compartment failure (class 3 only)
61Global Maritime
Position Reference SystemPosition Reference System• Class 2 and 3 Operations require 3 or
more position references, preferably different types.
• Older system used only 1 at a time and switched to the standby system upon failure
• Currently systems are weighted together to form a blended position with a Median Test (voter).
62Global Maritime
63Global Maritime
SubsurfaceReference
Beacon No. 3
SubsurfaceReference
Beacon No. 2
TranspondedAcoustic
Signal fromBeacon
Acoustic SignalTransmission
from Hydrophone
Ships Course
HydrophoneShipFix
SubsurfaceReferenceBeacon No. 1
Long Base Line System
SingleHydrophone
Threecloselyspacedsensors
Individualcycle of toneburst
Free runningBeacon
Single Hydrophone phase comparison system
ToneBurst
Phasemeasuringreceiver
Phasemeasuringreceiver
Phasemeasuringreceiver
PositionComputer
Phase delay used tocompute position
Types of Acoustic Systems
Short Base Line System
UltrashortBase Line System
Courtesy of Nautronix
Courtesy of Nautronix
Courtesy of Nautronix
Pages
64Global Maritime
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SECTION SLIDESECTION SLIDE
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Laser BasedLaser Based
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Pos
ition
Ref
eren
ce S
enso
r P
roce
ssin
gS
enso
r V
alid
atio
n
Sen
sor
Cal
ibra
tion
Laser Radar
Beacon 1
DGPS (REF)
T.W. Beacon 2
68Global Maritime
Processing of Position SignalsProcessing of Position Signals • Redundant Operations require 3 or more
position references, preferably different types.
• Older system used only 1 at a time and switched to the standby system upon failure
• Currently systems are automatically weighted together to form a blended position
• Then used by to update the Kalman Model and come up with a ‘best’ position error and velocity estimate.
69Global Maritime
Median Check (‘voting’)Median Check (‘voting’)
• Problem with seemingly ‘perfect’ measurements
• Requires a minimum of 3 position feedbacks• Compares all feedbacks to the middle
(median) value• Any that exceed an operator determined set
point are rejected from the weighted average• So rejects “perfect”measurement
70Global Maritime
InteractionsInteractions
• VRS – Acoustic, Taut Wire, DGPS, Fan Beam, Artemis
• Gyro – position calculation, HPR, DGPS, survey
• Thruster Feedbacks into Kalman
• UPS – through these
• Power info to DP
71Global Maritime
Other Control SystemsOther Control Systems• Pitch, Speed and Rudder Servos
• AVR
• Governors
• Power Management System
(phase back, thrust reduction, DP limit
- predictive or reactive)
• SW, LTFW, HTFW Cooling
72Global Maritime
Weak PointsWeak Points• Auto Manual Changeover
• Power Interface
• Networks
• Diodes
• Consistent worse case failure
73Global Maritime
DP ADVANTAGESDP ADVANTAGES&&
DISADVANTAGESDISADVANTAGES
74Global Maritime
WHY DP?WHY DP?
75Global Maritime
Benefits of DPBenefits of DP• Reduced deployment time & no anchors
• Increased mobility of the unit (survey work, dive work) and DP drill ships are self propelled (No tugs) Escape from hurricanes
• Accurate station keeping, independent of water depth, in nearly all weather (2-3 meters accuracy)
• Greater freedom in design phase of the vessel. Greater deck loads, Able to carry all the required equipment all the time
76Global Maritime
Drawbacks of DPDrawbacks of DP• Increased CAPEX• Higher OPEX (balanced by quicker
deployment time)• Increased maintenance and equipment
requirements• Not a passive system, DP control room
requires 24 hours a day manning. • Requires additional skilled labor (ETs and
DPOs)• Can go wrong dramaticallyCan go wrong dramatically
77Global Maritime
APPLICATIONSAPPLICATIONS• Once used only when mooring was not an option
– Used worldwide for numerous applications• CraneCrane ,DiveDive, ROV, Buoy Handling,• Pipe layPipe lay, rock dumping, dredging• Cable Lay, AccommodationAccommodation• Offshore Offloading Tankers, FPSO• Platform Support, Drilling • Seismic, Cruise
78Global Maritime
DP CAPABILITYDP CAPABILITY
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DP CAPABILITYDP CAPABILITY• The purpose of is to have a plots for
the operators that shows the limitthe limit that cannot be exceeded if position is to be kept when the
• most effective thrustermost effective thruster suddenly stops
• or the worse case failureworse case failure occurs.
80Global Maritime
The max. operational station keeping capability for The max. operational station keeping capability for the DP system be calculated for:the DP system be calculated for:
All thrusters operational with maximum thrust
All thrusters, except the most effective operational with max. effective thrust
The maximum number of thrusters and/or power units that could be operational after the worst single failure.
81Global Maritime
DP Capability PlotDP Capability Plot
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CAPABILITY CASESCAPABILITY CASES• Polar plot form for various current speeds,
e.g.1.0, 1.51.5 and 2 knots• Co-incident with wind and associated wave
loads fully developed sea• Realistic allowance for losses - thruster
interaction, tunnel length, high current, control system response, etc.
• Footprints and full scale confirmation
84Global Maritime
FMEAFMEAFMEA?FMEA?
!!!!!!!!FMEA?FMEA?
!!!!!!!!
85Global Maritime
FMEAFMEA
• FFAILURE
• MMODES
• &
• EEFFECTS
• AANALYSIS
86Global Maritime
FMEA and TrialsFMEA and Trials
• FFailure MModes and EEffects AAnalysis • Required by IMO, IMCA and Classification
Societies for class 2 and class 3 vessels• Seeks to ensure no single faultno single fault that could
result in loss of position• Needs to be proven in practice during
FMEA proving trialsFMEA proving trials– Failures are simulated and results
documented
87Global Maritime
OBJECTIVES OF DP FMEAOBJECTIVES OF DP FMEA
DRIFT OFFDRIFT OFF DRIVE OFFDRIVE OFF LARGE EXCURSIONLARGE EXCURSION HIDDEN FAILUREHIDDEN FAILURE SINGLE ACT OF MAL OPERATIONSINGLE ACT OF MAL OPERATION
In principle can any of the known DP In principle can any of the known DP incidents happen on this vessel?incidents happen on this vessel?
88Global Maritime
FMEAFMEA• A formal FMEA study.• The modes that should be considered are; • Sudden loss of major items of equipment• Sudden or sequential loss of several items of
equipment with a common link• Control instability failures and their method of
detection and isolation• Faults that can be hidden until another fault
occurs should also be considered• The likely operator responses
89Global Maritime
FMEAFMEA• Operator responses to the failures should be in the
operations manual for operational scenarios for which the vessel is intended.
• The FMEA should also consider likely operational scenarios – shallow water– high tidal streams– working close to installations
• FMEA updated if modifications are made that are likely to effect the FMEA
90Global Maritime
FMEA Proving TrialsFMEA Proving Trials• DP vessels have to undergo FMEA proving trials, in addition
to and after, dockside testing, commissioning and customer acceptance trials.
• Failure modes should be simulated to prove the FMEA• Results of such tests independently documented by a 3rd
party• Performance should be demonstrated in both the intact and
various failed conditions• Proving trials be properly documented and the results
available • Value lost if findings not transferred to operators
91Global Maritime
ANNUAL TRIALSANNUAL TRIALS• Re checks redundancy of the system• Demonstrate DP to potential clients • Prevent repetition of tests when taken
on hire• Introduce problems newly found by
the industry
BUT the system is not perfect!!!!!!!!
92Global Maritime
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OPERATION, TRAINING OPERATION, TRAINING AND DOCUMENTATIONAND DOCUMENTATION
94Global Maritime
OPERATIONOPERATION• Every DP vessel should have an
operations manual that is particular to that DP system and the operating practice of the owners or operators of the vessel.
• Cover all the work for which the vessel is designed or likely to be used. It should not be what the DP vendor supplies but reference this document (not repeat it)
95Global Maritime
OPERATIONS MANUAL OPERATIONS MANUAL include but not be limited toinclude but not be limited to
• Capability plots and verification trials data• Proving trials data• Working profiles and capabilities of equipment• DP alerts, emergency responses and procedures• Responsibilities and communications• Approach, setting up, checking and testing of the DP system• Reporting and recording• DP footprints• Manning
96Global Maritime
DOCUMENTATIONDOCUMENTATIONJob Specific Documentation• In addition to the operations manual -
each work location, task or operation of the DP vessel may require a document particular project if the general document will not suffice e.g. project safety plan HAZOP/HAZID exercises and close out documentation.
97Global Maritime
DOCUMENTATIONDOCUMENTATION• Check Lists, Tests and Trials• Vessel acceptance trials results • Annual trials for quality assurance of the DP
system• Mobilisation checks for new charter• DP bridge check list for new location• ECR check list for new location• Watch status check lists• Acoustic and Taut Wire Logs• Schematics of DGPS options .
98Global Maritime
DOCUMENTATIONDOCUMENTATION
• Reporting and recording • DP log books • Data logging• Print outs• Incidents
• Maintenance, modifications & service
99Global Maritime
TRAININGTRAINING• IMO MSC 738 - Training and Experience of Key DP
Personnel• Nautical Institute accredited DP log books and
certificates• A shore based induction course – 4 to 5 days• At least one month as an under study trainee DPO• Shore based simulator training – 4 to 5 days• Six months supervised training as Junior DPO• Apply to Nautical Institute assessed and signed of by
Captain• Requirements for familiarization when on a new vessel
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WEATHER PRECAUTIONSWEATHER PRECAUTIONS
??????????????
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WEATHER PRECAUTIONSWEATHER PRECAUTIONSDPO’s should pay attention to any
indications of impending weather changes - sudden shifts in wind force and direction, and tidal changes
to ensure that timely action is taken to reduce the possibility of a critical excursion that exceeds the safe working limits.
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WEATHER PRECAUTIONSWEATHER PRECAUTIONSObtain regular & frequent weather forecasts
for the area, use of fax facilities and charts.Info.from other units in the vicinity about
prevailing weather conditions in their areas.Use of experience to assess the prevailing
conditions and likely trends.The environmental information measured by
the DP system and any trendsUse of onboard meteorological instruments
103Global Maritime
WEATHER PRECAUTIONSWEATHER PRECAUTIONSNotes:-Notes:-
Vessel is to work to upwindupwind (or up current) of a platform or obstruction the additional additional powerpower that might be required to reach a safe situation
DP capability based on fully developed sea so wrong impression at beginning of a storm
Any doubt the vessel should move clear deselect thrusters according to the worst deselect thrusters according to the worst case failurecase failure and see if position is maintained.
104Global Maritime
INTERNATIONAL, GOV. & REGINTERNATIONAL, GOV. & REG
105Global Maritime
INTERNATIONAL, GOV. & REGINTERNATIONAL, GOV. & REGClass Societies – ABS, BV, DNV
and LloydsIMO – DP guidelinesFlag StatePort AuthorityIMCA – Design and Operation of
Dynamically Positioned Vessels
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ASSESSMENT TOOLSASSESSMENT TOOLS
??????????????
107Global Maritime
BASIC ASSESSMENT TOOLSBASIC ASSESSMENT TOOLS IMCA/UKOAA Marine and DP AuditBlack BookFMEA and Trials IMCA MembershipCapability Plots Proven Incident Reporting Independent Third Party for Annual TrialsNo warning AuditsPersonnel,Qualifications,assessment and
ownership
108Global Maritime
AFTERNOON SESSIONAFTERNOON SESSION
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AFTERNOON SESSIONAFTERNOON SESSION• FOUR GROUPS --- DP PROBLEMS – FOUR GROUPS --- DP PROBLEMS –
(KNOWLEDGE TRANSFER)(KNOWLEDGE TRANSFER)
• PIPE LAY• ACCOMMODATION• HEAVY LIFT• DIVING
Closing combined session on the way forwardDP Incidents – Chris Jenman
110Global Maritime
AFTERNOON SESSIONAFTERNOON SESSION Equipment Failure, Drift Off, Drive Off, or Excursion Operator Error Three reference systems Proximity of platform - clearances Anchor Wires Clearances Use of tugs and of safety anchors DP Simultaneous operations Acoustic Frequencies Communications
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ACCOMMODATIONACCOMMODATION
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ACCOMMODATIONACCOMMODATION• Gangway instrumentation• Gangway possible damage to
platform• Alarms and Auto lift
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HEAVY LIFT
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HEAVY LIFTHEAVY LIFT• Lifting wire tension• Simultaneous operations with Ballasting• Heavy Lift Mode
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PIPELAY
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PIPE LAYPIPE LAY• Time to abandon pipe• Pipe tension interface• Pipe tension effect on DP• Backing over the pipe
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DIVING
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DIVINGDIVING
• Umbilical
• Down Lines (inc acoustics and taut wires)
• Shallow Water
• Taut Wires
• Movements
119Global Maritime
LUNCH BREAK!!!!LUNCH BREAK!!!!
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