At first glance, she hasn't changed and still looks askance at you from her native Tuscany. But on closer inspection, the Leaning Tower of Pisa has leaned a little less in recent years.
The famous tower leans less and less but continues to attract millions of tourists each year.
"She's still recovering , explains engineer Roberto Cela to AFPTV, watching the famous leaning tower shine in the winter sun. And it will be many more years before this stops" he assures. Symbol of the power of the maritime republic of Pisa in the Middle Ages, the medieval campanile of 55.86 m (south side) and 56.71 m (north side) began to lean rapidly after the start of its construction in 1173 The sagging was due to too soft ground. This characteristic, which has made it famous throughout the world, has been deemed dangerous. The experts even feared for its survival and decided 30 years ago to undertake a vast consolidation project.
The Tower of Pisa had recovered 41 cm following works
Listed as a UNESCO World Heritage Site, the marble monument was closed to the public in January 1990 and for eleven years for security reasons, its inclination reaching a maximum of 4.5 meters from the vertical. Following the work, carried out between 1993 and 2001 under the supervision of an international committee led by engineer Michele Jamiolkowski, the tower had recovered 41 cm from the vertical. And according to recent measurements, 4 cm have since been added. "We installed a series of tubes underground, on the side where the tower leans , explains Roberto Cela, who directs the Opera Primaziale Pisana (OPA), the association in charge of the main monuments of Pisa. We removed material from the subsoil by drilling very carefully and thanks to this system, we recovered half a degree of slope" , he says.
An AFP video of the Tower of Pisa... straightening up.
The Leaning Tower of Pisa "will never be completely straight"
To understand the movement of the 14,500 ton monument, the experts take measurements every hour, some with automatic pendulums, others manually using the surveyor's optical level. "The tower tends to warp and reduce its slope in summer, when it is hot, because it leans to the south, so its southern face is heated and the stone expands. And in expanding, it straightens" , explains engineer Nunziante Squeglia, who has been studying and measuring the tower for 25 years. The tower was much more mysterious when I arrived. We didn't really know why she was leaning and why the phenomenon was accentuated" he points out. According to him, the tower studied from all angles for more than a century still holds many mysteries, such as the remains of what looks like a domed roof inside the building. Its function remains unexplained to this day.
Despite all the work campaigns, the tower "will never be completely straight" , says his colleague Robert Cela. " During its construction, there were attempts to straighten it, adding stone to one side, so that it has a slight banana shape" , he notes. As thousands of visitors do every day - there were 3.2 million in 2017 - Alvin, a Singaporean tourist takes photos of his friends "holding" the tower in the background. "Oh, I didn't notice that its slope had gone down. Is that because everyone is pushing it?" he jokes, before assuring that he would be the first to push her the other way if she straightened up a little too much.