Underwater repair projects across Europe, Asia and Africa help operators avoid drydocking and minimise downtime
From emergency hull damage in Southeast Asia to precision propeller work in Northern Europe and complex structural repairs in West Africa, the past few months have once again demonstrated the global reach and versatility of Hydrex’s underwater repair teams.
Operating across continents and climates, Hydrex diver/technicians have successfully completed a wide variety of underwater repairs, often under tight deadlines and in challenging conditions. The common denominator in all these projects is clear: vessels stayed operational, drydockings were avoided, and owners remained in control of their schedules.
Dakar: two vessels, two complex solutions
Few recent Hydrex interventions illustrate our flexibility better than in Dakar, where two very different repair scenarios were handled back-to-back.
The first involved a vessel with serious hull damage requiring immediate reinforcement. Hydrex teams designed and installed four custom-fabricated doubler plates over the damaged areas. Each plate was carefully shaped to match the hull, secured in place and fully welded, with additional reinforcements added to ensure structural integrity. The vessel was able to continue operations without interruption.
The second case, involving an LNG carrier, required a permanent repair solution. Severely deformed and cracked shell plating inside a ballast tank called for a more advanced approach. Hydrex installed cofferdams to create a dry working environment, allowing damaged steel to be removed and new insert plates to be welded in place under controlled conditions. The repair was carried out to class approval and completed efficiently, without drydocking.
Thruster replacement in freezing conditions
In Stockholm, a ferry required a full bow thruster replacement right in the middle of winter.
Snow, low temperatures and limited daylight made the operation more demanding, but careful planning ensured everything ran smoothly. Equipment was mobilized from Antwerp, while the team coordinated closely with the vessel’s schedule to carry out the replacement during a planned downtime.
Using proven underwater replacement procedures, the existing thruster was removed and a fully assembled unit installed without the need for a dry environment. Once the thruster was secured and tested, the ferry was ready to return to service. The operation clearly demonstrated that even highly specialized underwater work can be executed reliably in extreme conditions with the vessel afloat.
West Africa: precision propeller work under pressure
In Lagos, a hopper dredger faced a critical issue: oil leakage from a controllable pitch propeller blade.
Hydrex mobilized quickly to carry out the repair underwater, avoiding costly delays. After identifying the faulty blade, the team removed it, inspected all components and confirmed that no structural damage was present. New seals and a sealing plate were installed according to class and manufacturer requirements.
The blade was then reinstalled, bolts tightened to specified torque and thorough testing carried out. The successful repair restored full functionality and allowed the vessel to continue operations without interruption, despite the logistical challenges of the location.
Offshore Congo: engineered solutions in remote conditions
When a container vessel at anchorage off Pointe Noire reported propeller damage after a suspected grounding, the situation required both speed and creativity.
Inspection revealed that all six blades were bent. With no drydock available nearby, Hydrex developed an alternative solution in consultation with class: cropping all blades to identical dimensions. A team and equipment were mobilized offshore, supported by a workboat.
The underwater cropping operation was carried out according to strict procedures, after which the blades were carefully finished to restore hydrodynamic efficiency. The vessel was able to resume operations with a safe and effective solution, demonstrating Hydrex’s ability to engineer practical repairs even in remote locations.
Rotterdam: permanent repairs without drydock
In Rotterdam, a supply vessel required a permanent insert repair after damage was discovered inside a bilge holding tank.
Instead of sending the vessel to drydock, Hydrex installed a cofferdam to access the damaged area from the outside. Once the compromised material was removed, the structure was inspected together with class, and approval was given for the installation of a new insert plate.
The plate was welded into place under controlled conditions, completing a class-approved, permanent repair while the vessel remained afloat. The operation once again highlighted how drydockings can often be avoided without compromising quality.
Oman: fast and effective temporary steel repair
A roro vessel in Sohar faced a different challenge after grounding damage tore the bottom hull.
