Lightning strikes they say and indeed it does. The problem is when it strikes our cities’ tallest skyscrapers. Why the tallest? Because the taller a building is, the more chances it has to be struck. For instance, the Empire State Building is struck by lightning about 25 times a year. Luckily, tall buildings have built-in protectors against lightning as it can cause unforeseen damage to a building’s system and infrastructure. These protectors are called lightning protection systems or LPS. Pretty straightforward, right? An LPS consists of systems that have three components: air termination systems, conductor systems, and Earth terminating systems. The first catch incoming lightning bolts, the second redirect the current and the third sends this current safely into the ground, where it can dissipate. Air termination systems consist of lightning rods. Although these usually come in a variety of designs, they are mostly made of conductive metals such as copper or aluminum. They are generally placed at the highest point of a skyscraper and they serve as a ‘terminal’ for lightning bolts to pass through, allowing the current to be directed along a safe path. What happens once lightning strikes them? What do the other two LPS components consist of? How effective are these measures at protecting buildings from lightning? What is the science, technology, and engineering behind these LPSs?
