The integrity of a vessel’s stern tube seals is very important. They prevent oil leaks and water ingress, ensuring smooth propulsion and environmental compliance. We have revolutionized seal repair methods, offering swift, cost-effective, and environmentally friendly solutions that eliminate the need for drydocking.

Innovative underwater seal repair techniques

One of our hallmark innovations is the development of the flexible mobdock—a mobile mini drydock that creates a dry underwater environment around the stern tube seal assembly. This technology allows for in-situ repairs, minimizing vessel downtime and avoiding the substantial costs associated with drydocking. The mobdock is adaptable to various seal types and sizes, accommodating the diverse configurations found across different vessels. Our diver/technicians are trained to handle complexities such as worn liners and unique stern tube designs, ensuring efficient and reliable repairs.

Global case studies demonstrating expertise

1. Double seal repair on roro vessel in Tasmania

Our teams carried out a dual underwater stern tube seal repair on a roro vessel docked at the Port of Burnie, Tasmania. Despite the vessel’s remote location, our technical department rapidly organized logistics and mobilized the necessary equipment.

Upon arrival, the diver/technicians performed a thorough underwater inspection of both stern tube seal assemblies. Using two flexible mobdocks simultaneously, they created dry, drydock-like conditions underwater. The split rings were dismantled, cleaned, and each of the four seals (two per assembly) was removed and replaced in close collaboration with the OEM technician.

This repeat customer knew from experience that Hydrex could deliver efficient, safe, and high-quality work—even from afar. Thanks to pre-packed, rapidly deployable equipment and extensive experience, we completed the task without any delays to the ship’s schedule.

2. Antwerp container ship repair

In Antwerp, a 300-meter container vessel experienced an oil leak due to entangled debris around its stern tube seal assembly. Our team swiftly mobilized, performed an underwater inspection, and removed the rope guard. Using the flexible mobdock, they created a dry environment to replace the damaged seals. The operation was conducted during cargo operations, ensuring the vessel remained on schedule.

3. Tenerife tanker operation

A tanker docked in Tenerife required immediate attention after a rope became entangled around its stern tube seal, leading to an oil leak. Our divers removed the rope and, employing the flexible mobdock, replaced the damaged seals underwater. The entire operation was completed efficiently, allowing the tanker to continue its voyage without the need for drydocking.

Advantages of Hydrex’s approach

• Cost efficiency: By eliminating the need for drydocking, shipowners save substantial costs.
• Time savings: Repairs are conducted swiftly, often during cargo operations, minimizing downtime.
• Environmental compliance: Prompt repairs prevent oil leaks, ensuring adherence to environmental regulations.
• Global reach: With a network of offices and support bases, we can mobilize teams worldwide at short notice.

Commitment to quality and collaboration

Hydrex performs all shaft seal repairs in collaboration with Original Equipment Manufacturers (OEMs), ensuring the use of appropriate materials and following the manufacturer’s specifications. Shipowners have the flexibility to supply their own OEM seals, or we can provide them as needed. This cooperative approach guarantees high-quality repairs tailored to each vessel’s specific requirements.