PROJECT FACTS

Damage / problem encountered:

I.PANTACHOS- A. VENTOURIS S.A. received an enquiry from Conbulk Shipmanagement Corporation shiping Company to perform several in-situ machining repairs related to vessel’s shafting arrangement.

More specifically, during DD and after dismanting of the shafting arrangement, the S/T bearing seats were found with severe ovality issues, in some steps over 0.15mm in diameter.

Αnother fact that added more to this challenge was the extra large size of the S/T bore Ø820mm and the machining length of the aft seat, approx.1500 mm.

Our company quickly responded to the enquiry, discussed the job’s scope and repair procedures with the Company’s technical representative and was promptly awarded the job.

We immediately started the preparations and modifications needed to carry out the requested repairs.

Rectification process followed:

• In- situ boring of stern tube Aft bearing seat 3 steps (Ø820 x Ø818 x Ø816 x 1450L mm) to oversize 2mm.
• In- situ boring of stern tube Fore bearing seat 2 steps (Ø820 x Ø818 x 600L) to oversize 2 mm.
• Calibration checks of machined bearing seats of stern tube fore and aft side.
• The alignment of our boring machine was carried out by our Service Engineers as per laser alignment measurements and guidelines.
• The final S/T laser sighting with both bushes in place, was conducted afterwards and was well within tolerance
• In- situ boring of intermediate shaft- crankshaft 12 coupling bores (Ø105 mm.)
• In- situ boring of intermediate shaft- propeller shaft 12 coupling bores (Ø105 mm.)
• Conduction of honing for 0.01 mm accuracy and to establish the least possible surface roughness.
• Calibration checks of 24 bores after machining and honing.

All the above-mentioned machining procedures were completed successfully owing to:

• The high technical expertise & know- how of our Service Engineers,
• the use of special, custom designed and engineered boring machine & compartments,
• the alignment of our boring bar assembly with the aid of state-of-the-art laser alignment equipment,
• the use special carbide cutting tools,
• the use of technologically advanced measuring tools.

Several fabrications- repairs related to shafting conducted on our workshop facilities:

• The high technical expertise & know- how of our Service Engineers,
• the use of special, custom designed and engineered boring machine & compartments,
• the alignment of our boring bar assembly with the aid of state-of-the-art laser alignment equipment and
• the use special carbide cutting tools.