The longest echo

In 2014, acoustics expert Trevor Cox crawled through a narrow pipe into a subterranean oil tank in Inchindown, Scotland ...

...One gunshot and 75 seconds later, he had set a new world record for the longest echo in a man-made structure.

Facts and figures

  • The Inchindown bombproof fuel oil tank was built over 80 years ago for the Royal Navy
  • The oil tank measures twice the length of a football pitch
  • The total reverberation time is 112 seconds
  • The world record reverberation time is 75 seconds*
  • The previous world record for a man-made structure was 15 seconds, which was also held by a structure in Scotland – the Hamilton Mausoleum in South Lanarkshire.


You can learn more about Trevor Cox’s dedication to amazing sound phenomena in our expert profile article.

*According to the International Standards Organization (ISO), the definition of rever-beration time is the time that a sound takes to decay until it is 60 dB below the level of the initial impulse sound.

Hear the recordholding gunshot in the underground chamber here.

Listen to Trevor Cox playing his saxophone with the world's longest echo: