In-situ repair of Thruster Housing
The Tug/supply vessel NS IONA was in dock for its planned 10-year classification survey.
Inspection revealed that the Steering Tube Bearing housings were damaged and out of tolerance due to ovality.
The Shipyard contacted us for assistance.
The repair solution was to machine off the damaged areas in the steering tube bearing housings and insert a bushing to regain the original dimensions.
We sent four service engineers to the Shipyard “Orskov Yard”, bringing two sets of mobile boring equipment to speed up the repair time.
In-situ, we bored out the steering tube bearing housing to a new dimension of 880 mm.
Meanwhile, back in our workshop, the manufacturing of two bushings has begun. The bushings were manufactured with oversize and sent to the Shipyard, where our team had completed the machining.
To freeze-shrink the bushings before mounting, we brought a purpose-built insulated box and liquid nitrogen to the location.
After mounting the new bushings, we carried out the final machining of the inner diameter of the bushing to the original dimensions.
This job was completed in only 5 days.
In-house urgent repair of Gearbox housing
The gearbox housing was sent to our workshop in Hirtshals, Denmark.
After cleaning and disassembly, we used our 3D scanning equipment to scan the gearbox housing connecting flanges to check for flatness. One advantage of 3D scanning is the accuracy and amount of data it provides, which helps in the decision-making process.
The 3D scanning showed that deflection was within acceptable tolerances.
Both bearing surfaces were damaged and found oval due to a bearing failure.
The solution was to rebuild the bearing surfaces by laser cladding using the material Inconel 625.
Due to the urgency of the repair, we used both of our two sets of laser cladding equipment working in tandem, so that that the two bearing surfaces could be built-up swiftly.
After laser cladding was completed, the surfaces were machined to the original dimensions.
Finally, the connecting flanges were 3D scanned again to verify that the flatness was still within tolerances.
The gearbox was returned to the customer, and the vessel was back in operation with minimal downtime.
Posidonia Shipping Fair
If you attend the Posidonia fair in Athens, you can meet MarineShaft personnel at stand 4.317,
which belongs to one of our representatives, the company MAST Maritime Services. Marketing Manager, Hanne Magnussen will be present from Tuesday until Thursday.
Thank you for your interest in our newsletters. We hope you keep us in mind for your next repair request.
MarineShaft A/S
Hanne Magnussen
Marketing Manager