One of the aims of the contractor was in fact to not block traffic during the demolition of the old bridge. Following an initial phase, in which large drum cutters were used, it was the turn of smaller models from MB - specifically, the models MB-R800 (applicable to excavators of between 10 and 22 tons in weight) and MB-R900 (for excavators of between 19 and 35 tons) - to complete the work.
The large drum cutters were used at the beginning for the primary demolition of the layers which made up the bridge. After this, in order to avoid too much stress on the structure, it was decided to use the MB Crusher drum cutters, the only cutters in the world fitted with the special patented system - direct drive twin motor system - which allows the differentiated distribution of power to the two cutting heads. In the case of operations on materials of varying hardness, the MB drum cutters adapt, applying power in proportion to the hardness of the material in question: this results in improved stability and a reduction in stress on the excavator arm.
The work was carried out in two steps: the first led to the removal of a 36 cm-thick layer of cement, later used for filling operations as it was recycled without being contaminated with other materials; and a second step was for the demolition of a further layer of tar, destined for dumping, as it was contaminated material. This was therefore a working method which resulted in significant benefits, also from a point of view of respect for the environment.
And that’s not all: despite the 8 days of intense work, it was not necessary to interrupt traffic, an essential factor for the successful completion of the operation: the particular manoeuvrability, precision and compact size of the MB drum cutters were determining factors in the optimisation of every step of the process, systematically demolishing the various layers that made up the bridge.
MB proved successful both from a logistic and environmental point of view.