PROBLEMS AND AIMS OF THE RESTORATION

The transfer of the two wings of the Clock Tower (1717) to private ownership brings an element of difficulty, even today, to restoration work. Restoration is limited only to the central part of the tower even though it is a three part monument whose origins are diverse.

The wings now in private ownership have undergone changes both in structure and in use that have had their effects on the general stability of the edifice.

In the course of engineer Walter Gobbetto’s non-interventionist, morphological visits and detailing of buildings and monuments within the City of Venice’s holdings in 1992, it was noted that the Clock Tower’s pendulum had moved. This was verified by the fact that it brushed across part of the clock’s housing mechanism during its diagonal movement between two opposing heights. It was verified also by the fact that the cables of the weights carried by the Mori, the Time and the automatic numbers, which touched a wooden frame, were now scraping against and had comsumed its surface.

The problems are dual therefore: How to intervene on only the central section of a building that is in reality made up of three parts; and the already noted subsiding of the edifice.

An analysis of the objectives of the restoration has brought together a wide range of observations in an effort to understand if the present stability of the building – which has noticeably changed with respect to its presumed structural regularity at the moment of its construction with walls measured with lead weights and floors with a level - should include the restoration also of exterior architectural features.

The misshapen cornices and window lintels, which can be noted on different floors both in the oldest part of the edifice as in the additions of the 1700s, are actually breaks in the underlying structure and represent instability. It is difficult at the same time to understand if what caused the damage is still present.

From this comes the importance attributed to metric surveying as a possible means of discovering structural deformities. The south facing section of the building for example has sunk in two different places (who knows when?) – one towards the main square and the other towards the Calle del Pellegrino and has been noted topographically over a range of 300 different points. All the floors have been levelled as a preliminary gesture and measurements taken both in horizontal and vertical, from top to bottom in an effort to discover the anomalies.

Sketches, prints, drawings and canvases (eg. Canaletto’s view of the Clock Tower) and photos from the 1800s and 1900s have been scanned, revised and superimposed on relief maps of the front of the tower to try to discover, with this new method, the amount to which the monument has yielded today as compared to what it was 200, 100 or 50 years ago.

To verify the general stabilty of the tower, a range of non-invasive tests have been carried out using methods such as endoscopy, sonar , ultrasound and magnetometry on all exterior walls and large areas of the floor, ceilings and walls. Excavation checks and coring of the foundations and underlying ground have not yet been able to be carried out but will be done at the end of winter in order to avoid problems caused by Venice’s flood season.

Monitoring carried out from 3.5.1997 till 31.12.1997 have given positive results regarding the state of the building.

Preliminary checks looked at not only the general stability of the structure but also all the interventions, on every portion, that the tower has undergone over the years.

The historical research documented and described in the main events on the “Important Dates” page found on this website, have described the salient points up until the large restoration of the 1850s.

But the research does not finish on the Feast of the Ascension in 1859; it continues on to this day. Venice City Council continues a close examination of its current archives in the Sopraintendenza ai Beni Architettonici e Ambientali and from its current Public Works (Lavori Pubblici) archive, not to mention the interview with architect dalla Toffola who, in 1975, conducted a partial restoration on the central exterior wing of the tower.