Throng

Robert Llewellyn hosts the show that examines the machines, processes and structures that form the backbone of 21st-century living. This week, Robert discovers how firefighters train for their most hazardous jobs. He witnesses operations at the world’s largest traffic-management centre in London; and catches a glimpse of a gigantic tunnel-boring machine in southern Spain.

How Do They Do It? puts the modern world under the microscope to explain the technology, designs and processes behind daily life. Robert Llewellyn (‘Red Dwarf’, ‘Scrapheap Challenge’) and a team of inquisitive researchers get their hands dirty in a bid to better understand the technology that keeps the modern world moving.

This week, Robert watches on as the Lancashire Fire Service trains its crews to tackle everything from blazing fuel tankers to search and rescue missions. He quickly discovers that fire training involves a lot more than scaling ladders and pointing hoses. Clad in sweaty, fire-resistant overalls, Robert finds out what it is like to crawl through a smoke-filled tunnel, before learning the importance of the different equipment and techniques required to put out burning gas and blazing oil.

Elsewhere, Robert reveals how London’s traffic is kept on the move. The average rush-hour speed in Central London is just 10mph – about the same as a century ago, when most vehicles on the roads were horse-drawn. Nowadays, however, London’s 8,700 miles of roads have to cope with more than 21 million journeys every day.

Keeping all those vehicles flowing smoothly is the job of the world’s largest traffic-management centre, where operators can directly control almost 3,000 of the city’s 6,000 sets of traffic lights. But even the lights outside the centre’s control can adjust to the flow of traffic, thanks to metal detectors buried beneath the tarmac. These detectors relay information about the number, size and rate of traffic, allowing the lights to adjust their timing automatically.

Ten miles an hour may seem slow, but the object of Robert’s next investigation moves at a mere 34 metres a day. Robert is in southern Spain to witness one of the world’s largest moving machines in action – the Tunnel Boring Machine, or TBM . Robert descends below ground to watch as a 1,500-tonne TBM slowly grinds its way under a mountain range, gouging out a new high-speed rail tunnel. It may be slow, but at the sharp end are 64 cutter blades capable of chewing their way through the rock with a thrust three times greater than the Space Shuttle at lift-off.