Customer's Challenge

Repairing a dredger vessel presents a complex and extensive scope of work due to the unique demands on its machinery, hull, and onboard systems. The specific repairs required depend on the vessel’s condition, age, operating environment, and dredging type. To meet a tight turnaround for redeployment, our client needed a large team working 24/7 to carry out concurrent machining repairs on both port and starboard equipment.

Solution

Given the unpredictable nature of dredger repairs, much of the work had to be assessed on-site, with impromptu repair decisions based on the actual condition of dismantled components. Our workshop team quickly adapted to these needs, modifying and preparing necessary equipment without delay.

To streamline communication, adhere to timelines, and align with yard activities, we assigned a dedicated project coordinator on-site. This coordinator facilitated seamless interactions between our client, the yard team, and our workshop crew, ensuring efficient information flow and synchronization across all stages of the repair process.

Our Expertise in Component Repair

Trailing Suction Hopper Dredgers (TSHD) are equipped with unique components designed for efficient dredging operations, the most notable being the drag arm, which functions much like a powerful underwater vacuum. This drag arm consists of a suction bend, lower and upper suction pipes connected by a double cardan hinge, and a drag head.

The suction bend is mounted in a trunnion that is part of the sliding piece. When deployed, the sliding piece guides the pipe outboard, lowering it until the suction bend aligns perfectly with the inlet below the waterline, enabling effective dredging below the surface.

Removable parts of the TSHD’s sliding piece were brought into our workshop, where we meticulously rebuilt the material and machined each piece back to precise specifications. Our expertise ensures that each component is restored to the required size, ready for optimal performance in demanding dredging environments.

Precision Overhaul of Port and Starboard Dredge Pumps

As part of the overhaul program for the port and starboard dredge pumps, our team restores worn sections of the pump casing to exact specifications. Using a laser tracker, we precisely measure the required material build-up before deploying a portable circular milling machine. The laser tracker also allows us to accurately mark the Pitch Circle Diameter (PCD) and hole locations, ensuring alignment after meeting the surface runout requirements.

This advanced approach guarantees a high level of accuracy and extends the life of dredge pump components, supporting reliable performance in demanding marine environment.

Corrosion Repair and Bolt Hole Restoration

In areas where the pump casing flanges show significant corrosion, we enlarge the bolt holes and install shrink-fit threaded bushes. This process ensures a secure fit for the outer casing bolts, effectively preventing leakage and maintaining operational integrity.

Winch Restoration and Precision Boring

Dredging operations place immense pulling force on winches, causing wear on the bearing housing. To restore optimal function, we bore the bearing housing and insert new bushes. Using a laser tracker, we establish the required datums—critical due to severe corrosion on the original bushes—ensuring precise gear spacing and parallel alignment.

This meticulous approach enhances the winch’s durability and performance, allowing it to withstand the high demands of dredging operations.

Thruster Mounting Face Resurfacing

We provided precise resurfacing of thruster mounting faces in overhead positions to ensure proper alignment and secure mounting. This service restores the mounting surface to optimal condition, supporting reliable thruster performance under demanding marine conditions.

Propeller Stern Boss Restoration

Excessive corrosion on the propeller stern boss required material build-up and precision machining to restore it to the correct size. To carry out this operation without removing the propeller, our team ingeniously modified a split-frame clamshell pipe cutter to perform the turning operation efficiently on-site.

Rudder Pintle Restoration

During routine servicing, damage was discovered on the rudder pintle. Our team promptly addressed this by deploying a portable boring machine to perform a precise skim on the surface, restoring the pintle to optimal condition for reliable operation.

Benefits

With a vast array of field service equipment, an advanced machine shop, and a team of highly skilled technicians, we provide comprehensive repair services tailored to meet exacting specifications. Our services include alignment checks, shrink-fitting of bushes, sleeves, and pins, as well as precision machining to address corrosion or build-up—restoring components to the original manufacturer’s tolerances.

Our meticulous planning enables us to navigate project complexities with efficiency, ensuring timely delivery and seamless execution. We take pride in our role in achieving a successful vessel turnaround and are grateful for our clients’ trust and enduring partnership.