Restoration Journal

Marble reborn: the source of the Duomo


28 April 2017

Each spring for the past six centuries or more, a process begins that is as ancient as it is new, capable of inspiring profound emotion through an annual miracle that celebrates the meeting between nature and mankind. In Candoglia, over just the past few days, the cutting of the marble that will be used for restorations of the Cathedral in the coming months has begun.

We travelled all the way up to the Duomo's source with the "Restoration Diary" in order to capture some images from what is one of the most important moments of the year for the Fabbrica.

the quarried block of marble (in the photograph) measuring 51 m3: the process of excavation is particularly delicate and requires great skill and careful scientific study

At one time, in order to extract the marble, black powder was used: a method, however, that involved significant risks and an enormous waste of material. In fact, since 1795, the Fabbrica has prohibited the use of mines

Today diamond wire is used to cut the stone

Having carried out the base and back cuts, the block of marble is then isolated from the rest of the mass. Hydrodynamic cushions are inserted in the vertical cuts, which are then inflated through the introduction of pressurized water (below, in the sequence). The spacing between the cuts is increased until it becomes possible to insert a hydraulic jack, which is used to further distance the two lips of the cut until the block (or part of it) finally overturns (in the video).