I.PANTACHOS- A. VENTOURIS S.A. received an enquiry from Thenamaris Ships Management Inc. to perform several in-situ machining repairs related to vessel’s shafting arrangement.




M/T Seabright


STX-B&W 6S50MC-C (11,110 HP)


46,177 DWT

D/D Location

Odessus Shipyard,

Varna, Bulgaria

Fwd stern tube inside Dia X L (2 steps) [mm]

Ø565 x Ø563 x 385L

Aft stern tube inside Dia X L (3 steps) [mm]

Ø565 x Ø563 x Ø561 x 970L

Reamer bolts holes M/E side [mm]

64 (12 pcs)

Reamer bolts holes propeller side [mm]

65 (10 pcs)

Intermediate shaft Dia X L [mm]

Ø 413 X 6,011

Propeller shaft Dia X L [mm]

Ø 460 X 6,557


More specifically, during DD and after dismanting of the shafting arrangement, it was found with severe misalignement problem. Even the white metal film of the stern tube bushes was completely melted and detached in several parts.

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 cast 3 steps aft (Ø565 x Ø563 x Ø561 x 970L mm) to oversize 6 mm.
  • In- situ boring of stern tube cast 2 steps fore (Ø565 x Ø563 x 385L mm) to oversize 6 mm
  • Micrometric measurement of stern tube fore and aft steps’ diameter.
  • Machining- off of the aft stern tube boss face with a specialized in situ equipment, for proper propeller – stern tube boss face contact.
  • In situ reaming of intermediate shaft- crankshaft 12 reamer bolts’ holes ( Ø64 mm.)
  • In situ reaming of intermediate shaft- propeller shaft 10 reamer bolts’ holes ( Ø65 mm.)
  • Conduction of honing for 0.01 mm accuracy.
  • Micrometric measurement of holes after machining and honing.
  • Tail shaft placed on the shipyard’s lathe for machining to remove offset misalignment on the conical and straight part.
  • Alignment and machining of the intermediate shaft’s journal on the shipyard’s boring machine.
  • Μachining and conduction of the final aft bush measurements.

The above mentioned machining procedures were completed successfully owing to

  • the use of our own special, custom-made equipment,
  • the provision of our own special carbide cutting tools and
  • the high technical expertise and advanced know-how of our service engineers.