There was a time when it was feared that the Leaning Tower of Pisa was about to collapse, as the tilt that made it famous threatened its very existence.
But in the year it celebrates its 850th anniversary, its guards ensure its stability.
“Today the bell tower is an immutable monument,” said Andrea Maestrelli, president of the association. Opera della Primaziale Pizzana (OPA), the 1,000-year-old entity that looks after the cathedral complex that includes the tower.
On Wednesday, August 9, the Foundation announced a program of events to celebrate the anniversary of the complex, ie UNESCO World Heritage.
On August 9, 1173, the first stone was laid for the construction of the Tower of Pisa. “Thanks to the donation of 60 coins made by a widow named Berta, for the construction of a bell tower in our cathedral”Archbishop of Pisa Giovanni Paolo Binotto said during Press conference on Wednesday.
The slope became alarming
In the early 1990s, the tower reached a 4.5° inclination and concerns about its stability led to an international effort to prevent it from tipping over. Work began in 1993 and lasted eight years.
Currently, in addition to local monitoring, the tower is monitored by satellite which means that even the slightest change in its position is noticed. Experts ensure that your future is well secured.
problems from the beginning of construction
The tower’s stability problems started early.
On August 9, 1173, the first stone of the bell tower of the Cathedral of Santa Maria Assunta was laid. Construction stopped when the third floor was built due to flooding and was only resumed in 1275, when three more floors were built, as the tower was leaning.
In an attempt to straighten the tower, these three floors were “pushed” in the opposite direction of the slope. The tower was completed in the mid-14th century, when the bell tower was added.
As the slope deteriorated towards the end of the 20th century, part of the soil under the foundations on the north side was removed by a series of boreholes, causing an imperceptible decrease in the slope.
The recent report of the monitoring group monitoring the monument highlighted this The slope slope is about 460 mm.Maestrelli said, adding that he has the same inclination he had at the beginning of the 19th century.
“From the latest report by the International Committee for the Protection of the Tower, what stands out is the preservation of a good drop of 460 mm in the eaves between the seventh frame of the bell tower and the foundation. Now the inclination of the tower is the same as documented at the beginning of the nineteenth century,” he said.
Today, this tower represents a case study at the center of one of the most complex monitoring systems in the world, explains Roberto Sella, Technical Director of OPA. Thanks to an agreement between Italy’s Ministry of Cultural Heritage and OPA, experts are integrating satellite observations with data collected on the ground.
Progress on this oversight will be presented next year, within the scope of a A series of events scheduled to commemorate the 850th anniversary of the founding of the tower.