In tunnelling logistics, an overhead track mounted on a large truss frame is specifically required with which car-changer/material-handling method for muck-car movements?

Introduction / Context:
Efficient muck handling inside tunnels often uses rail-bound cars and specialized car-changing systems at transfer points. Some systems require elevated rails or overhead tracks to quickly swap loaded and empty cars without blocking the main track. This item probes identification of the method associated with a truss-mounted overhead track arrangement.

Given Data / Assumptions:

• Setting: car-changing station at or near the portal/transfer point.
• Alternative methods: grasshopper, passing track, California crossing, Dixon conveyor.
• Feature in question: overhead track on a large truss frame.

Concept / Approach:
The Dixon conveyor method integrates conveyors with railcars and often uses elevated/overhead track arrangements supported by trusses to allow gravity-assisted or conveyor-assisted transfers while maintaining clearance for equipment underneath. Other methods rely on on-grade sidings, portable turnouts, or crossings and typically do not require a substantial truss-supported overhead rail system.

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