Full Scope Rudder Repair:

Repair of 40-tonne rudder blade and manufacturing of a new rudder stock

 

 

This significant repair project, which is currently ongoing at MarineShaft’s workshop, involves a chemical tanker that suffered an incident, bending the rudder blade and requiring the renewal of the rudder stock and other essential rudder components.

Upon request, MarineShaft dispatched a service technician on-site to assess the damage and repair feasibility.

MarineShaft could provide a full-package solution, offering both rudder blade repairs and manufacturing of a new rudder stock and related components.

Due to the size of the rudder blade – nearly 40 tonnes – the rudder blade was too large for road transport and was instead shipped from a European shipyard to MarineShaft by sea.

 

Precision Repair Using 3D Scanning

MarineShaft used 3D scanning technology to assess the rudder blade’s deformation accurately. The repair will involve replacing specific plates and reinforcing the structure with welding.

The manufacturing process includes:

Manufacturing of a new rudder stock.

Manufacturing of a new pintle with shrunk-on sleeve.

Manufacturing a new rudder stock bearing and housing.

Manufacturing of a new pintle bearing and housing.

Based on their on-site measurements, MarineShaft will machine and conduct a blue-fit test to ensure the rudder stock upper cone aligns perfectly with the steering gear in its original position. Along with the rudder blade, MarineShaft also received the steering rotor for fitting.

MarineShaft will conduct the final blue fitting to the new rudder stock, which will be supervised and approved by the involved Class NK.

The material for the new rudder stock is sourced from our stock of class-certified shaft materials, ensuring minimal lead time.

 

Case: Skandi Vega – A Complex Offshore Repair

MarineShaft recently completed a reapir for the DOF vessel Skandi Vega, which required heavy machine capacity, mobile machining equipment, and specialized repair expertise.

Skandi Vega is a large, powerful offshore vessel designed for deep-water anchor handling.

The vessel was docking at the Danish Shipyard Fayard, where MarineShaft was commissioned to perform on-site machining of cylinders and repair of the Anchor Handling Frame.

 

 

On-site machining of cylinders

Three shark jaw cylinders suffered from wear and cavitation and required repair. MarineShaft has mobile machining equipment capable of handling large-scale components.

To reduce repair time, MarineShaft set up three machining units on board Skandi Vega. Each cylinder measured Ø1035 mm with a length of approximately 2,580 mm. Additionally, MarineShaft machined six towing pin cylinders to new dimensions of Ø530 mm and approximately 2,450 mm in length.

This repair also included welding and re-machining the tops of the towing pin cylinders.

In-house repair of 55-tonne heavy Anchor Handling Frame

The anchor handling frame (AHF) was delivered to our workshop in Hirtshals in three separate truckloads, where our skilled technicians began the extensive repair process.

This large equipment occupied a significant portion of our workshop, and our heavy machinery capabilities proved invaluable.

This job included repair of:

Two AHF arms

Center pipe shaft

Thrust Rings

Adapter Bearing Boss

Fitting Shear Bolts

Robotic welding with minimal heat input

Advantaged laser cladding technology also played a role in this repair. MarineShaft used this amazing low-heat-input welding technique for the repair and welding of damages to the STB and PS arms and for the repair of the bearing boss.

After laser cladding, MarineShaft machined all components back to their original dimensions. Laser cladding only imparts 1/10 of the heat input to the base material compared to regular welding, and it requires no post-heat-weld-treatment, reducing repair time by 2-3 days.

Following the repairs, the equipment was fully assembled, inspected, and class-approved by DNV.

Please see link to latest newsletter with same two cases

https://mailchi.mp/dfffdc64462b/repairnewsmarineshaft2025_1?e=[UNIQID]