Challenges with Mooring System Design for Floating Offshore Installations

Krish Thiagarajan Sharman
Prof. & Endowed Chair in Renewable Energy

Dept. of Mechanical & Industrial Engineering
UMass Amherst

Friday, Jan. 31, 2020, 3:10pm
Chase 105

Moorings are one of the more vulnerable components of an offshore energy production system. Many mooring failures go unreported, and those that have a consequence and need to be reported give an impression of high levels of unknown risk. For example, an annual probability of failure of 0.3% was estimated for mooring systems for floating production systems in the Gulf of Mexico based on reported failures between 2001 – 2011. Given the translation of recommended practices from the oil and gas industry to the offshore renewable industry, some risks and challenges posed by mooring systems need to be understood in this context.

Choice of mooring system design for offshore floating platforms can profoundly affect the stationkeeping and global performance and of these systems. I will present one  research problem in each of these aspects. I will first discuss an interesting weathervaning instability of turret-moored floating platforms. The case studied is a ship-shaped tanker that is moored alternately in regular head waves, and in bi-directional seas. In the second part of the discussion, I will look at shock loads on mooring systems for an offshore wind turbine platform. Experimental data and long term probability models will be used to understand the behavior of a mooring system and design safety factors. The talk will conclude with our ongoing research on synthetic mooring lines.


Krish Thiagarajan Sharman, an expert on marine renewable energy and energy producing offshore structures, has been appointed to the Endowed Chair in Renewable Energy in the Mechanical and Industrial Engineering Department at the UMass Amherst College of Engineering. He is a Fellow of the Society of Naval Architects and Marine Engineers and leads the Ocean and Marine Engineering Group at UMass Amherst. In that context, he studies: marine renewable energy, including wind, wave, tidal, and thermal energy conversion; hydrodynamics and fluid-structure interaction; marine and offshore platform design; aquaculture engineering; and experimental and computational fluid dynamics.