The Leaning Tower of Pisa is the bell tower of the cathedral of the Italian city of Pisa.
Although designed to stand vertically, the tower began to lean shortly after construction began in 1173 due to a poorly laid foundation and unstable soil that allowed the foundation to shift. When the Pisans entered war, construction was stopped allowing the underlying soil to settle. If construction had continued, the tower would have toppled.
Construction started again over a century later. Engineers tried to compensate for the tilt by making upper floors taller on one side than the other. This made the tower lean in the other direction.
The tower is 183 feet from the ground on the lowest side and 186 feet from the ground on the highest side. At the base, the walls are 13 feet apart. At the top, the walls are 8 feet apart.
The tower has two staircases. The north-facing staircase has two fewer steps (294) than the south-facing staircase (296).
Prior to restoration work that was performed in 1990 and 2001, the tower leaned at an angle of 5.5 degrees. The tower now leans at about 3.99 degrees. This means that the tower is over 12 feet from where it would stand if the tower were perfectly vertical.
The scaffolding on the tower is there to help repair visual damage (mostly corrosion and blackening).
On January 7, 1990, the tower was closed to the public for fear that it would collapse. The bells were removed to relieve some weight and cables were tied around the third level and anchored several meters away. Apartments and houses in the path of the tower were vacated. In the end, 50 cubic yards of soil were removed from underneath the higher end. The tower was straightened, returning it to the exact position that it occupied in 1838. After a decade of corrective reconstruction and stabilization efforts, the tower was reopened on December 15, 2001. In May 2008, another 77 tons of earth were removed. For the first time the tower’ history, engineers declared the tower stable.
The Leaning Tower of Pisa is no longer the world’s most lopsided building. That title was been taken by a German church steeple in Suurhusen which leans at 5.19 degrees.
The Westcoast Blogger