I’m walking in the air…..

I was recently reminded of a trip to Las Vegas in 2010, which included the Grand Canyon and, specifically, the Skywalk. This is a glass horseshoe walkway that cantilevers over the canyon and is, quite frankly, terrifying. On the furthest extreme of the structure I found myself next to an American woman, both of us clinging ferociously to the handrail, firmly believing that our lives depended upon this. She was terrified that the while thing would collapse and I was convinced that some supernatural force was about to pick me up and hurl me into the void. In both cases, clinging to the handrail was fundamentally futile.

Fortunately, I was able to explain to her that the building that we had just walked through was acting as a counter balance to the cantilever. For instance, if you pile enough bricks on one end of a scaffold plank you can stand confidently on the other end, even if it is over a swimming pool. The building provided the kentledge (for that is what it is called) for the pair of steel beams to stick out over the edge and form a parapet to the walkway.

By the time I had finished there was a small audience of tourists who were marginally reassured by knowing how the thing works, demonstrating that structural engineering can perform a social service for passing civilians.

Sadly, they were absolutely useless at assuring me that a mystical animal – condor, roc or dragon, maybe – was not going to toss me over the side as sport and/or food for its young. I am only here to tell the tale because I bravely closed my eyes, clung to the handrail and made my way back into the building in small jerky movements.