nergy-efficiency retrofit centred on the installation of a Wake Equalizing Duct (WED), supported by structural steelwork, underwater hull preservation, propulsion maintenance and precision alignment, demonstrating Navalrocha’s capability in complex vessel retrofits.
Drydocking at Navalrocha
Wake Equalizing Duct (WED) retrofit and comprehensive drydocking programme
The INSULAR underwent a major drydocking programme at Navalrocha centred on the installation of a Wake Equalizing Duct (WED), an advanced energy-saving device designed to optimise water flow into the propeller, improve propulsion efficiency and reduce fuel consumption. The project required extensive engineering planning, precision fabrication and strict alignment control throughout the installation process.
The WED retrofit involved the manufacture of dedicated support structures, installation of owner-supplied duct sections, precision alignment, certified structural welding, continuous dimensional verification during welding, non-destructive testing, pressure and vacuum testing of associated duct arrangements, renewal of sacrificial anodes and restoration of the protective coating system around the completed installation. These activities demanded close coordination between structural, mechanical and quality control teams to ensure the hydrodynamic device was installed within very tight tolerances.
Alongside the retrofit, the underwater body underwent an extensive preservation programme including high-pressure washing, grit blasting, surface preparation and the application of advanced silicone coating systems to the hull, sea chests and bow thruster tunnel. Hull markings were renewed, sacrificial anodes replaced, and underwater appendages prepared to maximise long-term corrosion protection and vessel performance.
Mechanical works included polishing of the controllable pitch propeller and bow thruster propeller, overhaul of the bow thruster gearbox, stern tube support during seal replacement activities, rudder inspections, sea chest maintenance and numerous valve overhauls. Additional structural repairs included renewal of ventilation duct steelwork, welded stud replacement and repairs to deck structures, handrails and cargo hold steel components, further enhancing the vessel’s structural integrity.
The successful completion of the INSULAR project highlights Navalrocha’s expertise in delivering complex energy-efficiency retrofits alongside multidisciplinary drydocking services. Combining advanced structural fabrication, precision alignment, underwater coating systems and mechanical engineering, all work was completed under rigorous quality assurance procedures and stringent health, safety and fire prevention standards.
