Stable Offshore Floating Depot with Tapered Hull
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Solution Overview
Problem
Existing offshore buoyant structures face challenges in achieving inherent stability without complex retractable columns, exceptional heave damping without vertical tendons, and quayside integration for offshore terminals that can transit through shallow waters while maintaining stability and reducing wave-induced accelerations.
Innovation Solution
A buoyant offshore terminal design featuring a hull symmetric about a vertical axis with a center of gravity below the center of buoyancy, incorporating upper and lower tapered side walls for radiation damping, optional fin-shaped appendages for added mass, and a tunnel for sheltered boat operations, allowing for quayside assembly and upright towing to the installation site.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If a floating structure uses a large waterplane area to achieve self-stability, then stability is improved, but heave seakeeping characteristics deteriorate
Solution Approach 1:
The structure divides the waterplane area into multiple segmented floating columns rather than using a single large continuous waterplane area. Each column provides localized buoyancy and stability, while the segmented configuration reduces the overall heave response to waves compared to a single large waterplane area.
2Stability of the object's composition
If the center of gravity is positioned below the center of buoyancy to achieve inherent stability, then stability is improved, but the structure requires complex ballast arrangements
Solution Approach 1:
The structure merges the stabilizing function into the hull form itself through the multi-column configuration and center of gravity positioning, eliminating the need for separate complex ballast arrangements. The inherent stability is achieved through the geometric configuration and mass distribution of the columns rather than added ballast systems.
3Object-affected harmful factors
If vertical tendons are used to restrain heave, then heave damping is improved, but device complexity and cost increase
Solution Approach 1:
The floating structure serves its own heave damping needs through its inherent multi-column geometry and radiation damping characteristics. The columns naturally provide heave restraint through their interaction with water during motion, eliminating the need for external vertical tendon systems while achieving comparable or superior heave damping performance.
4Object-affected harmful factors
If the hull size is increased to reduce wave-induced accelerations, then seakeeping characteristics are improved, but the structure cannot transit through shallow waters
Solution Approach 1:
The structure segments the hull into multiple slender columns rather than using a single large-hulled platform. This segmentation allows each column to have a small individual draft suitable for shallow water transit, while the collective arrangement of multiple columns provides the mass and geometry needed to reduce wave-induced accelerations through radiation damping.
5Stability of the object's composition
If retractable columns are used to achieve stability, then stability is improved, but device complexity increases
Solution Approach 1:
Instead of using retractable columns that move between extended and retracted positions to achieve stability, the invention uses fixed columns arranged in a specific geometry that provides inherent stability in all conditions. The stability is achieved through the invariant geometric configuration rather than through active retraction or extension mechanisms.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The design provides inherent stability, exceptional heave damping, and the ability to transit through shallow waters, reducing wave-induced accelerations and enabling safe and efficient operations for offshore platforms.
Implementation Method 1
The seakeeping characteristics of a buoyant structure are influenced by a number of factors, including the waterplane area, the hull profile, and the natural period of motion of the floating structure
Implementation Method 2
A floating structure has several design requirements: Adequate reserve buoyancy to safely support the weight of the superstructure and payload, stability under all conditions
Implementation Method 3
Adequate reserve buoyancy to safely support the weight of the superstructure and payload
Implementation Method 4
The total mass includes added mass i.e., the mass of the water around the hull of the floating structure that is forced to move as the floating structure moves. As the total mass (including added mass) of the structure increases, the natural periods of motion of the structure become longer
Data Source
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AI summary
An offshore depot having a vertically symmetric hull, an upper inwardly-tapered wall and a lower outwardly-tapered wall that produce significant heave damping in response to heavy wave action. Ballast is added to the lower and outermost portions of the hull to lower the center of gravity below the center of buoyancy. The offshore depot includes a tunnel formed within or through the hull at the waterline that provides a sheltered area inside the hull for safe and easy launching/docking of boats and embarkation/debarkation of personnel. When the watertight tunnel doors are all shut, the tunnel may be drained to create a dry dock environment within the hull. The offshore depot includes berthing and dinning accommodations, medical facilities, workshops, machine shops, a heliport, and the like.