How many men does it take to change a light bulb…atop Britain’s tallest spire? Nail-biting moment workers scale 404ft Salisbury Cathedral to replace air traffic warning beacon March 16, 2017 by Fulcrum This is the hair-raising moment two workers at Salisbury Cathedral ascended Britain's tallest spire to change the warning lights for air traffic. Mark Duell for Mailonline 15 March 2017 FulcrumShareTweetShare