Construction mode detection for autonomous offshore heavy lift operations

Offshore platforms and windmills are constructed by assembling huge mechanical structures transported by heavy lift vessels. The construction process comprises two interconnected operations, the dynamic positioning (DP) of the vessel and the lifting of heavy loads. The DP system is commonly designed and tuned for the case that there is no...

QUAD Lift Workability Analysis: Evaluating the Dynamic Interaction Between Two Dual crane Vessels using a Frequency Domain Modelling Technique

A QUAD lift is a new lifting method in which dual crane vessels combine their vessel capability to increase their offshore lift performance. The use of the Jumbo J-Class vessels in a QUAD lift creates the opportunity to increase the offshore lift capacity and to install structures with larger dimensions. When floating vessels are close to each...

Backstepping Control of Heavy Lift Operations with Crane Vessels

Offshore structures with large mass are installed and removed by heavy lift vessels. During offshore constructions, two safety-critical interconnected operations take place, the dynamic positioning of the vessel and the lifting of the heavy structure by an immovable boom crane on the vessel. Existing studies on offshore boom crane control...

Design of a Feeder System for Offshore Wind Turbine Installation with an SSCV

With increasing demand for renewable energy, the offshore wind industry is ever growing. Wind turbine generators (WTGs) proceed to grow in numbers and in size, wind farms are located further offshore, in deeper waters, poorer soil conditions or in areas prone to earthquakes. These changes make it increasingly difficult to find capable and...

Developing a method to assess the workability of an offshore heavy lifting operation

This master thesis describes a method to determine the workability of an offshore heavy lift operation. By creating wave realisations based on and statistically equivalent to measured ocean weather data, a quick assessment of the risk of failure can be achieved.

A conceptual solution to instable dynamic positioning during offshore heavy lift operations using computer simulation techniques

This Msc graduation study covers the installation of topsides on a jacket by an offshore heavy lift crane vessel, and its related problems. One of the problems take place after the topside is hoisted on the jacket, during the weight shift from the hoist cable onto the jacket. The topside then exerts large horizontal forces upon the crane and...