RAILWAY BRIDGE. Replacement of metal railway bridge over the Purón River. Asturias (Spain)

The replacement of the existing metal section with a span of 50 m was carried out by moving the new bridge over the existing one, raising the set of the two sections with hydraulic jacks with a vertical stroke of 7 m, moving the old section under the new one in its elevated position to its removal and descent from the new section to its final position. The operation, unique in Spain, made it possible to make the change in a 36-hour traffic cut, overcoming the prohibition of opening access roads for cranes in an area with ecological protection.