Gantry System for Replacing Trackside Girders
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing girder lifting cranes are often too large to be staged on the railroad side of elevated platforms, making it difficult to remove and replace girders without obstructing the street-side, and they cannot efficiently handle lifting pre-cast slabs in confined areas.
Innovation Solution
A gantry system with rotating crane assemblies and support posts that can be positioned on existing girders, allowing for compact operation and efficient lifting of girders and pre-cast slabs, utilizing a trolley beam and hoists to move loads along the crane arms and between crane assemblies.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If traditional cranes are used to lift girders from the street side, then lifting capability is sufficient, but the crane occupies too much space and cannot be staged when street side is unavailable
Solution Approach 1:
The gantry system transitions the crane operation from street-side (horizontal dimension) to railroad track side (vertical/different spatial dimension) by using support posts that extend upward from the track level to support the crane arm, enabling staging in previously inaccessible space
Solution Approach 2:
Support posts serve as intermediary structures between the railroad track level and the crane arm, transferring load from the crane through the support posts down to the track structure, enabling crane operation without street-side staging
2Area of stationary object
If crane size is reduced to fit confined areas, then staging flexibility improves, but lifting capacity for heavy girders and pre-cast slabs is insufficient
Solution Approach 1:
The support posts provide counterbalancing support to the crane arm, distributing the load of heavy girders and pre-cast slabs between the hoist system and the support posts, enabling confined-area staging without sacrificing lifting capacity
Solution Approach 2:
Support posts act as load-bearing intermediaries that share the weight burden, allowing a smaller crane configuration to handle heavy loads by distributing forces through the support post structure to the railroad infrastructure
3Ease of operation
If cranes operate from street side, then lifting access is adequate, but railroad track access is blocked and operation from railroad side becomes necessary
Solution Approach 1:
The system enables crane operation to move from horizontal street-side access to vertical railroad track side access by utilizing the space above the tracks, supported by posts extending from track level to crane arm level
Solution Approach 2:
The gantry system with support posts and crane arm configuration can perform multiple functions: lifting girders from railroad side, installing pre-cast slabs, and operating in confined spaces where traditional cranes cannot be staged
Data Source
AI summary
A gantry system has at least one crane assembly, at least one support post, and at least one hoist. The crane assembly has a stationary base, a rotating base, and a crane arm. The rotating base is attached to both the stationary base and the crane arm in such a ways as to allow the rotating base and the crane arm to rotate while the stationary base remains stationary. The crane arm is supported on its far end by a support post. The crane assembly is configured such that the support post rests on an in-place girder. A hoist is attached and can move along the crane arm to position a railway component, such as a replacement girder and/or a precast panel.