Table of Contents
Abstract
The Leaning Tower of Pisa is the world’s most famous example of soil-related problems. Even more, the stabilization process of this enigmatic tower proved to be among the greatest challenges that were faced by architectural conservationists and civil engineers. This paper digs deep into the available literature to provide information about the tower of Pisa, the underlying history of its construction and the motivations behind the architectural masterpiece portrayed through the tower. Even more, the paper gives a history of the town of Pisa, and describes the measures taken to ensure that the tower attains permanent stabilization. Indeed, this paper aims at proving that The Leaning Tower of Pisa is one of the most recognizable buildings in the world behind that famous tilt and fascinating history.
Introduction
The Leaning Tower of Pisa is located next to the Cathedral of Pisa, in Piazza dei Miracoli (Square of Miracles) in the city of Pisa, Italy. Situated approximately 10 km from the Ligurian Sea is the town of Pisa, which developed as a port near river Arno. The town retrieves its fame for being home to the Leaning Tower, a freestanding tower with a white marble bell. The Leaning Tower of Pisa is known worldwide due to the unintended tilt that it has towards one side.
The structure is the third oldest in the town’s Cathedral Square, with the Baptistery and the Cathedral being the only other structures that were constructed earlier. Its exact location is behind the Pisa Cathedral, where it was strategically erected to attract people to the Cathedral. During its construction, the tower began to tilt owing to what structural engineers attributed to the inadequate foundation on the ground that was too soft on one side, hence its inability to contain the weight of the structure. Over the subsequent decades of construction, the tilt increased up until the period when the structure was stabilized in the late 20th century and early in the 21st century.
History of Pisa, Italy
Pisa is a coastal town whose history dates back to the period when Italy was referred to as the Roman Empire. The town was a Roman port and merchandise center, as history spells the town existed prior to the creation of the Roman Empire. Reading from the ancient Roman texts, Pisa is referred to as an old town, though it remains unclear who among the Pelasgi, the Greek, the Ligurians and the Etruscans founded the town. As a port, Pisa was largely used as a commercial center, but it played a significant role during wars. Using the strategic location of the town, the Romans were able to launch naval attacks against the Carthagenians, Ligurians and Gauls.
In the 12th and 13th centuries, Pisa recorded tremendous growth that was attributed to the role it played as a military and economic center. It was during this period that the town expanded beyond the shorelines to become a big city that was defined by unique culture and religious symbolism. However, late in the 13th Century, the Battle of Meloria of 1284 saw Pisa lose to Genoa, hence ushering in the beginning of a steady decline of Pisa. As at 1510, the Florentines had captured Pisa, as Pisa surrendered its independence to the conquerors. One of the factors that led to the decline of the strategic role played by Pisa is the emergence and growth of Livorno, a city that would soon become the most important port of Tuscany. Soon after, in 1871, Pisa became a part of the Italy. In recent history, Pisa was targeted frequently during the World War 2, obligating the Italian government to invest heavily in restoring the city’s heritage. Today, Pisa is considered a cultural hub of Italy, and is a renowned tourism center that hosts the Leaning Tower of Pisa.
Architectural description
The town of Pisa is among the oldest towns in Italy, as discussed above. The wealth that led to the growth of the town was created by shipping interests. The Cathedral was among the earliest monumental designs of Pisa, and it represented the classical cathedral designs that were identifiable with ancient Europe.
The Leaning Tower of Pisa was constructed between 1173 and 1370, a period during which it was completed in three phases. This tower stands at a height of over 55 meters from the ground on the lower side, and 56 meters on the higher side. The tower weighs over 14,000 metric tons, with its walls having a width of approximately 2.4 meters at the base. The overwhelming weight of the tower is among the reasons behind the difficulty encountered in finding a clay foundation that could sustain the construction. From the North Side, the Leaning Tower of Pisa has 294 steps, while from the Southside; it has 297 steps (towerofpisa.org). The inclination of the tower, prior to the restoration efforts conducted between 1990 and 2001, was 5.5 degrees. Today, the tower leans at about 4 degrees.
Having taken over 800 years to complete, the architectural design of the Leaning Tower of Pisa was a miscalculation that never reflected the original design of the tower. Upon the initial stages of its construction, the Leaning Tower of Pisa had only two floors, a factor that made it impossible for people to notice the tilt. When the constructors added an extra floor, the leaning began, prior to the indefinite stoppage of the construction.
We can do it today.
Tower of Pisa construction
The construction of the tower commenced in 1173, where the architect Bonnano Pisano supervised the process. At the beginning, the architect envisioned a bell tower that would be a manifestation of the pride of Pisa, and a reflection of the wealth that was identifiable with the city during this period of military success and prosperity. The construction process occurred in three stages that span 199 years.
In 1178, construction works on the tower were halted on the tower after it began to sink. This was because of the weak foundation that was only three meters deep. This complemented the unstable subsoil that was too weak to hold the construction. During the century-long stoppage, Pisa was in a war with Florence before the works resumed in 1278. At this time, the underlying soil had settled, and Camposanto architect Giovanni di Simone took over the construction process (NOVA Online). By the time the architect took notice of the tilt he instructed builders to add an extra height to the upper stories on one side of the Tower, hence the curve that the tower represents today. However, in 1284, the construction was stopped again during the period that Battle of Meloria happened.
During the actual construction of the Tower in the early 12th century, the Tower leaned north, but the builders put masonry blocks on each level to rectify the lean of axis. The seventh floor of the construction was completed in 1319, under the supervision of Tommaso di Andrea Pisano. This architect made a significant mark in ensuring that the Gothic elements of the bell chamber were harmonized with the Romanesque design of the tower. As of 1372, the bell chamber was finally added. The tower has seven bells with bell having a note of the musical major scale. The largest bell was installed in 1655.
Wars and Economic strife
The construction of the Leaning tower of Pisa was largely affected by wars. During the earliest stages of the construction, the war between Pisa and its neighboring city, Florence in 1178 led to the first stoppage of the construction process. The war lasted for almost a century, the period within which the builders stopped the construction. During this war, the town of Pisa defeated the neighboring Florence, hence strengthening its position as a regional military and commercial center.
The next war, the battle of Meloria affected the construction processes significantly. This battle occurred in 1284, and marked the beginning of the decline of Pisa as a town. The Battle of Meloria pitted the Pisans against the Genoans (Role, pg 8). In this battle, the Pisa lost to Genoa, but managed to regain control of their town, thereby resuming the construction of the tower. During the time when the construction of the tower was completed, Pisa was enjoying a relatively long spell of military stability. This would last for two centuries, before the ultimate conquer of the town by the Florentines in 1509. The loss of independence to the Florentines meant that Pisa would no longer be in control of its economic direction.
The loss of independence to the Florentines in 1509 was partly linked with the rise and growth of other economic powerhouse towns in the Tuscany belt. The Roman Emperors preferred towns such as Livorno to conduct military expeditions, a factor that directed majority of the economic resources to the neighboring towns. Soon, Pisa had no resources to finance the expansion of the city and the reconstruction of the tower. This was a season of economic strife that exposed the vulnerability of Pisa.
Counter argument
Today, the Leaning Tower of Pisa is considered one of the greatest architectural masterpieces in the world. Amidst all the tourists that this structure attracts, it presents significant risks that should not be ignored. To begin with, the tower faces the risk of structural failure, which can be attributed to the fragile masonry. Despite the fact that engineers have devoted resources towards stabilizing the structure, the possibility of collapse is eminent, as the subsoil around the foundation can break up. Straightening the tower is a suggestion that would help mitigate these risks.
Conclusion
Between 1990 and 2001, the Leaning Tower of Pisa was reconstructed. Soil was extracted at a slow pace from the North side, and cables used to prevent it from destabilizing (Reina, pg 68). With the use of advanced computer technologies, engineers remodeled the tower and handed it over to the civil authorities on June 16th 2001, whereby it was rendered open for public.
- NOVA Online. “NOVA Online | Fall Of The Leaning Tower | History of Interventions.” N.p., 2000. Web. 12 Oct. 2017.
- Reina, Peter. “Soil Extraction Saves Teetering Tower Of Pisa.” Engineering News-Record.” ENR: Engineering News-Record 246.17 (2001): 68. Web.
- Role, Raymond. “War-Games Of Central Italy.” History today 49.6 (1999): 8. Web.
- “Leaning Tower of Pisa, Italy: Guide to the Tower of Pisa.” Leaning Tower of Pisa. N.p., 2017. Web. 12 Oct. 2017.