A Physical Feasibility Study of a Spider-Man-Like Grapple-Line Swinging Suit: Pendular Urban Locomotion with Tethered Anchors

A human can, in principle, cross a city by swinging on launched tethers, but only within tight limits set by tether tension, anchor strength and human g-tolerance. We model an 85 kg user on a 30 m tether as a variable-length pendulum with quadratic air drag, then follow each release with a drag-affected ballistic flight. Starting from a horizontal tether, the user reaches 21.9 m/s at the bottom of the arc and the tether carries 2.6 times body weight (3.0 without drag). The best release point is about 40° past the bottom, which carries the user roughly 82 m horizontally per swing with drag (102 m in vacuum). Reeling in 4 m of line near the bottom of the arc, the mechanism by which a child pumps a playground swing, adds about 10 kJ per swing and lifts release speed by 25%, but demands roughly 20 kW of peak winch power. The binding constraints are not the swing itself: they are anchors able to hold 8–10 kN on arbitrary building surfaces, winch power density, and catch loads if the tether goes slack. We size each subsystem, compare five anchor technologies, and list the failure modes that would have to be engineered out before any human trial. The concept is inspired by the web-swinging of the fictional character Spider-Man; this paper treats only the real physics.