Lean Into It
A new slant on the Tower of Pisa.
Written by Filed under Science & Technology
The Tower of Pisa has been called “the world’s most famous construction mistake” and “the world’s longest-standing impending structural collapse.” Yet it remains upright in spite of its age and precarious lean, not to mention the numerous invasive restoration projects it has endured. Ironically, it took the 1989 collapse of the mundanely perpendicular Civic Tower in Pavia, for Italians to get serious about stabilizing their country’s most famous architectural structure. From early 1990 until December 2001 it remained closed to the public while engineers implemented a complex $30 million rescue plan. The Tower still looks as if it might collapse at any moment, but in reality, it is more stable now than at any time in the past few centuries.
In the recent book “Tilt: A Skewed History of the Tower of Pisa” (Simon & Schuster), author Nicholas Shrady recounts the history of the Tower of Pisa in all of its off-kilter glory. Fittingly, “Tilt” has a difficult-to-describe slanted binding that makes it as distinctive among hardcovers as the Tower is among man-made structures. Failure recently had the opportunity to ask Shrady a few questions about the Tower, as well as his book’s unique binding.
Would you describe the Tower of Pisa as the product of flawed construction?
Most certainly. To begin with, the Tower of Pisa, as well as the other buildings in the so-called Campo dei Miracoli—the cathedral, the baptistery, and the Camposanto cemetery—are all built on what is essentially a former bog. Consequently, the subsoil is forever shifting and prone to flooding. When the architect (who remains unknown) projected the structure he failed to sufficiently account for the unstable terrain, and began to build what would be a 14,700 metric-ton tower of marble and limestone atop a mere three-meter deep foundation. The Tower of Pisa, in other words, was destined to tilt because it was flawed from the outset.
When and why did the Tower come closest to toppling over?
In 1838, a local architect named Alessandro della Gherardesca thought that it would be wise to excavate a catino [walkway] around the base. Workers promptly hit a subterranean water channel, the whole base of the campanile flooded, and the structure began to tilt anew after centuries of relative stability. The incident serves to illustrate a recurring theme—that is, most of those who have professed to want to “save” or “improve” the Tower of Pisa have been those who have come closest to toppling it.
What made the 1934 attempt to stabilize the Tower so disastrous?
To the Italian Fascists, the Tower of Pisa was an inappropriate symbol for a nation with imperial designs, and Mussolini ordered it shored up and stabilized. Not surprisingly, the remedy proved as brutal as Fascist politics—361 holes were bored into the foundation and pumped full with 90 tons of cement. The measure again shattered the Tower’s hard-found equilibrium, but no one dared protest. As it happens, Mussolini owned the cement factory.