Together with the Two Towers, the Fountain of Neptune is undoubtedly the most emblematic monumental complex in Bologna (fig. 1) Commissioned by the papal legate Cardinal Carlo Borromeo and supervised by Bishop Pier Donato Cesi, the fountain is the last in a series of works that created the current appearance of Piazza Maggiore, the imposing emblem of good government and the munificence of the newlyelected pope, Pius IV.1 In particular, the fountain was intended to be the spectacular proof of an impressive urban water system (for a long time the only source of running water in the city). One of the main junctions of this system is located immediately below the fountain. Its design and construction was entrusted to two artists: The architect and painter from Palermo, Tommaso Laureti, and the Flemish sculptor born in Douai, Jean de Boulogne, known as Giambologna. Between 1563 and 1567 they built what is probably one of the most extraordinary examples of Renaissance fountains enhanced by its magnificent location, i.e., the intersection between the cardo and decumanus in the centre of the urban area. It is an absolutely extraordinary artefact due to its size (the statue of Neptune alone equals Michelangelo's David, i.e., roughly 4.10 metres, while the wet area is approximately 250 square metres), quality of detail (the details of Neptune's face are remarkable), engineering and static features (currently tested and proven capable of withstanding earthquakes with ample safety coefficients), hydraulic system (it can channel in slow motion over two litres per second of water to the jets, i.e., without machinery to pressurise it) and solutions to ensure it functioned perfectly (e.g., eight funnels capable of maintaining the vast underground area dry). For a thorough, detailed description of its design and construction, we recommend the wonderful book by Richard J. Tuttle entitled The Neptune Fountain in Bologna. Bronze, Marble &c Water in the Making of a Papal City.2 However, contemporary observation of the fountain allows us to introduce the topic we will be writing about here. If it were notfor the presence of tf)e basin, Neptune would now look simply like a statue rather than a fountain due to the very limited, sporadic water features and an overall absence ofthejets of water. As illustrated by the extremely beautiful drawing executed by Marcantonio Chiarini in 1763,3 the latter were undoubtedly the key feature ofthe original composition of the designers/builders (fig. 2). To preserve the fountain from its obvious, ongoing deterioration, tf)e Municipality in collaboration with the University of Bologna and the Institute for the Conservation and Restoration of the MiBACT (ISCR) opened a worksite in 2015. The key feature ofthe conservation project was its hydraulics. The study began by reconstructing the hydraulic system and functioning of the fountain as specified in the original project; it went on to review the changes that took place over the years, changes that have made the fountain what it is today, i.e., based on a solution introduced in the late nineteenth century when the original system was connected to the first new urban aqueduct. The study provides an explanation for the current deterioration of the marbles and bronzes and clarifies why the fountain never functioned properly from day one. It also explains how to make it work properly using the system installed during the restoration project performed in the late eighties4 and, above all, how the splendid Renaissance fountain can, for the first time in its life, faithfully implement Tommaso Laureti's design of the jets. In particular, a fluid dynamics engineer and an expert hydraulics engineer5 developed an appropriate jet system capable of (1) restoring the fountain's original function and (2) using appropriate water features to eliminate, or at least curtail the deterioration caused by percolation. The design of the jet system was developed based not only on information in texts written by Laureti,6 the inventor of the water supply system, but also the aforementioned tables by Chiarini illustrating a possible configuration. The design also considered the estimates drawn up in 2003 regarding its possible carrying capacity.7 The trajectory of the jets was calculated to restore the original design and appearance developed by the designers. For various reasons it is extremely difficult to study and simulate the activation of the jets of water in a historical fountain, test their trajectories and formulate a design proposal. These difficulties include: damage to parts of the system, temporal superimposition with other studies and interventions, the need to avoid accidental deterioration of the original materials, and the fact that different solutions had to be tested and verified. The potential provided by digital simulations overcome these limitations by reproducing conditions and operations that in real life would be much more complex and burdensome.
Apollonio, F.I., Gaiani, M., Foschi, R. (2016). New water for the neptune fountain in bologna: simulation of the design of the multi-jet system. DISEGNARE IDEE IMMAGINI, 2016-(53), 68-79.
New water for the neptune fountain in bologna: simulation of the design of the multi-jet system
Apollonio F. I.;Gaiani M.;Foschi R.
2016
Abstract
Together with the Two Towers, the Fountain of Neptune is undoubtedly the most emblematic monumental complex in Bologna (fig. 1) Commissioned by the papal legate Cardinal Carlo Borromeo and supervised by Bishop Pier Donato Cesi, the fountain is the last in a series of works that created the current appearance of Piazza Maggiore, the imposing emblem of good government and the munificence of the newlyelected pope, Pius IV.1 In particular, the fountain was intended to be the spectacular proof of an impressive urban water system (for a long time the only source of running water in the city). One of the main junctions of this system is located immediately below the fountain. Its design and construction was entrusted to two artists: The architect and painter from Palermo, Tommaso Laureti, and the Flemish sculptor born in Douai, Jean de Boulogne, known as Giambologna. Between 1563 and 1567 they built what is probably one of the most extraordinary examples of Renaissance fountains enhanced by its magnificent location, i.e., the intersection between the cardo and decumanus in the centre of the urban area. It is an absolutely extraordinary artefact due to its size (the statue of Neptune alone equals Michelangelo's David, i.e., roughly 4.10 metres, while the wet area is approximately 250 square metres), quality of detail (the details of Neptune's face are remarkable), engineering and static features (currently tested and proven capable of withstanding earthquakes with ample safety coefficients), hydraulic system (it can channel in slow motion over two litres per second of water to the jets, i.e., without machinery to pressurise it) and solutions to ensure it functioned perfectly (e.g., eight funnels capable of maintaining the vast underground area dry). For a thorough, detailed description of its design and construction, we recommend the wonderful book by Richard J. Tuttle entitled The Neptune Fountain in Bologna. Bronze, Marble &c Water in the Making of a Papal City.2 However, contemporary observation of the fountain allows us to introduce the topic we will be writing about here. If it were notfor the presence of tf)e basin, Neptune would now look simply like a statue rather than a fountain due to the very limited, sporadic water features and an overall absence ofthejets of water. As illustrated by the extremely beautiful drawing executed by Marcantonio Chiarini in 1763,3 the latter were undoubtedly the key feature ofthe original composition of the designers/builders (fig. 2). To preserve the fountain from its obvious, ongoing deterioration, tf)e Municipality in collaboration with the University of Bologna and the Institute for the Conservation and Restoration of the MiBACT (ISCR) opened a worksite in 2015. The key feature ofthe conservation project was its hydraulics. The study began by reconstructing the hydraulic system and functioning of the fountain as specified in the original project; it went on to review the changes that took place over the years, changes that have made the fountain what it is today, i.e., based on a solution introduced in the late nineteenth century when the original system was connected to the first new urban aqueduct. The study provides an explanation for the current deterioration of the marbles and bronzes and clarifies why the fountain never functioned properly from day one. It also explains how to make it work properly using the system installed during the restoration project performed in the late eighties4 and, above all, how the splendid Renaissance fountain can, for the first time in its life, faithfully implement Tommaso Laureti's design of the jets. In particular, a fluid dynamics engineer and an expert hydraulics engineer5 developed an appropriate jet system capable of (1) restoring the fountain's original function and (2) using appropriate water features to eliminate, or at least curtail the deterioration caused by percolation. The design of the jet system was developed based not only on information in texts written by Laureti,6 the inventor of the water supply system, but also the aforementioned tables by Chiarini illustrating a possible configuration. The design also considered the estimates drawn up in 2003 regarding its possible carrying capacity.7 The trajectory of the jets was calculated to restore the original design and appearance developed by the designers. For various reasons it is extremely difficult to study and simulate the activation of the jets of water in a historical fountain, test their trajectories and formulate a design proposal. These difficulties include: damage to parts of the system, temporal superimposition with other studies and interventions, the need to avoid accidental deterioration of the original materials, and the fact that different solutions had to be tested and verified. The potential provided by digital simulations overcome these limitations by reproducing conditions and operations that in real life would be much more complex and burdensome.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
