London Heathrow is the busiest international airport in the world.

Canals, then railways transformed travel in earlier times, but by the 20th century the sky was the limit. Heathrow Airport was at the very centre of this expanding universe.

Opened to civilian traffic in January 1946, Heathrow was intended to handle 9,000 flights a year. Today 475,000 planes land or take off from its six runways. With the construction of Terminal 5, total passenger traffic is set to rise to 90 million annually.

Richard Rogers and Partners designed Terminal 5, which opened in 2008. Constructing it was a massive engineering challenge. It has a huge, single-span, undulating steel frame roof. High-level cranes were forbidden, so the 2,000 construction workers had to use methods their Victorian forebears would recognise.

But today’s huge civil engineering projects also have to balance many other important factors nowadays, including ecological, environmental, residential, and security issues.