Securing roofs.

The Duomo of Milan, a symbolic monument of the Lombard capital and one of the largest churches in Europe, is subject to continuous maintenance work, which is why several years ago a semi-permanent structure was erected to allow the transport of the material needed for the work at height. This structure is placed several tens of meters above the ground and has been secured using facilities against falls from height, as established by current safety regulations.

The intervention was structured on several levels: first, the path from the hoist, located at the end of the metal structure, to the cathedral was secured. This is an installation that presents several difficulties: the tube structure, the reduced air draught and the size of the passageway, a narrow corridor in which the operators need to move as freely as possible. Considering the characteristics of the receiving structure and the needs of the workers, Genesi technicians chose a system against falls from heights on a rigid track that complies with EN 795 type D standard, which in case of a fall generates a minimum arrow and at the same time ensures maximum freedom of movement for the operators thanks to the shuttle that runs freely along the entire track; the installation consists of a track with an integrated rectangular profile that is also used for fixing, which in this case was done by bracing the structure’s tube with special steel clips designed specifically for the site.

To access the area where the hoist is located, there are metal ladders with rungs interspersed with a small balcony. A flexible rope system with steel clips that brace the ladder uprights was chosen to secure them. On the upper end is placed the energy absorber, and on the lower end the tensioner that keeps the cable at the right tension. The system was completed with anchor points attached to the structure by counter plates and installed to allow operators to move safely on the balcony between ladders.

On the external metal structure there is also a grating surface with a trapdoor that is used for loading and unloading materials on the sides of which two type A anchorage points have been fixed counter-attached to the 60-mm-diameter pipe of the structure by means of a special support: this solution allows workers to be able to work in complete safety even when the trapdoor for transporting materials at height is open.

The interventions did not only concern the external part of the Cathedral: on the heads of the transept there are glass windows that need to be regularly maintained; the workers in charge access these windows from the external terraces and upon entering the Cathedral they find themselves on a balcony 13 m long and a few tens of centimeters wide protected only by a small metal parapet. To secure this area, Genesi technicians intervened by installing flexible rope fall protection systems that comply with UNI EN 795 Type C. The ends of the lifelines were mounted on stainless steel plates attached to the marble with four threaded bars and two-component resin.