MSc in Oil & Gas and Offshore Engineering

Course Information Package

Course Unit TitleANALYSIS AND DESIGN OF OFFSHORE MOORING SYSTEMS
Course Unit CodeMOE509
Course Unit DetailsMSc Oil & Gas and Offshore Engineering (Required Courses) -
Number of ECTS credits allocated7
Learning Outcomes of the course unitBy the end of the course, the students should be able to:
  1. Carry out static analysis and design of single- and multi-leg mooring systems.
  2. Evaluate the mean wind and current forces on ships and floating structures.
  3. Identify and evaluate in an engineering approach several damping components on the floating structure.
  4. Participate and function qualitatively and quantitatively at a superior knowledge level in a mooring design team.
Mode of DeliveryFace-to-face
PrerequisitesNONECo-requisitesNONE
Recommended optional program componentsNONE
Course Contents

Module A – Review of mooring systems and anchor linecomponents

·       Spread, multi-leg systems.

·       Single – point moorings concepts.

·       Mooring lines (composition of mooring lines,dimensions, etc.).

·       Buoys.

·       Anchors.

 

Module B - Static analysis and design of single- and multi-leg mooring systems

·        Static analysis of a single mooring line.Equations for elastic and in-elastic catenaries. Methods of solution.

·         Compositelines made up from segments of different materials. Use of buoys. 

·       Static analysis of a multi – leg mooringsystem.

·       Design of a single mooring line according torules.

·       Design of multi-leg mooring systems.Engineering approaches.

·        Restoring forces of several types of mooringsystems (single- and multi-leg configurations, TLP type mooring). Exact andapproximate solutions.

·        Introduction to mooring line dynamics.

 

Module C – Wind and Current fields and forces

·      Wind velocityprofiles, gustiness, wind spectra.

·      Current velocityprofiles.

·      Mean wind and currentforces on ships and floating structures.

 

Module D - Higher-order body-wave interaction

·      Mean-, slowly- andfast-varying second-order exciting wave forces.

·      Exact and approximatesolutions.

 

Module E - Damping sources and methods for their evaluation

·      Mooring line damping.

·      Second - order wavedrift damping.

·      Friction and dragdamping on the structure. Engineering approaches.

 

Module F - Solution of motion equations of moored floatingstructures

·      Solutions in thefrequency – domain.

·      Solutions in the time– domain.

 

Module G - Synthesis and Case Applications

·      Case study – Project:Computer software supported analysis of a multi-leg mooring system.

Recommended and/or required reading:
Textbooks
  • D.T. Brown, G.J. Lyons: “Catenary Moorings design Design Manual”, Bentham Press, Offshore Technology Series, 1994
  • Anchoring of Floating Structures, Design Guides for Offshore Structures, co-ordinated by CLAROM, AREGEMA, Editions Technip, 1990.
  • Handbook of Offshore Engineering, Ed. By Subrata K. Chakrabarti, Elsevier, Amsterdam, 2004, Elsevier Ocean Engineering Book Series, ISBN-9780080443812 (set).
  • O.M. Faltinsen: “Sea Loads on Ships and Offshore Structures”, Cambridge University Press, Cambridge Ocean Technology Series, Cambridge, New York, 1990
References
  • Floating Structures, a Guide for Design and Analysis,
  • Vryhof Anchor & Rope Manuals.
  • Mavrakos, S.A.: “Deep Water Moorings: Arrangement, Configuration, Behaviour and Evaluation”, WEGEMT Association Twenty Fourth School on Surface Support of Subsea Activities, Glasgow, March 1998.
  • Mavrakos, S.A., Papazoglou, V.J., Triantafyllou, M.S., Chatjigeorgiou, J., “Deep Water Mooring Dynamics”, Marine Structures, 9, 1996, 181-209.
  • Brown, D.T., Mavrakos, S.A., “Comparative Study on Mooring Line Dynamic Loading”, Marine Structures, 12 (3), 1999, 131-151.
  • Mavrakos, S.A.: “XMOOR users’ manual”, Laboratory for Floating Structures and Mooring Systems, National Technical University of Athens, 1995.
Planned learning activities and teaching methods

The taught part of course is delivered to the studentsby means of lectures, conducted with the help of computer presentations.Lecture notes and presentations will be available through the web for studentsto use in combination with the textbooks.

Lectures will besupplemented with a case – study project that will be carried out using thecomputer software XMOOR, suitable to analyse multi-leg mooring systems.Moreover, lectures will be supplemented with homework assignments to developcomputational skills on the various modules of the course. 
Assessment methods and criteria
Assignments15%
Project25%
Final Exam60%
Language of instructionEnglish
Work placement(s)NO