Once the load was transferred to the new structure and the original pile demolished, the last segment of the metal structure was installed. Subsequently, the second load transfer maneuver was carried out, which consisted of two phases:

– At first the load is transferred from the deck and later lock nut hydraulic cylinders are located on both sides of the definitive support axis.
– Afterwards, the support devices are installed, whose position corresponds to the original support axis of the aqueduct. The loading maneuver is carried out with a controlled descent of the hydraulic jacks.

The geometry of this structure, with an inverted L shape, is conditioned by the admissible gauge and by the position of the axis of the deck supports, since the fundamental premise of this action was not to affect the current configuration of the aqueduct. Another peculiarity is that two 1800mm diameter pipes run inside the box that supply the right bank of Bilbao and that required maximum precision in the deformations of the deck. The displacements measured during the operation were within the range of estimated values.

The use of lock nut hydraulic cylinders with low height is the perfect tool in such kind of situation where the space available is really minimum. With a pushing force from 60 to 500 tons and with a stroke range from 45mm to 50 mm they are low profile and low height and perfect to be used in confined areas with locking collar to hold the load on fully safety, suitable for lifting and pushing operations.