In 1970, the Guinness Book of World Records listed the world’s longest echo at 15 seconds long. That’s pretty embarrassing compared to the new record of one minute and 12 seconds.
Trevor Cox, Professor of Acoustic Engineering at the University of Salford, discovered the echo while researching for his book, Sonic Wonderland: A Scientific Odyssey of Sound.
The record was broken in the oil storage complex at the Inchindown tunnels in Scotland, which used to serve as fuel tanks for the Royal Navy. There are no doors that lead to the tunnels, so Cox had to enter through 18-inch wide oil pipes.
Trevor Cox’s guide fired blanks from a pistol a third of the way into the oil storage tank. Cox captured the sound and was surprised to discover the world’s longest echo, hear it below:
Images by RCAHMS.