Anti-Sag Variation for a long-span cable (ASV)

This document describes an original mechanical device designed to simultaneously solve two critical problems in suspended cable structures (suspension bridges, aerial tramways, cable conveyors, Hyperloop systems): (1) excessive vertical sag variation caused by moving loads, and (2) catastrophic structural failure caused by ship or vehicle collisions. The system, called ASV (Anti-Sag Variation), introduces a vertical prestressing cable anchored to the ground at midspan, combined with a hydraulic jack and an automatic two-stage mechanical disconnector. The device reduces sag variation by a factor exceeding 1,000 compared to conventional designs, and provides passive collision protection that prevents bridge or tramway destruction. For a TGV load of 380 tonnes on a 500 m span, the residual sag variation is limited to 3 mm. Wind lateral forces at 108 km/h reduce the safety factor from 4.0 to 3.87 — a negligible effect. All components are described and claimed herein as intellectual priority of the inventor, Dominique Mareau.1.