Friday, November 19, 2010

Brunelleschi's Timeless Masterpiece

     Preface: Bricks and mortar have always fascinated me. During my freshman year in college, I worked a part-time job as a brick tender and laborer at a gymnasium project. I erected scaffolding, hauled bricks, mixed mortar, and quickly learned that the masons were kings of the construction site. Their craft, which has been around for thousands of years, is highly respected.

When we planned our trip to Italy this year, we included Florence, a vibrant city, rich in history, art, and architecture. The essay below tells of our experience of coming face-to-face with Brunelleschi’s architectural engineering feat, the world’s largest masonry dome, built more than five centuries ago.

Cityscape of Florence

Brunelleschi’s Timeless Masterpiece
Non-fiction essay and photos
by Gregory E. Larson, AIA
          I looked out the train window at the Italian landscape as the high-speed Eurostar approached Florence, Italy. A few minutes earlier, Gretta and I rocketed along the countryside and through the tunnels at 160 miles per hour, but now we were slowing down. While the train made its slow curve into the terminal, I strained my neck, looking in every direction. Ah, there it is . . . the Duomo (One of the Italian terms for cathedral). The large, red-tiled dome of Santa Maria del Fiore was a beacon with its white cap and golden sphere and cross for all to see. It would be our compass, our point of reference for the next four days. 

          The Duomo is a structure that defines the Italian Renaissance period.  It speaks of a time when the conditions were ripe for advancement in technology and art, and when Florence became one of the cultural launching pads for Western civilization.  The Duomo is the largest masonry dome ever built, a massive structure that overshadowed the city of Florence when it was completed.

 Florence Duomo
          We walked from the train terminal, rolling our luggage along the crowded stone streets and sidewalks to the piazza in front of the cathedral, and stood in awe of the church and dome. How was it possible for the Florentines to design and build such an enduring structure? How were they able to get all the material into the air and set it into the proper place, to withstand wind, earthquakes, wars, and gravity itself? Thousands of tons of carved stone, marble and brick have withstood the test of time and nature.

Santa Maria del Fiore (Duomo)

     The current cathedral replaced an older church structure that had been built in the sixth and seventh centuries.  Construction began in 1292, and continued for over 150 years.  There were many architects involved in the different parts and stages of the project.  The design and construction was overseen by the Woolen Guild, a group of city leaders.

          Numerous design competitions had occurred, but a final master plan was eventually approved by the Guild and by city referendum. The plan included a large cupola or dome that spanned 140 feet. It would be larger than any dome in existence. The leaders and the city proceeded on faith that a solution would emerge, even if by divine guidance.

          Fillipo Brunelleschi (1377-1446) was an artisan and a goldsmith; not the person one might expect to oversee the design and construction of the Duomo.  But, he was a true Renaissance man.  As a goldsmith, he learned intricate procedures for making jewelry and clocks.  He became fascinated with the gears and mechanisms that were required to make them function.  Born prior to Leonardo da Vinci (1452-1519) and Michelangelo (1475-1564), Brunelleschi helped establish the tradition of sketches and coded notes when creating new inventions and machinery.
          In 1401, Brunelleschi lost the Florence competition to design and build the baptistery bronze doors to Lorenzo Ghiberti. Shortly thereafter, he went to Rome to further study art and architecture. After several years, he returned to Florence to win the competition to design and build the Duomo.

          In the autumn chill, we bought tickets to climb to the top of the Duomo, and began the long process of climbing the equivalent of a 25-story building, one step at a time. The stairs at the beginning of the climb were wrapped around the columns, or internal piers of the dome. While we climbed the stairs, I thought of the arguments that raged in the early design process, when the leaders debated whether or not to have exterior flying buttresses, which evoked the gothic architecture of the north, or a more Romanesque design which would internally support the weight of the tall structure, and would be more representative of the designs in the regions around Florence. The internally-supported structure was the more popular choice.

          Eventually, we arrived at the base of the dome, and our path opened to a balcony walkway that was inside the cathedral.  The frescoes of biblical characters, frozen in their baroque poses, hovered on the dome above us.  In the hushed atmosphere and the mellow light, we looked down at the church tourists who appeared like ants moving across the inlaid stone floor 171 feet below.

Frescoes on the dome interior

View to the cathedral floor...171 feet below
          I tried to imagine what the masons thought centuries ago as they climbed the stairs each day, with their trowels and tools, along with their lunch and wine in their bags. It must have been a surreal environment for the workers, perched high above the church floor, with the sun above, and the pigeons landing nearby on the newly-set bricks and mortar.

          For such a large dome, Brunelleschi had many challenges to overcome in the design and construction.  Most domes built in that period had a temporary understructure to hold the stone and mortar in place until it was completed.  The Duomo’s size prevented any temporary framework.  No trees existed that were large enough, nor was there any way to lift and hoist the trees above the cathedral piers and walls.  The dome was too high above ground to build any wooden scaffolding from the ground below.  The masonry would have to support itself as the dome construction progressed upward, and the workers would have to trust that Brunelleschi’s design would support them as they built the inward-curving masonry walls.  The scaffolding was anchored to the masonry construction, and was moved upward as construction progressed.  Brunelleschi specifically designed a platform below the masons’ perch to prevent them from looking down while they worked.

          Gretta and I continued upward on the narrow stone stairway.  We climbed in the sandwich space between the inner and outer shell of the dome.  I was able to touch the individual bricks and see the masonry ribs between the two dome shells.  Every so often, I peeked out through one of the nine vents that are located in each exterior dome section.

          For Brunelleschi and the workers, the construction logistics were staggering.  Over four million bricks, along with the mortar materials, had to be lifted hundreds of feet into the air and precisely placed at the proper curve and elevation.  Brunelleschi’s watchmaker skills were put to use as he secretly developed sketches and plans for lifting and positioning devices.  He is credited with inventing an ox-driven hoist with a reverse mechanism that allowed the crane operator to raise, lower, or stop the suspended load without requiring the oxen to change directions on their circular path.  His hoist designs were a major breakthrough for large construction projects and are considered the first inventions of modern-era construction cranes.

          We gasped for breath and our calf muscles burned as we climbed the last rise of steps along the curve of the dome to the top.  The bright sunlight pierced the opening as we stepped out onto the observation deck at the base of the lantern, or the dome’s cap.  At a height of 295 ft., we were at the top of the crowning achievement of Florentine history.  The only portion of the structure above us was the spire with the eight-foot diameter sphere and crown at the very top of the dome.

Observation area at the dome's lantern

          The dense city of Florence lay before us, with patches of sunlight and cloud patterns washing the streets and buildings in the cool, steady breeze.

          Sprinkles of rain began to fall, and my thoughts turned again to the workers who constructed the dome in all types of weather.  The tramontana, or the severest storms from the mountains, caused them to cease work. The project was also halted when leaders were concerned that city-state skirmishes were imminent. The masons were asked to travel to strategic outlying castles to fortify the stone walls.

         The dome construction continued from 1421 to 1436.  There was a lantern design competition, won by Brunelleschi.  The ball and cross at the very top were designed by Verrocchio.  Construction of the lantern, built with white Carrara marble, was completed in 1446, barely a month before Brunelleschi died.  His remains now rest in a crypt below the cathedral.
          For the remainder of our four days in Florence, I continually peered towards the Duomo, my anchor.  It was the dominant feature on the cityscape from places such as the Boboli Gardens, the Piazza Michelangelo, and the Ponte Vecchio.

          I looked out from the windows in our room on the piazza in front of the cathedral and watched the townspeople and tourists scurry about. I imagined the pride of the fifteenth-century Florentine citizens had in their city and church, as they went about their daily work in the shadow of the massive dome. It is a pride that still exists in the hearts of the townspeople today.
Brunelleschi's Timeless Masterpiece

King, Ross. Brunelleschi’s Dome. New York: Penguin Books, 2000.

Prager, Frank D., and Scaglia, Gustina. Brunelleschi – Studies of His Technology and Inventions. Cambridge, Massachusetts: MIT Press, 1970.