Crane-Mounted Guide Members for Offshore Load Stability
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Solution Overview
Problem
Existing offshore load handling technologies, such as tugger winches, struggle to effectively control large loads in high sea states due to limitations in deck space, safety risks, and inability to handle loads in harsh marine environments with significant wave heights exceeding 1.5m, leading to costly delays and potential abandonment of construction operations.
Innovation Solution
A method and apparatus using crane-mounted guide members that act in compression and tension to restrain horizontal movement of loads during overboarding and lowering, synchronizing with the slewing crane to maintain control and stability, and extending differentially to accommodate geometric requirements and movement away from the slewing axis, allowing for safer and more efficient operations in higher sea states.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If tugger winches are used to control lateral movement of loads, then load stability is improved, but deck space is cluttered and safety risks increase in high sea states
Solution Approach 1:
The patent extracts the load control function from deck-mounted tugger winches and relocates it to crane-mounted guide members. The guide members are attached to the crane boom and load, providing lateral control without occupying deck space. This separation moves the control mechanism from the vessel deck to the crane system itself, eliminating the clutter and safety risks associated with multiple deck-mounted devices.
Solution Approach 2:
The patent merges the load control function with the existing crane system by attaching guide members to the crane boom. Instead of using separate deck-mounted tugger winches, the control mechanism is integrated into the crane structure, combining lifting and lateral control functions in a single system. This reduces the number of independent devices needed and simplifies the overall arrangement.
2Adaptability or versatility
If more tugger winches are deployed to handle larger loads in harsher sea states, then operational capability is improved, but deck space occupation and safety risks worsen
Solution Approach 1:
The patent employs dynamic guide members that can extend and retract, and rotate to follow the crane boom's movement. The guide members are not fixed in position but adapt their configuration based on the crane's slewing angle and load position. This dynamic behavior allows the system to maintain effective load control across a range of sea states and load sizes without requiring additional static devices that would clutter the deck.
Solution Approach 2:
The crane-mounted guide members serve multiple functions: they provide lateral control during load overboarding, maintain control during crane slewing operations, and adapt to different load sizes and configurations. A single guide member system on the crane can handle various operational scenarios that would otherwise require multiple specialized deck-mounted devices, improving versatility without increasing safety risks.
3Stability of the object's composition
If guide members are made rigid to effectively restrain load movement, then load control is improved, but ability to accommodate geometric requirements and movement away from slewing axis worsens
Solution Approach 1:
The guide members are designed with dynamic characteristics, allowing them to extend and retract to accommodate different geometric requirements. The guide members can also rotate or pivot to follow the crane boom's movement and adjust to loads that move away from the slewing axis. This dynamic flexibility maintains effective load control while adapting to varying operational geometries.
Solution Approach 2:
The patent changes the physical parameters of the guide members, allowing them to vary in length, angle, and position. By adjusting these parameters, the guide members can maintain optimal control geometry for different load positions and crane configurations. This parameter variability enables the system to accommodate geometric requirements while preserving load control effectiveness.
Data Source
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AI summary
A method of overboarding and lowering a load from a vessel comprises using a vessel- mounted crane to lift the load from a deck of the vessel, to move the load off the deck into an outboard over-water position and to lower the load from the outboard position into the water. The method further comprises placing at least one guide member acting in compression between the load and an upstanding supporting structure of the crane to restrain horizontal movement of the load relative to a boom of the crane; and lowering the guide member to continue restraining horizontal movement of the load while lowering the load from the outboard position into the water. A related guide apparatus comprises at least one guide member that is movably connected to a mount for movement relative to the mount around and parallel to a slewing axis of the crane.