One of the most memorable scenes in the classic American movie Sweet Home Alabama features the glassblowing shop Deep South Glass, and the phenomenon of lightning striking a sandy beach to create intricate and delicate glass sculptures. In the movie, Jake attracts lightning by using lightning rods stuck into the sand during a storm. A lightning bolt strikes–instantaneously melting the sand to form a twisted, branching piece of clear, shining glass.
Although there was no storm, no movie set, and no one was trying to attract lightning strikes, Victory Electric crews encountered a similar phenomenon when they came upon a downed power line that left behind a visible burn path littered with glass bubbles and fragments.
“The temperature of an electrical arc on the ground is more than 36,000° Fahrenheit, which is hotter than surface of the sun, and is powerful enough to melt concrete into glass,” said Mikey Goddard, vice president of safety.
The downed power line, discovered by crews in south Dodge City on June 8, likely went down due to persistent high winds, which continued to wear at the wire. When a wire is repeatedly bent at a particular location, the wire becomes fatigued, loses its elasticity, and eventually breaks. In this case, the wire broke at the tie, which is where the power line wire is attached to the insulator. The energized, burning line landed on a concrete street, which is made up of a sand and stone mixture. Traditionally, glass is made by heating sand to a minimum of 3,200°, and the silicon dioxide present in the sand melts to form glass.
“While the visible burn path and glass bubble effect was neat to see, it also clearly demonstrates the terrifying power of electricity,” Goddard added. “Downed power lines can carry an electric current strong enough to cause serious injury or even death. As little as 1/10 of an amp can kill a person, and in this instance where the glass bubbles formed, the fault current was more than 600 amps.”
If you come across a low or fallen power line, adhere to the following safety tips.
It is critical to treat all downed power lines as energized and dangerous, even if they look "dead". Lines do not have to be arcing or sparking to be live. You cannot tell if a power line is energized just by looking at it.
When you see power lines on the ground, stay at least 30 feet away from it and anything touching it, call emergency dispatch or Victory Electric, and if possible, stay on site until crews arrive to warn others from unknowingly encountering a dangerous situation.
The proper way to move away from the power line is to shuffle away with small steps, keeping your feet together and on the ground at all times. This will minimize the potential for a strong electric shock.
If you encounter any glass formations, be extremely cautious. The glass, and the surrounding surface area, will be extremely hot to the touch and can take hours to cool. In addition to burns, a person also risks wounds or embedded slivers from the sharp, fragile glass fragments.
Do not let appearances deceive you. Just because a power line wire has an insulated covering doesn’t mean it’s safe to touch or handle. The insulation is designed to help prevent flickering and outages caused by tree limbs, squirrels and other critters, but it is NOT like an extension cord where you can safely grab and move it.
While it’s true the power and heat from a bolt of lightning can melt sand to form glass sculptures, the portrayal of how it happens in Sweet Home Alabama was a figment of Hollywood's imagination. Glass formed by lightning striking sand is called a fulgurite, and it looks very different from the glass sculptures resembling tree branches in the movie. According to Utah Geological Survey, fulgurites are usually 1 to 2 inches in diameter and up to 30 inched in length. A fulgurite exterior is a hard, crumbly, gray or brown texture and coated in partially melted grains of sand. The inside is a translucent, clear or whitish glass tube.
Other than a handful of successful trials by teams of scientists from the University of Florida who used highly advanced technology, expensive materials and extended periods of time, there is no record of any person successfully triggering lightning strikes to make fulgurites, specifically with a lightning rod on a beach.