Human Cantilever Bridge Model (1887)
What can you build with three men, two chairs, two piles of bricks, and four broomsticks?
To demonstrate the stability of the cantilever, Benjamin Baker designed a demonstration with three men, two chairs, two piles of bricks, and four broomsticks. With their outstretched arms, the people on the left and right serve to transfer the load of the suspended person (center) to the anchors (pile of bricks on left and right).
The Forth Bridge is a cantilever railway bridge across the Firth of Forth in the east of Scotland, 9 miles west of central Edinburgh. Completed in 1890, it is considered as a symbol of Scotland (having been voted Scotland's greatest man-made wonder in 2016), and is a UNESCO World Heritage Site. It was designed by English engineers Sir John Fowler and Sir Benjamin Baker.
After the collapse of an earlier Tay Bridge in 1879 (with the loss of an estimated 75 lives), Benjamin Baker and Sir John Fowler submitted a design to the Forth Bridge Company on the cantilever and central girder principle. Fowler and Baker were well-established engineers whose long list of achievements included a substantial role in constructing the London underground rail network.
For many years an exponent of the use of cantilevers as the most effective means of constructing long-span bridges, Baker devised the human cantilever to explain the principle at a lecture to the Royal Institution in London in 1887. As he explained, "when a load is put on the central girder by a person sitting on it, the men’s arms and the anchorage ropes come into tension, and the men’s bodies from the shoulders downwards and the sticks come into compression." The man seated in the centre was Kaichi Watanabe, a Japanese engineer and student of Fowler and Baker who was in the UK to learn Western engineering techniques. ~ Public Domain Review
The “Human Bridge Cantilever Model” photo has lived on to inspire generations of engineering students. More info here
Give me three men, two chairs, two piles of bricks, and four broomsticks and there's nothing I couldn't do.
No, no, I was thinking strictly in terms of engineering. However, substitute women for the chairs and Hostess Twinkies for the bricks and maybe there's something there.