Fairlead Guide Means for Anchoring Chain Tension Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional fairleads for anchoring floating installations, such as offshore oil rigs, experience undesirable tensions and unsuitable bendings in the intermediate section of anchoring chains due to angular variations of the downstream structure, leading to structural bulkiness and reduced strength.
Innovation Solution
A compact and resistant fairlead design featuring a downstream structure with two lateral plates and guide means, including a U-shaped bearing for pivot connection, a sliding surface, and locking mechanisms with a counterweight, which reduces or eliminates tension on the intermediate section by guiding the anchoring chain without causing unsuitable bendings across various inclinations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the downstream structure is offset under the line of passage of the chain to avoid hampering displacement, then the chain can move freely, but the structure becomes bulky and strength is reduced
Solution Approach 1:
The guide means is positioned in the plane of the intermediate section of the anchoring chain, rather than offset below it. This dimensional repositioning allows the guide means to effectively guide the chain change of direction without requiring additional offset space, thereby avoiding structural bulkiness while maintaining chain displacement freedom and structural strength
2Adaptability or versatility
If the downstream structure pivots to fit the inclination of the downstream section, then the fairlead adapts to various angles, but the intermediate section undergoes undesirable tensions and unsuitable bendings
Solution Approach 1:
The guide means is designed with a curved surface that provides a smooth transition path for the anchoring chain, ensuring that the chain maintains a consistent bending radius regardless of the downstream structure's angular position. This equipotential design eliminates undesirable tensions and unsuitable bendings in the intermediate section while preserving adaptability to various inclinations
3Ease of operation
If the pivot connection means are offset to avoid hampering chain displacement, then the chain moves freely, but the structure becomes bulky
Solution Approach 1:
The pivot connection means is positioned in the plane of the intermediate section of the anchoring chain rather than offset below it. This repositioning in another dimension allows the pivot connection to function effectively without requiring additional offset space, thereby reducing structural volume while maintaining chain displacement freedom
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 fairlead provides efficient guiding of the anchoring chain with reduced tension and enhanced structural integrity, maintaining stability and strength regardless of the downstream structure's inclination, thus ensuring reliable anchoring of floating installations.
Implementation Method 1
the upstream end of each of said lateral plates comprises a U-shaped bearing receiving an arm complementary of said upstream structure and cooperating together through a stud, to form the pivot connection means
Implementation Method 2
the guide means includes a lower surface intended to form a sliding surface for a section of the anchoring chain extending between the upstream and downstream sections
Implementation Method 3
a jaw composed of two jaw members (or cheeks) articulated about axes of rotation parallel to each other
Implementation Method 4
an inert mass, called 'counterweight ', which is coupled in movement with said jaw members and which is operable in height between a lower position and an upper position
Data Source
AI summary
Disclosed is a fairlead intended to engage with an anchor chain, for a system for anchoring a floating installation to the ground. The fairlead includes two structures assembled by pivot connection of axis, one upstream, for rigidly connecting the fairlead to the floating installation, and the other downstream, including—a unit for blocking the translational movement of the anchor chain, and—a guide, for guiding a change in direction of the anchor chain. Furthermore, the downstream structure includes two lateral plates delimiting the passage of the chain, the upstream end of each of the plates including a U-shaped bearing receiving an additional arm of the upstream structure and engaging together via a journal, the guide extending between the internal branches of the two bearings.