Florence
The initial designs and construction began in 1294 by an architect called Arnolfo Di Cambio. The construction period hit many obstacles preventing the work from commencing; the death of Cambio and the Black Death. It wasn't until 1349 that the structure began to grow resulting in the completion of the campanile in the 1380. During this stage there where plans to expand the original design incorporating the divide of the nave into 4 squares bays.
The original design had specified an octagonal dome starting 52m off the floor and spanning 44m. The dome due to political conflicts between the North and South of Italy wasn't allowed to follow the medieval Gothic style. Instead it was required to convert back to the classic dome style that featured during the Italian Renaissance. In order to abide by these requirements the buttresses, (common in the Gothic architecture) where forbidden as they were seen as ugly. Due to a lack of construction knowledge in this field the construction of the dome came to a halt until an architect called Filippo Brunelleschi invented a 'miracle of design and engineering' (N.Parkyn, 2002).
Work began in 1420 constructing the octagonal dome. Brunelleschi designed a double shelled dome, the inner with a hole at the top for light and the outer for weather protection. The only connection between the outer and inner dome was at the base which was also relied upon to prevent spreading (hoop stress). Horizontal stone and iron chains were connected to the inner dome to provide addition protection against spreading. The chains themselves where stiff octagonal parallel rails with cross ties, their shape distributed the pressure so that the 8 corners didn't take the entire burden.
Due to limitation with the amount of timber available for formwork, Brunelleschi applied a Herrington brick pattern. This enabled the structure to reach the desired design heights as it was self supporting. He decided to replace the stone with a lighter material, brick.
Additionally the system of ribs within the inner dome contained slits which provided support for platforms, coupled with masonry rings (at 9 different elevations) allowing work to progress without scaffolding.
Adequate hoisting mechanisms where invented to lift the materials to elevations required. Once the dome was completed the construction of the lantern began and was completed in 1461 by Michelozzo, due to Brunelleschi's death. A ball and cross was then added and the cathedral of Florence now dominates Florence's skyline, symbolising a magnificent breakthrough in engineering design.
The original design had specified an octagonal dome starting 52m off the floor and spanning 44m. The dome due to political conflicts between the North and South of Italy wasn't allowed to follow the medieval Gothic style. Instead it was required to convert back to the classic dome style that featured during the Italian Renaissance. In order to abide by these requirements the buttresses, (common in the Gothic architecture) where forbidden as they were seen as ugly. Due to a lack of construction knowledge in this field the construction of the dome came to a halt until an architect called Filippo Brunelleschi invented a 'miracle of design and engineering' (N.Parkyn, 2002).
Work began in 1420 constructing the octagonal dome. Brunelleschi designed a double shelled dome, the inner with a hole at the top for light and the outer for weather protection. The only connection between the outer and inner dome was at the base which was also relied upon to prevent spreading (hoop stress). Horizontal stone and iron chains were connected to the inner dome to provide addition protection against spreading. The chains themselves where stiff octagonal parallel rails with cross ties, their shape distributed the pressure so that the 8 corners didn't take the entire burden.
Due to limitation with the amount of timber available for formwork, Brunelleschi applied a Herrington brick pattern. This enabled the structure to reach the desired design heights as it was self supporting. He decided to replace the stone with a lighter material, brick.
Additionally the system of ribs within the inner dome contained slits which provided support for platforms, coupled with masonry rings (at 9 different elevations) allowing work to progress without scaffolding.
Adequate hoisting mechanisms where invented to lift the materials to elevations required. Once the dome was completed the construction of the lantern began and was completed in 1461 by Michelozzo, due to Brunelleschi's death. A ball and cross was then added and the cathedral of Florence now dominates Florence's skyline, symbolising a magnificent breakthrough in engineering design.