Sacrificial Stinger Impact Absorber for Marine Pipelaying
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Solution Overview
Problem
Existing pipelaying vessels face operational inefficiencies and extensive damage due to freak waves, which can cause violent stinger motion and significant impact, leading to potential destruction of the stinger and suspension assembly, especially in deepwater operations where stingers are large and heavy.
Innovation Solution
Incorporation of sacrificial stinger impact absorbers designed to absorb impact energy from violent stinger motion, allowing the absorbers to fail while maintaining the integrity of the stinger and vessel anchoring points, thus reducing damage and maintaining operational efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a stinger suspension assembly is used to support the stinger during pipelaying operations, then the stinger can be properly positioned and supported, but the assembly becomes vulnerable to extensive damage from freak waves causing violent stinger motion
Solution Approach 1:
The patent applies beforehand cushioning by incorporating sacrificial impact absorbers into the stinger suspension assembly before operation. These absorbers are pre-positioned to cushion against freak wave impacts, allowing the main stinger and vessel structures to withstand extreme forces without damage. The absorbers are installed in advance and remain dormant during normal operations, activating only when needed.
Solution Approach 2:
The patent implements this principle by using sacrificial impact absorbers that are designed to be replaced rather than repaired after freak wave impacts. These absorbers are relatively inexpensive components that can be quickly swapped out, minimizing downtime and maintenance costs compared to protecting the entire stinger suspension assembly permanently.
2Object-affected harmful factors
If traditional shock absorption methods (fluidic shock absorbers) are used to mitigate freak wave impacts, then impact energy can be absorbed, but the cost and complexity of the system increases significantly
Solution Approach 1:
The patent replaces complex, expensive fluidic shock absorbers with simple, inexpensive sacrificial impact absorbers. These absorbers use basic mechanical components like breakable links or deformable elements that can be easily manufactured and replaced, dramatically reducing system complexity and cost while maintaining effective impact mitigation.
Solution Approach 2:
The patent extracts the essential function of shock absorption from complex fluidic systems and implements it through simple mechanical sacrificial elements. By taking out only the necessary impact absorption capability and implementing it through basic breakable or deformable components, the system achieves the same protective function with minimal complexity.
3Strength
If the stinger and suspension assembly are designed to withstand all possible impacts, then damage resistance improves, but the cost and structural weight increase significantly
Solution Approach 1:
Instead of designing the entire stinger assembly to withstand all impacts, the patent uses inexpensive sacrificial absorbers that fail in place of the main structures. This allows the stinger and suspension assembly to be designed for normal operations only, significantly reducing weight and cost while maintaining protection through the sacrificial components.
Solution Approach 2:
The patent converts the harmful effect of impact forces into a beneficial protective mechanism by designing sacrificial absorbers that are intended to fail. The controlled failure of these absorbers protects the valuable stinger and vessel structures, turning potential damage into a planned, manageable event that preserves the main system.
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 use of sacrificial stinger impact absorbers effectively mitigates the impact of freak waves, preventing extensive damage to the stinger and vessel, ensuring continuous pipelaying operations by absorbing enormous impact energies at a lower cost compared to fluidic shock absorbers.
Implementation Method 1
a sacrificial stinger impact absorber which is adapted to absorb impact energy resulting from a violent stinger motion
Implementation Method 2
the (frangible members of the) absorber while the remainder of the stinger and stinger suspension assembly are designed to remain intact
Data Source
AI summary
A marine pipelaying vessel with a pipeline stinger connected to said vessel, preferably pivotable, and forming a downwardly directed support for pipeline to be laid. The vessel further includes a stinger suspension assembly between the stinger and the vessel from which the stinger is suspended at least during operation, preferably the stinger suspension assembly allowing to lower and raise said stinger. The stinger suspension assembly includes a sacrificial stinger impact absorber which is adapted to absorb impact energy resulting from a violent stinger motion, e.g. induced by a freak wave. Preferably, the impact absorber forms an elongatable structure, e.g. a telescopic structure, which is elongated under impact energy absorption.