Buoyancy Element for Cable Retraction Safety
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Solution Overview
Problem
The existing methods for dismantling the last cable between two masts, such as the reel line method, face challenges in securing the free end of the cable during removal, particularly in sensitive areas like power line crossings, leading to safety concerns, costly and time-consuming measures, and increased economic efforts due to the need for night or weekend work.
Innovation Solution
A method involving a pulley line with pulleys attached to the last rope, where a buoyancy element, like a helium-filled balloon or flow guide, is used to keep the free end of the auxiliary line above the mast, preventing it from falling, allowing safe retraction without the need for line closures or costly scaffolding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the reel line method is used to dismantle the last cable, then the dismantling process can be completed, but the free end of the cable cannot be secured against falling, creating safety risks
Solution Approach 1:
A buoyancy element (balloon) is introduced as an intermediary device attached to the free end of the cable. This mediator provides upward buoyant force to counteract gravity, preventing the cable end from falling without requiring complex mechanical restraint systems or safety scaffolding.
Solution Approach 2:
The buoyancy element acts as a counterweight providing upward force to balance the downward gravitational force on the cable. By attaching a helium-filled balloon to the cable end, the system creates a force equilibrium that prevents the cable from falling to the ground during dismantling.
2Reliability
If safety scaffolds and line closures are implemented to prevent cable falling, then safety risks are reduced, but costs and processing time increase significantly
Solution Approach 1:
The buoyancy element serves as a simple intermediary that eliminates the need for time-consuming safety scaffolding erection and line closure procedures. The balloon can be quickly attached to the cable end, allowing dismantling to proceed without administrative delays or complex setup procedures.
3Reliability
If multiple buoyancy elements are used to support heavy power lines, then the lines can be prevented from falling, but the surface exposed to wind increases, making recovery difficult and increasing accident risk
Solution Approach 1:
Instead of distributing multiple buoyancy elements along the entire cable length, the invention applies a single buoyancy element locally at the critical point - the free end of the cable. This localized approach provides sufficient support to prevent falling while minimizing the total surface area exposed to wind forces.
Solution Approach 2:
The buoyancy element is designed as a simple, lightweight, disposable component that can be easily attached and removed. Rather than using heavy, complex buoyancy systems that create wind resistance, a lightweight balloon provides the necessary function temporarily during the dismantling process and is then discarded.
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
This method reduces safety risks, avoids road or rail closures, and decreases costs by enabling safe and efficient dismantling of cables without the need for extensive safety measures, such as night work or additional staffing, while maintaining control over the retraction process even in adverse wind conditions.
Implementation Method 1
a buoyancy element, like a helium-filled balloon or flow guide, is used to keep the free end of the auxiliary line above the mast, preventing it from falling
Data Source
Figure 1~3
Figure 4
AI summary
The invention relates to a method for dismantling a cable (1) stretched between two masts (2, 3), in particular for dismantling an earth wire as the last cable between overhead line masts, characterized by the following steps: a pulley line (10) with pulleys (5) is deployed between the masts (2, 3) on the cable (1), the pulley line (10) is tensioned and the pulleys (5) are tipped over, the last cable (1) is pulled out over the pulleys (5) of the pulley line (10) while secured, an auxiliary line (4) is pulled into the pulleys (5) between the masts (2, 3), the auxiliary line (4) is tensioned and the pulleys (5) are tipped over, the pulley line (10) with the pulleys (5) is pulled away from the auxiliary line (4) and only the auxiliary line (4) is now stretched between the masts (2, 3), a buoyancy element (7) is attached to one end of the auxiliary line (4) attached, after which the auxiliary line (4) is released at this end and simultaneously the auxiliary line (4) is retracted at the other end,wherein the buoyancy element (7) is designed such that the buoyancy element (7) with the free end (9) of the auxiliary line (4) remains at or above the height of the mast top during retraction.