Anchor Handling Well Design for Workboat Stability
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Solution Overview
Problem
Existing anchor handling vessels with limited gross tonnage experience deck immersion and increased risk of damage when lifting heavy anchors, due to the moment exerted by the anchor on the hull, particularly when the handling line runs over the bow roller.
Innovation Solution
An anchor handling vessel design featuring a well that opens at the deck and hull side, with a handling system that lifts the anchor close to the vessel's center of gravity, utilizing a guide pulley positioned within the well's perimeter to minimize the lifting moment, and a double-hulled well for enhanced integrity, along with a removable bow roller and knuckled bilges for easier anchor guidance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the handling line runs over the bow roller located at the end of the hull, then the anchor can be handled effectively, but the vessel experiences deck immersion and tilting due to the large moment exerted by the heavy anchor on the hull
Solution Approach 1:
The bow roller is removed from the traditional position at the end of the hull. Instead, the handling line is guided through a well structure that opens to the sea, extracting the problematic bow roller function and replacing it with a well-based guidance system that minimizes the moment arm and prevents deck immersion
Solution Approach 2:
A guide pulley is introduced as an intermediary element within the well structure. This pulley guides the handling line through the well and positions it closer to the vessel's center of gravity, acting as a mediator that reduces the destabilizing moment while maintaining anchor handling functionality
2Stability of the object's composition
If a well structure is introduced to guide the handling line through the hull, then the lifting moment is minimized and deck immersion is prevented, but the vessel structure becomes more complex
Solution Approach 1:
The well structure is integrated into the hull form itself, merging the anchor handling function with the hull structure. The well opens through the hull side and bottom, combining structural elements to guide the anchor and handling line without requiring separate complex external structures
Solution Approach 2:
The well structure serves multiple functions: it guides the handling line, positions the anchor close to the center of gravity, provides structural support, and integrates with the hull form. This multi-functionality reduces the need for additional specialized components, offsetting the initial structural complexity
3Stability of the object's composition
If the guide pulley is positioned within the well perimeter close to the center of gravity, then the moment exerted on the vessel is minimized, but the well structure requires precise geometric configuration
Solution Approach 1:
The well structure is designed with specific local geometric features including knuckled bilges at the bottom and an oblique arrangement. These localized quality features guide the anchor naturally into the well and position it correctly, reducing the need for high-precision manufacturing throughout the entire structure
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
Prevents deck immersion and maintains the screw immersed, reducing the risk of vessel damage while safely handling heavy anchors, ensuring stable operations during lifting and lowering.
Implementation Method 1
the anchor handling system comprises an anchor handling gantry having a guide pulley for the handling line which is arranged above the well
Implementation Method 2
the anchor handling system comprises a winch for winding or unwinding the handling line
Data Source
Figure 1
Figure 2
Figure 3A
AI summary
The present invention relates to a vessel (1) comprising a hull (2) with a bottom (3) and a circumferential hull side (5), a deck (4), and a well (11). The well opens out at the bottom, the deck and the circumferential hull side. The vessel further comprises anchor handling system (6) for handling an anchor with a handling line (8) through the well. The present invention further relates to an assembly comprising a vessel and an anchor and a method for operating the above vessel.