With a privileged geographic location and favorable climate, the Lisnave shipyards, built in the Sado River estuary in the 1970s, represent a major national infrastructure, welcoming clients from around the world. Its ongoing modernization and maintenance justify the various interventions carried out over time.

Intervention goal

The Lisnave hydrolift, an extraordinary feat of engineering, serves to lift ships out of the water for maintenance operations. Its semi-buried structure consists of reinforced concrete walls and slabs. The 320-meter-long lock was built in sections, with expansion joints featuring water-stop profiles. Due to settlement issues in the foundations, the water-stop joints failed. This project aimed to waterproof the lock joints of the hydrolift that showed defects.

Applied Technique

To restore the watertightness of the defective expansion joints, specific waterproofing systems were installed: the Jeene system for exposed joints with the lock emptied, and the Carpi system for joints in permanently submerged sections.

Additional information

The main constraint of the project was the requirement that system installation should cause minimal disruption to the normal operation of the hydrolift. Indeed, the lock's functionality is essential to allow the entry and exit of ships to the three ship repair Lisnave. Another key aspect of this project was the execution of underwater works.