It was constructed as a freestanding bell tower for Pisa Cathedral. The construction of the Leaning Tower of Pisa began in August 1173 and lasted 344 years. It began to tilt in 1178, when work on the second level began. The lean was caused by one of the sides sinking into the soft ground. The tower is 853 feet high and there are 52 steps leading up to the top.
The tower has been called the "wedding cake" because of its distinctive shape with thin layers stacked upon each other. The bottom layer is about 16 inches thick while the side layers are about 30 inches thick. The weight of the tower is mainly concentrated at the base because there are no walls to bear the weight. If it were a walled city, the weight would be distributed over a larger area and some parts of Pisa might even have felt the effect of the tower's tilt.
Pisa has had more success than most cities building towers. There have been many attempts to build taller towers using technology from the day. But none of them have succeeded in reaching the height of the Leaning Tower of Pisa.
The fact that this famous tower is leaning makes it easy to find on Google Maps. And every time you search for it, you see that it is still standing after all these years.
But the tower is not safe.
John Burland, a British engineering specialist, headed the team. The leaning tower of Pisa is the cathedral's freestanding bell tower in the Italian city of Pisa. The 56-metre tower, famous for its unintended tilt, took nearly 200 years to build. Work began in 1173, and five years later, it began to tilt. The cause of this unusual phenomenon has never been determined with certainty but it may have been due to design flaws, bad construction practices, or natural causes such as an earthquake. What is certain is that the tower remained standing despite the lean because it was built to be stable.
The tower is not as tall as originally constructed because part of it was demolished after it fell into disuse during a period of Pisan history known as the "Wandering Republic". When money became available for building projects again in the late 15th century, the people wanted to restore the tower to its original height. But since they did not know how it had been damaged over time, they set about repairing it by nailing new floorboards over the old ones. These new floors are what cause the tower to appear taller today than it did when it was first built.
The tower remains in Pisan territory but is under the protection of the United Nations Educational, Scientific and Cultural Organization (UNESCO). It has been listed as a World Heritage Site since 1979.
In addition to being an architect, John Burland also designed Pisa's Cathedral and its surrounding buildings.
The Tower of Pisa's lean enters the tale in 1173, when building begins. It had began to tilt by the time its builders reached the third storey, in 1178, due to the soft ground. The Pisa Leaning Tower is now more than five meters off perpendicular. However, because of its deep foundations, it remains standing.
The tower continues to lean slowly but steadily. In fact, since its restoration in 1990, the tower has been leaning by about half a millimeter each year. By the end of this century, it will be completely off-axis.
How does the weight of the tower affect the ground under it? When the tower was built, there were already large stones at the site, which made perfect bases for the tower's legs. But over time, these stones have moved slightly, forcing the tower to lean against them.
The legs of the tower are not fixed in place; instead, they are free-floating objects within the body of the tower. This allows the tower to respond to uneven surfaces without damaging itself. As the base of the tower becomes heavier or lighter depending on what material is placed there, this affects how much pressure is applied to the ground beneath it. If the ground is hard, then the tower will have no problem standing up straight.
When did the Leaning Tower of Pisa begin to sag? After the first three of the tower's planned eight storeys were completed in the late 1170s, it became clear that the Tilting Tower of Pisa was leaning. The uneven settlement of the building's foundations on the soft ground created the tilting. By the early 14th century, the lower part of the tower was leaning by about 2 degrees.
The reason for the leaning of the tower has long been a subject of speculation. Some say it is because the ground underneath it is moving.
Others believe that it is due to the weight of the tower itself. Yet more think that it is due to some combination of the two. The fact is that we will never know for sure what caused the tower to lean because there are no records describing its construction.
The earliest written evidence of the leaning tower comes from 1321 when it was mentioned by an Italian poet called Bonanno Latini. He described how much it upset people that the tower was leaning!
Almost a hundred years later, in 1349, another writer named Giovanni Pucci described how he had seen the tower when it was not tilted and said that it had taken six years to build it! This suggests that the tower may have already been leaning at the time it was built.
The Pisa Leaning Tower The Leaning Tower of Pisa (Italian: Torre Pendente di Pisa) or simply the Tower of Pisa (torre di Pisa ['torre di' pi: za; 'pi: sa]) is the campanile, or freestanding bell tower, of the cathedral of Pisa, noted worldwide for its roughly four-degree lean, caused by an unstable base. The present tower was built between 1164 and 1246 to a design by Guglielmo de' Cantoni, with modifications through the years.
It is located in Piazza del Duomo on the eastern side of the city center of Pisa. The leaning tower has been called the "Sistine Chapel of Europe" because of its similarity in design to the Sistine Chapel in Rome. It also resembles a candleholder with both poles bent toward the center of the earth.
The tower's current angle of tilt is approximately 4 degrees, but it has been reported to be as much as 5.5 degrees.
Including its belfry, the Tower measures about 140 feet high. But due to the tilt, the top of the belfry is some 20 feet higher than the bottom. The maximum height of the tower from the base to the top of the belfry is about 180 feet.
It is not known who ordered the construction of the tower, but it has been suggested that it was probably designed by either Alberti or Brunelleschi.