Beier Radio - Dynamic Positioning Induction Course
Beier Radio - Dynamic Positioning Induction Course
Beier Radio - Dynamic Positioning Induction Course
a
a
a=0.3 mile
=45
TRACK CONTROL (HIGH SPEED) MODE STARTING CONDITIONS
NOTE: e When the Track Control mode is switched on, the vessel moves to the nearest leg of th
route and then, follows the next one.
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PRACTICAL OPERATION OF A DP SYSTEM
CONTROLS AND INDICATORS
Each of two Operator Consoles consists of an LCD display with touch screen, Main Control
Panel, and Alarm Speaker.
All computers, PLCs, power supplies, interconnecting LAN data, busses and sensors are
duplicated by redundant circuits. Both systems are identical and either one may be selected as
Master and the active console at start-up.
When the Master console is active it controls the vessel. The Hot Standby console is passive
and it displays all actions of the Master console only. It is possible to transfer control from the
Master to the Hot Standby system at any moment. At this time, the Hot Standby system
becomes the Master and vice versa.
One Operator Console is Forward Facing and another is Aft Facing. All descriptions and figures
in this Manual are for Forward Facing Console (Master).
POWER PUSHBUTTON
Used for switching system power On/Off. The button is illuminated when the power is on. To
switch power off, it is necessary to hold this button for 2 seconds, after which the Computer will
be shut down. Then, the LCD and Touch Screen power and Control Panels power is switched off
immediately and all other system components will automatically be switched off in 3 (three)
minutes.
The Power pushbutton is equipped with a green LED Indicator, which is illuminated when the
Computer is connected and is an indicator of Control Panel and Computer operation.
NOTE: Each Operator Console (A and B) should be switched On/Off separately.
STEERING SELECTOR
The Steering Selector is the main switch, which allows the IVCS 2000 to accept control. It is not
a part of the IVCS 2000 system and it is located on the Steering Console. There are two positions
of the Steering Selector:
Bridge Vessel Control from Bridge Control Station.
DP Vessel Control from the IVCS 2000 (Master console).
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PRACTICAL OPERATION OF A DP SYSTEM
BRIDGE MODE INDICATORS
The red Bridge LED Indicator is illuminated, when the IVCS 2000 is in the Bridge Mode, i.e.
Vessel Control is provided from the Bridge Station when the Steering Selector is in the Bridge
position. When the IVCS 2000 (DP) controls the Vessel, the Bridge LED indicator is not
illuminated.
MANUAL PROPULSION CONTROLS
Heading Control Knob - This is the stay-put Rotary Control Knob with center detent,
which directly controls the proportional heading control moment when Manual Heading
Mode is selected. When the Autopilot Mode is selected, the Control Knob is used to
control rudder angle.
Position Control Actuator (Joystick) - This is two-axis stay-put Joystick used in Manual
Position Mode, for selecting thrust levels for the fore-aft and athwartships axis. Force
level is proportional to the deflection in each axis.
It is also possible to control the Vessel Speed vector by Joystick in the Manual Speed
Vector Mode.
Matching Indicators - These are intended to indicate the Joystick and/or Rotary Knob
adjustment necessary to maintain the current DP thrust when changing to manual from
automatic position keeping. It eliminates the unwanted jump in positioning control,
which would otherwise occur.
CONTROL TRANSFER PUSHBUTTON AND INDICATOR
The Accept Control Pushbutton is assigned for Control transfer between Master console and
Hot Standby console and between Main Control Panel and Portable Control Panel of the
Master Console. A green LED Indicator in the Accept Control Pushbutton indicates that
console is in control. When first switching the IVCS 2000 on, the Main Control panel of the
Master console becomes active.
To start Control Transfer Procedure between Master and Hot Standby, press the Accept
Control button on the Operator Console, where control is to be transferred to, and hold it for
two seconds. Control is then transferred to this console, its LED indicator becomes illuminated
and that on the previous console becomes extinguished.
The procedure to start Control Transfer Procedure between Main Control and Portable Control
Panels of the Master Console is the same as described above.
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PRACTICAL OPERATION OF A DP SYSTEM
NOTE: If the Portable CP is connected to the Hot Standby Main CP, the Control Transfer
Procedure is the same.
The Accept Control Touchscreen Control Button on the display serves the same function.
Enter Pushbutton This is used to acknowledge the Touchscreen button requests. The
button on the top of Joystick lever and the Enter Touchscreen Control Button on the
display serve the same function.
Alarm Acknowledge - This is used to acknowledge new alarm conditions as displayed in
the alarm window (and on last alarm/message line) of the led.
Lamp Intensity - There are two buttons dimmer +/- on the control panel, which are
used for increasing/decreasing panel illumination. for lamp test, press both these buttons,
simultaneously.
Hold Heading Pushbutton And Indicator - the hold hdg pushbutton and indicator can
be operated only in the j/dp and auto pilot modes and is used to lock in the present
heading for automatic course control. A momentary press will engage, the led indicator
goes out, and the system passes to the manual heading mode. To take manual control, it
will be necessary to synchronize the heading knob with its led indicators.
HOLD POSITION PUSHBUTTON AND INDICATOR
The Hold POS Pushbutton and Indicator can be used only in the J/DP Mode and is used to
select the Auto Position Mode. When pressed momentarily, the actual vessels position is locked
in for automatic position holding. When held down steady, the LED indicator goes out and the
system passes to the Manual Position Mode. To take manual control, it will be necessary to
synchronize the Joystick with its LED indicators.
CENTER OF ROTATION PUSHBUTTON AND INDICATOR
Press the Remote COR button to transfer Center of Rotation from center of gravity to stern or
to bow, depending on settings made in the Parameters Window (Joystick section). This function
can be used only when the Manual Heading Mode is activated.
AUDIO VOLUME
The Audio Volume Knob is used for volume control of voice alarms on the external loud
speaker.
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PRACTICAL OPERATION OF A DP SYSTEM
CONTROL FROM LCD WITH TOUCH SCREEN
After switching power on and the system has self-loaded and the Main Screen appears on the
LCD, DPO can choose one of the following options by touching the display at the desired Mode:
Real Mode. Starts the IVCS 2000 operation in Real Mode.
Simulator Mode. Starts the IVCS 2000 in Simulator Mode. Before this mode is started, it
is necessary to set the initial conditions (using a Numeric keypad) in the window for
vessel and environment conditions. Then, press OK Softkey to load the IVCS 2000 in
the Simulator Mode.
VESSEL INITIAL CONDITION SETTING FOR SIMULATION MODE
ENVIRONMENT INITIAL CONDITION SETTING FOR SIMULATION MODE
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PRACTICAL OPERATION OF A DP SYSTEM
Services. This mode allows the service engineer to monitor the system operation, using
the following submodes:
Monitor Runs the special Monitor Utility, which can be used for monitoring of
data exchange between the IVCS 2000 and PLCs.
PLC Faults Runs the special utility, which monitors PLC failures.
Alarm Viewer Runs the Alarm Viewer.
COM Ports Runs the special utility, which monitors the raw data.
Shut Down. Choose this option to start the Computer Shut Down procedure. After that,
hold the Power button on the Main Control panel for 2 seconds and the power will
automatically be switched off in 3 minutes.
DISPLAY AREA STRUCTURE
The display is divided into 5 fixed areas:
Status Line. This field contains the selected mode title, date, and time.
Alarm/Message Line. The last current not acknowledged (or last not acknowledged).
alarm message from the J/DP System is indicated in this field.
Mode/Function Control Buttons area. Selected buttons are illuminated green.
Left Operator Selected Page.
Right Operator Selected Page.
The following Operator Selected Pages are provided in the IVCS 2000:
Hold Plot & Auto Thrusters.
Position &
Heading
Display.
Alarms.
Sensors.
Reference
Systems.
s. Parameter
.
Manual
Thrusters
e. Select Rout
Track Control.
ROV position.
Capability
Diagram.
System
Monitor.
nitor. Power Mo
Autopilot.
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PRACTICAL OPERATION OF A DP SYSTEM
The following additional windows can appear in front of the display upon pressing certain
buttons (e.g. Auto HDG, Auto POS, Select Windows, etc.):
Data Input Windows.
Select Window.
More detailed description of display areas and windows follows:
STATUS LINE
- Exit Key
STATUS LINE
Time and Date are displayed in the left part of the line.
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PRACTICAL OPERATION OF A DP SYSTEM
The middle part of the line contains messages about the selected mode of system operation:
Bridge Control.
Vessel name is displayed in the right part of the Status Line.
GE LINE
The foll n is located in this line (from left to right):
Simulator Mode.
ALARM/MESSA
owing informatio
The sym essage group (Error, Warning, Information). bol, defining m
Field of message acknowledgement.
Time stamp.
Message text.
LAST ALARM / MESSAGE LINE
MODE/FUNCTION CONTROL BUTTONS AREA
The Main Softkeys are located in this area.
Active Main Softkeys are green and can be pressed. Passive Main Softkeys are grey. Structure of
active Softkeys is defined by chosen mode.
MODE/FUNCTION CONTROL BUTTONS AREA
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PRACTICAL OPERATION OF A DP SYSTEM
l or
Joystick Pushbutton to acknowledge (then the button becomes bright green), press any active
Main Softkey for cancellation (or press the Cancel button in the additional window).
After pressing a Main Softkey, it blinks. Press the ENTER Pushbutton on the Control Pane
Button Groups:
MODE Group the IVCS 2000 mode selection. Only one button can be pressed at the
same time.
JDP J/DP mode On/Off.
AP Autopilot mode On/Off.
HDG Group Heading Control mode switching. Only one button can be pressed at the
same time.
MAN J/DP Manual Heading Control and AP Manual Course Keeping modes On.
AUTO J/DP Auto Heading Control and AP Auto Course Keeping modes On.
TRACK
submode of the Track C
AP Track Control (High Speed) mode On / System Selected Heading
ontrol (low Speed) Mode.
ROV - System Selected Heading submode of the ROV Follow Mode (ROV following
with heading directed to the moving target at every moment).
POS Group J/DP Position Control mode selection. Only one button can be pressed on
the same time.
MAN J/DP Manual Position Control mode On.
AUTO - J/DP Auto Position Control mode On.
ROV - Remote Operated Vehicle Following mode On.
TRACK J/DP Track Control (Low Speed) mode On.
Speed Vector - J/DP S Speed Vector submode
On.
emi-Automatic Position mode Manual
Man Surge - J/DP Semi-Automatic Position mode Manual Surge & Auto Sway
submode On.
Man Sway - J/DP Semi-Automatic Position mode Auto Surge & Manual Sway On.
FUNC Group the IVCS 2000 func
same time.
tions On/Off. Several buttons can be pressed at the
Remote COR Set Remote Centre Of Rotation.
AWC - Active Wind Compensation.
SYS the IVCS 2000 operation control buttons.
Select Window setting of Left/Right Operator Selected Pages.
ACK Alarm Acknowledge Button. Press this button to acknowledge an alarm
displayed in the Last Alarm / Message Line.
Enter acknowledgement of a softkey pressing.
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PRACTICAL OPERATION OF A DP SYSTEM
DA NDOWS
Dat n
structur
ADDITIONAL WINDOWS
TA INPUT WI
a I put windows are used for parameter values entering and basically have the following
e:
Indicators.
Editing Fields.
Numeric or Alpha-numeric keypad.
ALPHANUMERIC AND NUMERIC KEYPADS
Numeric Keypad - the Numeric keypad consists of:
Digital softkeys.
Left Arrow and Right Arrow Choice of edited field.
+/- Set direction (e.g. North South).
OK Acknowledgement of entered value(s) and closing of Data Input Window.
Cancel.
Alpha-Numeric Keypad - The Alpha - numeric keypad is used for entering both
letters and digits. It consists of:
Alphabetical / Digital Softkeys.
Left Arrow and Right Arrow Choice of edited field.
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PRACTICAL OPERATION OF A DP SYSTEM
Num/ABC switcher.
Space Softkey.
Delete Softkey.
OK Acknowledgement of entered value(s) and closing of Data Input Window.
Cancel.
NOTE: To enter a letter, you should press a corresponding softkey once, twice or three times,
depending on the letter location on the softkey. For example, to enter the b letter, press the
soft y
he l displayed:
ke twice.
T fo lowing Data Input Windows could be
Heading Setpoint Editor - appears upon pressing the Auto HDG Main Soft Key or at
heading settings in the Parameters Window. It consists of the numeric keypad and the
following indicators:
Hold Button. Press this button to put Actual Heading into the Editing Field.
Offset Button New Heading Setpoint input as offset of Actual Heading value. Upon
pressing the Offset Button, value of Editing Field become zero, after which the
Heading Setpoint offset can be set.
Min Pwr. Press this button to display an automatically calculated Min Power
Heading value in the Heading Editing Field. Press the OK softkey to automatically
hold calculated Heading value.
Position Setpoint Editor - appears upon pressing the Auto POS Main Soft Key or at
Position settings in Parameters Window. It has the numeric keypad and the following
indicators structure:
Latitude Editing Field.
Longitude Editing Field.
Hold Button Press this button to put Actual Vessel Lat. and Long. into the Editing
Fields.
Offset Button New Position Setpoint input as offset of Actual Position Setpoint.
Upon pressing the Offset Button, values of both Editing Fields become zero, after
which, the Position Setpoint offset can be set. Offset value and direction are
determined by:
Position Display View Mode:
South and West East).
(Forward Astern and PORT
Lat. and Long. offsets for True Mode (North
ay offsets for the relative mode Surge and Sw
STBD).
Set Units (see View Settings).
Meters.
. Feet
Cables.
Position Setpoint Offset function is not provided for Lat./Long. Units .
remote COR for the COR Selection Window to COR Switch - Press Main Softkey
appear.
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PRACTICAL OPERATION OF A DP SYSTEM
COR SWITCH
COR Selection Window has the following button structure:
COR Position Buttons for setting Center of Rotation:
In Bow.
In Center (gravity center).
In Stern.
The set COR is indicated by white color.
OK Acknowledgement of set COR and closing of COR Selection.
Cancel.
ROV Active - Press the ROV Main Softkey in the POS Group for the ROV Active
Window to appear. Using this window the DPO can pause/proceed ROV Following at
any moment.
ROV MODE SWITCH
Track Control (Low Speed) Active - Press the TRACK Main Softkey in the POS
Group for the Track Control (Low Speed) Active Window to appear. It has the same
structure as the ROV Active Window. Using this window the operator can
stop/proceed Track Control (Low Speed) at any moment.
Route Name Editor - appears upon pressing of the Route Name Softkey in the Select
Route Window. It consists of the alphanumeric keypad and editing field.
Waypoint Editor - appears upon pressing of the Edit Point Softkey in the Select Route
Window. It has the same structure as the Position Setpoint Editor.
Parameters Setting - Data Input Windows with numeric keypad appears at different
parameters setting, such as:
Initial conditions setting for Simulator Mode.
Set Turn Radius for Track Control (High Speed) Auto Pilot parameters.
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PRACTICAL OPERATION OF A DP SYSTEM
k Control (High Speed) Auto Pilot parameters. Set Off Track Limit for Trac
t ack Control (Low Speed) Track Control parameters. Se Turn Radius for Tr
t ntrol (Low Speed) Track Control parameters. Se Speed for Track Co
t Se Off Track Limit for Track Control (Low Speed) Track Control parameters.
Set Reaction Radius for ROV Following ROV parameters.
Set Speed for ROV Following ROV parameters.
Set DGPS Lat/Lon Sensor Deviation parameters.
Vessel estimated position offset Reference Systems Window.
Current and Wind settings Capability Diagram Window.
Thruster limits settings Capability Diagram Window.
Starting Conditions Setting - Data Input Windows with numeric keypad are also used for
starting conditions setting for Simulator Mode of the IVCS 2000 operation.
SELECT
Press th
rows. Left
for
The fol
Date And Time Editors - Date or Time Editors appear upon pressing of the respective
Set button in the System Settings Parameters Window. Both of them consist of the
alphanumeric keypad and editing field.
WINDOW
e Select Window Main Softkey to load this window. There are two identical button
row is used for window selection in the Left Operator Selected Page and the right row
the Right Operator Selected Page. Buttons for selected left and right windows are white.
lowing Windows Select Buttons are in this area:
. Alarm Alarm List Window
Param Parameter Windows.
a M p Position & Heading Display.
Auto Thr Hold Plot (DP Capability Diagram) & Auto Thrusters Control Window.
Man Thr Manual Thrusters Control Window.
PM Power Monitoring Window.
Sensor Sensors Window.
Ref Reference Systems Window.
ROV ROV Following Window.
Ro ute Select Route.
Trc Ctr T rack Control Window.
Diagram Capability Diagram.
System Monitor Window.
Auto P t ilo Autopilot Window.
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CTICAL OPERATION OF A DP SYSTEM PRA
HOLD PLOT & AUTO THRUSTERS WINDOW
This window is divided in two
parts. The upper one is the Hold
Plot window and lower is Auto
Thruster window.
Hold Plot - This window
shows (in digital and
graphical form) Fore-Aft
and Athwartships control
forces and rotary
moment of the vessel.
Also, the area of
achievable control forces
and moment (Capability
Plot) is shown in this
window. The Capability
Plot shows Joystick and
Knob positions, external
disturbances forces and
moment. There are two
graphical indicators in the Hold Plot Window:
The same actuators are used for control forces (Fore-aft and Athwartships) and
Control Rotary Moment Indicator presented in the form of a graphical line scaled in
% (-100% +100%). The grey rectangle indicates Area of Realizable Control Moment.
The white bar represents Actual Control Moment. The yellow symbol indicates knob
position (value of control moment set by knob).
Control Forces Indicator - is the square scaled in % of fore-aft and athwartships
control forces (-100% + 100%). The Grey polygon indicates the Capability Plot of
Control Forces (Fore-aft and athwartships) at the present time. Modification of the
shape of the Capability Plot during control moment changes is determined by the
following:
Control moment generation. Therefore at a fixed control moment, a portion of the
actuators power is already used, and only the remaining actuator power can be
used for control force generation.
The Control Forces Indicator also contains:
Actual Control Force vector white vector from coordinate origin. This vector is
always located within the Capability Plot (grey).
Joystick Position control force vector set by the Joystick (yellow symbol). The
set control force vector cant be developed outside of the Capability Plot for a
given control moment.
Disturbance Forces vector - green vector from coordinate origin.
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PRACTICAL OPERATION OF A DP SYSTEM
The following data is represented (in digital form) in the right part of the window:
Joystick Gain:
Normal.
High.
Progressive.
Actual control forces and moment in percent and tons:
Fore-Aft Control force X.
Athwartships Control force Y.
Yaw Control moment M.
Disturbance forces and moment in percent and tons:
Fore-Aft disturbance force X.
Athwartships disturbance force Y.
Yaw i d sturbance moment M.
Joystick and knob position in percent.
The following data is represented (in digital form) in the left part of the window:
Control Force Monitoring - Graphical indication of Control Forces and Moment, scaled
Mo
in percent, is located at the left side of the Hold Plot Window. Control Forces and
ment values are represented as vertical bars: X, Y and M.
Color Thruster Allocation Logic (TAL) Indicator (circle) is located to the left of the
XYM symbols:
Green color of TAL Indicator determines presence of distribution.
Red color of TAL Indicator indicates absence of even one of Control Forces or
Control Moment.
There is an analogous color distribution for Control Force and Moment Indicator symbols:
Green symbol color:
X availability of Fore-aft Control force.
Y availability of Athwartships Control force.
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PRACTICAL OPERATION OF A DP SYSTEM
PARAMETERS WINDOW
These windows are used for
input and modification of
parameters necessary for the
system operation. The
windows are divided into
the following areas:
Buttons for selection
of the parameters
group are located in
the right part of the
window
Parameter values
(for the c en group)
and editing buttons
are located in the left
part of the
Parameters Window.
Below the set
parameter fields, the
possible parameter
input values are
presented (light
grey).
At the foot of the
window, the
following buttons are
located:
Apply for input of set parameter values.
Cancel cancellation of parameters modification.
Default input default values.
More detailed description of each parameter group follows.
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PRACTICAL OPERATION OF A DP SYSTEM
JOYS C
The fol
TI K PARAMETERS (JST)
lowing parameters can be set in this window:
et the following values: Joystick Gain. By selecting the Change button it is possible to s
and knob movement and force
uts). Maximum force equals 50%
Normal linear relation between Joystick lever
exerted by the thrusters (and Joystick and knob outp
of the available force limit.
ent and force exerted
force equals 100% of the
High linear relation between Joystick lever and knob move
um
m
by the thrusters (and Joystick and knob outputs). Maxim
available force limit.
Progressive non-linear (up to 50% as Normal gain and as High gain thereafter),
ers
rce
relation between Joystick lever and knob movement and force exerted by the thrust
(and Joystick and knob outputs). Maximum force equals 100% of the available fo
limit.
ange button it is possible to set the following
positions of Center of Rotation:
Center of Rotation. By selecting the Ch
In Bow.
In Stern.
This is the J/DP Heading Control group of parameters. The Heading Mode Parameters Window
con n
The set COR value will be used when pressing the Remote COR button on the Active Control
Panel and also this value will be set in COR Selector by default.
HEADING MODE PARAMETERS (HDG)
tai s the following parameters:
y the
ading. Using < and > buttons it is
e: 6, 12, 18, 24, 30, 60, 120 deg/min.
Rate of turn. This enables an operator to specify the rotation speed to be used b
system when rotating the vessel to a new he
possible to set values from the rang
eter allows an operator to specify an alarm limit for the
ntinuously by the system, and an alarm is
g < and > buttons it is possible to set values from
, 30 deg.
Heading Limit. This param
heading. The vessels heading is monitored co
given if the limit is exceeded. Usin
the range: 2, 3, 5, 10, 15
Heading Controller sensitivity adjustment. Range of its Heading Gain is the parameter for
values is from 1 to 10.
Heading Gain value 1 corresponds to low steering accuracy and to small magnitudes
of control moment.
Heading Gain value 5 corresponds to standard regulator with good accuracy and
acceptable control activity.
Heading Gain value 10 sets maximum steering accuracy but at the expense of
frequent steering corrections in heavy seas.
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PRACTICAL OPERATION OF A DP SYSTEM
In calm weather it is recommended to increase the Heading Gain value for more
commended to decrease the Heading
Gain value for reduced actuator operation.
accurate course holding. In heavy seas it is re
Set Heading is used to se
Setpoint Window appears,
t a new course. By pressing the Set button, the Heading
where the new desirable Heading can be entered.
POSIT TERS (POS)
This is the J/DP Positioning Control group of parameters. The Positioning Mode Parameters
Window contains the following parameters:
ION MODE PARAME
rator to specify the Fore-Aft speed to be used by the IVCS
position. Using < and > buttons it is possible to set the
Fore-Aft Speed enables an ope
2000 when moving to a new
required speed value.
s an operator to specify the Athwartships speed to be used by
ng to a new position. Using < and > buttons it is possible
ue.
Athwartships Speed enable
the IVCS 2000 when movi
to set the required speed val
perator to specify an alarm limit for the deviation from the
e vessels position deviation is monitored continuously by the
ven if the limit is exceeded. Using < and > buttons it is
lues listed below (only in ft).
Position Limit allows an o
given positioning point. Th
system, and an alarm is gi
possible to set one of the va
ter for Position Controller sensitivity adjustment. Range of its Position Gain is the parame
values is from 1 to 10.
Position Gain value 1 corresponds to low positional accuracy and to small magnitude
and frequency of control moment.
Position Gain value 5 corresponds to a standard regulator with good accuracy and
acceptable control intensity.
racy, however the control can Position Gain value 10 sets maximum positional accu
be very intensive, especially in heavy sea conditions.
In calm weather it is recommended to increase the Position Gain value for more
accurate position keeping. Under heavy sea conditions it is recommended to decrease
the Position Gain value to reduce thruster activity.
Spe ain is the parameter for Speed Controller sensitivity adjustment. Range of
its u
ed Vector G
val es is from 1 to 10.
S e
sm
p ed Vector Gain value 1 corresponds to slow set speed value monitoring and to
all magnitude and frequency of control moment.
standard mode with good accuracy and Speed Vector Gain value 5 corresponds to a
acceptable control intensity.
S e p ed Vector Gain value 10 sets maximum rate of set speed value monitoring,
however the control can be very intensive, especially in heavy sea conditions.
Set
the Po
ent d
Position is used for setting a new point of positioning. By pressing the Set button,
sition Setpoint Window appears, where the new Point of Positioning can be
ere .
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PRACTICAL OPERATION OF A DP SYSTEM
This is the AP Automatic Course Keeping Control group of parameters. This window contains
the foll i meters:
AP MODE PARAMETERS (AP)
ow ng para
nables an operator to specify the rate of turn to be used by the system
d > buttons, it is possible to set
24, 30, 60, 120 deg/min.
Rate of turn. It e
when rotating the vessel to a new heading. Using < an
value from the range: 6, 12, 18,
ws an operator to specify an alarm limit for the
a onitored continuously by the system, and alarm is
ttons, it is possible to set value from
Heading Limit. This parameter allo
is m he ding. The vessels heading
given if the limit is exceeded. Using < and > bu
the range: 2, 3, 5, 10, 15, 30 deg.
Controller sensitivity adjustment. Range of its Heading Gain is the parameter for Heading
values is from 1 to 10.
H s
steering.
eading Gain value 1 correspond to low course accuracy and with small amounts of
Heading Gain value 5 corresponds to standard regulator with good accuracy an
acceptable control activity.
d
Heading Gain value 10 sets maximum course accuracy but with increased steering
activity, especially in heavy seas.
for improved course
.
At calm weather, it is recommended to increase the Heading Gain
accuracy. In heavy seas it is recommended to reduce the Heading Gain to minimize
steering corrections
R d imits. Using <
a
deg.
TR H SPEED) MODE PARAMETERS:
ud er Limit. This parameter allows an operator to set rudder angle l
nd > buttons. It is possible to set values from the range: 5, 10, 15, 20, 25, 30, 35, 40
ACK CONTROL (HIG
specify a turn radius for passing a
waypoint in the Track Control (High Speed) Mode.
Turn Radius. This parameter enables an operator to
Off track Limit. This parameter is used for setting a distance (from the vessel to a track)
within which the vessel can move on either side of the track. When this limit is exceeded,
the system gives an alarm.
Track Gain. This parameter is used for Track Controller sensitivity adjustment. Range of
its values is from 1 to 10.
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PRACTICAL OPERATION OF A DP SYSTEM
THRUST LIMITS (THR LIM)
This is a J/DP Mode group of
control signals values for every
it is possible to set required lim
parameters. In this window, an operator can set maximum allowed
actuator, which is controlled by TAL. Using < and > buttons
it values for each actuator:
Bow Thrusters.
Stern Thrusters.
Propeller Ahead Thrust.
Propeller Astern Thrust.
Actuato nts from maximum nominal thrust, rudder limit - in degrees.
Wh limit, this limit is set for both Bow thrusters at the same time.
Stern T oth bow thrusters at the same time.
The se represented on Actuator Indicators in Auto Thr and Man Thr
Window indow.
RO F AMETERS (ROV)
This is ntrol group of parameters. The ROV Follow Mode Parameters
Window contains the following parameters:
Rudder Limit.
r limits are set in perce
en changing the Bow Thruster
hruster limit is set for b
t Actuator Limits are
s and Capability Diagram W
V OLLOW MODE PAR
the J/DP Positioning Co
ollow Speed - a constant speed of vessel movement when under ROV follow. ROV F
which defines a circle of operation, within which the ROV can
l moving. It only moves when it crosses the boundary of
of this circle is the ROV.
Reaction Radius (RR),
move without causing the vesse
the circle of operation. The center
SR), which is determined as % of RR value.
TRAC C ERS (TRACK)
ns the following parameters:
Stop Radius (
K ONTROL (LOW SPEED) MODE PARAMET
This is J/DP Mode group of parameters. This window contai
Track Control Strategy: Stop/Non stop. This parameter allows an operator to select one
of two possible strategies for waypoints passing in the Track Control (Low Speed) Mode.
Vessel Speed setting a constant vessel speed value for movement at Track Control
(Low Speed).
Off track Limit. This parameter is used for setting a distance (from the vessel to a track)
within which the vessel can move on either side of the track. When this limit is exceeded,
the system gives an alarm.
BEIER RADIO 90
PRACTICAL OPERATION OF A DP SYSTEM
Track Gain. This parameter is used for Track Controller sensitivity adjustment. Range of
VIE
This param
selecting u s Window contains the following settings:
its values is from 1 to 10.
W SETTINGS
eters group is used for the selection of Position Display configurations and for
nits of measure. View Setting
uni
Grid on/off. This is a True View parameter, allowing basic grid according to the selected
ts of measurement.
Sub Grid on/off. This is a True View parameter, with a smaller grid for ease of distance
viewing.
Units units may be selected from the following list:
m meters.
ft feet.
cb cables (0.1 of nautical mile).
Lat. Long. (geo) setting geographical coordinates on the Position Display. When
s are selected it is im these unit possible to set the Positioning Point offset.
Note, that units setting also has effect on the ROV Follow Window and Reference
Systems Window.
Pallet Day/Night. It is intended for LCD color and brightness changes as appropriate for
day or night viewing.
Auto View. This is the parameter for settin
where the vessel silhouette is being re-dr
g the Position Display to the re-drawing mode
awn when approaching the Position Display
boundary (ON position).
View switching the viewing mode between True/Relative (Earth or Vessel Frame).
Show DP on/off. Position set point target on/off on the Motion Plot (except for the Auto
Positioning Mode).
Show Beacons switching between showing all beacons and showing only ROV beacon
on the Motion Plot.
Scale imaging scale selection. The range of scaling is 128 0.125. The vessel silhouette
on the Position Display is not scaled at small scale.
tkey): 10, 30, 60, 600, 1800, 3600 sec. Each time
NO :
is dupli & Heading Display Window.
Trace On/Off. This parameter is used to activate display of vessel track on the Position
Display, step range (Step Sof
switching to Trace On, the vessel track is started anew.
TE that only knots are used in the IVCS 2000 as speed units. Parameters #4 - #8 setting
cated in the Position
BEIER RADIO 91
F A DP SYSTEM PRACTICAL OPERATION O
SENSORS SETTINGS
This parameters group is used for the selection of HPR type and changing ROV and Reference
beacons. These settings can be also changed in the ROV Following Window (see item 0). Also
the sensor deviations (constant errors) are shown in this window, but the operator cannot change
them. Sensors Window contains the following settings:
HPR Type press the respective Change button to switch between Sonardyne,
Simrad, and ATS II Nautronix hydro-acoustics.
Reference Beacon.
ROV Beacon - one of the active beacons can be set as ROV or as Reference by pressing
the respective Change button. Press the Apply button to acknowledge.
NOTE: ROV Beacon cannot be changed in the ROV Following Mode. HPR Type and Reference
beacon can be changed only when HPR Sensor in the Reference Systems Window is disabled.
POWER LIMITS
In this window, an operator can set maximum allowed power consumption for actuators
(thrusters and propellers) and maximum allowed power production for Main Engines and
generators. Power limits set in this window are considered by the IVCS 2000 during Thrust
Allocation (see item 0). When power consumption/production within these limits is not enough
for system operation, an alarm appears. Using < and > buttons, it is possible to set required
limit values for the following actuators:
Bow #F Thruster.
Bow #A Thruster.
Stern #F Thruster.
Stern #A Thruster.
Port Diesel.
Stbd Diesel.
Port Generator.
Stern Generator.
Port Propeller.
Stbd Propeller.
Power limits are set in percents from maximum consumed/produced power.
Set power limits are indicated in the Power Monitoring Window of the IVCS 2000.
BEIER RADIO 92
PRACTICAL OPERATION OF A DP SYSTEM
SYSTEM
Thi a
System
SETTINGS
s p rameters group is used for setting proper date, time and time zone.
Settings Window contains the following settings:
System Date. This is a parameter for setting date (in month-day-year format).
System Time. This is a parameter for setting time.
Time Zone. This parameter is intended setting time zone.
In this
When t ped, an alarm appears.
Using
GENERATOR LIMITS
window, an operator can set low and high voltage and frequency limits for generators.
hese limits are overstep
< and > buttons it is possible to set required limit values for the following generators:
Port Generator.
Genera
specific
Stbd Generator.
tor limits cannot exceed maximum voltage and frequency values, defined by generators
ations.
BEIER RADIO 93
PRACTICAL OPERATION OF A DP SYSTEM
MANUAL THRUSTER WINDOW
This window is used:
For Actuators state monitoring (upper part).
For manual control of the actuators in the Stand By Mode (lower part).
For manual control of actuators, which are disconnected from automatic control, in J/DP
Mode (lower part).
It is also possible to switch on/off actuators in Auto Mode.
There are two areas in this window:
Actuators state monitoring (upper part) indicates the following state data (for every vessel
actuator):
Run indicator colored circle indicator of Engine Run signal, the color indicates
status:
Green actuator is started and ready for operation.
Red actuator is not ready for operation.
Grey actuator Engine Run signal is not present for this vessel.
Fault indicator colored circle indicator shows:
Red color actuator is failed.
Grey color actuator is operable correctly.
Mode actuator operating mode:
IVCS 2000 Auto.
IVCS 2000 Manual.
Bridge mode.
Actuator RPM command (if available).
Actuator RPM feedback (if available).
Actuator Pitch command (if available).
Actuator Pitch feedback (if available).
Force (T) actuator thrust (ton).
Actuators control part (lower) allows an operator to switch on/off actuators in Auto Mode
and manually control actuators in the Stand By Mode and actuators, which are
disconnected from automatic control, in J/DP Mode. The following buttons and
indicators for each Actuator are located in this part of the Manual Thruster Window:
Softkey for switching Actuator on/off into Auto Mode operation (Actuator Control
Buttons), analogous.
Digital indicator Actuator Set Value (white).
BEIER RADIO 94
PRACTICAL OPERATION OF A DP SYSTEM
MANUAL THRUSTER WINDOW
Digital indicator Actuator Actual Value (yellow).
Softkeys for Manual Actuator Control (). Light gree
indicates that the Actuator is disconnected from the Auto Mo
n color of the button
de and it is possible to
control it manually. Dark green button colour indicates that the button is passive,
or slow adjustment on a unit, press a
because the Actuator is used for control in Auto Mode. - Actuator Set Value
increase and - Actuator Set Value decrease. F
Softkey once. For fast changes, hold the button down continually until the desired
adjustment is achieved.
Actuator Graphic Indicator After switching off an Actuator, its setting is saved and it
can be changed later by the Manual Actuator Control buttons.
BEIER RADIO 95
PRACTICAL OPERATION OF A DP SYSTEM
ROV FOLLOW WINDOW
This window is used for:
Raw data monitoring from
active beacons.
on for ROV Beacon selecti
Following.
ion for
on.
Reference beacon select
determining vessel positi
type selection. Acoustic(HPR)
ROV Processing Results
monitoring.
The window is divided into four areas.
Raw data from beacons:
Bearing (true or relative).
Distance to beacon.
Depth (from beacon to
ground).
eters section of the window.
tion to acknowledge. At that
moment, the selected button changes to bright green, the
For Distance and Depth units
are set in accordance with
position display settings.
Active beacon buttons are dark
green. An operator can set one
of the active beacons as an
ROV or as Reference by
m pressing the respective Change button in the HPR Para
Press the Apply button in the HPR Parameters sec
symbol appears over the
Motion Plot
OV button
Beacon Data Trend Monitoring indicator, the ROV symbol appears on the
instead of the respective beacon symbol, the ROV Main Softkey and the R
in the Heading Setpoint Editor become active.
There are graphical indicators for Beacon Data Trend Monitoring, which indicate the
following possible situations:
Beacon is not active white zone.
No beacon data black zone.
Valid beacon data green zone.
Invalid beacon data red zone.
BEIER RADIO 96
PRACTICAL OPERATION OF A DP SYSTEM
The color indicators (circle) show beacon status:
Grey beacon is not active.
Red beacon is failed and is in use.
Green beacon is operable and in use.
The button in the upper left corner of this section selects display of all active beacons or
only ROV beacon on the Motion Plot.
HPR Parameters
HPR Type press the respective Change button to switch between Sonardyne,
Simrad and ATS II Nautronix hydro-acoustics.
Reference Beacon.
ROV Beacon.
ne e beacons can be set as ROV or as R O of the activ
tton
eference by pressing the respective
h . Press the Apply button to acknowledge.
Win
C ange bu
NOTE: ROV Beacon cannot be changed in the ROV Following Mode. HPR Type and
Reference beacon can be changed only when HPR Sensor in the Reference Systems
dow is disabled.
ROV Processing Results
Bearing (true or relative).
Distance to ROV.
Depth (from ROV to ground).
X and Y ROV coordinates (earth reference).
ROV Following Status
Pause ROV Following Mode is switched on and ROV following is paused.
Following The vessel is following the ROV.
Not active ROV Following Mode is switched off.
SELE OW
This w ration in the Track Control (Low
Spe /H
CT ROUTE WIND
indow is used for preparing the system for ope
ed igh Speed) Modes. It allows an operator to carry out the following operations:
Route List Editing.
Set Active Route.
Editing of Waypoint List for every route, route name, and Status.
The window is divided into two areas.
Route List (upper part). - This part contains list of routes, where route name and status (H
for High Speed and L for Low Speed) are indicated.
BEIER RADIO 97
PRACTICAL OPERATION OF A DP SYSTEM
NOTE: If the Select Route window is active, then a graphic presentation (polyline) of the
e Route List appears on the Motion Plot. Upon closing the Select
Route Window, all route polylines disappear from the Motion Plot except of the Active
current route from th
route representation (see below).
The following control buttons
are located from the right of the
Route List:
and Softkeys for
route selection.
Set Active - press this
button to set the current
route as Active route.
The selected route row
color is changed to dark
red.
Graphic presentation of
selected route
on the Motion
the
appears
Plot (dark red polyline)
and remains there
during all the time of
route active status.
Waypoint list of the
selected Active route
the Track appears in
Control Window.
The Track Main
omes active
of route
(for Low Speed
g the Track Main Softkey becomes active when the system is in the J/DP
r High Speed Tracking - when the system is in the Autopilot Mode).
Softkey bec
depending
status
trackin
Mode, fo
To cancel Active route, select it and press the Set Active softkey.
To set another route as Active, select route and press the Set Active Softkey.
NOTE: It is prohibited to change active route when the IVCS 2000 is operated in the
Track Control (Low Sped / High Speed) Modes.
Add Route - press this button to add a new route into the list. A row with new route
appears above the current route.
Edit Route - softkey is used for current route editing. Upon pressing this button, the
lower part of the Select Route Window becomes active.
Del Route deleting the current route from the list.
BEIER RADIO 98
PRACTICAL OPERATION OF A DP SYSTEM
Route particulars (lower part of the window) - This part is used for current route
on and editing. It shows the waypoint list of selected route (number
and coordinates of WP), route name, and status. The following control buttons are
particulars indicati
located in this part of the Select Route window:
Route Name - upon pressing this button the Rote name Editor appears, allowing
editing name of the route.
Set Status - use this button to change status of the selected Route.
n the IVCS 2000 is operated NOTE: It is prohibited to change status of active route whe
in the Track Control (Low Sped / High Speed) Modes.
and Softkeys for way point selection.
Add Point. Pr
a row with new waypoint appears above the current waypoint route.
ess this button to add a new waypoint into the WP list. NOTE - that
Edit Point Softkey is used for current WP editing. Upon pressing this button, the
Waypoint editor appears where an operator can input WP coordinates.
Del Route deleting the current waypoint from the list.
OK and Cancel acknowledge buttons.
NOTE: Control buttons of the lower part of the screen become active only after
Edit Route control button, in the upper part of the window.
his window is used for the IVCS 2000
rack Control (Low Speed / High Speed)
odes monitoring. The window is divided
to two areas:
pressing the
TRACK CONTROL WINDOW
T
T
M
in
The upper part displays Active Route
characteristics:
Route name.
Route Status.
Waypoint List of Active Route.
Row with a GOTO waypoint is
marked out.
Use the and Softkeys to look
through the list.
NOTE: All data appears in the upper
part of the Track Control window
only after Active Route setting.
BEIER RADIO 99
PRACTICAL OPERATION OF A DP SYSTEM
The following Track Control data is indicated in the lower part of the window:
Track Status (only for Low Speed Tracking):
Pause Track Control (Low Speed) Mode is switched on and tracking is paused.
Following The vessel is following along a route.
Not active Track Control (Low Speed) Mode is switched off.
Number and Lat. Lon. coordinates of the GOTO waypoint.
Tracking data: XTE, BOD, BTW, DTW.
Track Control strategy: Stop/Non stop (only for Low Speed Tracking).
Note: All data appears in the lower part of the Trac
Track Control (Low Speed / High Speed) Mode.
k Control window only after loading
CA
This wi o
Capability
different s
environme l
maximu
vessel c
By examin g
clearly nal
limits for environmental
conditions heading for
most safe o r
There a t
Window p
PABILITY DIAGRAM
nd w contains results of the IVCS 2000
a An lysis and allows an operator to set
sy tem configuration and select
nta conditions to forecast the
w ather conditions, in which the m e
an maintain position and heading.
in this window, an operator can
see the current (or forecasted) operatio
current (or set)
and select an optimal
pe ations.
re wo modes of the Capability Diagram
o eration:
D g
p
Real Mode - In this mode, the system
ther indicates the maximum wea
conditions in which the vessel is able to
continue DP operation for current system
configuration (thrusters set and
maximum loading), actual current
c d on itions (speed and direction), and actual wind direction. To operate the Capability
ia ram Window in the Real Mode, press the Real Mode control button in the middle
art of the window.
H her conditions for which the vessel can
maintain position and heading for set system configuration (thrusters set and maximum
loading), set current conditions (speed and direction) and set wind direction. To operate
ypothetic Mode - Forecast of the maximum weat
BEIER RADIO 100
PRACTICAL OPERATION OF A DP SYSTEM
the Capability Diagram Window in the Hypothetic Mode, press the Hypot Mode control
button in the middle part of the window.
The Capability Diagram Window has the following structure:
The upper part of the window contains the Capability Plot, where the following
information is indicated:
Circle Grid, where each of concentric circles points a wind speed value and rays
determine relative vessel heading direction.
Blue-red arrow points North direction.
Wind direction (actual for Real Mode and set for Hypothetic Mode) yellow triangle
with symbols HW.
Current direction (actual for Real Mode and set for Hypothetic Mode) green
triangle with symbols HC.
Area, within which the vessel can maintain position and heading depending on wind
speed.
This area is determined by the actual current speed and direction and the actual wind
direction for the Real Mode and by set current speed and direction and set wind
direction for the Hypothetic Mode.
The middle part of the window is used for:
Operational Mode selection: the Real Mode and the Hypot Mode control buttons. The
following values indication for the Real Mode and setting for the Hypothetical Mode:
True current speed.
True current direction.
True wind speed (can not be edited in the Hypothetic Mode.)
True wind direction.
To edit wind and cur press the Edit softkey.
Special editors appear, where an operator can set desirable values.
rent settings in the Hypothetic Mode,
used for monitoring (for the Real
l a
The lower part of the Capability Diagram window is
Mode) and setting (for the Hypothetic Mode) thrusters configuration and maximum
o ding (actuator limits) and contains the following:
Indicators of Auto or Manual actuator using in the IVCS 2000.
To
control button. A special editor
e
Indicators of actuator limits.
modify actuators set or actuator limits in the Hypothetic Mode, press an actuator
appears, where an operator can set desirable value of
actuator (using a Numeric keypad) and switch on/off an actuator on/off into Auto Mode
op ration.
BEIER RADIO 101
PRACTICAL OPERATION OF A DP SYSTEM
SYSTEMS MAIN FUNCTIONS
ENSATION
Contro ents are generated to compensate for wind disturbance. It is possible to
use i AWC, a Mode Feed Forward Controller works
independently of the selected J/DP mode, countering the wind disturbance before it can move the
vessel.
RE O
his function can be used only when the Manual Heading Mode is activated. DPO can choose
ter of rotation.
THRU
DPO can set any desirable com rs, rudders, and thruster, and also can choose
e desired cation algorithm.
THRU N
Used o moment the fore-aft and athwartships forces and rotary
moment, which are necessary for vessel position and heading control, are calculated. The
require by the thrust of propellers, rudders, and thruster. The
turning
If the t
and m
ACTUATOR LI
It is p s for every rudder, propeller, and thruster in vessel
configu io d propeller RPM limits.
ACTU
Upon connection/disconnection of one or several propellers, rudders, or thruster from the system
or upon them being manually controlled by the operator, the Thrust Allocation function will
automatically redistribute thrusts for the new actuator configuration.
ACTIVE WIND COMP
l forces and mom
th s function in all J/DP modes. In
M TE CENTER OF ROTATION
T
center of gravity, bow, or stern as the cen
ST ALLOCATION
bination of propelle
thrust allo th
ST ALLOCATION FUNCTIO
nly in J/DP mode. At any given
d forces and moment are provided
angle and/or thrust of the various actuators are controlled to provide the necessary forces.
hrust of propellers, rudders, and thruster is not enough for provision of the required forces
he Thrust Allocation function gives a priority to the generation of rotary moment.
MITS
oment, t
ossible to set control limit
rat ns: rudder angle deflection limits an
ATOR CONFIGURATION
BEIER RADIO 102
PRACTICAL OPERATION OF A DP SYSTEM
CONSEQUENCE ANALYSIS SYSTEM
The fol 000 Capability Analysis System:
lowing functions are included in the IVCS 2
tion (thrusters set and maximum loading), actual
current conditions (speed and direction), and actual wind direction.
Indication of the maximum weather conditions in which the vessel is able to continue DP
operation for current system configura
aximum weather conditions for which the vessel can maintain position
con
The weather conditions are determined by a one-minute mean maximum wind speed.The result
of the a
Forecasts of the m
and heading for set system configuration (thrusters set and maximum loading), set current
ditions (speed and direction), and set wind direction.
nalysis is displayed graphically as a polar plot.
BEIER RADIO 103
POSITION MEASUREMENT EQUIPMENT
Position accuracy, reliability, and consistency are critical for DP operation. Therefore, the most
important concern of the DPO is maintaining adequate and reliable position measurement
equipment.
The number of position measurement equipment used will depend upon a many factors,
especially the level of risk involved in the operation, the IMO Equipment Class in force for that
operation, the availability of references of a suitable type, and the consequences of loss of one or
more position references.
Five types of Position Measurement Equipments (PMEs) are generally used on DP vessels,
operating separately and independently of the DP system, and using an interface to feed
information to the DP:
Hydroacoustic Position Reference (HPR).
Artemis.
Taut Wire.
Differential Global Positioning System (DGPS).
Laser-based systems.
Normally, the DP system can handle multiple PME input by pooling the information to provide a
continuous "best fit" of position data. This process is a function of the mathematical modeling of
the system.
BEIER RADIO 104
POSITION MEASUREMENT EQUIPMENT
HYDROACOUSTIC POSITION REFERENCE (HPR)
Acoustic energy propagates underwater at a much higher efficiency than in air. Acoustic energy
has been developed over many years and has been applied to DP position reference. HPR uses
underwater acoustics to determine position and track ROB, equipment, and more. A variety of
alternative acoustic position measurement equipments are used. Most of them are based upon the
range measurement possible, related to the time travel of acoustic signals underwater. Three
types of HPRs are generally used:
ULTRA OR SUPER-SHORT BASELINE SYSTEM (USBL OR SSBL)
The most commonly used HPR for
DP position reference purposes.
A transducer, mounted in the hull of
the DP vessel, transmits an
interrogating pulse.
This pulse automatically activates
one or more transponders positioned
on the seabed. And, a reply is
transmitted.
The transponder receives the reply.
And, the time difference between
transmission and reception is used to
compute the range and angle at the
transducer head (short baseline).
Thus, the DP vessels position relative to the transponder is determined.
In the USBL system, the acoustic transmit and receive elements are combined into one hull-
mounted transducer. This communicates at acoustic frequencies with one (or more) subsea
transponders, in order to provide positioning. In its basic configuration, the system consists of a
control and display unit, a transceiver unit, a transducer unit mounted on the end of a probe in the
vessel's bottom, and a transponder located on the seabed.
Position measurements are based upon range and direction data determined from transponder
replies resulting from interrogation. Up to five transponders can be interrogated in turn within
the same area. Simultaneous use of multiple transponders is made possible by utilizing different
interrogation and reply frequencies for each transponder.
The system measures the range of a transponder relative to the transducer by measuring the time
elapsed between transmission of the interrogation signal and reception of the reply. This time
lapse is made up of the through-water return time of the acoustic signal plus the turnaround time
BEIER RADIO 105
POSITION MEASUREMENT EQUIPMENT
within the transponder. This latter is a fixed known value, and once allowed for, the distance, or
Slant Range may be deduced.
The direction of the transponder is measured at the transducer as the source direction of the reply
signal. This is determined from time-phase comparisons made between pairs of transducer
receiving elements within the transducer head. Typically, 48 elements are used to make up the
receiving unit within a transducer.
In a typical positioning mode, the processor commands the transceiver to transmit the
interrogation signal. The transponder reply is detected by the transceiver which measures the
time delay and the time-phase data. This data is passed to the processor to allow determination of
slant range and direction. This information is combined with roll and pitch values obtained from
the VRS in order to obtain information referenced to the vessel co-ordinate frame.
Positioning data is shown on a display in terms of a graphic (map) display of vessel and
transponder positions, and in the form of tabulated alphanumeric.
SHORT BASELINE SYSTEMS (SBL)
An array of transducers
(hydrophones) are installed under the
DP vessel. And, the distances
between transducers are used as
baselines.
A transponder positioned on the
seabed transmits periodic pulses at a
known frequency. And, the time
difference between transmission and
reception at three or more transducers
is used to compute the vessels
position relative to the transponder.
LONG BASELINE SYSTEMS (LBL)
An array of three or more transponders are positioned on the seabed. (Four or more are
used to give an element of redundancy.) Because the transponders are not attached to the
moving vessel, the system can operate independently of VRU input, eliminating many
problems associated with vessel motion.
Distances between transponders are used as baselines.
A single transducer under the DP vessel communicates with the array of transponders.
And, only the range is determined. In other words, the DP vessels position relative to the
transponders is computed. Since the depth of the transducer is a known variable, using
BEIER RADIO 106
POSITION MEASUREMENT EQUIPMENT
this provides a further improvement
in position quality. If the object to be
positioned is an ROV and the depth is
not accurately known, or variable,
then a further unknown quantity must
be calculated, requiring additional
range measurements. LBL is
generally used in deepwater
(>1000m) drilling operations.
dvantage of the LBL system over other HPR variants.
Angle measurements are not required
at the transducer. Because of this a
major source of error, angular
distortion in reply signal paths due to
ray bending or refraction, is
eliminated. Errors in range measurements caused by ray bending are less significant. The
accuracy achievable is the major a
The elimination of the need for attitude input from VRS also increases accuracy
compared to USBL and SBL systems.
ADVANTAGES OF HPRS
Self contained position measurement equipment.
HPRs can be left on the seabed to provide reference for the DP vessel to returned to.
HPRs can also serve as markers for equipments on the seabed.
Relatively high accuracy.
More options to suite prevailing DP operations. For example LBL, SBL, USBL, or
SSBL.
LIMITATIONS OF HPRS
Roll and pitch affect the angle measured at the transducer head. Therefore, the angle must
be corrected using input from VRU for accurate position determination.
Turbulence from the vessels thrusters, noise, and poor acoustic conditions can cause
inaccuracy in HPR positioning.
HPR signals spreads with increased distance. Hence, accuracy is reduced in very deep
water.
Attenuation causes HPR signals to be absorbed by water. The frequency of transmission,
water pressure, salinity, an temperature influence the amount of absorption.
HPR signals experience refraction (bending) during transmission. Speed of propagation,
layers in the water column, water temperature, pressure, and salinity influence refraction.
BEIER RADIO 107
POSITION MEASUREMENT EQUIPMENT
ARTEMIS
PRINCIPLES AND OPERATION OF ARTEMIS
Artemis is the trade name for a
positioning system developed by
Christian Huygenslaboritorium BV.
Principle of this system is based on
getting the range and bearing of a
movable vessel from a known fixed
position.
Procedure for setting up Artemis:
One directional antenna is
mounted on a drilling rig,
platform, or other fixed structure.
The other directional antenna is
mounted on the DP vessel.
Operational control is initiate from
the DP vessel.
Both antennas are aligned and locked. A microwave link is then established
between them to facilitate data transfer.
The range or distance is measured at the DP vessel based on the time difference
between emission and return of a signal.
The bearing or direction of the DP vessel is measured at the fixed structure.
When a fixed structure is unavailable, a beacon may be used in place of an antenna on a
floating structure. For example, Offshore Loading Terminal (OLT). In this case, it is
impractical to measure bearing at the floating structure. Hence, bearing determination is
made at the DP vessel.
ADVANTAGES OF ARTEMIS
Provides geographic position reference. Unlike many PMEs that only provide relative
position.
Not affected by precipitation because it operates on 9.2 9.3 GHz.
Localized position measurement equipment. Therefore, it is convenient for customization
to suite the DP operation.
Relatively high accuracy.
Long Range.
BEIER RADIO 108
POSITION MEASUREMENT EQUIPMENT
LIMITATIONS OF ARTEMIS
A correction must be factored into the DP system for the antenna offset from the center of
gravity of the vessel. The range and bearing data is based on antenna to antenna.
X-bank (3cm) radar signal interferes with Artemis signal despite the fact that the 3cm
radar uses horizontally polarized waves while Artemis uses vertically polarized waves.
Correction must also be applied to Artemis data to compensate for rolling and pitching of
the DP vessel.
Excessive heat on the oil rig or platform may interfere with the Artemis if within close
proximity.
Artemis is affected by line-of-sight obstruction.
The fixed unit has to be configured and calibrated correctly.
Personnel on fixed unit may be needed to set up unit on their end.
Vulnerable to power supply problem at Fixed end.
BEIER RADIO 109
POSITION MEASUREMENT EQUIPMENT
TAUT WIRE
Short range position reference useful where a vessel may spend long periods in a static location,
and where the water depth is limited. Taut Wire System is useful for DP operation in the same
location for an extended period of time, where the water is not too deep. There are two types:
VERTICAL TAUT WIRE
A crane assembly is fitted near the side
of the vessel.
A depressor weight is suspended by a
wire attached to constant-tension
winch.
The depressor weight is lower to the
seabed.
Constant tension is set on the winch.
The winch adjusts the length of the
wire to maintain constant tension as
the vessel wanders.
Angle sensors (inclinameters) at the
end of the boom measure the angle of
the wire.
The length and angle of the wire deployed indicate the position of the sensor relative to
the depressor with. This information is corrected for the vessel pitch and roll. And, used
to determine the vessels position.
HORIZONTAL OR SURFACE TAUT WIRE
Because it is not a long-range system, it is generally used for relative DP when operating
near another vessel or fixed structure, i.e. crane barge, accommodation "Floatel"
operations.
The principle of operation is basically similar to the vertical taut wire. However, the wire
is attached to a prominent point on a fixed structure instead of a depressor weight.
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POSITION MEASUREMENT EQUIPMENT
TAUT WIRE REFERENCE DISPLAY
After the Taut Wire has been deployed and accepted as a position reference in the DP
system, a display screen with pertinent Taut Wire information is accessible.
Information on the screen will usually include the position of the depressor weight,
angular and structural limits, water depth, etc.
ADVANTAGES OF TAUT WIRE
Quick and easy to deploy system.
Mechanical system, therefore, it can be repaired on board when necessary.
Very accurate in moderate water depth.
All weather operation is possible.
Localized position measurement equipment.
Good reliability.
Assistance from external sources to set up or operate is unneeded.
LIMITATIONS OF TAUT WIRE
The system can be affected by strong current.
Accuracy deteriorates in very deep water.
r. Short range only, especially in shallow wate
ditions. Adversely affected by surface debris or ice con
Relative position measuring system only.
erwater activity. Wire may hamper ROB, diver or other und
osition. Taut wire has to be redeployed each time vessel has to shift p
Possibility of positional error caused by weight dragging.
ctivity. Wire may be fouled by ROV, divers, or other underwater a
Susceptible to mechanical damage.
rmally connected to UPS), and cooling. Reliant on vessel main power (not no
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POSITION MEASUREMENT EQUIPMENT
GLOBAL POSITIONING SYSTEM (GPS)
GPS is a satellite-based, passive-ranging navigation system which
provides latitude, longitude, and attitude data worldwide. GPS
consists of 21 satellites, with 3 spares.
The GPS satellite system is controlled by the US Department of
Defense. The US Department of Defense reserves the right to turn-
off GPS completely or to reduce the 20m civilian accuracy for civilian use is still not
sufficient for most DP operations.
The GPS accuracy generally available for civilian use (Standard Positioning Service) is
within 20m.
Differential corrections are applied to GPS data to
improve accuracy for DP use.
Fixed reference stations are located at strategic
positions on earth.
Each reference station uses the data from GPS
satellite and its known position to compute a
correction for each satellite.
The reference stations transmit the corrections to
the vessel via a data link.
The vessels GPS receiver automatically applies
the correction to position data received form the
satellites.
DIFFERENTIAL GLOBAL POSITIONING SYSTEM (DGPS)
Differential GPS improves civilian position accuracy to 1m - 5m.
Differential Correction Network.
Multiple reference stations provide differential information.
Network DGPs reference stations offer more stability and accuracy compare with data
from an individual reference station.
Differential Correction Network.
mprove civilian position accuracy to 1m- 3m. DGPs network stations generally i
ormation The notion of Available Quality is designed to simplify DGPs status inf
available to the DPO.
rine Contractors Association (IMCA) proposed a DP Quality
The International Ma
Indicator (DQI) system that consists of numeric values from 1 to 9 to represent the
operating status, reliability, precision and redundancy of DGPs data. The larger the value,
the higher the DGPs data available. Generally, 5 to 9 is adequate for DP operations.
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POSITION MEASUREMENT EQUIPMENT
ADVANTAGES OF DGPS
Relatively high accuracy.
Many satellite constellations available.
Global coverage with the exception of Polar regions.
Proximity to drilling platforms or oil rigs (these structures interfere with satellite signals
and differential corrections).
LIMITATIONS OF DGPS
Accuracy affected by solar flares activities.
Accuracy deteriorates with increase distance from reference stations.
Drilling platforms, oil rigs or other large structures interfere with satellite signals and
differential corrections.
Additional cost for differential correction.
RELATIVE GPS
A procedure used to dynamically position a vessel off a moving, instead of a fixed
position.
DP shutter tankers often us relative GPS when loading via a bow hose form the stern of a
Floating Production Storage and Offloading (FPSO) vessel.
The FPSO may be turret moored to allow it to weathervane. Consequently, heading and
position wandering occur. The stern of the FPSO moves to reflect heading and position
change. Thus, the shutter tanker is faced with a complicated dynamic positioning
situation.
DARPs (Differential, Absolute and Relative Positioning System )placed on the FPSO is
used to resolve the complications resulting from relative dynamic positioning.
ts position THE FPSO uses Network DGPS to get and absolute position. And, relays i
information to the shutter tanker via a UHF link.
to determine the range and bearing from The shutter tankers computer uses the UHF data
the stern of the FPSO. This position reference information is used by the shutter tankers
DP control system for relative Dynamic Positioning.
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POSITION MEASUREMENT EQUIPMENT
LASER-BASED SYSTEMS
Laser System is useful for DP operation conducted in the same location or slow moving vessel.
LASER SETUP
A typical setup scenario for laser based systems is for the vessel to back-up to the rig or structure
and place targets. The vessel would then move away from the rig or structure and select laser on
the DP system and wait for the signal to connect.
NOTE: There have been instances where workers with reflective tape have caused the system to
wander.
ADVANTAGES OF LASER
Laser is effective and accurate when operating within close proximity to oil rigs,
platforms, or other large structures that may interfere with DGPS signal.
Quick and easy to set up. Proximity to drilling platforms or oil rigs (these structures
interfere with satellite signals and differential corrections).
LIMITATIONS OF LASER
Laser is affected b precipitation in the atmosphere.
The range of the laser is limited to a few thousand meters.
Reflective targets are required on fixed structures.
There are two types of laser systems commonly used:
FANBEAM
The Fanbeam system is an alternative short range laser based positioning and tracking
system. The system consists of a vessel borne laser unit and a reflector, providing range
and bearing.
A reflector positioned on a fixed or movable structure reflects the light.
The laser unit receives the reflection. And, the image and bearing are determined.
A VRU for pitch and roll compensation is needed.
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POSITION MEASUREMENT EQUIPMENT
Advantages Of Fanbeam
Low cost compared to other measurement equipments installation.
Target does not require any support services once installed.
Targets in expensive to make, i.e. plywood, pvc.
High accuracy within 20 cm.
Limitations Of A Fanbeam
Not as effective when the sun shines directly into the lenses.
The lenses can be affected by condensation, rain, and salt spray.
The system may suffer interference from reflective items in the area of the target.
Practical, useful range for DP is around 200-250 meters.
CYSCAN
CyScan is a short-range, laser-based, high precision positioning and tracking system
consisting of a rotating laser placed on a stabilized platform which compensates for pitch
and roll.
Three or more retro-reflective targets are fitted on the DP vessel at defined spacing along
a baseline.
The laser emits a pulse of light which is reflected back. The time interval between
emission and reception and angle are used to determine the DP vessels position relative
to the laser.
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POSITION MEASUREMENT EQUIPMENT
POOLING AND WEIGHTING PRS DATA
Pooling is the process of combining data from Position Measuring Equipments (PMEs)
when two or more PMEs are activated, to optimize the overall position data.
The pooling process is based on Weighted averaging to use the advantages of each
activated PME.
The limitations of each APME is minimized b the combined advantages.
.
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POSITION MEASUREMENT EQUIPMENT
PME CHARACTERISTICS
Type
Range
Max. Depth
Accuracy
HPR 5 times water depth 4,000 m 1-2% of water depth
Artemis 30 km n/a +or 1 m
Taut Wire 25% of water depth 500m 2% of water depth
DGPS Unlimited n/a +or 3m
Laser Up to 2000m
250m practical DP use
n/a Less than .5m
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POSITION MEASUREMENT EQUIPMENT
GLONASS SYSTEM
Global Navigation Satellite System (GLONASS) is the Russian version of the United
States GPS system.
GLONASS, like GPS, uses pseudo-range measurement from time and satellites position
to determine position.
GLONASS satellites high orbital inclination of 65 degrees offer better position coverage
in higher latitudes, compared to GPS constellation (55 degrees).
Some GLONASS satellites are not consistently operational for position determination.
Hence, GLONASS is not always available for continuous position update.
Combined GPS/GLONASS receivers use both satellites systems. This ability increases
the number of satellites available for position coverage.
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POSITION MEASUREMENT EQUIPMENT
PRINCIPLE OF EMULATION AND LIMITATIONS
Emulation is the process of interfacing data from position references in the DP system.
LIMITATIONS OF EMULATION
Since most DP systems are proprietary, any update to the system has to be factored in to
the emulation process by the manufacturer of the DP system.
Bypassing this requirement may result in unsatisfactory results.
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ENVIRONMENT SENSORS AND ANCILLARY EQUIPMENT
VERTICAL REFERENCE FOR DP INPUT
Dynamic Positioning maintains a vessels
position by controlling Surge and Sway.
Dynamic Positioning maintains heading by
controlling Yaw.
Heave, Pitch, and Roll, on the other hand, are
monitored to enhance position data from
Position Measuring Equipments (PMEs).
As the vessel rolls or pitches, positions of
PMEs are offset from the center of gravity of
the vessel. This offset may also be interpreted
by the DP system as an actual position change
of the vessel.
Some vessels such as cruise ships may have
stabilizers to damping roll.
Vertical Reference Sensor (VRS), Vertical
Reference Unit (VRU) or a Motion Reference
Unit (MRU) is fitted in the DP vessel to
measure pitch, roll, and heave.
The terms Vertical Reference Sensors )VRS)
and Vertical Reference Unit (VRU) are
interchangeable.
The DP control system uses data from VRS,
VRU, or MRU to compensate for the offset of
various position reference sensors from the
centre of gravity of the vessel.
For Dynamic Positioning purposes, the effects
of pitch and roll are more critical to position
keeping than heave.
A simple VRS consists of a damped
pendulum in a chamber containing a viscous
fluid. Detector coils converts the position of
the pendulum to an analogue voltage to
represent angles of roll and pitch. A more
complex VRS has facility to measure heave.
Motion Reference Unit (MRU), on the other hand, uses linear accelerometers to measure
accelerations and calculates inclination angles.
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ENVIRONMENT SENSORS AND ANCILLARY EQUIPMENT
GYRO COMPASS IN A DP SYSTEM
HEADING REFERENCE
Gyro compass provides heading data to the DP system.
DP vessels that require redundancy have two or more gyro compasses.
If only two gyro compasses are installed, the DP system is limited to monitoring the
difference in heading data. And, issuing a warning, if this difference exceeds a certain
value.
If three gyro compasses are fitted, the DP system can use two-out-of-three voting to
determine a gyro failure, and give a warning accordingly.
Heading reference may also be available from strategically positioned DGPS receivers
and motion sensors.
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ENVIRONMENT SENSORS AND ANCILLARY EQUIPMENT
WINDSENSORS WITHIN A DP SYSTEM
Wind has the potential to blow a vessel off position. Therefore,
DP systems need wind speed and direction data from
windsensors:
To compute the effects of the wind on the vessels
superstructure and hull.
To determine thruster force necessary to counteract the
effects of wind.
To calculate Weathervane or Minimum Power
Heading.(Common in shutter tanker operations).
Several types of windsensors are fitted aboard vessels.
Generally, a windsensor commonly consists of a rotating-cup
type transmitting anemometer, with a separate windvane to show
wind direction.
Impeller attached Weathervane
Rotating Cup Anemometer
Another type of windsensor has the impeller attached to the windvane.
WIND SENSOR FEED FORWARD FUNCTION
The windsensor has an input to the mathematical model. However, the mathematical model takes
time to evaluate and respond to changes in the vessel or environment.
The wind, on the other hand, can suddenly gust without warning. Hence, the windsensor is also
connected to the DP system by a feed forward function to bypass the mathematical modeling
process. This function enables the DP system to immediately react to a radical change in wind
condition.
LIMITATIONS OF WINDSENSOR INPUT
The accuracy of windsensor input in the DP system is influenced by the following factors:
Windshadowing resulting from masts, stacks, adjacent oil rig, platform or other vessel
obstructing the wind.
Malfunction in the windsensor (i.e. rotating cups or windvane becoming stuck).
Reliability of wind data from the windsensor selected by the DPO.
.
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ENVIRONMENT SENSORS AND ANCILLARY EQUIPMENT
Data from the windsensor is essential in DP operations. The speed and direction of the wind are
important factors in the calculation of the weathervane or minimum power heading. Some
vessels such as shuttletankers and FPSOs require the vital information in order to keep the
correct attitude at all times.
The windsensors are coupled into the DP system by means of a feed forward function, which
bypasses the mathmatical model, in addition to being included in the modeling process. This is
also known as wind feed forward.
DESELECTING WINDSENSOR INPUT
Two or more windsensors positioned at opposite ends of the yardarm enable the DPO to select or
deselect a windsensor, depending on the prevailing circumstances.
The disadvantage of deselecting windsensors is wind data to the mathematical model and feed
forward function are discontinued. However, the DP system uses wind data stored in the
mathematic mode.
ADVANTAGE OF DESELECTING WINDSENSOR
During helicopter operation, if the helideck is close to windsensor, the downwash of air from the
helicopter rotor will trigger the feed forward function, Hence, the DP system will issue thruster
command to react to an apparent gust.
Deselecting windsensors during this critical operation will ensure that the vessel is not
inadvertently reacting to a fictitious gust.
Caution: Keep in mind when reselecting windsensors that the DP system may interpret the
difference between the constant wind value in t mathematical model and the prevailing wine
condition as a gust. And, react accordingly.
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ENVIRONMENT SENSORS AND ANCILLARY EQUIPMENT
OTHER SENSORS
INERTIAL NAVIGATION SYSTEM (INS)
Rate Gyroscopes (sensors used to measure rate velocity) and accelerometers (sensors used to
measure acceleration in various axes) are combined to compute the vessels heading, altitude and
position.
Note: Unlike a DGPS receiver which determines position relative to satellites, INS is self-
contained. While INS cannot determine an initial position, it accurately computes position
relative to an initial position. Hence, combining DGPS and INS enhances DP capabilities.
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ENVIRONMENT SENSORS AND ANCILLARY EQUIPMENT
MESSAGES ON DP SYSTEM AND PRINTER
Dynamic Positioning systems are designed to consistently check for inconsistencies, faults, and
warnings. Unique to the IVCS 2000, is a voice alarm in plain English.
When critical conditions are detected, messages (reports) are generated. These messages, are
constantly displayed on the LCD monitor and/or printed in an abbreviated format. Most DP
systems have a dedicated display area or facility for Messages. The type of information on
display will consist of:
Date and time of message generation.
Message text.
Message reference number.
Message type (Alarm, Warning or Information).
Source of origin (e.g. computer A or B).
Status of message (acknowledged or not, active, inactive, etc.).
Additional data.
All messages are printed out hard copy by a printer. I addition to the brief message text, the DPO
may consult a message listing, either on paper or on-screen help file, to provide a much greater
description of the causes and effects of the message.
Basically, DP systems issue three categories of messages:
Alarm.
Warning.
Information.
In the IVCS 2000 DP system, the three categories of messages are:
Error.
g. Warnin
n. Informatio
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ENVIRONMENT SENSORS AND ANCILLARY EQUIPMENT
Alarm messages are issued with a flashing lamp and audible alarm whenever the system
discovers a situation which adversely affects DP operation. The DPO must acknowledge the
alarm, check the contents of the alarm message, and determine a corrective course of action, in
order to rectify the situation. The following messages qualify as Alarm:
Setpoint Alarm
Limits
Exceeded.
Position Out of
Limit.
System Fault.
Thruster #2
Feedback
Error.
Warning messages,
appear on the alarm
display and printer, are
issued with flashing
lamp alarm whenever
the system discovers a
situation which will adversely affect DP operation, but do not have any serious effect on the
performance of the system. The DPO must also acknowledge warning alarms, and check the
contents of the message in order to rectify the situation. The following messages qualify as
Warning:
No windsensor selected.
Wind Direction Difference.
Thruster #1 High Force.
If system tests do not report the same message after a specific timeout period, the message
becomes inactive. Generally, inactive Alarm and Warning messages need to be acknowledged by
the DPO before they are removed from the active message display list, while Information
messages are removed automatically when they become inactive.
Information messages are issued without a flashing lamp or audible alarm to inform the DPO of
important issues that will not adversely affect DP operation. Reference Reject HPR 1 qualifies as
information.
CATASTROPHIC FAILURE MESSAGE
Catastrophic Failure indicates and extremely harmful situation that would cause the vessel to
loose DP capability, i.e. loosing heading (gyro compass) or position (DGPS) input. Alarms and
Warnings associated with catastrophic failure must be check and acknowledged by the DPO.
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ENVIRONMENT SENSORS AND ANCILLARY EQUIPMENT
CORRECTIVE ACTION FOR ALARMS/WARNINGS
The DPO must fully understand any alarm or warning message before acknowledging it.
Regardless, the DPO may consult an on-screen help field or message listing to get a detail
explanation of the abbreviated alarm or warning message.
If one of two gyros selected by the DPO experiences a catastrophic failure (signal loss) for
example, the DPO must ensure that the alternate gyro is selected in order to maintain heading
input into the DP systems.
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POWER GENERATION AND SUPPLY
Dynamic Positioning vessels, compared with conventional merchant vessels, have a much higher
need for power due to all the systems and redundancy required for DP operation.
DIESEL ELECTRIC DP VESSEL
Generic power generation and distribution for a dive support vessel.
In a typical diesel-electric DP vessel, power may be generated as follows:
Six diesel generators, fitted in two separate machinery spaces.
The generators send power to a split HT (high tension) switchboard.
The switchboard busbars are installed in separate spaces, also. And, are connected by
a bus switch.
The bus switch is opened to isolate the two halves of the switchboard so each can
operate independent of the other. When the bus switch is closed, the two halves
connect.
Each busbar provides power to one main propeller, and at least one thruster at the
bow and stern. This provides redundancy should a fault develop in one busbar.
A Diesel Electric DP Vessel has a diesel engine connected to an electrical
alternator/generator.
Alternators/Generators provide power for the diesel electric engine by a bank of diesel
driven alternators also called generators for this purpose. One of the advantages of this
type of operation is the cost saving on fuel. Another advantage is the ability to take
generator on and off line when they are not needed.
Switchboard is an essential part of a diesel electric vessel. The alternators/generators
feeds the switchboard at which time the switchboard distributes the power. The typical
switchboard is 480 volt and split into two sections, the port board and starboard board.
These two side are connected by bus tie breakers. Proper setup of this equipment is
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POWER GENERATION AND SUPPLY
necessary in order to have a workable DP operation. DP technicians have simplified this
process over the years with computer systems and more modern equipment. Different
types of DP systems have different requirements from the bus-ties. An abnormal power
condition, such as a generator taking on too big of a load and tripping, may cause a
blackout. When this happens the other generators try and assume the remaining load and
one of them may trip causing a blackout. This is why the bus-tie switches are important
and should be monitored. A bus-tie on a DP 2 system can either be open or closed in
order to fix any problems while maintaining position. The main purpose is so a single
fault failure will not cause the vessel to lose DP. A DP 1 type vessel might only have a
280 volt switchboard but will be split like the 480 volt.
In a typical diesel-electric DP vessel, power may be generated:
Six diesel alternators, fitted in two separate machinery spaces.
The alternators send power to a split HT (high tension)switchboard.
The switchboard busbars are installed in separate spaces also. And, are connected by a bus
switch. The bus switch is opened to isolate the two halves of the switchboard so each can operate
independent of the other. When the bus switch is closed, the bus bars connect the two halves.
Each busbar provides power to one main propeller, and at least one thruster at the bow and stem.
This provides redundancy should a fault develop in one busbar.
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POWER GENERATION AND SUPPLY
POWER REQUIREMENTS
Power is critical for the operation of various subsytems in the DP system.
The power generation system must be capable of rapid increase in production to met high
power demands by the control system, while scaling back when power demand is low,
in order to conserve fuel.
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POWER GENERATION AND SUPPLY
POWER MANAGEMENT SYSTEM
Power Management is the system that efficiently matches the level of power to the
existing conditions and having adequate power for future conditions. Diesel-electric
powered vessels generally have sufficient generators, connected to a switchboard driving
the necessary motors.
In new modern vessels, the power management systems have the ability to start and stop
generators, trip certain systems before others, distribute load sharing through the system.
Power Management is the process of producing enough power to meet the demand of the
DP system, while economizing fuel consumption.
Redundancy level required determines the complexity of the power management system.
In a typical diesel-electric power vessel, enough alternators are connected to the
switchboards to produce the required power. When power demand increases, more
alternators come online. When, power demand decreases, the reverse occurs.
Power Management system is generally designed to prevent large motors from starting
until enough alternators are online to produce the required power.
In order to have redundancy, the power generation system is divided into tow halves. The
tow plants are fitted in separate machinery rooms, Moreover, switchboards are
subdivided to isolate faults or prevent blackout when necessary.
A Power Management system included in the IVCS 2000 provides:
The power monitoring for each of thrusters, CPPs, Shaft Generators, Main Engines.
The actuators (thrusters and CPPs) power limiting in order to prevent Shaft
Generator and Main Engine overload.
system
Reduced power consumption of the CPP and thruster connected to the same Shaft
Generator with the thruster, which is being started, in order to start the thruster motor.
UNINTERRUPTED POWER SUPPLY
The electronic components of the DP system (console, computers, position measuring
equipment, environmental sensors, etc.) need a stable power supply. Excessive power fluctuation
may not only blow some fuses, it can also damage sensitive electronic equipment. Moreover, DP
electronic components must have backup battery power in case the vessel experience a blackout.
These battery backups systems are called Uninterruptible Power Supplies (UPS).
DP class 2 and 3 must have redundant UPSs and have a minimum duration of 30 minutes of
operation. There are other types of UPSs on the market and many have longer durations. A
better system would be to setup two systems for redundancy in case of a UPS failure. UPSs
should be tested on a regular basis as they do not last forever. They come in many different price
ranges from inexpensive to very expensive. The vessel would be bettered served with a reliable
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POWER GENERATION AND SUPPLY
Provisions For Uninterrupted Power Supply:
Case 1 - Various peripheral elements of the DP system are given dedicated individual
UPS. For example, one independent UPS unit for each of the two DGPS receivers in a
DP system.
Case 2 - One large capacity UPS facility to provide power to several components in the
DP system.
SIMPLEX UPS SYSTEM
Two separate supplies Master and Alternative, are taken from individual busbars. These supplies
go into charging rectifiers, which converts the ships a.c. to 120 v. d.c. The d.c. then supplies the
inverters, and backup batteries. When the vessel loses power, the batteries provide power to
essential DP electronic components for about 30 minutes.
NOTE: The batteries do not power the thruster and taut wire winch.
Inverters in the simplex UPS system convert the 120v. dc. into the a.c. voltage and frequency
required by the DP electronic components. Outputs from the Master and Alternative Inverters are
synchronized in phase. The static switch sends the power from Master or Alternative inverter to
the DP electronic components. Although the static switch is dependable, it is not redundant.
Hence, it is a source of single-point failure. Consequently, the simplex UPS system is limited to
use in Equipment Class 1 DP vessels.
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POWER GENERATION AND SUPPLY
DU
Each of two independent UPS systems is used to provide power to half of the DP system. Each
UPS has a backup battery for redundancy.
TRIPLEX UPS SYSTEM
A DP Equipment Class 3 vessel will have a third UPS system installed for triple redundancy.
PLEX UPS SYSTEM
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POWER GENERATION AND SUPPLY
WINDOWS
POWER LIMITS
In this window, the DPO can set maximum allowed power consumption for actuators (thrusters
and propellers) and maximum allowed power production for Main Engines and generators.
Power limits set in this window are considered by the IVCS 2000 during Thrust Allocation.
When power consumption/production within these limits is not enough for system operation, an
alarm appears.
Using < and > buttons it is possible to set required limit values for the following actuators:
Bow #F Thruster.
Bow #A Thruster.
Stern #F Thruster.
Stern #A Thruster.
Port Diesel.
Stbd Diesel.
Port Generator.
Stern Generator.
Port Propeller.
Stbd Propeller.
Power limits are set in percents
from maximum consumed/produced power.
et power limits are indicated in the Power Monitoring Window of the IVCS 2000.
GENERATOR LIMITS
In this window an operator can set low and high voltage and frequency limits for generators.
When these limits are overstepped, an alarm appears.
Using < and > buttons it is possible to set required limit values for the following generators:
S
Port Generator.
Stbd Generator.
Generator limits cannot exceed maximum voltage and frequency values, defined by generators
specifications.
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POWER GENERATION AND SUPPLY
SYSTEM DIAGNOSTIC WINDOW
The System Diagnostic Window is
used for:
The IVCS 2000 hardware
monitoring.
Testing of the system
operability.
Determination of the current
system configuration.
The upper part of the System
Dia o ws system gn stic Window sho
stru ll system
hardware components are indicated:
cture diagram where a
I/O boxes connected with
pper row
):
vessel actuators (u
of rectangles
Bow Forward Thruster.
Bow Aft Thruster.
Stern Forward Thruster.
Stern Aft Thruster.
Port propeller.
Starboard Propeller.
indicates state of the
Color of the rectangle
respective I/O box:
Green color I/O box is
correctly operated.
Red color I/O box is
failed.
Genus Bases A and B are presented as two horizontal lines located under the I/O bo
Color of the line indicates state of the bus:
xes.
Green the bus is correct and in operation. This means that at least one of I/O boxes
is operated through this bus. It is possible that both Genius buses are green.
White bus is correct and Hot Standby.
Red bus is failed.
ters A and B states are determined by color of the respective rectangle: PLCs and Compu
Light Green PLC/Computer is correct and in operation (Master).
Dark Green PLC/Computer is correct and Hot Standby.
Red PLC/Computer is failed.
Port and Stbd Steering Systems states are determined by color of the respective rectangle:
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POWER GENERATION AND SUPPLY
Green Correct connection between PLC and Steering Gear.
Red No connection between PLC and Steering Gear-Rudder control is not
available.
Ethernet connections between
ind
PLCs and Computers are presented with color lines,
icating the state of connection:
Green connection line is correct.
Red connection line is failed.
B, and PCP) are presented as rectangles located in the
of the rectangle indicates state of the respective Control
Control panels (MCP A, MCP
lower row of the diagram. Color
Panel:
Light Green CP is active. Connection line between CP and Computer is light green.
Dark Green CP is not active. Connection line between CP and Computer is white.
Red color CP is failed or
CP and Computer is red als
no connection with CP. At that connection line between
o.
Sensor sets are presented as tw
indicates sensor state:
o black boxes with sensor lists. Color of the sensor name
Green sensor correctly sends data to the IVCS 2000.
Red no data from sensor.
The fo color circle indicators are presented in the lower part of the
System
llowing AC/DC Monitoring
Diagnostic Window:
a rgizing from 24 VDC A and B Power suppliers: Av ilability of I/O boxes ene
power supply is available. Green color of indicator
izing. Red color no energ
a in Housings A and B energizing from 24 VDC A and B Power Av ilability of Ma
suppliers:
Green color of indicator power supply is available.
Red color no energizing.
in Housings A and B energizing from internal 24 VDC Power Availability of Ma
suppliers:
or power supply is available. Green color of indicat
Red color no energizing.
UPS A and B failure indicators:
Line Failure (115 AC ship power failure).
Low Battery.
Replace Battery.
Grey color of indicator no failure signal.
NO
second n
Red color failure.
TE: In the case of Low Battery the Operator Console will be automatically shut down in 30
s a d the following inscription will be displayed:
System is automatically shut down.
Low battery.
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POWER GENERATION AND SUPPLY
SYSTEM STRUCTURE DIAGRAM
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POWER GENERATION AND SUPPLY
POWE
The o
Window
R MONITORING WINDOW
P wer Monitoring
is used for:
Thrusters power
consumption,
parameters and
state monitoring.
and
at
Engines
generators power
producing,
parameters and
st e monitoring.
Circuit breakers
state monitoring.
The following indicators
gen
(Power o
Devices):
Thruster Motor
Start Preparing.
are represented for each
thruster, engine,
erator, and CPP
M nitored
age -
Power Monitored
Device Im
Indicates the state of the Power Monitored Device.
The following group of parameters is monitored for all Digital Parameters Indicators -
Power Monitored Devices, except for the Shaft Generators:
Power.
RPM.
r parameters are the following:
Pitch (except engines).
As for the Shaft Generators, thei
Power.
Frequency.
Voltage.
icator - Shows the consumed/produced Power Consumption/Generation Graphic Ind
power level.
r - Shows the state of the circuit breaker connecting the Power Ci cuit Breakers Image
Monitored Device to the bus.
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POWER GENERATION AND SUPPLY
START Pushbutton - Is presented only for the thrusters. Enables starting the Thruster
Motor Start Preparation Procedure. Changes to the Ready to start state after the
Preparation Procedure has been executed.
Power Monitored Device Status Indicator - The colored circle Indicator; the color is
indicating status:
Grey not ready (option).
White device under manual control.
Green device under automatic control.
Red device Alarm.
Power Monitored Group Graphic Bar Indicator - Shows the power consumption and
generation for the Power Monitored Device Group.
Red lines on all graphical indicators represent the set power limits.
ALARM MONITOR
The Alarm Monitor contains the list of all alarms and control buttons for Alarm List viewing. It
can be loaded by one of two ways:
Select Services Alarm Monitor option on the Main Screen.
Press the Monitor Softkey in the Alarm Window of the IVCS2000.
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POWER GENERATION AND SUPPLY
The Alarm Monitor window is similar to the Alarm Window of the IVCS2000. It contains the
following:
Alarm List, presented as a table, with the following fields in each string:
The symbol, defining message group (Error, Warning, Information).
Field of message acknowledgement.
Date.
Time start Time of alarm.
End stop Time of alarm.
Event text of alarm message.
Control Buttons:
and Softkeys for alarm selection.
ACK Softkey for acknowledging of selected alarm.
Prev and Next Softkeys for moving screen pages (up and down).
Clear Softkey for cleaning of alarms storage. Press this button to keep only 3
months history of alarms.
Exit Softkey .
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OPERATIONS USING DYNAMIC POSITIONING
APPROACHING WORKSITE
The Dynamic Positioning Vessel, in many cases, can be considered the command center of the
DP operation. Hence, it is imperative that DPOs fully appraise every detail relating to the
pending project.
Details to consider prior to arrival at the worksite must include the following:
Location and/or parameter of the worksite.
Depth of water at and around the worksite.
Traffic in vicinity of worksite.
Obstructions above and below the water.
Possible hazards relating to DP operation.
Weather forecast for the area of operation.
Tide and current predictions
Details to consider prior to arrival at the worksite must include the following:
Available thrusters.
Equipment redundancy required for the operation.
Available position references and limiting factors (i.e. rigs, platform, and other large
structures may interfere with GPS signals).
Communication Channel to contact platform or other vessel involved with DP operation.
Details to consider prior to arriving at the worksite must include the following:
Coordinate with engine room (i.e. time, power requirement, communication lights, etc.).
Contingency plans for power blackout, abandoning DP operation, exiting worksite, and
more.
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OPERATIONS USING DYNAMIC POSITIONING
TRANSFERRING FROM CONVENTIONAL NAVIGATION TO DP
CONTROL
During the approach to the worksite, the vessel has to switch control from the navigation bridge
to the DP console. Several factors must be considered when determining when and where to
switch over to the DP console including:
Physical location of the DP console relative to the navigation bridge (i.e. the DP console
is in the After Bridge on some vessels. In the case of shutter tankers, the DP console is in
the Bow House).
Vessel traffic in the immediate vicinity.
Proximity to the 500m zone, if applicable.
The DP system requires some time to build a mathematic model for the prevailing
circumstances. Without the model, the vessel will have difficulty maintaining position.
CHECKLIST
Utilizing a checklist for this switching over process will help ensure that essential DP items are
examined. A checklist is a guide which lists essential items to be examined. In some cases, the
checklist will give the examination sequence and tolerance for the each item.
Generally, the DPO on duty will have to maintain the following checklists:
Pre-DP.
Pre-operational.
Watch hand-over.
Periodic DP (i.e. every six hours).
NOTE: The Machinery Control Room (MCR), ROV crew, Deck crew, and Surveyors may have
their own checklists.
Checklist Recommendations:
If possible, two DPOs should complete the checklistone reads out and initials each item
while the other does the actual check.
Avoid racing through the checklist. DP is a gradual process.
Use the checklist as a memory aid only so you dont lose sight of the big picture.
Update the checklist to reflect modification or upgrade in the DP system. If the checklist
is a controlled document, file a non-conformance to get the require change.
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OPERATIONS USING DYNAMIC POSITIONING
SWITCHING FROM MANUAL TO FULL DP MODE
After completing the pre-DP checklist, maneuver the vessel as close to a complete stop as
possible, before switching to full DP. Keep in mind that if the vessel still has headway when you
switch to full DP, the thrusters may overwork to maintain position. Hence, the vessel could
experience a partial or complete blackout, depending on the level of redundancy.
A more practical approach is to engage full DP mode, one axis at a time:
Steady the vessels heading prior to pressing the Auto Yaw button. In this mode, the DP
system automatically controls the heading. And, the DPO manually controls Sway and
Surge with the joystick. This mode is referred to as J SAH (J oystick control with Auto
Heading).
Manipulate the joystick to reduce motion in the X-axis (fore and aft) as close to zero as
possible. Then, engage Auto Surge.
Repeat the above procedure for the Y-axis (sideways) and press Auto Sway.
Caution: Avoid making a heading change, using the Heading Input option, when the vessel has
only Auto Yaw and Surge or Auto Yaw and Sway engaged. This could lead to some unsuspected
vessel reaction.
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OPERATIONS USING DYNAMIC POSITIONING
LOGBOOK RECORDS
The vessels logbook is an official record of pertinent events equivalent to a black box in an
airplane. As a rule, any information that could be used to reconstruct an operation or incidence
for analysis, should be entered into the ships logbook.
Some companies have policies relating to what should be recorded in the ships log; and,
acceptable format to use. In addition, some DP vessels have an automatic voice and event
recorder on the bridge.
Events to be recorded in the vessels logbook should include, but are not limited to the
following:
Essential communication, i.e. permission to proceed into the 500m zone.
System failures.
DP incidence and repairs.
Details of DP operation.
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OPERATIONS USING DYNAMIC POSITIONING
COMMUNICATION DURING DP OPERATIONS
Any operation that requires successful cooperation between various parties - i.e. charterer,
marine department, engineers, surveyors, deck crew, divers, etc. has the potential for conflict.
Communication is crucial to the success of any DP operation.
Every single person involved in the DP operation must be briefed about the overall operation in
order to see the big picture. In addition, it is essential that everyone knows exactly what is
expected of him/her.
DP WATCHKEEPING
The nature of the DP operation and class of vessel will dictate manning requirement. For
example, a non-redundant DP supply vessel delivering supplies to an oil rig might have only one
DPO on watch at a time. However, a construction vessel carrying out dive operation will have at
least two DPOs present on the bridge at any time.
Regardless of manning requirements, DPOs on all vessels are involved in hand-over procedures.
Some vessels have hand-over checklist. For some vessels, the hand-over is informal.
The following information will greatly enhance the hand-over process:
The vessels heading and position.
Vessel traffic around the worksite.
Details of the DP operation and expected changes.
DP systems performance.
Status of Position Reference Systems and any restriction.
Level of redundancy.
Current weather conditions and forecasts.
Internal and external communications.
Expected helicopter operations.
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OPERATIONS USING DYNAMIC POSITIONING
UTM SYSTEM OF PROJECTION AND COORDINATES
Universal Transverse Mercator (UTM) system of coordinates, produces the high level of
accuracy required for most Dynamic Positioning related operations. Hence, UTM is a viable
alternative to reduce distortion resulting from the conventional Mercator projection. Mercator
Projection is formed by a placing a cylinder tangent to the Earths equator.
Lines of longitudes (measured east-west) converging at the poles are stretched in the cylinder so
that they are straight and equidistance.
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OPERATIONS USING DYNAMIC POSITIONING
Consequently, latitudes (measured north-south) are proportional stretched. Thus, distortion,
resulting from the stretching, is minimal at the Equator and increases to a maximum value at the
poles.
Since, most DP operations are carried out well away from the equator, a more accurate system of
coordinates was neededUTM. In the UTM system of coordinates, Northings and Eastings,
measured in meters, are used to express a position. Universal Transverse Mercator (UTM) was
developed in 1936 and adopted by the US army in 1947.
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OPERATIONS USING DYNAMIC POSITIONING
This projection is based on a cylinder placed tangent to a selected meridian.
Thus, the area within 3 on each side of the selected meridian has minimal distortion.
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OPERATIONS USING DYNAMIC POSITIONING
A single Transverse Mercator projection only yields a useful zone of 6 width of longitude (3 on
each side of the selected meridian). Hence, that is obviously not enough to cover the whole
terrestrial sphere without distortion. Consequently, the cylinder is rotated in 60 steps (six degrees
per step) UTM to ensure every point on Earth is within 3 degrees of a central meridian. In
addition, each zone is then divided into 100,000 meter squares (100 000 x 100 000).
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OPERATIONS USING DYNAMIC POSITIONING
In order to cover the entire Earth, the terrestrial sphere is divided into 60 zones of 6 longitude.
The zones start at 180 meridian and are numbered consecutively eastward.
THE ZONES ALSO EXTEND FROM 84 N TO 80 S.
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OPERATIONS USING DYNAMIC POSITIONING
Zone 1, for example extends from 180 meridian to 174 W longitude, with the central meridian
at 177W).
Eastings are measured
increasing to the east. In
addition, the central
meridian is given a false
datum value of 500,000.
Hence, Eastings for a
position east of the central
meridian will increase
from 500,000 to the
position.
Eastings for a position
west of the central
meridian will decrease
from 500,000 to the
position. This resolution
results in positive Eastings
values throughout the
zone.
Northings are measured increasing to the north. For example, the Northings for a position in the
Northern hemisphere is measured from the Equator (zero reference) northward to the position.
Northings for a position in the Southern hemisphere is measured from the Equator. However, in
this case, the Equator is given a false datum of 10,000,000. Hence, Northings value decrease
from the Equator southward. This resolution results in positive Northings values increasing
northward throughout the globe.
Advantages of UTM Systems of Coordinates:
Minimal distortion within a zone.
High accuracy.
Accuracy is consistent throughout the glove.
UTM is popular in DP operations.
Disadvantages of UTM System of Coordinates:
High distortion at the poles.
Northings and Easting are measured from false origins.
A complete reference requires Northings, zone number, and Eastings.
Combining different UTM zones lead to major distortion.
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OPERATIONS USING DYNAMIC POSITIONING
DATUMS USED IN DP OPERATIONS
Three popular datums used in DP operations:
Universal Transverse Mercator (UTM ) system gives position in terms of zone number,
Northings and Eastings in meters.
Latitude and Longitude coordinates system, give position in terms of North or South and
East or West relative to the Equator and Greenwich meridian respectively. Coordinates
are given in degrees and minutes.
Local coordinates system gives position in terms of distances North/South (X) and
East/West (Y) from a local reference pointfanbeam reflector, HPR transponder, taut
wire depressor weight location, etc.
DIAGRAM BASED ON UTM COORDINATES
In order to draw a worksite diagram based on UTM coordinates:
Select the central meridian in the zone closest to your position.
Plot the Northings for your position relative to the Equator.
Plot the Eastings for your position relative to the central meridian in your zone.
Caution: U.T.M. coordinates based on the central meridian in a zone will not align with
coordinates for the same location based upon another central meridian. Draw all diagrams for the
DP operation to the same projection and central meridian datum.
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OPERATIONS USING DYNAMIC POSITIONING
EMERGENCY AND CONTINGENCY PLANNING
P operation leave little room for error. DPOs must
rely n
that cou ition and heading.
The ult
DP ope using the least amount of thrusters power to prevent
pos l
must be
The dynamic nature and precision require of D
o operating procedures, prevailing circumstances, and experience to anticipate situations
ld cause the DP vessel to loose pos
imate goal of emergency and contingency plans is to allow the vessel to safely terminate
ration, and escape from the location
sibe blackout. If an escape is not possible, on a dive vessel for example, position and heading
maintained.
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OPERATIONS USING DYNAMIC POSITIONING
CAPABILITY OF DP VESSELS
Assessing a vessels DP capability is a prerequisite for determining whether the vessel can meet
the demands of a particular operation. Several sources are available to help assess the DP
vessels capability:
FMEA (failure modes and
effects analysis).
ERN Numbers.
Capability Diagram.
Footprint Plot.
The Capability Plot/Diagram
contains results of the IVCS
2000 Capability Analysis and
allows an operator to set different
system configuration and select
environmental conditions to
forecast the maximum weather
conditions in which the vessel
can maintain position and
heading. By examining this
window an operator can clearly
see the current (or forecasted)
operational limits for current (or
set) environmental conditions
and select an optimal heading for
most safe operations.
There are two modes of the
Capability Diagram Window
operation:
Real Mode - In this mode, the system indicates the maximum weather conditions in
which the vessel is able to continue DP operation for current system configuration
(thrusters set and maximum loading), actual current conditions (speed and direction), and
actual wind direction. To operate the Capability Diagram Window in the Real Mode,
press the Real Mode control button in the middle part of the window.
Hypothetic Mode - Forecast of the maximum weather conditions for which the vessel can
maintain position and heading for set system configuration (thrusters set and maximum
loading), set current conditions (speed and direction) and set wind direction. To operate
the Capability Diagram Window in the Hypothetic Mode, press the Hypot Mode control
button in the middle part of the window.
BEIER RADIO 154
OPERATIONS USING DYNAMIC POSITIONING
The Capability Diagram Window has the following structure:
The upper part of the window contains the Capability Plot, where the following
information is indicated:
Circle Grid, where each of concentric circles points a wind speed value and rays
determine relative vessel heading direction.
Blue-red arrow points North direction .
Wind direction (actual
with symbols HW.
for Real Mode and set for Hypothetic Mode) yellow triangle
Current direction (actual for Real Mode and set for Hypothetic Mode) green
bols HC. triangle with sym
Area, within
speed.
which the vessel can maintain position and heading depending on wind
This area is determined b
direction for the Real M
direction for the Hypothe
y the actual current speed and direction and the actual wind
ode and by set current speed and direction and set wind
tic Mode.
The middle part of the window is used for:
Operational Mode selectio
following values indication
n: the Real Mode and the Hypot Mode control buttons. The
for the Real Mode and setting for the Hypothetical Mode:
True current speed.
True current direction.
True wind speed (can not be edited in the Hypothetic Mode).
True wind direction.
To edit wind and current
Special editors appear, wh
settings in the Hypothetic Mode, press the Edit softkey.
ere an operator can set desirable values.
The lower part of the Capability
Mode) and setting (for the Hy
loading (actuator limits) and
Diagram window is used for monitoring (for the Real
pothetic Mode) thrusters configuration and maximum
contains the following:
Indicators of Auto or Manual actuator using in the IVCS 2000.
Indicators of actuator li
mits.
set or actuator limits in the Hypothetic Mode, press an actuator
cial editor appears, where an operator can set desirable value of
eric keypad) and switch on/off an actuator on/off into Auto Mode
To modify actuators
control button. A spe
actuator (using a Num
operation
BEIER RADIO 155
OPERATIONS USING DYNAMIC POSITIONING
ST
The fol
ATUTORY REQUIREMENTS FOR DP OPERATIONS
lowing documents contain statutory requirements and guidance relating to DO operations:
"Gu sitioning Systems," (IMO document idelines for Vessels with Dynamic Po
MSC/Circ.645)
doc
"Guidelines for the Design & Operation of Dynamically Positioned Vessels," (IMCA
ument)
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OPERATIONS USING DYNAMIC POSITIONING
DP EQUIPMENT CLASSES AND APPLICATION
Summary of IMCA (International Marine Contractors Association) guidelines for DP vessels:
Equipment Class 1 - Loss of position may occur in the event of a single fault.
2 - Loss of position should not occur from a single fault of an active
y occur after failure of a static component such as cables, pipes, manual
valves etc.
Equipment Class
component or system such as generators, thruster, switchboards remote controlled valves
etc. But ma
Equipment Class 3 - Loss of position should not occur from any single failure including a
completely burnt fire sub division or flooded watertight compartment.
CLASSIFICATION SOCIETY NOTATIONS
American Bureau of Shipping (ABS), Det Norske Veritas (DNV), Lloyds Register of Shipping
(LR) issued class notations for DP vessels.
CORRESPONDING CLASS NOTATION
Description IMO Equipment LR DNV ABS
Manual position control and
automatic heading control under
spcified maximum environmental
conditions.
DP(CM)
DNV-T
DPS-0
Automatic and manual position
and heading control under
specified maximum environmental
conditions.
Class 1
DP(AM)
DNV-AUT
DNV-AUTS
DPS-1
Automatic and manual position
and heading control under
specified maximum environmental
conditions, during and following
an single fault excluding loss of a
compartment. (Two independent
computer systems).
Class 2
DP(AA)
DNV-AUTR
DPS-2
Automatic and manual position
and heading control under
specified maximum environmental
conditions, during and following
an single fault including loss of a
compartment due to fire or flood.
(At least two independent
computer systems with a separate
backup system separated by A60
division).
Class 3
DP(AAA)
DNV-AUTRO
DPS-3
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OPERATIONS USING DYNAMIC POSITIONING
DP EQUIPMENT REQUIREMENTS
SUB S
SY TEM OR COMPONENT MINIMUM REQUIREMENTS FOR GROUP DESIGNATION
Equipment Class:
IMO 1 2 3
DNV AUT AUTR AUTRO
LR DP(AM) DP(AA) DP(AAA)
ABS DPS-1 DPS-2 DPS-3
Power System:
Generators and Prime Movers Non-Redundant Redundant Redundant, separate compartments
Main S 1 1 w/bus tie 2 w/normally open bus-ties in separate
compartments
Bus Tie Breaker 0 1 2
Distribution System Non-Redundant Redundant Redundant, separate
compartments
Power Management No Yes Yes
Thrusters:
Arrangement of Thrusters Non-Redundant Redund t Re ant, separate c mpartments an dund o
Control:
Auto Control: # Control Computers 1 2 2+1 in alternative control station
Manual Control: Joystick Yes Yes Yes w/auto heading
Single Levers for Each Thruster Yes Yes Yes
Sensors:
Position Reference Systems 2 3 3 including 1 in alt. control station
External Sensors:
Wind 1 2 2 ( of which in alt. c ntrol station) 1 o
VRS 1 2 2 ( of which in alt. c ntrol station) 1 o
Gyro 1 2 3 ( of which in alt. c ntrol station) 1 o
Other 1 2 2 ( lt. c ation) 1 of which in a ontrol st
UPS
1 1
1+1 in separate compartment
Alternative Control Station for
No
No
Yes
Back-Up Unit
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OPERATIONS USING DYNAMIC POSITIONING
DP OPERATIONS IN SPECIALY VESSELS
ynamic positioning (DP) technology was developed primarily to facilitate innovative
xpansions in the oil and gas exploration industry. However, the success of DP has made it
or vessels performing a variety of tasks.
NDERWATER UPPORT V SSELS
upport vessels deploy divers riety of underwater operations including inspection,
tion, configuration, recover ey, and Due to s associated with dive
dive support vessels ave several arrangements in place to protect divers.
D
e
feasible f
DIVING AND U S E
Dive s
nstalla
for a va
i y
h
, surv more. hazard
operations, DP
Major DP systems are du p ens
gardless of possible failur odes.
plicated or tri licated to ure that divers are recovered
re e m
The length of the divers umbilical is restricted to preve om being sucked
g propeller, thr ther le.
nt him/her fr
into a rotatin uster, sea water intake, or o underwater obstac
In addition, a tender or stand d e by diver is use to tend to th divers umbilical.
For dive operations in wate eper than 30 ust wear an atmospheric
diving suit (ADS) or a remo operated vehicle (ROV) is e ployed.
HIPS
involved with oil or gas
dril wanders
to the extend that the conne tion to the well is
ase of hydrocarbons could
ge the environment. In addition,
ng to the well can be ostly and ti
g.
r de 0 meters, a diver m
te m
DRILLS
Drillships are directly
exploration. Hence, if the lship off
position c
severed, uncontrolled rele
pollute and dama
reconnecti c me
consumin
Dy
is used to keep
namic Positioning, usually class III syste ,
the drillship as directly above
the well as possible.
m
Lower main riser ang is constan
ored to ensure the vessel remains within
3.
le tly
monit
Water circles may be established to represent
distances corresponding to riser angles.
A riser angle in excess of 3 is an indication
that the drillship is drifting off location to the
extend that the connection to the well may part.
Some DP systems on drillships have riser angle mode function to ensure that the
drillship is automatically maneuvered to reduce the riser angle.
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OPERATIONS USING DYNAMIC POSITIONING
CABLE LAY AND REPAIR VESSELS
Cable Lay and Repair Vessels have to load and lay fragile fiber-optic cables. Therefore, DP
systems in these vessels enables them to have more control when handling cables.
DP also enables these vessels to maintain position and heading when they come to the end of the
nnection. During this operation,
e water is often shallow with strong current.
Pipelay nsion in the pipeline during laying operation in
ord o
lay, usually close to the coast, to complete the shore-end tie-in co
th
PIPELAY VESSELS
vessels have to maintain a constant te
er t prevent damage to the pipeline.
Pipeline tension data is automatically transmitted to the DP system.
vessel to The system then provide the necessary thrusters commands to enable the
maintain tension.
NG AND DREDGING VESSELS
over untrenched pipelines. DP systems
over the pipeline to be covered. Hence,
nly and economically.
problems in some areas of the ocean.
e vessels are used to ensure accuracy in
dred n handy for several dredging operations.
SH
A F t O) is generally a a turret moored tanker
whi w ther. FPSOs often use shutter tankers to
transpo ion, the shutter tanker has to maintain a
relative Hence, the shutter uses DP for relative
position
In addition, these vessels have to lay the pipeline along an exact track. Hence, DP
enables these vessels to follow the required track.
ROCKDUMPI
Vessels engaged in rock dumping are generally used to c
in these vessels provide accurate track and speed control
the auto-track mode allows vessels to spread rocks eve
Rockdumping vessels are also used to remedy erosion
Vessels engaged in dredging operations range from clearing channels and harbors to recovering
road o st nes and building aggregates. DP systems in thes
gi g a defined area. The auto-track mode comes in
UTTLE TANKER AND FPSO VESSELS
loaing Production, Storage, and Offtake units (FPS
ch eathervanes to maintain heading into the wea
rt the oil. As the FPSO wanders about her posit
position to prevent breaking the loading hose.
ing off the FPSO.
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OPERATIONS USING DYNAMIC POSITIONING
ACCOMMODATION AND FLOTEL UNITS
Accommodation and Flotel Units are generally barges used to support oilfield operations. These
barges have to maintain position off other vessels or structures. Hence, DP is used when water
depth, seabed activities, or other hazards render anchoring impossible.
CRANE BARGES AND CONSTRUCTION VESSELS
Crane Barges and Construction vessels are used in construction and de-commissioning
operations in the oilfield. These vessel are also used in wreck recovery or salvage work. Since
these vessels have to operate relatively close to object (s) being lifted, they have to maintain
position and heading to prevent collision. DP systems in these vessels are often more feasible
than anchoring.
SUPPLY AND STANDBY VESSELS
Supply and standby vessels usually come in close
proximity to oil rigs, platforms, barges, or other
vessels for replenishment operations.
DP systems on these vessel enable them to stay on
location a safe distance from obstructions. Hence,
hazards associated with collisions are greatly
reduced.
CRUISE AND PASSENGER VESSELS
Cruise and Passengers vessels are being built very large. However, the controlling depth of most
channels remains the same. Consequently, these vessels are being designed with relatively
shallow drafts for easy port access and large freeboards to accommodate more passengers. This
raft/freeboard combination causes a challenge for maneuvering in restricted waters. Dynamic
Positioning is used in these vessels to increase maneuverability.
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OPERATIONS USING DYNAMIC POSITIONING
OTHER VESSEL TYPES
Heavy-Lift Vessels - Vessels engaged in lifting heavy equipment, an oil platform for
example, may wander off position when trying to lift or discharge cargo. DP systems
enables these vessels to maintain position and heading when loading or discharging.
Military Operations - Some military vessels have DP systems installed to facilitate
critical operations, for example, underway replenishment, mine countermeasures, etc.
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OPERATIONS USING DYNAMIC POSITIONING
DP OPERATIONS IN SHALLOW WATER
Dynamic Positioning in shallow water is degraded due to the following factors:
Strong currents in the vicinity of operation will cause the thrusters to work harder.
Thereby, more power is consumed and the possibility of failure is increased. In addition,
more noise is generated in the water.
The reduced distance between HPRs transducers and transponders results in thrusters
activities interfering with acoustic signals. Dynamic Positioning in shallow water is
degraded due to these factors.
Tautwire system may become unreliable because of the shallow depth.
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OPERATIONS USING DYNAMIC POSITIONING
DP OPERATIONS IN VERY DEEP WATER
Dynam
tides.
In a it
ic Positioning in very deep water is complicated by the occasional presence of strong
dd ion, position references may become unreliable for the following reasons:
m
designed for depth down to 2000m, becomes inaccurate due to the angular resolution in
very deep water. And, the wire tends to bend in strong tides.
Taut wire system looses accuracy beyond depth of 300m. Even the taut wire syste
Hydroacoustic Position References (HPR) loose reliability in very deep water because
acoustic energy spreads with increased distance.
The Long Baseline systems (LBL) gives better accuracy in very deep water. However,
the refresh rate is relatively slow because sound travels in sea water at a rate of 1500
m/s.