1. TMR4225 Marine Operations,
JAMSTEC website:

2. Some JAMSTEC vehicles

3. TMR4225 Marine Operations, 2007.02.01 Lecture content: ROV types
Rov operations
Hydrodynamics of ROVs
Simulation as a tool for operational validation
ROV pilot training

4. ROV overview
ROV:
Remotely Operated Vehicle with umbilical connection to mother vessel
Umbilical is used for power transfer to the vehicle and for communication between it and its pilot
Important working tool for subsea installations and maintenance
Increasing depth rating – systems designed for operation down to 2500 – 3000 m
Umbilical handling is critical for most ROV operations

5. ROV types/classes A common classification is:
Low cost observation ROV (electric)
Small observation ROV (electric)
Large observation/light work ROV (electric)
Ultra-deep observation/sampling ROV (electric)
Medium light/medium work ROV (electro/hydraulic)
Large heavy work/large payload ROV (electro/hydraulic)
Ultra-deep heavy work/large payload ROV (electro/hydraulic)

6. Hydro Products RCV 225 on sea trials for Taylor Diving, 1976

7. This 1980 photo of a Diver handing a wrench to an RCV 150 while an RCV 225 observes is a perfect illustration of the "passing of the baton" from man to machine

8. Deep Ocean Engineering Phantom 300 Under-ice Dive

9. Canyon's Quest ROV being recovered off Hawaii in 2003

10. Oceaneering Magnum, used most often in drilling support

11. Subsea 7 – Hercules rated for 2000 m waterdepth

12. Perry Trenching system

13. Work Class ROV systems operating worldwide
Oceaneering International, Inc.
152
Subsea 7 (Halliburton/Subsea) 78
Stolt (Stolt/Comex/Seaway) 35
Sonsub (Saipem) 59
Fugro (ex Racal/Thales) 36
Canyon (Cal Dive) 23
Technip-Coflexip 22
Others- Approximate number of specialty systems, plus systems operated by smaller companies. (Source: Drew Michel interviewing contractors March 2004) 30
Total Systems
435
From MTS ROV site, 2004 estimates

14. Examples of ROVs Check organisational web sites
Check suppliers and operators websites:

15. NTNU ROV Minerva NTNU has bought an ROV for biological research
2 Dr. ing studies have been allocated to develop tools and procedures for scientific use of the ROV
For more info see the web site:

16. Minerva ROV

18. ROV deployment

19. ROV operational goals Visual inspection
Inspection of underwater structures
Observation of ongoing work tasks on subsea structures
Biological observation
Different types of mechanical inspection
Non destructive testing
Mechanical work
Biological sampling, water column and bottom

20. Flow characteristics for standard operations
ROV
Non-streamlined body
Mostly turbulent flow due to separation on edges
Low speed
Large angles of attack; have to be able to operate in cross current
Different characteristics for up and down motion
Complex flow due to interacting thrusters
Umbilical drag can be high for operations at large depths
Tether management system can be used to remove umbilical
induced motion of ROV

21. ROV umbilicals
Vessel motion and indusced motion at the upper end of the umbilical
Umbilical geometry resulting from depth varying current
Use of buoyancy and weight elements to obtain a S-form to reduce umbilical forces on the ROV
Induced transverse vibrations of umbilical
Forces and motions at lower end of umbilical

22. Equation of motion for ROVs
6 degree of freedom (6DOF) model
No defined steady state motion as a baseline for development of motion equations
ROVs are usually asymmetrical up-down and fore-aft
As far as possible the ROVs are designed for port-starboard symmetry
See section 4.6 of lecture note for ROV motion equation

23. Hydrodynamic added mass/moment of inertia
6 x 6 matrix
Non-diagonal terms exists
Terms may have different values for positive and negative accelerations, especially for heave and pitch motion
Ideal fluid sink-source methods can be used
Motion decay tests can be used to find some terms
Generalized Planar Motion Mechanism tests can be used to find all terms
Simplified 2D crossections can be used to estimate some of the terms

24. Velocity dependent forces (drag and lift)
Non linear terms are important
Streamlining of bouyancy elements influence both drag and lift forces and moments
Motion decay tests can be used to find some drag terms
Generalized Planar Motion Mechanism tests can be used to find all terms

25. Minerva ROV

26. MINERVA tests Drag tests, varying speed
Drag test, varying angle of attack
Full scale tests
Use of vehicle to generate input to parametric identification of mathematical model characteristics
Exercise no. 4 includes comparison of own calculations with model test results for MINERVA

27. Minerva 1:5 scale model test

28. Minerva 1:5 scale model test

29. Other forces Gravity and buoyancy forces and moments
Thruster forces and moments
Control forces from any additional control units
Umbilical forces
Environmental forces
Interaction forces from bottom and/or sea bed structures

30. Summary ROV
Observation platform to support topside operators performing complex subsea work tasks
Workhorse for installation and maintenance tasks
Tether management system is a must for ”workhorse” ROVs