Did you know that if you took every single human being that ever lived and put them in the Grand Canyon, they still wouldn't fill the huge chasm in Arizona? The 277 mile long canyon is on average one mile deep, and has a volume of 4.17 trillion cubic metres.
A Massive Welding Job
As if the Grand Canyon wasn't already incredible enough, a few years ago they built a glass floored skywalk that extends out over the canyon at a height of over 1,200 metres, so tourists can experience a view of this giant natural wonder that was never before possible.
Welding the Grand Canyon Skywalk U Shape
The U-shaped skywalk was the brainchild of the late David Jin, who, along with various genius engineers and architects, decided to build this unbelievable feat of engineering for the Hualapai Nation of Native Americans. The skywalk, which was opened in 2007, juts out 21 metres from the edge of the canyon, and features glass walkways that are slightly over three metres wide. This skywalk contains many hundreds of tonnes of steel, and this is how they welded it...
Lincoln Electric Welders
The steel anchors for the huge structure were flux-cored, welded using a variety of machines from Lincoln Electric. These 15 metre anchors are weighted by cement, to help secure the structure against the 90 miles per hour upward gusts it must deal with. The main 'U' is built from two huge box girders made of A572 grade 50 carbon steel, which were welded using an automated Lincoln submerged arc welder. This high tech, computer-controlled machine used both AC and DC arcs in tandem; a technique that proved to be highly productive, attaining weld speeds approaching 75 centimetres per minute. The girders were built from 2 inch thick steel, and are almost one metre wide.
Highest Man-Made Structure on the Planet
The magnificent skywalk is rated to a live load of almost 500kg per square metre, and is now classed as the highest man made structure on the planet. The structure is designed and built to withstand all that nature can throw at it, including an earthquake measuring 8 on the Richter scale, occurring just 50 miles away. If you get the chance, go and check out the incredible feat of welding that is the Grand Canyon Skywalk - if you're brave enough, that is!