Leaning Tower of Pisa

The Leaning Tower of Pisa (Italian: Torre pendente di Pisa) is the most well-known inclined building in the world and symbol of the city of Pisa in Italy.

The tower was planned as a free-standing bell tower ( Campanile ) for the cathedral in Pisa. Twelve years after the foundation stone was laid on August 9, 1173 when the construction had reached the 3rd floor, the tower stump to the southeast began to decline. Then the building was interrupted for about 100 years. The next four floors were built at an angle to compensate for the misalignment. After that, the building had to be interrupted again, to 1372, the belfry was completed. The tilt of the tower is based on the underground from loamy mud and sand, which deforms under the weight. According to recent excavations he stands at the edge of a former island right next to an old, already silted harbor basin at build time. The tilt of the tower is at the end of the renovation work around 4 degrees., Corresponding to a deflection at the head of 3.9 m (at approximately 55.8 m height).

According to legend, a native of Pisa, Galileo Galilei discovered the laws of falling bodies in experiments on the tower.

In 1987 the ensemble from the tower of the neighboring cathedral, baptistery and the cemetery of the UNESCO declared World Heritage Site.

Architecture

The 55 meter high and 12 meter diameter Campanile consists of 14,200 tons of white Carrara marble and has seven bells, but a longer time were not allowed to ring because of the danger of collapse. He should be the highlight of the whole plant of the Piazza dei Miracoli. It differs from the usual square towers in central Italy and is in a great contrast to the pointed towers of northern Europe. It rests on a helical foundation of 700 m³ quarry stone and mortar, height of 100 meters would be builders Bonanno let the bells ring. The city wall around this area is 3.57 meters thick. In addition to the input month and year of the start of construction are engraved: In August 1173, however, certificates always named in 1174, because for the Pisans began after damaligem calendar the new year is already on 25 March..

The Campanile had - except that he should wear the bells - yet another function. If an external danger then fled the clergy in the tower. Wall openings and tabs in the cylinder shaft made ​​it possible to collect on each floor beams and floors as needed.

Each floor has a door out to the gallery of columns, each consisting of 30 columns. On the south side lead above six steps to the bell tower, on the north side only four. The stairs to the top observation deck to Brunelleschi inspired to build a similar stairway to the lantern on the dome of the Duomo in Florence.

From 7 January 1990, the 14,500 -ton tower for visitors had to be closed because the skew is too dangerous. There was a global call for a structural engineer to work out the best solutions for stabilization and submit.

After 13 years of restoration measures in which the tower was re-erected by 44 centimeters, he is re-opened for tourists since December 2001. Groups of visitors can climb the tower on the hour and half hour in groups of a maximum of 40 visitors for a period of 30 minutes.

The Leaning Tower of Pisa is not the building or the schiefste schiefste tower in the world, as many think. Nevertheless, he is one of the most lopsided buildings, which are accidentally erected in this imbalance.

Interior view of the tower

Tour at the bell level

Marble staircase

Look at the bell level

Upper Aus-/Eingang of the staircase

Bells

The seven bells of the cathedral are struck from static caution only by internal electromagnetic hammers, namely by 12 noon clock and before each of the fairs.

Previously, the bells were used liturgically according to their names, such as the Terza for third, the third hour of the liturgical day, so at 9 clock in the morning, or the Vespruccio for vespers, 18 clock. The ringing was done by hand; on feast days, the bells were full - a Slancio - swung.

The smallest bell from 1501, called Vespruccio, has a very slim sugar loaf shape. The bell Del Pozzo is a true to original reproduction cast its predecessor, cast in 1606 by Nicolaus Castellum.

Bell San Ranieri ( 1735)

Bell Del Pozzo ( 1606, 2004)

Bell Vespruccio (1501 )

Remedial measures

Attempts to rescue the Middle Ages, the construction by special construction measures such as sloping floors and walls thinner and lighter on the overhanging side failed, so only 54 meters were built from the originally planned height of 100 meters.

Since the temporary closure in 1990 various remedial measures had been taken. In May 1992, the Campanile was secured with steel tires on the second floor, since there had shown dangerous cracks in load-bearing marble. A total of 18 of these tires were mounted. In addition, 600 tons of lead ingots were stored as a counterweight to the north in July 1993 in the foundation. Thus, the tilt of the tower has been reduced in 1993 to a centimeter. 1995 further restructuring measures ( soil freezing and steel cable anchoring ) were performed in the sequence, however, it increased the incline. Then the higher side of the base with 900 tons of lead was complaining that the inclination stopped.

A committee of international experts, which should decide on the remedial measures of the tower ( from 1990 to 2001 under the direction of Michele Jamiolkowski ), could be bound to any particular measures and was therefore dissolved in late 1996 by the Italian Government. After the great earthquake of September 1997, the Committee was, however, reinstated. It was agreed in the autumn of 1998 the majority to a new step in the reorganization of the Campanile, the so-called soil extraction method ( designed by John Burland for an idea of the engineer Fernando Terracina from the year 1962). For this purpose the following year deep holes were drilled into the ground under the northern part of the tower, so that approximately 50 m³ of material was removed. The soil slumped slowly, and finally the bottom of the tower, and the whole tower was directed increasingly to the north on. The overall slope of the tower was reduced from 5.5 degrees before the start of the renovation work ( around 1990 ) to about 4 degrees. Thus, the tower is expected to be secured for the next 300 years. After completion of the remedial measures the tower on 15 December 2001 was released to the public.

To secure during this work, the tower was secured in 1998 with two large metal cables of 103 meters in length, so that he could not collapse by unexpected movements.

During construction work to secure the building an old Roman road has been discovered which was still listed in the original plans, as well as a medieval grave including complete skeleton.

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