M/V Karina Danica suffered from leak problems in hub/pitch propellers

MarineShaft has recently carried out a complete renovation of the propeller equipment from
cargo vessel MV Karina Danica.

MV Karina Danica is now back in operation after a planned drydocking stay at the shipyard NAUTA in Gdansk/Gdynia, Poland.

During the docking, it showed a leak somewhere in the stern tube system. Oil was found in the hub and pitch propeller blades, and seawater had run into the system and caused cavitation.

The owner of MV Karina Danica H. Folmer & Co. decided to send the propeller equipment to our workshops in Denmark.

The equipment was disassembled, cleaned, and thoroughly measured/tested.

The MV Karina Danica overhaul included both repair and replacements:

• Straightening of all four blades
• Welding of cavitated areas on blades
• Grinding and polishing
• Machining of sealing surfaces
• Balancing
   
• Laser cladding of blade carrier surface with two layers of bronze
• Machining of slot
• Manufacturing of 4 new gliding shoes
   
• Manufacturing of one new push-pull rod.
• Replacement of 2 safety valves
• New sealings.

We have a large stock of raw material for new manufacturing. However, for this repair, the customer delivered the raw material for a new push-pull rod and sealings, as it had already been bought.

We assembled the propeller equipment, and after function and pressure tests, we could return the equipment to the vessel.

Thanks to our skilled technicians, our machine capacity and a good co-operation with the customer this repair was carried out in only 11 days.