Knowing that the films would present the big picture — including the larger historical, social, and environmental issues associated with the building of big things — I was free to operate on a much smaller scale. Using some but not all of the examples chosen for the films, this book focuses entirely on the connections between the main planning and design problems that had to be solved and the solutions that were eventually built. There is something reassuring about the fact that whether structures inspire or simply intimidate with their scale, each is generally the result of a logical and therefore accessible sequence of events. Once we recognize that the elements of common sense and logic play at least as important a role in this process as imagination and technical know-how, even the biggest things we build can be brought down to size.
The kinds of construction material thay may have been considered include an all-wood post-and-beam structure (inexpensive but not fireproof), timber beams on a single stone pier (not entire fireproof but less of an obstacle to river traffic), and a single foot crossing. The three small arches were added to reduce pressure against the bridge during flooding.
For each piece of a full-size wooden pattern was pressed into a bed of sand and then carefully removed. The resulting cavity was filled with molten iron. Using traditional carpentry joints, such as dovetails, mortises, and tenons, the builders would have put the finished pieces together from a fairly lightweight scaffold instead of a heavy timber centering, which would have brought river traffic to a standstill.
Rather than simply using sheer mass to defeat the wind, Eiffel designed to outsmart it. He created open airy structures through which the wind could pass more easily and which required less material to build — another important consideration in these remote locations.
Half of the construction time for the entire bridge was spent building the foundations.
The diggers build a fire right up against the face of the tunnel. When the rock gets very hot, they throw cold water against it. The sudden change in temperature causes the rock to split, making it easier to break up.
Building the tunnel was a 21-year struggle, with over 15 years of actual construction, claiming 200 lives and costing more than 5 times the original estimate.
The borings had given the wrong impression about the depth and consistency of the clay. The workers ran into areas of gravel, which has no stand-up time. There were numerous floods. One was so serious that the project was abandoned for 7 years.
But even in the state-of-the-art Channel Tunnel, things did not go exactly as planned. All the preliminary exploration had suggested that the British TBMs would have to contend only with dry conditions, and it was with this in mind that they were designed. Needless to say, it wasn’t long before a large amount of water began pouring in through fissures.
Getting the spoil out of any tunnel requires careful planning from the beginning, as does finding a new home for it. When the tunnel is 32 miles long, the amount of spoil generated makes this planning critical.
Although Hoover is an arched gravity dam, it is highly unlikely, given its enormous weight, that the arch was really necessary. But people seem instinctively to trust arches, and just seeing that curved crest pushing back against the water makes anyone standing on the dam feel secure.
Concrete is a mixture of crushed stone, sand, and cement. When water is added, the cement undergoes a chemical reaction called hydration. This results in the formation of crystals that tie themselves and the rest of the ingredients together. But hydration also produces considerable heat. If this heat dissipates too quickly or unevenly, cracks can form.
The Aswan High Dam took 30K workers almost 10 years to complete and claimed 500 lives in the process.
Although he’d never actually seen a dome in person, he believed that a new country’s most important building — its capitol — would be taken a lot more seriously with a dome on top.
Cast iron could create the look of the great domes of the past, and it could do it far more economically than masonry. It was the ideal solution for an impatient young country wishing to import a little traditional respectability — and it was fireproof.
Although steel will not burn, it will weaken if exposed for too long to every high temperatures.
While beams can be more or less the same size regardless of which floor they are on, the strength and therefore the sizes of the columns depend very much on their placement in the skeleton.
When these massive structures rise side by side, they really do turn our city streets into dark, windy, inhospitable canyons. Even taken individually, these buildings seem intent on overwhelming, belittling, or at the very least ignoring it. The problem is, it is not so easy for us to ignore them.