Time Scanners: How was Petra built?
Ahead of his Time Scanners show on the National Geographic Channel, structural engineer Steve Burrows tells us how the magnificent sandstone city of Petra was built.
How can we learn more about history’s greatest buildings and the methods used to construct them? One way is 3D laser scanning, which captures the ruins in all their glory and recreates virtual replicas. In their new National Geographic programme Time Scanners, structural engineer Steve Burrows, who worked on Beijing’s ‘Bird’s Nest’ Olympic stadium, and presenter Dallas Campbell use this technology to uncover the secrets of ancient sites around the world.
In the first of a series of interviews to be posted on , Helen Cahill caught up with Steve to find out more about Petra, the vast city in Jordan that was carved directly into the dusky pink rock face.
Why is Petra such an extraordinary place, from an engineer’s point of view?
The scale of Petra is just immense – 10,000 people lived there. So it’s huge, and it is made of sandstone – in the desert. It only rains for a short period of time [each year], but very violently. So, what happens with sand and rain? The sand washes away! Yet, these carved buildings have lasted 2,000 years. They had to build these incredible buildings out of sandstone, and then protect them from the rain.
They also had to hold the water from these short interludes of rainfall for the rest of the year, so that they could use it while waiting for the next period of rainfall. So they had to have swimming pools – huge bodies of water in the desert.
How was Petra fashioned out of this sandstone?
We figured out how they did it through the laser scanning. They put giant steps into the mountain so that they could see the quality of the rock, and by building these steps there was nobody hanging by ropes or dangling dangerously off the mountain, so they were able to stand on safe ledges while they did their work. They wanted to make sure the masons were safe because these people were highly skilled and there weren’t many of them – nobody wanted them to die moving things.
We were also able to explore how they made fields in the desert and how they brought water to the centre of Petra. How did they make sure everyone had enough, when it rains only a few days a year? Again, we worked that out through the laser scanning. We really started to get into the minds of these incredible civil engineers.
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Tune in to the National Geographic Channel on Tues 25th February at 9:00pm to find out more about the ancient city of Petra.