Guide Float Cradle for Stable Vessel Recovery at Sea
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Solution Overview
Problem
Existing vessel recovery systems face safety risks due to uncontrollable movements and potential collisions between a vessel and a host ship, especially in rough sea conditions, and lack effective stabilization during the raising process.
Innovation Solution
A recovery device with a cradle having negative buoyancy, connected to an upper frame via hangers with variable lengths, and a guide float with positive buoyancy, allowing for three degrees of freedom in rotation and translation, along with stabilizing hangers to dampen shocks and limit rocking, ensuring safe and controlled vessel transfer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a basket is used to support the vessel during recovery, then the vessel can be raised from the sea surface, but the unit formed by the basket and vessel rocks violently when raised above sea level due to loss of water stabilization
Solution Approach 1:
A guide float is introduced as an intermediary element between the cradle and the upper frame. This guide float provides hydrodynamic stabilization when the cradle-vessel unit is raised above the sea level, acting as a mediator that maintains stability without requiring the entire unit to remain submerged. The guide float's hydrodynamic properties stabilize the unit during the critical transition phase when water stabilization is lost.
2Stability of the object's composition
If stop elements are provided to restrict yaw movements of the basket-vessel unit, then yaw movements are limited, but the unit may collide with these stops causing equipment damage
Solution Approach 1:
The patent converts the potentially harmful collision with stop elements into a beneficial controlled interaction. Instead of rigid stops that cause damage, the system uses a guide float with controlled yaw movement capabilities. The guide float's hydrodynamic characteristics allow it to interact with water in a way that naturally limits yaw movements while avoiding hard collisions, transforming the harmful impact force into a controlled hydrodynamic response.
3Adaptability or versatility
If the basket is made submersible to recover both surface and submarine vessels, then versatility is improved, but the risk that the vessel will strike the basket increases significantly
Solution Approach 1:
The system is segmented into distinct functional elements: a cradle for supporting the vessel, a guide float for stabilization and guiding, and an upper frame for lifting. The guide float acts as a separate guiding element that the vessel follows, rather than the vessel directly interacting with the lifting structure. This segmentation allows the cradle to be submersible for versatility while the guide float provides a safe guidance path that prevents direct vessel-cradle collisions.
4Ease of operation
If hangers with variable lengths are used to connect the cradle to the upper frame, then the cradle can be raised and lowered, but the movements of the host ship are imparted progressively to the vessel causing shocks
Solution Approach 1:
The guide float provides beforehand cushioning by stabilizing the cradle-vessel unit during the raising process. Before the unit is fully raised and before rigid connection is established, the guide float's hydrodynamic stabilization anticipates and dampens the shocks that would otherwise occur when host ship movements are imparted to the vessel. This prior cushioning prevents the harmful effects of progressive movement transfer.
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 device effectively stabilizes the vessel during recovery, reducing the risk of collisions and damage by decoupling movements between the vessel and host ship, using lightweight and compact hangers to manage rocking through natural wave phases, thus ensuring safe and efficient transfer.
Implementation Method 1
a guide float capable of having a predetermined positive buoyancy, the guide float being interposed between the cradle and the upper frame so that the cradle is intended to support the guide float during the raising of the cradle
Implementation Method 2
The hangers are flexible elements which allow relative movement between the basket and the host ship while forming a permanent connection between the basket and the host ship. During the raising of the vessel to be recovered, once it is supported by the basket and connected to the rail, reducing the length of the hangers allows the movements of the host ship to be imparted progressively to the vessel to be recovered
Data Source
AI summary
A device for recovering a vessel at sea from a surface station, the recovery device includes a cradle with negative buoyancy, intended to support the vessel, a lifting device comprising an upper frame and a set of hangers connecting the cradle to the upper frame, lengths of the hangers being variable so as to make it possible to raise and lower the cradle, a guide float capable of having a predetermined positive buoyancy, the guide float being interposed between the cradle and the upper frame so that the cradle is intended to support the guide float during the raising of the cradle, the guide float being configured and connected to the cradle in order to guide the vessel moving on the surface of the water with a speed of movement comprising a positive component along an axis x associated with the upper frame, toward a front part of the guide float when the guide float has the predetermined positive buoyancy, the guide float being in connection with three degrees of freedom in rotation with the cradle.