The mighty load-bearing structure of the statue of the Redeemer
The project of the load-bearing and structural part of the statue, and the calculations of the resistance of the reinforced concrete and internal load-bearing reinforcement were entrusted to the well-known engineer Luigi Musumeci, with whom Bruno Innocenti closely collaborated during the early stage of the casting.
A great number of studies and investigations were carried out on several aspects, including the strength, flexibility and time of deterioration of the various materials, and their compactness and resistance to severe weather conditions and sea salt. The mighty reinforced-concrete structure, made out of no less than 14 tonnes of iron, was anchored to the foundations that had been dug in the rock of the mountain and were more than two metres deep and three metres wide.
The structure was designed so as to allow a slight oscillation, in order to prevent its being damaged by the strong winds, which, on that peak, can reach a speed of more than 140 km an hour.
The material of which the statue is made, whose composition was painstakingly determined by Bruno Innocenti through a great number of trials, is a carefully-balanced mixture of white cement and flakes of white Seravezza marble in several sizes. An intricate network of iron reinforcements, connected and soldered to all the structures, runs through the entire statue, within its thickness. It has been devised so as to ensure the utmost strength.
Within the hollow space inside the statue, an iron ladder runs through it from the foundation to an opening in the head, which cannot be seen from the ground, and where the lightning rod has been installed.
It was necessary to design and build a new road to make it possible for the heavy lorries that carried the great plaster moulds and the iron, marble, cement and other materials for the construction of the statue to easily reach the summit of Monte San Biagio.
The statue is 21.20 metres from head to foot (it has no pedestal);
the spread of the arms is 19.75 metres;
the statue weighs about 500 tonnes;
the head is 3 metres from the chin to the top;
the thickness ranges from 15 to 30 centimetres;
the head has a reinforcement embedded in its thickness, so it is technically defined as “self-supporting”.