Stabilizing the Tower of Pisa

by Sister Hilda Kleiman, OSB

What the droves want to find suspended in the clear Tuscan air is logic.

In his uniquely designed Tilt: A Skewed History of the Tower of Pisa (public library), Nicholas Shrady gives a brief account of how this famous tower came to be built and of the many attempts to prevent its fall before it was finally stabilized.

Credit: Johann H. Addricks - CC BY SA 3.0

Shrady explains that even as the Italians attempted to preserve the tower, its value to Pisa was in its flaw:
Never mind that the tower is one of the buildings (and arguably the least captivating in purely aesthetic terms) in the Campo dei Miracoli, which also includes the duomo, or cathedral, of Santa Maria Maggiore, a baptistery, and the Camposanto cemetery - what the droves want to find suspended in the clear Tuscan air is logic. Without a tilting campanile, Pisa would fall off the map, and the locals know it.  It is no small irony that the Tower of Pisa, built as a symbol of the wealth and power of a medieval maritime republic, has become the very commodity on which the local economy depends (5).

The cathedral and the tower - Credit: Jose Luiz - CC BY SA 3.0

The facade of the cathedral - credit: Silko - CC BY SA 3.0

The roof of the cathedral - Credit: Jose Luiz - CC BY SA 3.0

The baptistry, cathedral, and tower - Credit: Massimo Catarinella - CC BY SA 3.0

Baptistry - Credit: Blorg - CC BY SA 3.0

Even though the tower is so well-known, it's architect is not:

The campanile, by contrast, while the best-known of the edifices which rise up in the Campo dei Miracoli, is, paradoxically, wholly annonymous; there is no signature or inscription, no epigraph or monogram, nor, indeed, any extant document to reveal the identity of the tower's architect (55).

The consistency of the Romanesque architecture of the Campo dei Miracoli is one of its most striking characteristics:

Had Deotislavi and the campanile's architect not chose to follow the schematic and stylistic motifs set down by Buscheto in the cathedral, the Campo dei Miracoli might have been a very different place, and this great conjunction of monuments might not have been a conjunction at all, but rather a study in discord.  As it was, the architects working in Pisa seemed to have shared a common aesthetic and a desire to project a collective architectural vision distinctly their own.  The Pisan Romanesque, like the Romanesque movement throughout western Europe, drew its inspiration from a host of architectural sources - Rome, Byzantium, Lombardy, and Isalm among them - but nowhere did the synthesis evolve as powerfully and with such spatial eloquence as at Pisa (59-60).

In 1999, the last of many commissions that had attempted to fix the tower removed soil from the higher north side of the tower:

In time, more than sixty tons of terreni limosi were extracted from beneath the campanile, and the 14,700-metric-ton-structure moved 40.6 centimeters, or 0.5 degrees, back toward perpendicular.  The seventh cornice now overhung the base by only four meters, the same as it had back in 1838 before the disastrous intrusion of Gherardesca.  The Tower of Pisa, Burland ventured to say upon completing the work, would be safe for another three hundred years.