The lighting of the flame in the stadium is an iconic moment in any Olympic games. The designer of the cauldron for the 2012 London games, Thomas Heatherwick, preserved the tradition but gave it a few new twists. As Heatherwick told a press conference in London, “When we were thinking about the cauldron , we were aware that cauldrons had been getting bigger, higher, fatter as each Olympics has happened and we felt we should not try to be even bigger than the last ones.
“It didn’t feel enough to just design a different shape of bowl on a stick so we were trying to rethink it fundamentally — this idea of having no cauldron and instead each country would bring together an object — no bigger than a few bits of paper — and that these children would carry these polished copper objects.”
The cauldron is made up of 204 unique, handmade copper petals, representing each of the countries taking part in the Olympics, attached to 28-foot-long steel pipes, which in turn are connected to the gas mains. Each petal had to be clicked into a specific rod. When the Olympics are over, the cauldron will be dismantled and the petals distributed to the 204 nations that took part in the opening ceremony.
An article in the Telegraph outlined the complex choreography that went into the top-secret installation and operation of the cauldron:
The time it took the athletes to come into the stadium — almost two hours — gave the cauldron team time to assemble the complex structure.
The cauldron was actually kept beneath a black cloth and hidden from view and beneath the stage. The petals were taken from each team and without anybody seeing taken below the stage to the cauldron where they were attached to the pipes out of sight of the crowd. When the process was completed, the cauldron, with the pipes at that stage still flat, was raised to the level of the stage but still kept under cloth. Only when the cloth was removed, did the cauldron appear.
There was a further technical difficulty in lighting the petals. Each contained an igniter within it and the team tested several different ways if getting the cauldron lit.
“In the end, each athlete lit a petal and that petal would light the next one and the flame would go around the ring,” said Mr Heatherwick.
“We had 45 seconds and each of these seven athletes had that time to do it before the whole cauldron became lit.”
It took the seven young athletes 45 seconds to light the flames and then a further 45 seconds for the cauldron to be raised. The inner ring is raised first followed by nine outer rings so that in the time it takes for the first ring to become vertical, the final one is just lifting into the air.
“The 204 petals were arranged in ten rings, the inner ring lifted first and the next ring and the next one. When the first ring became fully vertical, the last ring was just lifting. It was like a dandelion with the seeds that you blow. It was technically very difficult to make it work. When it worked last night, it was a huge relief.” (source)
Also a triumph of art, science, and engineering.