Investigations and project hypotheses for the recovery and enhancement of the value of a military site: the case of the Ancona Citadel

Transcription

1 Structural Studies, Repairs and Maintenance of Heritage Architecture IX 43 Investigations and project hypotheses for the recovery and enhancement of the value of a military site: the case of the Ancona Citadel A. Fausto Pugnaloni & F. Fiori dardus - Università Politecnica delle Marche, Italy Abstract The case of building recovery in military architecture involves many problems: the lack of historical documentation, the difficult interpretation of the individual building components, the historical evolutions and the attribution of new destination use. The Cittadella represents one of the must important examples of military architecture in Ancona. During the XVI century, the city had a great transformation: from merchant square to Armi square for a new system of walls and fortifications. The Cittadella constitutes the most important of its architectural elements and shows the ability and the genius of Antonio da Sangallo il Giovane, the architect of fortresses. The project of Cittadella recovery concerns the walls with its eight ramparts, the buildings and the other handmade arts. We studied the architectonic elements of the buildings, and we have used them to reconstruct the model of the complex whole with metrical and geometrical correct properties. We also studied a method to examine the complex whole to recover the superficial set of the area (merloni, troniere, bastioni...) Keywords cultural heritage, military architecture, buildings recovery, history, fortress, model, project. 1 History City walls and the urban plan, strictly related to the technical, political and social needs, used to represent individual reality born together with cities, whom defense came from the rising rules and their mercenary troops in the second half of the XV century. Defensive works of Malatesta, Montefeltro, and Della Rovere constitute the bases of armed architecture in the Marche, and their

2 44 Structural Studies, Repairs and Maintenance of Heritage Architecture IX characteristics have lead them through the centuries. That s why in this area the debate began about city walls which were forced to renew themselves with new functions so as to conserve themselves and fit to the orography. The XVI century proposed to military engineering a confrontation with cannonade techniques. Strongholds were usually built on the hills before the use of heavy artillery became common, their walls were as high as possible and the interior paths were winding and difficult so as to create the last defensive resource. Afterwards, the fortress was forced to assume the urban dimension to contain a lot of artillery, men, and materials. So the XVI century left behind castle architecture, that was previously substituted by the strongholds and then by fortresses. Meanwhile, citadels began to appear that ensured safeness for themselves and for the cities they were built in: they were a last shelter for the troops and the citizens and a domain pivot. The Citadel of Ancona, a defence complex built on a design by Antonio da Sangallo il Giovane, is one of the most important examples of sixteenth-century military architecture. With its pentagonal anthropomorphic plan dictated by the orographic conditions of the site and by the desire to include pre-existing fortifications, it was added to the town s defence system, becoming its most significant element. Figure 1: Garrisons map. Figure 2: Marche in the XV century. Figure 3: Marche in the XVI century.

3 Structural Studies, Repairs and Maintenance of Heritage Architecture IX 45 Its design and construction took place at a crucial time for the city: the submission of the former Free Republic by the Papal State on 20 September This event led to profound changes in the life of the town no less than in it s urban plan. Ancona, which in the early 16 th century was still a harbour and a centre of international exchange, was progressively turned into a stronghold. Architect Giacomo Fontana, describing its characteristics in a report to the pope, Sixtus V, wrote that it stood in the most pleasant and agreeable part of the Adriatic coast in a wide and sweet Valley atop three pleasant large Hills ; it had around its circle of walls, both on the side of the sea and on that of the countryside, eight Ramparts, four forbici, eleven cavaliers, five principal Gates and nine minor gates. It was maintained that an additional fortification was necessary because Ancona was the most important Adriatic outpost of the Papal State and would have succumbed in case of attack, despite the effective protection afforded by its advantageous natural position, due to the evolution of warfare techniques. This stated reason hid the real political will that led to the construction of the Citadel. Clement VII decided to submit Ancona, and the excuse was found in the anticipation of an armed landing by the Turks, which required a reinforcement of the town with modern means. The new Ottoman artillery was no match for Ancona s wall and lunettes: ramparts were needed. The building works began in 1532 on the site of the ancient stronghold of Saint Catherine, erected in the 14th century by order of the Malatesta and subsequently demolished owing to its expensive maintenance. Construction of the new defence system took a long time. With regard to the early, Renaissance period of the work Rocchi wrote: In adapting the building to the characteristics of the site, Antonio confirmed his renown in the study of the terrain. On 13 February 1538, pope Paul III recalled Sangallo to Rome to undertake the fortifications of the City. Chief engineer of the Ancona works was appointed Pellegrino Tibaldi, who directed the work until Other famous engineers like Giambattista Peloro followed one another as the Citadel system was extended and modified to match the fast evolution of warfare techniques: in , Giacomo Fontana erected the ramparts of Saint Augustine and Saint Lucy, connecting the latter to the Citadel with a wall and linking the two ramparts one to the other with curtains. After 1575, he completed the Tenaglia built by Paciotto. At the end of the 16 th century, the system has been finished in its essential and complete form of Citadel and Campo Trincerato (Fortified Camp). Since by the time of its return under papal domination, under Gregory XVI in 1838, the Citadel, which maintained a considerable strategic value, was in a state of complete neglect, the ramparts and curtains were restored ( ). At the end of the 19 th century the city acquired new importance as a military base of the new Italian State. The defence system that can still be identified in the town s structure was reinforced and extended at this time. The Citadel was still the strongest point in the circle of walls, but the defence strategy was modified to include a complementary system of advanced forts and bulwarks in key positions on the surrounding hills: Forte Scrima, Forte Pelago, Forte Altavilla, Forte Garibaldi, Forte Montagnolo, Forte Venanzio. The end of its independence and the transfer to Venice of the Fleet headquarters marked the end of the military relevance of Ancona. The Citadel

4 46 Structural Studies, Repairs and Maintenance of Heritage Architecture IX was progressively abandoned and was used first to house a barracks dedicated to Tibaldeo Branzini and then as a storage site. The most profound and visible changes to the buildings of the internal perimeter were made in this period, with continuous adjustments to different, contingent requirements and the irreversible loss of their function and configuration until the present state of neglect and disrepair of the whole complex. Figure 4: 1569 G. Fontana Prospective view of Ancona. 2 Historical documents One of the main problems to be faced when attempting to make a historical reconstruction of a military site is the scarcity of documents. Also in the present case, our work met with several difficulties, especially as regards the design phase and the early construction stages. Very few sketches and construction indications of the original design are thus available, all of which are held at the Gabinetto dei Disegni e Stampe of the Uffizi. To the first phase of the activity of Sangallo in Ancona ( ) are to be ascribed the early concepts of the new defence system, and to the second phase ( ) the plan and representation of the Citadel, built or still in construction, and a hypothesis of Campo Trincerato, whose Tenaglia was later to be designed by Francesco Paciotto. Of the subsequent period, up until about 1790, there are no documents except for accounts and news of repairs. From this time onwards, however, we have crucial information reported and summarised in the documents held by the Museum and Library of the Historical Institute of Culture of the Military Engineers (ISCAG, Rome): a rich trove of graphic documents relating to projects and building works carried out in the Citadel throughout the 19 th century. In particular there are plans and projects that regard the bulwark system (the new Gregoriano rampart, the Barberino, etc.) and the inner buildings. Among the numerous plans and views of Ancona, sometimes reporting scarce or else fantastic details, those of Giacomo

5 Structural Studies, Repairs and Maintenance of Heritage Architecture IX 47 Fontana held at the Vatican Library and Archives are especially significant: the plan illustrating the Citadel and Campo Trincerato (1590), at which he had worked enclosing with walls Paciotto s Tenaglia, represents clearly the development of the bulwarks and curtains at the end of the 16 th century In the documents mentioned above, the wall system of the Citadel is exhaustively described in its essential evolution until the present time. All the changes undergone by the buildings inside the perimeter throughout the 20 th century are also documented. By contrast, no documentation has been recovered regarding the latter buildings with reliable indications of their precise configuration and the changes made from the 16 th to the 19 th century. Any further information on the original plans and evolution can therefore only be inferred from a detailed investigation of the complex of the Citadel. Figure 5: Modello grafico of the Ancona Citadel. 3 A restoration protocol The present investigation directed at gaining a detailed knowledge of the Citadel system takes place in the framework of a wider programme of restoration and enhancement of the architectural, historical and cultural value of this site both at the level of the town and on a broader scale. Law no. 579 of 31 December 1993 has authorised the Marche Regional government to purchase from the State the Rocca della Cittadella of Ancona on condition that it be used as a sede di rappresentanza of the Marche Region and as a multifunctional centre to host social and cultural initiatives. In January 1998 the regional government drew up a preliminary document, reporting the essential lines of the project and the proposed utilisation of the complex, involving other local and regional bodies: the municipality of Ancona, the regional Soprintendenza per i Beni e le Attività culturali, the regional Soprintendenza per i Beni Architettonici e del Paesaggio, and the Polytechnic University of Marche. These activities led on 12 July 2002 to the signing of a programmatic agreement by these bodies to approve the integrated project of recovery and

6 48 Structural Studies, Repairs and Maintenance of Heritage Architecture IX restoration of the Cittadella di Ancona and its financing, a project in which each body is participating with its respective competences and prerogatives. The municipality of Ancona is drawing up a detailed urban plan of the surrounding area in view of its future use, assessing the new problems connected with access roads and parking spaces. The Soprintendenza per i Beni Architettonici e per il Paesaggio is in charge of a project of recovery of the whole circle of walls. The Polytechnic University of Marche, signally the Department of Architecture, Survey, Drawing, Urban planning and History, has the competence required to contribute to the recovery of the military complex, which will be coordinated with those of the other bodies; in particular, it provides the technical and scientific skill required for the analysis and critical survey of the site. Given its historical and architectural significance and its local symbolic role, the Citadel and its several aspects have long been the object of study by this Department. Now, in view of its recovery and restoration, its various elements are being investigated: the surfaces, i.e. all the open spaces included in the wall curtains; the walls, curtains and ramparts; the built elements; and the underground spaces, with tunnels and chambers opened under nearly the whole of the wall perimeter. Each of these elements is being studied in its different aspects with appropriate techniques to gain a detailed knowledge of the site, a crucial starting point in view for its demanding structural and functional recovery. The challenge lies in the effort to adapt a massive, closed, purposely inaccessible group of buildings to a function that presupposes openness and accessibility without changing its character. A careful historical analysis can lead to formulate hypotheses on the site s evolution which may or may not be confirmed by different study techniques that will be used: dimensional metric survey, critical survey, survey of the architectural and structural components and of the superficial apparatus to map their deterioration, reports on the built structures, geological and geotechnical reports, reports on plants and vegetation, and surveys of the existing buildings above and below ground. 4 Focus The investigation methodology is illustrated below with reference to three significant elements in view of the future public use of the site: the Edificio di Gola, the new sede di rappresentanza della Regione Marche, the Walls, Curtains and Ramparts, and the Surfaces, the latter viewed both as a series of routes of access to the site and as panoramic areas. 4.1 The Edificio di Gola The most complex and significant building of the site is the Edificio di Gola, a massive element that must have constituted an effective barrage and allowed, with a donjon on one side and a sentry walk on the other, to control the two sides and the respective curtains facing the countryside: low on the ground and arising from it with a scarped face, it had on its outer front an effective defence in the three cannon pits placed on the overlying terrace. This is the most ancient and

7 Structural Studies, Repairs and Maintenance of Heritage Architecture IX 49 inhomogeneous building, erected exploiting the fourteenth-century remains of Saint Catherine s fortress; it was enlarged and modified soon after its construction, probably by Antonio da Sangallo himself, and was then altered by the French in 1799 and subsequently at the time of the Unification of Italy with the addition of a whole new floor. Our study has allowed the intricate and massive wall faces, vaulted chambers and chambers endowed with flying arches supporting massive counterscarp walls to be traced (figs.6-7). This phase of the investigation has uncovered key elements in the evolution of the building that had previously been evidenced by the historical reconstruction as elements of interest to assess the evolutionary phases of its life. Samples of these elements have been collected for assays; their results have ascertained that the original construction must have been conceived as a second defence curtain on the side facing the countryside, as also shown on period reproductions, and subsequently extended by adding a building with a façade exhibiting a double order of arches continuous with those of the ramp climbing to the cannon terrace (fig.8). The French walled up the great arches facing the drill-ground, resulting in their present appearance. The nineteenth-century additions are clearly evident, signally the rifle racks, which reflect the evolution of the building s utilisation. This profound change in the original appearance has however become an integral part of its present identity, both in terms of the space occupied and of furnishing. The new floor also represents a very useful space for the new use to which the building will be put, and will allow the enhancement of the value of the overall volume and its panoramic view, preserving the better conserved rifle racks. Figure 6: 3D model of the Edificio Figure 7: Vaulted elements of the di Gola. Edificio di Gola. 4.2 The walls, curtains and ramparts Here the interventions mainly consist in the removal of the infesting plants that also cause structural damage. This work, which lies in the competence of the regional Soprintendenza per i Beni Architettonici e Paesaggistici, will aim at the conservation and restoration of unsafe or severely damaged parts. After an attentive study of wall faces and an assessment of their deterioration, the restoration work is uncovering the suggestive and imposing beauty of the ancient

8 50 Structural Studies, Repairs and Maintenance of Heritage Architecture IX walls and their original shape. The restoration of the parapet and of the collapsed portions of the walls has been carried out using period materials and techniques. Figure 8: Reconstruction of the Edificio di Gola before the alterations made by the French. 4.3 Restoration of the surfaces The hill on which the Citadel stands is characterised by a microclimate that in the last few decades has favoured the growth and development of plants and weeds, some of which are not typical of the area. Human activity has contributed with the partial reforestation of the site, including ornamental plants. The Citadel, originally bare of trees on the embankments to escape detection by the enemy (fig.9), is now profoundly changed by high-trunk trees planted ever since the 1950s in the name of an abstract need for greenery, which has transformed the inside of the fortress into an uncontrolled patch of forest. The loss of the frame of the countryside and the high-trunk trees on the embankments against the walls have altered its proportions, making it less imposing. In addition, the end of military use in the 20 th century and the earthquakes of 1972 and 1997 have caused further damage and destruction, turning some areas into a mass of ruins and stones dominated by the vegetation as nature retakes possession of the place. Hence the need for a project of recovery and conservative restoration of the surface apparatus before the reclamation of the buildings for the projected new uses. All of this requires the identification of the meaning of the extant traces, namely of the original function of the corresponding structures Figure 9: 1920 c.a. (source: C. D. S., Municipality of Ancona).

9 Structural Studies, Repairs and Maintenance of Heritage Architecture IX 51 Figure 10: Example of a data sheet. Here, too, the historical analysis has an important, indeed preliminary role: after identifying the four main homogeneous portions of the inner part of the fortified perimeter, i.e. top portion of the walls, free surfaces, roads and paths, and accessory architectural structures, each was analysed with historical stratigraphy and a critical assessment of its present state. These data have been collected and summarised in individual data sheets (fig.10), which therefore report the historical evolution of each element allowing their critical evaluation, an essential operation in view of their conservative restoration. This method has evidenced the need for multiple, discrete interventions throughout the inner areas of the site, which have been classified into categories and summarised with drawings (fig.11): Restoration of the parapet Recovery of the merlon with gun-embrasure Reconstitution of the surface layer of turf and soil Reconstitution of the surface layer of turf and soil at the cavaliere alto of Saint Barbara Reconstitution of the surface paving and/or turf and/or soil layer of the barracks square Restoration of the stairway of access to the Citadel Reopening of the blocked entrances to the tunnels Reinforcement of the entrances to the practicable tunnels Restoration of the covered pedestrian routes Restoration of the ramp leading to the barracks square Restoration of the fumante della camera di tiro Restoration of the underground storage areas Restoration of the casematte Restoration of the fumanti delle camere di tiro and of tunnel flues

10 52 Structural Studies, Repairs and Maintenance of Heritage Architecture IX Restoration of the cannon housings Restoration of the sentry-box Restoration of the well and cistern. Figure 11: Example of a drawing of the restoration activity. The stratigraphic analysis, associated with a critical study of present-day structures, will allow one to draw up a project of restoration and enhancement of the value of the Citadel directed at recovering the rests of the historical structures and at evidencing their connections by way of routes to give rise to new perceptual relationships and tourist and cultural itineraries. As regards the underground tunnels, the project envisages their reopening as an essential reading key of the workings of the ancient war machine. The tunnels will be cleaned of debris, litter and soil so as to proceed with the static reinforcement of the brick vaults, the reopening of the exits walled up in the 20 th century, the restoration of the existing pavement, the installation of electric lighting, and the restoration or replacement of the entrance gates. References [1] Mezzetti C., Pugnaloni F. - Dell architettura militare: l epoca dei Sangallo e la Cittadella di Ancona, Edizioni Erebi, Ancona, [2] Albertini C. - Storia di Ancona, (sec. XVIII), Libri XVIII, (ad annos). [3] Natalucci M.- La Cittadella di Ancona, in Bollettino Istituto Storico e di Cultura dell Arma del Genio, XXX Luglio [4] Santini G. - Diario dell'assedio e difesa di Ancona nel 1849, L'Aquila, 1925.