Overhead Crane Assembly Passing Mechanism
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Solution Overview
Problem
Current overhead crane systems in container terminals face challenges such as limited processing speed, congestion, and inefficient space use due to the inability of rail-mounted gantry cranes (RMGs) to pass each other and their high dead weight, which restricts stack density and increases 'digging time' for bottom-layer container transport.
Innovation Solution
The development of overhead cranes with truss frames that can completely accommodate containers, allowing them to be hoisted and transported within the frame, enabling multiple cranes to operate in the same lane and pass each other, reducing the need for extensive rail systems and lowering the dead weight by distributing the load more efficiently.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If rail-mounted gantry cranes (RMGs) are used to transport containers, then containers can be moved along ground-level rails, but the cranes cannot pass each other and require extensive rail systems occupying large surface area
Solution Approach 1:
The patent transitions from ground-level rail operation to elevated overhead rail operation. By moving the crane system to a third dimension (height), multiple cranes can operate in the same horizontal lane without blocking each other, as they can pass vertically. This eliminates the need for extensive lateral rail systems while increasing processing speed through parallel operations.
Solution Approach 2:
The overhead crane system is divided into modular components: overhead rails mounted on existing structures, individual crane units that can operate independently, and container spreaders that can be attached/detached. This segmentation allows multiple cranes to share the same overhead rail infrastructure, reducing total rail length while maintaining high throughput.
2Stability of the object's composition
If RMGs are used with high dead weight to ensure stability, then structural stability is improved, but the dead weight of 150 tonnes to transport a 30-tonne container increases energy consumption and reduces efficiency
Solution Approach 1:
The overhead crane design uses the building structure itself as counterweight and support. The crane beams are anchored to the building's load-bearing structure, eliminating the need for heavy self-supporting gantry legs. This reduces the moving mass from 150 tonnes to a fraction, dramatically lowering energy consumption while maintaining stability through structural integration.
Solution Approach 2:
Instead of using heavy physical gantry structures, the patent copies the support function from the building's existing structural framework. The overhead rails utilize the building's columns and beams as support elements, transferring the stability requirement from the crane itself to the building infrastructure.
3Quantity of substance
If stacking height is increased to improve stack density, then space utilization is improved, but digging time increases when containers from bottom layers need to be transported
Solution Approach 1:
Multiple overhead cranes operating in parallel on the same lane enable continuous container handling. While one crane is retrieving a container from a deep stack position, another crane can simultaneously handle containers at different positions. This parallel operation eliminates the sequential waiting time (digging time) that would otherwise be required when accessing bottom-layer containers in high stacks.
Solution Approach 2:
The system dynamically allocates multiple cranes to different stack positions and operations based on real-time needs. When bottom-layer containers need retrieval, the system can dynamically assign available cranes to assist, rather than requiring sequential single-crane operations. This dynamic resource allocation maintains high stack density while minimizing digging time through coordinated multi-crane operations.
4Productivity
If a single lane with multiple cranes is used to increase processing speed, then operational efficiency is improved, but crane failure requires rescue operations and reduces reliability
Solution Approach 1:
Each overhead crane is designed with universal capabilities to perform multiple functions: normal container handling, rescue operations for failed cranes, and frame transportation. The cranes carry rescue equipment and can manipulate other crane frames, making the system self-rescuing. This multi-functionality ensures that a single lane with multiple cranes maintains high productivity while achieving self-reliability through built-in rescue capabilities.
Data Source
AI summary
An overhead crane (21, 22) for hoisting and moving containers (2) includes a rail track (23, 24) which rests on the ground via columns (25), and a frame (31, 32) which is displaceable along the rail track (23, 24) and is provided with elements for picking up and hoisting containers (2). In particular, the frame (31, 32) is suitable to accommodate at least one container (2) completely. In an assembly (20) of at least two overhead cranes (21, 22), the rail tracks (23, 24) of the overhead cranes (21, 22) extend at different levels with respect to the ground, substantially parallel with respect to each other, and rest on the ground via common columns (25). One of the advantages of this arrangement is the fact that the overhead cranes (21, 22) can pass each other.