The Shattering Effect of Lightning-Pressure from Heating of Air by Stroke Current

The shattering effect attributed to lightning is due to lightning's secondary effect-the pressure impulse of air heated by the lightning. At distances over a few tens of feet, we know this as thunder, but at less than 10-20 ft, this pressure can be great enough to destroy many man-made structures. By combining results from several sources, it is possible to determine the intensity of this pressure from the stroke current magnitude and the distance from the stroke terminal to the susceptible structure. From this it becomes apparent the lightning-protection systems need to take into account this pressure aspect as well as the electrical current path to earth, as presently specified.