Offshore Upending Device Asymmetric Pivot Axis
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Solution Overview
Problem
Existing offshore structures with upending devices for elongate support structures, such as wind turbine foundations, face instability issues due to the need for a vessel-sized frame that covers the deck and influences vessel stability, requiring a pivot axis in the middle, which complicates the upending process and necessitates a tie-back system.
Innovation Solution
A compact offshore structure with a pair of upending devices, each with a pivot axis near the side, allowing for stable upending by displacing the connector member towards a lower position, eliminating the need for a tie-back system and enabling the use of smaller hoisting means, with a carrier arm and lever arm configuration that supports the elongate structure during pivoting.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a vessel-sized frame is used to cover the deck for upending, then the upending structure can support the elongate offshore structure, but the stability of the vessel is substantially influenced and the device becomes large
Solution Approach 1:
The upending device is divided into separate modular components: a frame assembly with pivot axis, carrier arms for supporting the elongate structure, and a pulling device. This segmentation allows the frame to be compact rather than vessel-sized, while still providing the necessary support capacity through the coordinated action of multiple smaller elements.
Solution Approach 2:
A pulling device acts as an intermediary element that transfers force from the frame to the elongate offshore structure. This intermediary mechanism enables the frame to support and upend the structure without requiring the frame to directly bear the full weight, thereby maintaining vessel stability while achieving the required support capacity.
2Ease of operation
If the pivot axis is arranged in the middle of the vessel, then the frame can pivot the elongate structure, but the vessel stability is compromised and the device complexity increases
Solution Approach 1:
The pivot axis is positioned asymmetrically at the edge of the vessel rather than in the middle, creating an unbalanced configuration that enables effective upending motion. This asymmetric placement allows the carrier arms to leverage the vessel's edge as a fulcrum, achieving the required upending capability while keeping the frame compact and maintaining vessel stability.
3Reliability
If a tie-back system is used to control the upending process, then the elongate structure can be securely upended, but the device complexity increases and deck space is reduced
Solution Approach 1:
The tie-back system has been extracted and replaced by a pulling device integrated into the frame assembly. This pulling device provides the necessary control and security for the upending process through a more compact mechanism that is directly attached to the frame, eliminating the need for separate tie-back arrangements.
4Force
If large hoisting means with high crane height are used, then the elongate structure can be lifted and upended, but the device size increases and deck space is reduced
Solution Approach 1:
The upending device utilizes dynamic motion through the pivoting carrier arms and the pulling device to achieve upending with reduced lifting forces. Instead of requiring continuously high lifting capacity, the system dynamically transitions the structure from horizontal to vertical position using the pivot axis as a fulcrum, allowing for more compact hoisting means and greater deck space.
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
This configuration ensures stable and compact upending of elongate support structures, maintaining the center of gravity close to the offshore structure, reducing crane height requirements, and providing more deck space for equipment, while allowing for precise control and handling of structures of varying dimensions.
Implementation Method 1
a pivot axis situated near the side of the offshore structure for pivoting the upending device between the loading position and the launch position
Implementation Method 2
a first end of the upending device having a connector member that pivotally connects to the elongate support structure
Implementation Method 3
a second end of the upending device being attached to a pulling device that is located on of the offshore structure
Implementation Method 4
The upending device is within reach of one or more hoisting means for lifting the elongate support structure
Data Source
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AI summary
The present invention relates to an offshore structure comprising an upending device for upending an elongate support structure from a substantially horizontal loading position on a deck of the offshore structure to a substantially vertical launch position outboard of the offshore structure. The upending device comprising a pivot axis situated near a side of the offshore structure for pivoting the upending device between the loading position and the launch position, a first end of the upending device having a connector member for pivotally connecting to the elongate support structure, the connector member in the launch position is in a position outboard from the side of the offshore structure, and a second end of the upending device is attached to a pulling device that is located on the deck of the offshore structure. The upending device is within reach of one or more hoisting means for lifting the elongate support structure.