Analysis of loads encountered during a single lift operation of offshore wind turbines

The success of offshore wind farm installations is often related to the costs and time taken to be completed. Current installation strategies require several critical offshore lifts for the completion of a single wind turbine, as in most cases each component gets installed separately. This is time-consuming and has a direct link to the cost of...

A hydrodynamic study on floating export cable systems: Using finite element method modelling to study the hydrodynamic behaviour and optimise the design of floating export cable systems

During ‘float-out’ installation of export cables, the cable is pulled to shore while floating, supported by inflatable floaters. Understanding the hydrodynamic behaviour of these cable-floater-systems (CFS’s) is important, to be able to relate the hydraulic environment to the cable stresses and determine the maximum allowed hydraulic conditions...

Preliminary Design Methodology Of Concrete Gravity-Based Foundations For Offshore Wind

To expand the economic operating range of offshore wind farms, less common but innovative solutions regarding support structures should be considered. To increase the popularity of gravity-based foundations (GBF) within the offshore wind industry, a better understanding of the hydrodynamics on GBFs, as well as an improved insight in the optimal...

Fatigue Safety Factors for Dynamic Power Cables: A reliability based approach

In contrast to traditional power cables for bottom-founded offshore wind turbines, power cables for floating wind turbines penetrate the water column and are exposed to cyclic loading. Due to the dynamic nature of the cable loading, the cables are prone to fatigue failure. Since the evaluation of the fatigue life of complex structures, like...

Fast aeroservoelastic models for load simulation: Linear wind turbine response model based on the BHawC code

The design of wind turbines is an iterative process in which load calculations and system performance analyses are done under various environmental conditions. Due to the complexity of wind turbine systems, fully coupled aero-hydro-servo-elastic codes are indispensable to represent the nonlinear behaviour of the system. However, nonlinear codes...

A dynamic design and analysis of the flexible hose of the deepsea mining system

Climate change is a recurring topic in the news and goes side by side with the energy transition. The energy transition focuses on using clean energy generated by resources like wind and water. Due to the increasing demand for technology that focuses on generating and storing clean energy, the demand for metals grows. These metals are currently...

Structural response impact on floating offshore wind turbine performance under operating conditions

A rapid increase in global energy demand and the international objective of increasing the contribution of renewable energy to satisfy this demand have spiked the interest in offshore wind energy. Depletion of suitable locations for bottom founded turbines has led to a new chapter in offshore wind development: floating wind farms. This...

Creating a local residual curvature during S-lay pipeline installation by lowering the stinger

Marine pipelines are often operated at high internal pressure and temperature. This loading condition results in the development of axial compressive forces that can cause the pipeline to buckle globally. Global buckling occurs when significant lateral motion is present in the pipeline and excessive feed-in occurs at that specific location,...

Validation of aero-hydro-servo-elastic load and motion simulations in BHawC/OrcaFlex for the Hywind Scotland floating offshore wind farm

Climate change, as a result from global warming, requires an energy transition: the reduction of greenhouse gas emissions from fossil fuels and a radical innovation of the global energy system to proceed apace. Offshore wind is an important source of clean, renewable energy, and it plays a key role in the transition. 80% of the worldwide...

Swaying piles during installation with seabed templates: Modelling dynamic behavior and a solution

Pre-piling templates are often used in the offshore industry to ensure the vertical installation of foundation piles for jacket structures. Boskalis is currently preparing a project that uses these templates in the Taiwan Strait, which is a region known for its relatively soft soils and seismic activity. Consequently, the piles are very long in...

Fatigue analysis for offshore power cable installation

Over the last decade, the demand for offshore power cables has increased significantly due to, in particularly, the emergence of offshore wind. Despite this growth, industry-wide rules and guidelines to analyse fatigue during cable installation operations are yet to be developed, even though fatigue can become an important...

Significance of Active Tension Compensation during S-lay Pipeline Installation

During S-lay pipeline installation, tension fluctuations in the suspended pipeline are compensated by the tensioner system on the vessel. The goal of this thesis is to answer the questions: to what extent does the active tension compensation (ATC) influence the pipeline integrity during offshore installation. Secondly, which tensioner model...

Dynamic Analysis of a subsea cable during cable installation: Improving operability of the cable installation for shallow and deep water

The investigation into the dynamic behavior of a cable during installation was done with the aim of improving cable installation for safety, operational and commercial value. In order to increase the operational limit of the vessel during cable installation, the investigation into improvement systems was desired. The workability of a vessel...

Vessel motion based criteria for pipeline Abandonment and Recovery operations

Offshore pipeline installation is limited by pipeline integrity during the laying process. Pipeline integrity is evaluated with the help of buckling checks, which help determining the feasibility of pipeline installation for a given sea condition. The operational limit of pipeline installation is determined during project preparation, by...

Modelling of the dynamic behaviour of a fall pipe system

This thesis describes the creation and validation a three dimensional numerical model in Orcaflex of a fall pipe system. It was used to investigate the system’s dynamic behavior under a range of normal and more extreme operating conditions.