TMR4225 Marine Operations, 2004'01'16

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TMR4225 Marine Operations, 2004.01.16

• What are you expecting to learn from todays
  lecture?
• Responses are collected in a separate word
  document

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TMR4225 Marine Operations, 2004.01.16

• My objectives for this lecture
• Establish a commen knowledge on operational
  parameters for different types of underwater
  vehicles
• Obtain a commen understanding of critical phases
  in a mission for an underwater vehicle
• Documented basic understanding of dominant flow
  regimes during different phases of a mission for
  underwater vehicles

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TMR4225 Marine Operations, 2004.01.16

• Examples of
• Submarines
• AUVs
• ROVs
• Work tasks for AUVs and ROVs

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Lecture notes Submarines, AUV UUV and ROV

• Present version contains Submarines and AUVs
• Ch. 4 on ROVs will be available 2004.03.05
• Notes includes web links, some may be rotten,
  some may be static and a few good ones are
  dynamic
• If you know of other web sites that have relevant
  content on subsea vehicles, send me an e-mail
• One vehicle will be used as a reference case for
  AUVs and ROVs repectively

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Lecture form

• Presentations
• Buzz groups
• Short questions
• 2-3 minutes discussions
• Oral presentation of buzz group results (keyword
  form)
• Work groups
• Work task related questions
• 5 minutes discussions
• Written presentation of work group results
  (keyword form/basic drawing)

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Nomenclature

• SNAME H-10 Panel
• ITTC standard notation for manoeuvring
• Forces and moments X,Y,Z K, M, N
• Yv force coefficient for sway speed
• Yvv is sway force due to sway speed, a linear
  damping force due to angle of attack of the
  vehicle
• A more compact notation can be obtained by usinga
  vector/matrix formulation of the equations of
  motion

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Axis systems

• Earth fixed system
• Vehicle fixed system
• Right handed system
• X-axis forward
• Z-axis downwards
• Positive deflection of control flaps/rudders are
  clockwise

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Buzz groups Question 1

• In what layers of the ocean space are each of the
  vehicle types used?
• Manned submarine
• AUV
• ROV

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Buzz groups Q1 answer

• Manned submarines
• 300 m waterdepth ( large military ones)
• - 11000 m extreme Trieste, sea space exploration
• 3000 m exploration of sea bed/

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Buzz groups Q1 answer

• AUVs
• 500 meters
• Military use, mine finding 150-200 m
• Offshore, mapping 3000 4000 m

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Buzz groups Q1 answer

• ROVs
• Use close to structures
• Not used in the wave zone
• Depth limited by umbilical, down to 1000m?
• Near the bottom, 1000 5000m

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Flow characteristics for standard operations

• Submarine in transit
• Streamlined body
• Mostly turbulent flow
• Constant transit speed
• Small perturbations, i.e. Sway/yaw/heave/pitch/rol
  l speeds and angles of control planes

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Flow characteristics for standard operations

• AUV
• Streamlined body
• Mostly laminar flow
• Constant transit speed
• Small perturbations, i.e. Sway/yaw/heave/pitch/rol
  l speeds and angles of control planes
• Or
• Zero/very low speed
• Large angles of attack from current
• Large angles of attack on control planes or heavy
  loads on thrusters

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Flow characteristics for standard operations

• ROV
• Non-streamlined body
• Mostly turbulent flow due to separation on edges
• Low speed
• Large angles of attack
• Complex flow due to interacting thrusters
• Umbilical drag and induced motion on the ROV

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Types of submarines

• Military submarines
• Norway Ula class (dimensions?)
• Cargo carrying submarines
• Bulk carriers
• Intervention vehicles for subsea oil and gas
  production
• Tourist submarines
• Tropical waters
• Norwegian coastline

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Buzz groups Question 2

• Discuss why no submarine bulk carriers have been
  realized?
• Groups 1, 3, 5,
• Discuss why non of the concepts for subsea oil
  and gas production submarines have been realized?
• Groups 2, 4, 6, .

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Buzz group Q2 answer

• Bulk carriers
• Great risks, consequences if something happens
  (rescue)
• Environmental problems, especially if nuclear
  powered
• More power then for surface vessels due to larger
  wet surface (for large slow speed bulk carriers
  80-90 of resistance is viscous)
• Load carrying capacity restricted due to
  increased steel weight
• Too expensive to build and operate (high quality
  steel, redesign of shipyards, scraping costs, .)
• Separate terminals, high investment costs
• Complex loading/unloading systems
• Maintenance process must be modified
• No need for this solution for ice free waters

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Buzz group Q2 answer

• Submarines for oil and gas subsea structure
  installation and maintenance
• No advantages compared to ROVs
• Not useful as diver platform for large depths
• High costs, both for vessel design/production and
  initial structure design to fit capacities of
  submarine
• No oil company is willing to be first user of a
  system based on submarine intervention

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Submarine summary

• Submarines are hydrodynamically well designed
• Commercial use of submarines is at present no
  alternative for subsea oil and gas production
• Development of military submarines will continue,
  but not at the same level as before
• Submarines for tourism will expand
• Manned vehicles will be used for exploration of
  deeper parts of the ocean space

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AUV overview

• AUV definition
• A total autonomous vehicle which carries its own
  power and does not receive control signals from
  an operator during a mission
• UUV definition
• A untethered power autonomous underwater vehicle
  which receives control signals from an operator
• HUGIN is an example of an UUV with an
  hydroacoustic link

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AUV/UUV operational goals

• Military missions
• Reconnecaince
• Mine hunting
• Mine destruction
• Offshore oil and gas related missions
• Sea bed inspection
• Pipe line inspection
• Sea space and sea bed exploration and mapping
• Mineral deposits on sea floor
• Observation and sampling

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Offshore oil and gas UUV scenario

• Ormen Lange sea bed mapping for best piperoute
  trace
• Norsk Hydro selected to use the Hugin vehicle
• Waterdepth up to 800 meters
• Rough sea floor, peaks are 30 40 meter high
• Height control of Hugin to ensure quality of
  acoustic data

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Group work spring 2003 SIN TMR4240Marine Control
Systems

• Future scenario for operation of a subsea oil
  and gas production system
• No surface operation
• Subsea Operational Centre
• Central landbased Operation Centre
• Short presentation of some of the group
  deliverables
• WG1 Path control and docking of AUV
• WG3 Intervention between subsea installation and
  AUV/ROV
• WG6 Multiple AUV operations for pipeline tracking

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Phases of an AUV/UUV mission

• Pre launch
• Launching
• Penetration of wave surface (splash zone)
• Transit to work space
• Entering work space, homing in on work task
• Completing work task
• Leaving work space
• Transit to surface/Moving to next work space
• Penetration of surface
• Hook-up, lifting, securing on deck

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Group work no. 1

• Describe physical factors to be aware of in the
  different phases of an AUV/UUV mission

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Group work no. 1 Student feedback

• Pre launch
• No group looked at this activity

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Group work no. 1 Student feedback

• Launching
• Launching arrangement A-Frame, crane etc
• Readiness for operation, eg. various equipment on
  board
• All openings on the hull surface must be closed
  (watertightness)

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Group work no. 1 Student feedback

• Penetration of splash zone
• Impact loads
• Hydro-elasticity
• Relative motion phase, amplitude, frequency
• Change of parametres from air to water (buoyancy,
  eigenfrequency, etc.)
• Wire tensions

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Group work no. 1 Student feedback

• Transit to work space
• Navigation/control system (current/flow/(diving)),
  DP
• Buoyancy during transit ( different layers of
  salinity in the sea)
• Resistance/propulsion/endurance/power supply
• Material/hullform ( the vehicle has to withstand
  high external pressure)

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Group work no. 1 Student feedback

• Entering work space, homing in on work task
• No group looked at this activity

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Group work no. 1 Student feedback

• Completing work task
• Battery capacity
• Check if mission is completed
• Check the current conditions
• Safe manoeuvring to avoid collisions, damage of
  propellers
• Interaction between thrusters

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Group work no. 1 Student feedback

• Leaving work space
• No group looked at this activity

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Group work no. 1 Student feedback

• Transit to surface/Moving to next work place
• Changing buoyancy (pressure/gravity)
• Resistance forces (transit between workfields)
• Current forces
• Wave influence near surface

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Group work no. 1 Student feedback

• Penetration of surface
• Movements induced by
• Waves
• Current (viscous forces)
• Buoyancy/gravity
• Reaching the surface -gt change of
• Wetted surface (viscous)
• Buoyancy (volume)
• According to the sea state, we can have very
  unstable system

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Group work no. 1 Student feedback

• Hook-up, lifting, securing on deck
• Sea state ship motion, AUV motion
• Effect of wind in the crane
• Centre of gravity of AUV
• Lifting
• Splash zone, wind, safety distance
• Securing on deck
• Safe lie bed

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Web sites

• http//www.ausi.org/research/research.html
• http//www.freesub.soton.ac.uk

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Section of FREESUB AUV database
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RD program on Underwater navigation

• Develop navigation systems to be used for
  missions with long period of submerged vehicle
• Error robust systems, optimal use of working
  sensors
• Develop mathematical models and algoritms for new
  sensors with extreme precision
• In water testing of new sensors and mathematical
  models
• Project is based on experience and solutions used
  for the HUGIN family of vechicles

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ROV overview

• ROV Remotely Operated Vehicle with umbilical
  connection to a mother vessel. Umbilical are used
  for power transfer to ROV and for communication
  between ROV and pilot

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ROV types/classes

• Observation ROVs
• Work ROVs
• Advanced intervention tasks
• High work construction capacity
• Optimisation of power efficiency
• Tether management system

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ROV operational phases

• Pre launch
• Launching
• Penetration of wave surface (splash zone)
• Transit to work space
• Entering work space, homing in on work task
• Completing work task
• Leaving work space
• Transit to surface/Moving to next work space
• Penetration of surface
• Hook-up, lifting, securing on deck

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ROV operational goals

• Visual observation
• Inspection of underwater structures
• Observation of ongoing work tasks on subsea
  structures
• Different types of mechanical inspection
• Non destructive testing
• Mechanical work

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Example of ROV operation

• See Oceaneering presentation

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Challanges for future ROV operations

• Better vizualisation
• Better planning
• Better reporting systems
• More training
• Simulation to verify access to work sites
• Central control of operations

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Necessary improvements for advanced ROV
operations

• 3D navigational tools
• 3D based planning tool
• Digital, visual online reporting
• Realistic simulator training
• Access verification using simulator during the
  engineering planning of the operation
• Central placed special control room

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Phases of ROV operation

• Pre launch
• Launching
• Penetration of wave surface (splash zone)
• Transit to work space
• Entering work space, homing in on work task
• Completing work task
• Leaving work space
• Transit to surface/Moving to next work space
• Penetration of surface
• Hook-up, lifting, securing on deck

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Oceaneering Ongoing work

• MIMIC
• Modular Integrated Man-machine Interaction and
  Control
• VSIS
• Virtual Subsea Intervention Solution
• (Switch to Oceaneering presentation, slides 16 -gt)

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Buzz groups question 3

• What are the critical activities for each of the
  phases in an ROV operation?
• One phase per buzz group

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Buzz group Q3 answer
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TMR4225 Marine Operations, 2004.01.16

• Sum up the 3 most important learning outcomes of
  todays lecture
• Have your expectations been fulfilled?
• If not, why not?
• Feedback is written up in a separate Word document