The construction of the famous Leaning Tower of Pisa started in 1173. The tower was originally built as a bell tower for the nearby Pisa Cathedral. It was designed by Bonanno Pisano, a local architect who was also responsible for other public works in the city.
The tower was constructed in three stages. The first stage was the foundation, which was built on a clay soil base. The second stage was the construction of the actual tower, which was made of white marble blocks. The third stage was the addition of the decorative elements, such as the arches, balconies and sculptures.
At the time of construction, the tower was intended to be a vertical structure. However, due to the weak foundation, the tower began to lean after the first stage of construction was completed. This tilt was exacerbated by the additional weight of the marble blocks and decorative elements added in the second and third stages.
Despite the tilt, the construction of the tower continued and it was completed in 1372. The tower has since become a symbol of the city of Pisa and an iconic tourist attraction. It is one of the most visited monuments in the world and has been declared a UNESCO World Heritage Site.
Causes of the Leaning
The primary cause of the leaning of the tower is the weak foundation. The clay soil base was unable to support the weight of the tower, which caused it to tilt. Additionally, the tower was constructed in three stages, with the second and third stages being heavier than the first. This further increased the tilt.
The tilt of the tower was also exacerbated by the fact that the city of Pisa is situated on a riverbank. This caused the ground to shift over time, which caused the tower to lean even more. Finally, the construction of the tower was not symmetrical, which caused the tower to tilt in an uneven manner.
Attempts to Stabilize the Tower
Since the completion of the tower, there have been several attempts to stabilize it. In the late 19th century, a series of lead counterweights were added to the north side of the tower in an attempt to reduce the tilt. In the early 20th century, a number of steel cables were added to the structure in an attempt to provide additional support.
In the 1990s, a project was undertaken to reduce the tilt of the tower. This project involved the removal of 70 metric tons of soil from underneath the north side of the tower and the addition of 800 metric tons of lead counterweights to the south side. This project was successful in reducing the tilt of the tower by 17 inches.
The Tower Today
Today, the tower remains one of the most iconic monuments in the world. It is visited by millions of tourists each year and is a symbol of the city of Pisa. Despite its tilt, the tower remains structurally sound and is expected to last for many more centuries.
Safety Measures
In order to ensure the safety of visitors, the tower is closed to the public when the wind speed exceeds 8 mph. Additionally, visitors are only allowed to climb to the top of the tower in groups of no more than 25 people. Finally, the number of visitors allowed to enter the tower is limited to 300 per day.
Conclusion
The construction of the Leaning Tower of Pisa started in 1173 and was completed in 1372. The tower has since become an iconic symbol of the city of Pisa and is one of the most visited monuments in the world. Despite its tilt, the tower remains structurally sound and is expected to last for many more centuries.
To ensure the safety of visitors, the tower is closed to the public when the wind speed exceeds 8 mph and visitors are only allowed to climb to the top in groups of no more than 25 people. Additionally, the number of visitors allowed to enter the tower is limited to 300 per day.