Between 1965 and 1966, the Amadeo spire, one of the structures located exactly level with the four pillars of the dome lantern and built in the early years of the 16th century, was the subject of an important restoration project carefully managed by engineer Carlo Ferrari da Passano.
The structure displayed evident fractures and was clearly in bad condition, to such a degree that it was deemed completely unsafe.
One of the main causes of the critical conditions in which it found itself was the inconsistency of the material used to build the foundations. These were therefore strengthened using suitable reinforced concrete, immediately after having implemented several measures relative to the top section of the spire.
Finally, an invisible stainless steel reinforcement was inserted to further strengthen the structure and also to fully preserve the original covering of the spire, which had been previously disassembled, photographed and stored in suitable conditions.
A meticulous operation, carried out with a view to safeguard one of the most important parts of the Cathedral.