REX (Return of Experience)

A real-world Return of Experience (REX) from GRIMPDAY 2025 (Geneva): during the “Skyscraper” scenario, a rooftop gondola rail anchor system started drifting once loaded by several teams, forcing an immediate stop—and ultimately the cancellation of the scenario.

This document breaks down the context (multiple highlines in tension), what was observed on site, and the technical reasons behind the movement (rail assembly, joints, tie-back spacing). You’ll also find the corrective actions and practical recommendations.

Download it to capture clear, field-tested lessons you can apply to your own operations and event setups.