Why Don’t the Bells in the Leaning Tower of Pisa Swing?

While the bells in the Leaning Tower of Pisa were originally designed to swing and were operated by ropes, due to the precarious, gravity-tempting, equilibrium-defying condition of the tower, it was decided that it was less risk to have the bells sounded by electromagnetic hammers, as they do today. A simple tap and the bell rings – while producing no destabilizing sway in the tower.

A brief history of the Leaning Tower of Pisa

In August 1173, construction began on the Leaning Tower of Pisa. The freestanding structure was intended to rise from the elegant Piazza dei Miracoli in the bustling and rich Tuscan city of Pisa. The main purpose of the tower was to house the adjacent cathedral’s set of impressive bells, while showcasing the magnificence and might of the city-state. 

Problems soon arose. Builders paused work after reaching just three stories, a hiatus that would last some 95 years. While politics or economics could have been contributing factors, it was likely that engineers, even then, had begun to observe a significant one-sided lean. It seems the bell tower had been situated above an ancient river estuary, with shifty silt and waterlogged sand being no suitable foundation for the heavy marble above.

When construction began again, builders attempted to compensate for the lean by elongating the walls of the tower on the short side. It didn’t help. In 1278, work was halted again when the southward tilt reached nearly 3 ft. The bell tower sat at an unfinished seven stories for the next 82 years. But in 1360, work resumed on the eighth and final story, meant to house the 10 metric tons of bronze bells. Again, the floor was built on a slant to mitigate the lean, which only continued to worsen. By 1550, the eighth floor was 12 ft. farther south than the base. 

Leaning Tower of Pisa bell tower and cathedral

Image: The Leaning Tower of Pisa, a marvel of bell tower engineering, with the Pisa Cathedral in the foreground, in Pisa, Italy.

The structure, even with its now-iconic lean, was an impressive feat of engineering. Rising 296 steps or roughly 288 feet, and wrapped in 200 Romanesque columns, the bell tower has survived at least four strong earthquakes since 1280. Over the years, subsequent preservation projects have attempted to stabilize and correct the lean, and it was recently announced that, for the first time in its history, the bell tower has stopped moving.

About the bells in the Leaning Tower of Pisa

Seven bells ring the topmost floor of the Leaning Tower of Pisa, one for each note of the major scale. Together, the bells weigh 23,150 lbs., from the smallest bell at 661 lbs. to the largest at 7,981 lbs. 

  • L'Assunta, tone of B, cast in 1654 by Giovanni Pietro Orlandi, weighing 7,981 lbs. 
  • Il Crocifisso, tone of C#, cast in 1572 by Vincenzo Possenti, weighing 5,428 lbs.
  • San Ranieri, tone of D#, cast in 1719–1721 by Giovanni Andrea Moreni, weighing 3,192 lbs.
  • La Terza, tone of Bb, cast in 1473, weighing 661 lbs.
  • La Giustizia, tone of G#, cast in 1262 by Lotteringo, weighing 2,235 lbs.
  • Il Vespruccio, tone of E, cast in the 14th century and again in 1501 by Nicola di Jacopo, weighing 2,205 lbs.
  • Dal Pozzo, tone of G, cast in 1606 and again in 2004, weighing 1,437 lbs.

The fifth bell, named La Giustizia (which translates to The Justice), was salvaged from another building in Pisa where it announced the execution of criminals and traitors. By the 1950s, the tower was deemed too structurally unstable to accommodate swinging bells, which can shift momentum to the tower and cause it to sway. The bells were hung dead, or stationary, in their yokes and are to this day tolled electromagnetically by a hammer located inside the bell. No swing, no sway, but still plenty of ring.

Cover image: A tourist snaps photographs of the bells within the Leaning Tower of Pisa while another waits to hear the bells ring, in Pisa, Italy.