In his book Brumelleschi's Dome: How a Renaissance Genius Reinvented Architecture (public library), Ross King explains the many obstacles that stood in the way of construction of the dome of Santa Maria del Fiore in Florence and how Brumelleschi overcame them to create his famous dome.
Brunelleschi used two thin shells and a system of primary and secondary ribs to construct the dome. Because he built the walls at a steep angle to reduce the thrust of the dome, it is a bit pointed rather than completely round.
|Florence Cathedral - credit: Giulio1996Cordignano CC BY SA 4.0|
|The ribs supporting the dome of the Florence Cathedral. credit: CC by PD-US|
In his chapter entitled "Men Without Name or Family," Ross explains the point of view of the common workmen who constructed the dome:
For the previous few months, the building site had been a hive of activity. One hundred fir trees, each 21 feet long, had been ordered for the scaffolds and platforms, and the first of almost a thousand cartloads of stone had been delivered. Peering over the edge of the tambour, the workmen could have seen spread below them in the Piazza del Duomo scores of these sandstone beams, as well as hundreds of thousands of bricks stacked high.
Life on the building sight would not be an easy or enviable one. The pay was low, the hours long, the work dangerous, and the employment sporadic due to bad weather. Most workers in the building trade cam from poor families, the popolo minuto, "little people." The unskilled laborers - men who carried the lime or bricks - were known as uomini senza nome e famiglia, "men without name or family." Altogether as many as 300 men worked on the dome, including those in the quarries (49-50).
According to King, Brunelleschi's achievement still holds a unique place in the history of domes:
Indeed, in height and span the cupola of Santa Maria del Fiore has never really been surpassed. Sir Christopher Wren's cupola for St. Paul's Cathedral in London, with a diameter of 112 feet, is smaller by 30 feet, and a more recent dome, that of the Capitol in Washington, D.C., is only 95 feet in span, less than two-thirds the size of the one in Florence. Not until the twentieth century were wider vaults raised, and then only by using modern materials like plastic, high-carbon steel, and aluminum, which have permitted the construction of vast tentlike structures such as the astrodome in Houston or the lightweight, prefabricated geodesic domes of Buckminster Fuller. Even so, it is no coincidence that, like Michelangelo, the master of large-scale concrete vaulting in the twentieth century, Pier Luigi Nervi, made a technical examination of Santa Maria del Fiore in the 1930s before developing the vaulting techniques he used in structures such as the Vatican audience hall and the Palazzo dello Sport in Rome. It seems wholly appropriate that this masterpiece that was executed by Filippo, the "treasure hunter" who once surveyed the ruins of Rome, should have become an object of study by the generations of architects who followed him (163-164).