Hydrex handles underwater repairs to three tankers

Apr 13 2018

Underwater repair specialist, Hydrex recently handled afloat repairs on three tankers.

In the first case, an emergency call was made for a permanent repair to a crack in the port side grey water tank of a 145 m chemical tanker, which was berthed in Amsterdam.

To get the job done during the ship’s port stay, Hydrex immediately fabricated a 700 mm x 300 mm insert plate, as well as a steel mobdock (mobile drydock) profiled to fit the curvature of the tanker's hull.

The mobdock was installed, enabling the diver/technicians to cut away the cracked area and weld the insert plate in place, using Hydrex's class-approved full penetration welding technique. All of this work was carried out during the tanker's scheduled call, and in close communication with the vessel’s superintendent and the attending class surveyor.

The permanent nature of this repair meant that no further action would be required at the ship's next drydocking.

A second project, this time In Punta del Este, Uruguay, saw Hydrex teams carry out both a temporary onsite repair to allow a 277 m tanker to keep to her schedule, leading to a permanent repair three months later when conditions had improved and more time was available.

She had suffered a hole in a ballast tank’s shell plating, but poor weather and fast currents, as well as limited time, meant that welding was not possible.

The divers were able to quickly install a doubler over the hole. The Hydrex technical department was then able to devise a more permanent repair, which involved installation of a cofferdam on the waterside of the damaged area, cutting away the affected area of bottom plating and welding in an insert plate. This repair was also carried out, using Hydrex's full penetration welding technique, tested ultrasonically by an independent inspector and approved by the attending class surveyor.

The third repair involved Hydrex's class-approved cofferdam technique, which was used on a 228 m tanker berthed in Rotterdam. This offered a quick, cost-effective alternative to drydocking in order to repair two leaking pipes.

"Overboard pipe repairs are vital for a vessel because there is a direct connection between the outside hull and the pipes. This means that any damage to the pipes can compromise the integrity of the hull. For this reason, the classification society will strictly monitor the condition of the pipes and will demand a fast and thorough repair of the damage," said Hydrex production executive, Dave Bleyenberg.

"We offer permanent afloat solutions for situations like this, bringing a high standard of care and professionalism to guarantee that a ship can sail safely afterwards, with the service delivered in as short a time as possible. We can renew damaged hull plating, repair cracks, repair or replace pipes and flanges, as well as undertaking installation of seachests, speed log or echo sounder housings.

"We have a wide range of standard mobdocks available, but a tailor-made mobdock can be created to fit a specific hull shape or purpose. Our goal is to keep our customers sailing with as little delay as possible," he explained.


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