The Pisan fleet was all geared up and zealous to start their journey towards the city of Palermo. They fought to conquer, and with this frame of mind, they had already defeated several territories like Messina in Sicily, or when they collaborated with the Genoese to take back the regions of Corsica and Sardinia from the infidel. They were slowly becoming of great importance for reigning over the seas as the people of Pisa actively participated in trade businesses and wars. Pisa was slowly becoming one of the most significant seaports for Italy.
When the fleet returned after conquering over Palermo with abundant treasures, the people of Pisa decided to memorialize their victories by building a cathedral complex. This complex would include a cathedral, a baptistery, a cemetery, and a bell tower.
The construction process of the bell tower began in 1173. The process continued successfully for the first few years as the foundation for the structure was laid, and the first two storeys were built. The problem occurred while constructing the third level as the architects started realizing that the structure is beginning to lean to one side. Various solutions were implemented in 1185 but failed.
It was later determined that the soil that was chosen for the construction of the bell tower was not appropriately strong to support such a large monument. Various inputs were put in by various architects over several years to fix this mistake and the bell tower was finally completed in 1370, which is now known as the Leaning Tower of Pisa!
So ironically, one mistake in analysis or calculations left us with one of the greatest architectural marvels of all time! The leaning tower of Pisa is amongst the most beloved and visited tourist spots in the world today. The arches made out of the shining marble, when hit upon by soft sunlight during sunset are breathtakingly beautiful and worth capturing. Italy is definitely a stop on most people’s travel bucket-list and watching the monument lit at night is like a dream come true for the photographer and the traveler in all of us!
This 60m high marble tower designed by Bonanno Pisano consists of 8 floors in total and weighs almost 14.5k tonnes. It is an accessible bell tower consisting of roughly 250 steps. It is a part of the Piazza Dei Miracoli, also known as the Field of miracles. It is surrounded by other splendiferous medieval monuments like the Pisa cathedral, the Camposanto Monumentale, and the Pisa baptistry. This cathedral complex is one of the best examples of Romanesque architecture. Romanesque style is highly prominent in Western Europe including Italy, France, Germany, etc. The various distinctive elements of this style include Corinthian capitals, open arches, groin vaults, and the extensive use of marble.
“So how is it still leaning and stable at the same time?” One might ask.
The tower was not planned to be leaning. It was due to the miscalculations during construction that the building started to lean towards its southern side.
The foundation is made of lime, sitting in a 5 feet deep circular pitch. The soil on which it rests mainly consists of sand, shells, and clay soil, which is not strong enough to support a large structure. The soil mix on the southern side was more compressible and hence, the building started sinking towards that side. After a point, the sinking stopped and the building started to topple which caused the northern side to move upwards towards the surface of the ground, heading towards a collapse.
The first two floors were built in 1173, and the third floor was constructed in 1178 when they realized that the building is leaning. The construction then stopped for almost a century and the work started again in 1272. This time, the next four floors were constructed at an altered angle, compared to the initially built structure but the leaning did not stop. The construction was disrupted again in 1284 because of war. The final edifice consisting of eight floors was completed in 1370.
In 1995, it was discovered that the tower was not just leaning still but was also rotating more and more at a rate of 2mm per year. The tower was immediately closed to the public for safety purposes and several efforts were made to preserve the monument from collapsing.
- Providing a counterweight on the other side was one of the ideas, and therefore, 600 tonnes of lead was used.
- Other methods included the use of Cables which were fastened onto the third floor of the tower and anchored hundreds of meters away.
- It was then determined by the various engineers and architects working on its preservation that removing certain layers of soil from beneath is the key! Therefore, the top layer or the sandy soil was extracted from beneath by using drilling equipment and the clay below compacted to give a stronger base. The drill was later filled with concrete to make a strong foundation. This helped in reducing the lean back towards the center by 20 inches!
By using these restoration techniques, the center of gravity for the structure was balanced carefully at its base. Currently, the leaning tower of Pisa is only 3 to 4 degrees tilted and post the restoration, the tower is expected to be stable for at least the next 200 years. It is highly important to conserve our heritage buildings because they are a reflection of the history and culture of that particular region and community which needs to be preserved for future generations in a fast-changing world.