Peter Takes on History
February 27, 1964
The Tower of Pisa Leans
In 1173 construction on La Torre Pendente di Pisa - the leaning Tower of Pisa - was begun . Of course, it started out as the "tower of Pisa." The leaning part was added later. The project took 200 years to finish though, to be fair, the guys weren't working every day. There were interruptions due to "engineering problems." But, after a couple of centuries the city was getting impatient. Towers were a big draw so they forced through the COA and opened the gates. Sure enough, the building turned into a hot tourist destination during the Renaissance. Kings and queens visited. In 1565 Galileo was baptized there! But on this day in history, February 27, 1964, 600 years after they opened for business, the city had to shut the gates, admitting the tower was on the verge of collapse and they were going to need some help to save it.
The tower sits in the Piazza dei Miracoli - the Square of Miracles - and it was certainly a miracle the thing was still standing. In the early 60's measurements indicated the top of the 180-foot medieval tower was hanging 17 feet south of the base and continuing to tilt. An earthquake, even a bad storm, could have toppled it!
Maybe the real miracle is that the city fathers green lighted this job in the first place. The town of Pisa was founded in 600 BC and named for the Greek word meaning “marshy land.” And yet their engineers are like, “What could happen?” I mean, the famous tower isn’t the only leaning tower in Pisa. There’s the bell tower of the Church of St. Nicola built three years before the leaning tower. There’s also the tower located on Viale delle Piagge and “Piagge” is Latin for “low plains prone to flooding.” These people couldn’t take a hint. I’m sure the tower for Radio Pisa - Hot FM is also dangerously unstable.
And it’s not like the tilting surprised anyone. No one walked by in 1650 and said, "Maybe it's me but, something doesn't look right." The architect noticed the problem by the time builders got to the third story. So, they stopped work and sent the stone masons home ... for 95 years. When work resumed the engineer knew he couldn’t do anything about the foundation so he tried to compensate for the lean by making the new stories slightly taller on the short side.
In 1278 the southward tilt was nearly three feet.
In 1360, with the lean five feet off center, they said, “OK this is going pretty well. Let’s go ahead and add bells.” Seven bells for a total of 23,000 pounds.
By 1550 the eighth floor was 12 feet south of the base.
One of the best ideas for stabilizing the tower would have been to keep engineers away from the darned thing! In 1838, an architect started digging around the foundation, hit water and the tower tilted another few inches south.
In 1934, Mussolini thought a Leaning Tower was an embarrassment to Fascism, authorized engineers to pump in 200 tons of concrete into the foundation and the tower abruptly lurched south again.
In 1989 after another Italian tower collapsed, they closed the tower and got serious. In 1995 engineers concocted an elaborate scheme to freeze the ground froze the ground around the tower and to do some drilling and filling and but the tower shifted south again.
The real solution turned out to be extremely slow soil extraction. Begun in 1999, by 2001, after an 18 inch correction, the Italian government declared victory and reopened the tower. Engineers calculate that the Italian government successfully kicked the can 300 years down the road.
Remind me and we'll check back.