multifunctional modular scale for access to pulvini and other parts of structure of bridges and viaducts below the viable plan to allow working not heavy.the ladder is composed of a tower to more forms to mount on the place with special hooks interchangeable anchoring the barriers (guard rails, guard rails, new jersey).the scale tralicciata is equipped with intermediate plans and is equipped with the mobile device to allow the rotation of the hinge pole below why become a catwalk posizionandosi orizzontalmind. the ladder during assembly set by specific tassellature structure lapping.