DP CPD

Output from 1 of 2 bow tunnel thrusters is solved to be frozen at 30% thrust to port, thrust levels on the other tunnel are changing constantly. Heading / position errors are within limits. Both thrusters must be online to meet required class for this operation alongside a platform. The DPO should…. Stop DP operations and move the vessel to safe location to effect thruster repair. .

WHEN conducting diving operations from a vessel on dp the length of the diver´s umbilical must be…. set to stop the diver 5 mts from a thruster. .

WICH of the following cannot adversely affect dgnss positioning system. Dense fog. Sunspot Activity. High HDPO Values.

Wich of the following will not have an effect on tunnel thruster performance. Deep water. Vessel Speed. Rough Seas.

When working in the vicinity of a large production platform or installation, the reference system that is likely to be unavailable due to shadowing would be,.. GNSS. Cyscan. RADIUS.

PINGER MAY BE DESCRIBED AS: an underwater beacon which transmits automatically a pre-set intervals. .

ENGINE room manning during dp operations should be as follows. The engine room should be manned at all times. .

many dp system have a “weathervane of minimum power heading” mode of control. when operating in this mode: The DP system continuously calculates the optimum vessel heading and adopts this value as the Set Point heading. The DP system computes and displays the optimum value of the heading allowing the DP operator to rotate the vessel to this heading. The DP operator is able to rotate the vessel to the optimum heading using the Joistick.

During rov operations a faulty feedback signal indicates that 1 of 2 bow tunnels thrusters has failed to full force but system checks indicate that the thruster is functioning properly. there is a loss of position and heading. the dpo should first…. activate the emergency stop for the thruster with the faulty feedback. .

A DP SYSTEM IS DIVIDED INTO SEVEN MAJOR HARDWARE ELEMENTS. WHICH ELEMENT IS THE USER INTERFACE FOR THE DPO?. DP OPERATOR STATION. GMDSS. ENVIRONMENTAL REFERENCE SYSTEMS. POSITION REFERENCE SYSTEMS.

WHAT IS THE MEANING OF DARPS?. DESIRABLE ARTEMIS RELATED POSITION SYSTEM. DIFFERENTIAL ARTEMIS RELATIVE POSITION SYSTEM. DIFFERENTIAL ABSOLUTE AND RELATIVE POSITION SYSTEM. DEGRADED ABSOLUTE AND RIGID POSITION SYSTEM.

WHAT IS PREFERENTIAL TRIPPING?. WHEN THE POWER MANAGEMENT SYSTEM TRIPS OFF NON ESSENTIAL LOADS AS CABIN CONDITION. .

A THRUSTER MALFUNCTION MAY BE DETECTED BY OBSERVING WHICH OF THE FOLLOWING?. THRUSTER DEMAND AND FEEDBACK DATA. REFERENCE ORIGIN HAS DRIFTED. MEASURED WIND SPEED HAS INCREASED.

A DP CLASS 2 OR 3 VESSEL IS FITTED WITH FOUR POSITION REFERENCE SYSTEMS (PRS): TWO DGNSS, TAUT WIRE AND LASER, IN THIS INSTANCE, WHY SHOULD THE DPO PREFER TO CONSIDER THE TWO DGNSS AS JUST ONE PRS?. DGNSS SYSTEMS ARE LESS RELIABLE AND ACCURATE THAN SURFACE SYSTEMS. THIS IS REQUIRED BY THE IMO EQUIPMENT CLASS RULES. COMMON-MODE FAILURES MAY OCCUR TO ALL DGNSS SYSTEMS, WHEREBY ONE EVENT COULD RESULT IN A LOSS OF ALL DGNSS POSITION REFERENCES. THE DP CLASSIFICATION SOCIETIES REQUIRE THIS.

IN DRILLING OPERATIONS, THE FOLLOWING SYSTEM MAY BE USEFUL IN KEEPING THE MARINE RISER IN ANGLE WITHIN LIMITS AT THE LOWER MARINE RISER PACKAGE (LMRP). RISE ANGLE SYSTEM. .

A VESSEL IS EQUIPPED WITH 3 AZIMUTH THRUSTER AT THE BOW AND 3 AZIMUTH THRUSTERS AT THE STERN. A FIXED AZIMUTH MODE IS AVAILABLE. WHEN MIGHT THIS MODE BE USED?. WHEN THE THRUSTERS ARE CONTINAULLY ‘HUNTING’ FOR DIRECTION IN LIGHT WEATHER CONDITIONS. .

THE THRUSTERS IN A DP VESSEL MAY BECOME INEFFECTIVE: REFERENCE ORIGIN HAS DRIFTED. MEASURED WIND SPEED HAS INCREASED. WHEN THE VESSEL IS OPERATING WITH A VERY LIGHT DRAFT.

BEFORE ENTERING THE 500 MTS PLATFORM EXCLUSION ZONE IN ORDER TO CONDUCT DP OPERATIONS, IT IS IMPORTANT THAT. THE VESSEL MUST BE SETUP AS PER THE FMEA / ASOG. ANY MAINTENANCE TO BE DONE INSIDE 500 METERS IS SCHEDULED. THE BUS TIE SWITCHES MUS BE CLOSED. ALL WIND SENSORS ARE SELECTED ONLINE.

A “POD” TYPE THRUSTER WILL. HAVE THE ABILITY TO PROVIDE THRUST THRUOUGH 360 DEGREES. .

UNDER WATER ACOUSTICS CAN BE UTILIZED FOR WHICH OF THE FOLLOWING APPLICATIONS?. MARKING UNDERWATER FEATURES OR HARDWARE. POSITION REFERENCE FOR DP PURPOSES. TRACKING ROVs OR OTHER EQUIPMENT. ALL OF THE ABOVE.

The ‘’Weathervane’’ or ´´ Auto Heading Select’’ facility is an essential function for which type of DP operation. Dive and ROV Support. Tanker Offtake. Dredging and Rock Damping. Pipelay.

Before entering the 500m platform exclusion zone in order to conduct DP operation it is important that: Contingency planning to establish vessel escape routes has been completed. Three position reference has been established on- line. All Wind Sensors are selected on-line.

In the Universal Transverse Mercator UTM co-ordinate system, why are false eastings applied?. To avoid negative numbers. To correct for the curvature of the earth. To make allowance for the correct longitudinal zone. To compensate for meridian convergence.

What is the main advantage of an Azimuth Thruster compared with non-Azimuth Thruster?. It is impossible for divers or the ROV to come into contact with the propeller blades. Maintenance costs are reduced. Azimuth Thruster can provide thrust in any direction. Azimuth Thruster are more fuel efficient.

The Wind Sensor Feed Forward facility is important because. It allows the DP system to take immediate action if the wind changes direction and/or speed. It is important to keep the ship beam on at all times. The Capability Plots is automatically updated. An alarm is activated if the difference between the Wind Sensor exceeds 3 degrees.

The equipment Class necessary for particular operation should decided. By reference to the IMO Equipment Class rules. After an assessment of the commercial and financial risks associated with the operation. By the vessel owner and client after a full risk assessment of the proposed operation.

A vessel has completed her approach to a worksite which is closed alongside a fixed plataform. She is in her final working position. Before giving the green light allowing commencement of ROV operation . It is essential that. A DP Location (Arrival) checklist has been completed. The vessel has been in Auto Position for at least 30 minutes. The platform has issued a Permit to work. All of the above.

Multiple Azimuth Thruster are fitted in close proximity to each other on a DP vessel. The DPO can select a function to prevent the exhaust wash from one Thruster affecting another, this function is called. Prohibited Azimuth Zone. Low Gin mode. Push Pull mode. Kalman Mode.

" As a general rule,control of what axis will receive priority for thrust allocation when in DP mode ". Sway. Surge. Yaw. Heave.

What input is required to enable auto-heading control whilst in Joystick Mode. Position reference system. Wind sensor. Gyro compass. Kalman filter.

An azimuth thruster is a. Controllable pitch tunnel thruster. Thruster giving 360 degrees directional control. Fixed pitch tunnel thruster.

When referring to DP Equipment Class , the term Redundancy means. The vessel is unable to maintain position and heading following any surge point failure. The DP Operator may be in danger of losing his job. The ability of a DP vessel to maintain position and heading subsequent a single failure on any point of the DP system.

A DP system function that performs calculations to verify that sufficient thrust and power is available to maintain position and heading in the event of a single point failure is called. Power Management is required on classes 2 and 3. Consequence Analysis it is required on classes 2 and 3. Consequence Analysis it is required on classes 1, 2 and 3. Thruster Allocation it is required on classes 1, 2 and 3.

Which of the following inputs is required before surge or sway can be automatically controlled?. Wind Sensor. Vertical Reference Sensor. Power Management System. Position Reference System.

The possibility of loss of Position and/or Heading is reduced by: Ensuring system redundancy to Equipment Class 2 or 3. Deploying multiple Position Reference Systems. Ensuring DP Operators are well-trained and experienced. Efficient and comprehensive operational planning.

What does the DP System use to calculate weighting (or confidence) for each Position. Distance from the receiver. Signal strength. Weather conditions. Relative spread of fixes.

How many Position Reference Systems should be available and online during a Class 2. 1. 2. 3. 4.

The function of DP system Redundancy is to: Enable the vessel to continue operations subsequent to a single failure. Allow the Captain to sleep better. Allow the operation to be safely abandoned after any single-point failure. Allow vessel to use a higher setpoint speed.

What is one disadvantage of a ship working using its DP system compared to being anchorage?. DP vessels are less maneuverable than a vessel positioning using anchors. A DP vessel takes longer to move between work locations. Continually running thrusters are hazards for divers and ROVs. A DP vessel can only work in very shallow water.

The following Position Reference System configurations are available for a DP Class 3, which is the best configuration?. 2 DGNSS and Laser. Taut Wire and two independent HPR systems. DGNSS, Laser, Artemis and a single HPR system. DGNSS, Taut Wire and a single HPR system with two transponders.

Under which of the following conditions may positioning be improved by increasing "control gain"?. When station keeping is poor due to high noise in the position reference sensors. When thrusters appear to be 'hunting'. When encountering increased wind or current conditions. During periods of poor visibility.

About what point does a DP vessel rotate when changing heading?. The vessel's Centre of Gravity. A point mid-way between bow and stern. The vessel's Centre of Rotation. The location of the motion sensors on the vessel.

The main purpose of Dynamic Positioning is to: Leave the positioning of the vessel to the computers in order that the operator on the. Maintain position and heading automatically. Maintain position, but not heading, automatically. Maintain heading, but not position, automatically.

Which of the following is NOT considered to be a 'Local' Position Reference System?. Hydroacoustic Position Reference (HPR). Taut Wire. Laser. DGNSS.

The DARPS Position Reference System is one in which: A shuttle-tanker may position relative to a moving point such as an FPSO. Differential corrections are received and used to increase the accuracy of positioning. Relative positioning is obtained using a combination of GPS and laser-based systems. The vessel is allowed to weathervane whilst maintaining position.

For DP Class 2 and 3 operations, at least three Position Reference Systems should be deployed and selected into the DP system. Why should they not all be of the same type?. So that if one PRS fails, the vessel remains fully operational. To protect against Common Mode Failure. Because of the improved accuracy available from this configuration. To provide two back-up references.

Dynamic Positioning can be defined as a system which: Controls a vessel's position and heading based on joystick inputs from a DP operator. Automatically controls a vessel's heading exclusively by means of active thrust. Automatically controls a vessel's position and heading exclusively by means of active thrust. Controls a vessel's position and heading based on manual inputs from individual thruster.

For DP Class 2 and 3 operations, at least three Position Reference Systems should be deployed and selected into the DP system. Why should they not all be of the same type?. So that if one PRS fails, the vessel remains fully operational. To protect against Common Mode Failure. . Because of the improved accuracy available from this configuration. To provide two back-up references.

How many Position Reference Systems should be available and online during a Class 2. 1. 2. 3. 4.

A DP system is divided into seven major hardware elements. Which element is the user interface for the DPO?. DP Operator Station. GMDSS. Environmental Reference Systems. Position Reference Systems.

The Sway is determined from data from: Position Reference Systems. Gyro Compasses. Vertical Reference Sensors. Draft sensors.

What is a vessel model?. A totally accurate description of a vessel's motions. A computer algorithm that calculates thruster set point signals. A mathematical description of how the vessel reacts to the forces acting upon it. A software routine continually monitoring redundancy level.

Which Position Reference System provides the DP system with a global position (i.e. Latitude and Longitude or UTM co- ordinates)?. FMCW Radar. Taut Wire. Laser. DGNSS.

What is the meaning of DARPS?. Desirable Artemis Related Position System. Differential Artemis Relative Position System. Differential Absolute and Relative Position System. Degraded Absolute and Rigid Position System.

Examples of Positioning Reference Systems (PRS) that can use multiple targets are: Laser and GNSS. Laser and DARPS. Laser and FMCW Radar. Laser and Taut Wire.

The possibility of loss of Position and/or Heading is reduced by: Ensuring system redundancy to Equipment Class 2 or 3. Deploying multiple Position Reference Systems. Ensuring DP Operators are well-trained and experienced. Efficient and comprehensive operational planning.

A DP Class 2 or 3 vessel is fitted with four Position Reference Systems (PRS); two DGNSS, Taut Wire and Laser. In this instance, why should the DPO prefer to consider the two DGNSS as just one PRS?. DGNSS systems are less reliable and accurate than surface systems. This is required by the IMO Equipment Class rules. Common-mode failures may occur to all DGNSS systems, whereby one event could result in a loss of all DGNSS position references. The DP Classification societies require this.

A local Positioning Reference System is measuring from a local Reference Origin. Examples are;. Artemis, Taut Wire, FMCW Radar and Laser. Artemis, DGNSS and Laser. DGNSS, Taut Wire and FMCW Radar. DGNSS, Artemis and FMCW Radar.

Why is it necessary for a vessel to be in Auto Position mode for a minimum of 30 minutes before starting work?. To allow the DPO to complete the pre-DP checklist. In order that additional position-reference systems may be enabled. To allow the system's mathematical model to build. To ensure that all thrusters are responding correctly.

If a position discrepancy among three or more Position Reference Systems is detected, the DP system will reject the drifting PRS as a result of the: Calibration test. Redundancy test. Median test. Consequence Analysis.

Redundancy, with respect to vessel heading input can be achieved by fitting: 2 or more Motion reference unit. A third DP Operator Station. An extra DP Control Computer. 2 or more Gyro Compasses.

Underwater acoustics can be utilized for which of the following applications?. Marking underwater features or hardware. Position reference for DP purposes. Tracking ROVs or other equipment. All of the above.

Which is the system that uses a single transducer and a calibrated array of transponders located on the sea floor?. Short Baseline (SBL) acoustic positioning. Super Short Baseline (SSBL) acoustic positioning. Long Baseline (LBL) acoustic positioning. Ultra Short Baseline (USBL) acoustic positioning.

Ultra Short Baseline (USBL) Hydroacoustic positioning is determined by: Range and bearing of a single transponder beacon. Difference in time of arrival of signal from a single pinger beacon to an array of hydrophones mounted on the vessel hull. Acoustic ranging from multiple transponder beacons in an array. Monitoring signals from a mobile transponder beacon.

When using a Global Navigation Satellite System (GNSS) what is the recommended. 1. 2. 4. 5.

Performance of an HPR system is often limited by acoustic conditions in the water. Oil leaking from the ROV. Noise from vessel thrusters. Conversations between divers. Noise from the Taut Wire winch.

A major reason for the loss of hydro-acoustic signals is: Pressure gradient in the water column. Marine growth. Engine vibration. Noise and aeration from thrusters.

When using a Hydroacoustic Position Reference (HPR) system, acoustic reception is not adversely affected by: Aeration in the water. Thruster noise. Heavy snowfall. Temperature layering in the water column.

The best placement, when possible, of HPR system transponder beacons will be: Downwind and down-current from vessel location. Down-current and upwind from vessel location. Upwind and up-current from vessel location. Downwind and up-current from vessel location.

Which of the following principles does a GNSS use to determine vessel position?. The GNSS receiver acquires radio signals from satellites, measures the time delay of signal reception and, with known satellite positions, determines multiple position lines. Range and bearing from reference station is determined from a communications satellite; position is therefore determined by the known location of the reference station. The vessel transmits data to the GNSS satellites, which then transmit position data to reference stations for retransmission to the vessel.

Which of the following is NOT a DGNSS quality factor?. The number of satellites being tracked. The Age or Latency of differential correction data. The value of HDOP. Adverse weather conditions.

When using a Hydroacoustic Position Reference (HPR) system, acoustic reception is not adversely affected by: Heavy snowfall. Aeration in the water. Thruster noise. Temperature layering in the water column.

How are HPR beacons deployed from a DP vessel?. Lowered to the seabed using a wire, which remains attached to the vessel. Lowered to the seabed using a wire, which may be buoyed off. Placed in position using an ROV. Any of the above methods may be used.

Which is the system that uses a single transducer and a calibrated array of transponders located on the sea floor?. Short Baseline (SBL) acoustic positioning. Long Baseline (LBL) acoustic positioning. Ultra Short Baseline (USBL) acoustic positioning. Super Short Baseline (SSBL) acoustic positioning.

Ultra Short Baseline (USBL) Hydroacoustic positioning is determined by: Monitoring signals from a mobile transponder beacon. Difference in time of arrival of signal from a single pinger beacon to an array of. Range and bearing of a single transponder beacon. Acoustic ranging from multiple transponder beacons in an array.

Multipath reception can be a problem for both HPR and GNSS Position Reference. Causing the system to listen to the wrong signal source. Creating a shorter than correct path for the signals. Decreasing the strength of the received signal. Confusing the distance and/or direction from the source through signal reflection.

A Dual Frequency GNSS receiver is used to: Achieve redundancy in the operation. (wrong answer). Improve accuracy by compensating for ionospheric delay. Get better positioning due to the higher positioning accuracy of military frequencies. Lock on to a satellite on one channel while scanning on another.

What is the maximum practicable range for FMCW Radar Position Reference Systems. 10 - 50m. 200 - 1000m. 5000m. 10000m.

In a Hydroacoustic Position Reference (HPR) System, a Responder Beacon is a device which: Is interrogated by electrical signal through cable, replying through water. Is Interrogated through water and replies through water. Sends continuous acoustic pulses from the sea floor. Is interrogated through water and replies via cable.

If a platform has just one Artemis antenna, how many vessels can be positioned using Artemis as a Position?. Two vessels provided that they have different frequencies. All vessels within a 5 km range. Five vessels. One vessel.

Performance of an HPR system is often limited by acoustic conditions in the water. Oil leaking from the ROV. Noise from vessel thrusters. Noise from the Taut Wire winch. Conversations between divers.

A vessel is using one HPR Pole/Transducer in Super Short Baseline (SSBL) mode. Four separate Transponder Beacons are in position and being interrogated. Three beacons are in fixed locations on the sea floor. The fourth beacon is designated 'mobile' and is located on an ROV. For DP Class purposes, this array qualifies as: Two Position Reference Systems. Three Position Reference Systems. Four Position Reference Systems. One Position Reference System.

What might be the 95 percent accuracy of a Differential Global Navigation Satellite System (DGNSS) using a modern commercial subscription service?. Less than 0.1 metre. Less than 1 metre. Less than 0.2 metres. Any of the above, depending on which service is chosen.

Which of the following may adversely affect the quality and accuracy of positional data provided by satellite-based position reference systems?. The close proximity of large platform structures. The DGPS antenna being located too high in the vessel. Interference from laser-based position reference systems. The use of the UTM co-ordinate system.

How does a Laser Position Reference System measure the bearing of a target?. By monitoring the height of the target. By combining the relative bearing of the target with the ship's heading. By measuring the time of flight to and from the target. With reference to information from the Motion Reference Unit.

When is it advisable to deselect the wind sensor?. When a helicopter is about to land on your vessel. When relocating the vessel to a new position under DP control. When relocating the vessel to a new position under DP control. When thunderstorms are in the vicinity.

A vessel is on DP close to a platform structure. A single Wind Sensor is selected. How will the vessel react if the hull and superstructure is in wind shadow and the Wind Sensor is suddenly exposed to the full force of the wind?. The system will apply thrust and move against the 'Current'. The system will maintain position with the average thrust used. The system will apply thrust and move against the wind. The vessel will drift-off.

How many gyro compasses should, according to IMO Equipment Class requirements, be available and online during a Class 2 operation?. 1. 3. 2. 4.

How does a Taut Wire determine vessel position?. Davit-head-mounted sensors monitor the tension in the wire to calculate relative position. It compares wire length measured at any given time with the value at the time of deployment. Davit-head-mounted sensors monitor the tension in the wire to calculate relative position. The sensor head measures the angle to the clump weight. This angle is used with either the measured wire length (or the vertical distance) from the sensor head to calculate the relative position.

Of the items listed below, which is the most important to the operation of the DP system?. The Doppler Log. The Gyro Compass. Wind Sensor. Navigation Radar System.

A cable vessel is engaged in ploughing operations using 'Auto Track' mode. Plough hawser tension is being measured and entered into the DP system. If feedback data from the plough hawser tension sensor is lost, then the probable result will be: The DP system reverts to 'Auto Position' mode. Position control will be lost. Plough tension will be displayed by the system as DP Current. The DP system reverts to Joystick mode.

What is the purpose of the 'Wind Feed Forward' facility?. Anticipating the wind force and correcting for it. Providing an immediate opposing thrust to rapid changes in the wind. Smoothing out peaks and troughs in wind data. Providing an opposing thrust calculated from drag coefficients.

The DP current is determined by: Calculation using the mathematical model. Measurement of the water velocity from the ship's Doppler Log. Comparison of the vessel velocity from DGPS to the Doppler Log value. Using thruster forces to determine velocity.

When the DP system is in full automatic control of the vessel, the DP current is: Determined from the mathematical model. Measured by current sensor. Ignored for the purposes of the model. Updated at 30 minute intervals.

A pipelay vessel is engaged in pipelay operations using DP. In addition to the normal range of position, heading and environment references, feedback may also be required in respect of: Water depth. The position of the pipe touchdown point. Vessel draught, from a draught sensor. Pipe tension values.

"A DP system using the 'preferred' method of sensor allocation is fitted with two Gyro Compasses; both are selected into the DP system and one is chosen as the 'preferred' Gyro. The system alerts you that there is a 'heading difference error' between the two Gyros. What would you do?". Call the Platform or Rig for assistance. Immediately change the preferred Gyro. Compare the two Gyros with the Magnetic Compass, before deciding whether to. Deselect both Gyros.

Some DP vessels are fitted with draught sensors, enabling continuous draught feedback to the DP system. This is to allow: Automatic correction of the height of Artemis and Fanbeam sensor antennas. Warning to be given of reduced under-keel clearance. Increased accuracy of data from the HPR system. Continuous update of the vessel model regarding changes to the shape of the vessel.

When using a Taut Wire positioning system, which of the following factors are significant?. The clump weight position must be accurately determined. Accuracy improves as deployed wire length increases. Accuracy deteriorates as water depth and/or angle of wire increases. Heavy rain can affect the accuracy of the Taut Wire system.

Which of the following can cause wind model errors?. Locating the vessel in a position which is partly sheltered from the wind. Increased thruster activity. Selection of more than three wind sensors. An incorrect estimation of the sea current.

What is the function of the Motion Reference Unit?. To measure Position. To measure Pitch, Roll and Heave. To measure Heading. To enable compensation for the wind force.