Anti-Hail Net Impact Energy & Cable Tension Calculator

Terminal velocity assumes a smooth sphere at steady state in still air; real hail is lobed, tumbling and often falling through a downdraught that adds to the speed, so the energy here is a floor rather than a worst case. The arresting force uses a linear energy-to-deflection conversion, which ignores how a net stiffens as it stretches — the true peak is higher and arrives faster. Cable tension is the reaction from a single stone; a storm loads the whole canopy at once and the structure must be checked against the accumulated load, not this figure. Structural design of canopy supports is engineering work requiring a qualified sign-off.