The Synchronised lifting system has been used to push the deck from below instead of pulling it from above. The system has two main advantages:
– There is no need to drill the deck, with its subsequent risk of damaging reinforcement
– The working area for repairing the half joints is free from obstacles

The operation is based on using long stroke jacks, FPT Fluid Power Technology model CRI150/300-GS-TA which perform a cycle of lifting 250 mm in each stroke, transferring the load to a support, and relocating the jack in an upper position for the next cycle. The towers have “blocks” which are piled up as the lifting operations progress.

This jacks and blocks system is resting on towers, and it applies the load on a spreader beam. The tower is founded on precast footings. The spreader beam has the function of avoiding excessive local stresses on the deck, which might be especially sensitive.

The Synchronised lifting system allow lifting and lowering operation on a synchronous way with a precision of 1 mm and all operation are managed via PC by the operator. The maximum lifting height reached is 1.4 meters. The machine is a PLC controlled lifting systems. The FPT Synchronous Lifting System allows the operator to carry on each stage of the lifting and lowering process in synchronicity via integrated management of the hydraulic and control elements. Unbalanced loads are kept leveled during the up and down phases, with a precision of 1 mm.

Structural checks are divided in two main areas:
– Checks on the deck. This is because the structural configuration is changed from a deck supported on a continuous line of bearings to one with only three points of support. There are new transverse forces and concentrated longitudinal forces which need to be checked.
– Checks of the full tower system, both steel and concrete elements