Pisa Online - tour della magnifica cittŕ della Torre Pendente Rassegna stampa sui lavori alla Torre di Pisa dal 1995 ad oggi
News about the Leaning Tower of Pisa since 1995

 

Tuscans Hold Their Breath / How to Keep the Monument From Falling

Putting a Modern Slant on the Tower of Pisa

By John Tagliabue
New York Times Service

PISA, Italy - As if a girdle of steel cables around its base, 830 tons of lead ingots stacked on the rim of its foundations and a steel fence skirting its perimeter were.not enough, the alluringly leaning tower of this maritime Tuscan city appears about to suffer further indignity.
If the plans of engineers entrusted with its welfare come to fruition, the 800 - year - old marble pillar will be girded sometime this spring with a heavy steel strap about one - third the way up its 187 - foot (57-meter) height. From the strap, two steel cables will be strung, then anchored to the ground nearly 350 feet away. The maneuver, which Italian newspapers have loosely compared to outfitting the - structure with suspendes, may for a while mar its marble grace.

But strapping the pillar is a first step in an elaborate plan to prevent it from tumbling over altogether.
The bracing cables will enable experts to work toward a more elegant and enduring solution to the central problem: the centuries-old slow tilting, by about one twenty-fifth of an inch every year, which if untended will cause the tower ona day to fall.
"I am not a technician, but it gives me peace of mind," Ranieri Favilli, the tower's octogenarian keeper, said of the plan. "I have the greatest confidence in the experts."
The experts are on an international panel entrusted by the Italian government with finding a way to protect the tower. Announcing the $7 million plan recently, Michele Jamiolkowski, the Turin University professor of engineering who heads the panel, said it.would "give us greater tranquillity in the pursuit of our labors."
What those labors consist of is a process called "controlled subsidence," meaning that the ground below the northern flank of the tower will be lowered to provide. a more level base. (The tower tilts south.).
Restoring it to the vertical is out of the question, of course. To begin with, the base is treacherously slanted. After the pillar was about one-third finished, and its perilous lean became obvious, construction was halted. It later continued closer to the perpendicular, but that could not offset the base's tilt.
Ultimately, Mr. Jamiolkowski says, the aim is to reduce the tower's lean to about five degrees from about five and a half degrees - and hold it there. That, the professor told Italian newspapers recently, "is enough to guarantee our tranquillity for hundreds of years."
But in a country where the best - laid plans often fall victim to procrastination or politics, skeptics abound. Over the years, some Pisans point out, the tower has shown greater stability than, say, Italy's governments, of which there have been more than 50 since the end of World War II.
Others, like Rina Staderini, one of 101 stallholders along the tower's western flank who peddle items like miniature plastic replicas of it, favor a strict hands-off policy.
" If they touch it, it will topple, " mrs. Staderini said. "If they leave it in peace, it will stay on its feet."
In 1965, after a drop in Pisa's water table caused the tilt to accelerate, a new law trasferred responsibility for the tower's well-being from Pisa to Rome. But the experts disagreed on a choice of therapy.
"It is as with a sick persón," said Mr. Favilli, the tower keeper. He is a retired agronomist appointed by Pisa's archbishop as the 97th holder of an office fohnded in 1089, before the tower was built, essentially to oversee construction of thé adjacént cathedral and baptistry.
"At times the choice of therapy is difficult," he said. "The experts are all luminauies, and are not always of one mind."
Work on the tower began in 1174, under Bonanno Pisano. It was completed when Tommaso Pisano capped it in 1350 with a belfry. In January 1990 the tower was closed to the roughly 800,000 energetic visitors who, despite its incline of roughly 16 feet from the perpendicular, clambered up its 294 steps yearly to enjoy the splendid panorama from the top.
The plan hit upon by Mr. Jamiolkowski and his panel is to exploit the stability afforded by the strap and cables to perform the riskiest part of the projett: pouring a ring of concrete underground around the foundations, then driving 10 steel cables from one side of this ring and anchoring them in firm layers of soil about 165 feet below the base.
This anchoring is necessary if, as the experts hope, the tower is to be reopened to visitors someday. The two cables and strap can afterwards be removed, though no one is willing to guess how soon that will happen.
Just how risky the operation is became evident in 1995, when excavations around the base suddenly caused the 14,000-ton tower to lurch nearly onetenth of an inch in one night. To pull it back, 230 tons of lead ingots were added to the 600 tons that engineers had begun gradually amassing on the rim of its base in 1992 as a counterweight.
Still more support was then provided by a girdle of cables wrapped around the lower portion of the tower; these are to be removed when all the work is finished.
Some Pisans do not want to see another corset and cables of steel go up.
"I am convinced that the tower will lose its fascination," said Francesco Giagnoni, a Pisan who has admired the structure's profile for 35 years while hawking woodel Pinocchios, leather purses and little Leaning Towers.
Yet, the tower as building site appears not to put off the tourists who are the source of livelihood not only for peddlers like Mr. Giagnoni, but also for Pisa's tour operators, hoteliers and holse-drawn-cab drivers.
"We'd read about it," said Teresa Marra, an American lawyel. after photographing three companions in the obligatory leaning pose in front of the tower. "In fact, I thought it would be more covered."

 

Pisa Online - tour della magnifica cittŕ della Torre Pendente Rassegna stampa sui lavori alla Torre di Pisa dal 1995 ad oggi
News about the Leaning Tower of Pisa since 1995

Copyright 1996-2014 PisaOnline.it - All rights reserved