We've been Building Big lately and if you haven't been you should be. For someone that doesn't comprehend physics or engineering these documentaries are captivating. The above photo is of the Firth of Forth Bridge in Scotland that was built over the Firth of Tay after the first bridge collapsed. It took 54,000 tons of steel; 194,000 cubic yards of granite, stone, and concrete; 21,000 tons of cement; and almost seven million rivets to build the bridge.
Yesterday, we had a field trip planned to Sloan Museum for some hands on activities involving canals and Michigan pioneers. Little did I know that all we had been doing previously would be reinforced at Sloan. I'm an accidental homeschooler, I've always got big plans and ideas and then I let my child lead. He watches, he does, he learns. Often times more than I realize.
The arched bridges and tunnels in the Building Big series were especially confounding because of the way the weight is distributed.
"Arch bridges are one of the oldest types of bridges and have great natural strength. Instead of pushing straight down, the weight of an arch bridge is carried outward along the curve of the arch to the supports at each end. These supports, called the abutments, carry the load and keep the ends of the bridge from spreading out." NOVA
If you don't have it all just right your bridge is not going to remain intact for long. Below is the finished structure before the supports are removed.
The supports are removed and it appears that his bridge is ready for traffic!
The other exhibits were just as compelling and of course educational but the second best part to building the arched bridge was that the gift shop had a replica of the Back to the Future DeLorean complete with a flux capacitor.
(And yes, that is Back to the Future on the t.v. in the background.)