We were asked to assist with the three corroded scrubber overboard pipes of a 292-meter bulker. The ship was not allowed to sail to drydock without a repair. We immediately sent a dive team to the bulker’s location in Ijmuiden, the Netherlands for a temporary solution.

Exhaust scrubbers are systems that filter out all harmful toxins from exhaust gasses of marine diesel engines. These can severely corrode the pipes of the scrubber which can result in water ingress if not handled quickly enough. For this reason the classification society requires regular thickness measurements to be performed. 

The latest inspection had revealed that the three pipes were heavily corroded and needed to be repaired. The ship was sailing to drydock where the pipes would be replaced, so a fast temporary solution was required.

Fast mobilization

A team traveled to the bulker’s location in Ijmuiden. After arriving at the ship they first performed an inspection of the damaged areas on both the waterside and the onboard side of the hull.

Our diver/welders then sealed off the outlets of the overboard pipes with custom cofferdams designed and constructed at our workshop.  This allowed for work inside the engine room without water ingress.

The team ground away the affected area before rebuilding it back to its original thickness. To give extra protection during the trip to drydock our men installed reinforcement shells around the pipes.

When the welding was complete the surface was cleaned and an MPI was carried out by an independent inspector.

The inside of the pipes was then coated with Ecospeed to keep them safe from further corrosion.

This product is produced by Hydrex sister company Subsea Industries (www.subind.net) and is highly chemically resistant. Ecospeed will also be used to coat the replacement pipes before they are installed in drydock. This will make sure that the owner will not have to call us again for the same problem.

Preventive maintenance

In this case a drydock visit had already been planned and a temporary repair was needed, but our teams can also replace a corroded exhaust pipe. This is a permanent repair that can be done while your vessel stays afloat.

If a pipe is already starting to corrode a leak is just a matter of time. You do not have to wait until it is fully corroded, we can also replace pipes preemptively. By performing the replacement before the leak occurs, our divers prevent a costly unscheduled repair later.