A famous photo taken in 1932 has been given a modern day equivalent.
The original photo showed 11 workers in flat caps precariously perched on a steel beam 800ft (240m) above the ground. It was taken by Charles C. Ebbets during construction of the RCA Building (renamed as the GE Building in 1986) at Rockefeller Center.
But in 2011, construction engineers in London swapped vests for high-vis jackets and safety harnesses on the 755ft (230m) tall building Heron Tower in central London.
Credit: Michael Crompton / N.I. Syndication.