EMHA is carrying out a specialist project on a naval vessel abroad that combines 3D measurement, on-site machining and shaft coating. Propeller shaft connections are re-machined and realigned with high precision. This ensures a reliable and durable connection under harsh maritime conditions.
Situation
An inspection of the propeller shaft and intermediate shaft connection revealed that the flanges needed to be re-machined to ensure a correct fit for the tapered bolts. This required extremely precise alignment and machining, as even minimal deviations can lead to stress, wear or failure of the connection. The client’s objective was to restore the connection fully in accordance with specifications, with verifiable accuracy and under the supervision of a classification society.
Approach
EMHA is managing this project from start to finish, bringing together a range of disciplines. Using a Leica Laser Tracker, our specialists first aligned the flanges with extreme precision, both axially and radially, to within 0.05 mm. This precise foundation enabled us to carry out the next step with complete control.
Our on-site machinists then bored the tapered holes with high precision. After each machining operation, the fit of the tapered bolts was checked using a blue fit test. This allowed us to verify the load distribution and contact pattern, achieving a minimum of 90% contact surface. The work is carried out under the supervision of a surveyor from a classification society, which provides an additional guarantee of quality.
EMHA then applies a high-quality screw shaft coating to the unprotected parts of the shafts, ensuring they are optimally protected against the effects of seawater.
Result
The propeller shaft connection once again fully complies with the specified tolerances and quality standards, with an optimal fit of the tapered bolts and stable power transmission. Thanks to the combination of precise 3D measurements, controlled machining and on-site quality control, the risk of future wear or malfunctions has been significantly reduced.
In addition, the applied coating ensures long-term protection of the shafts, which extends their service life and reduces maintenance costs. The client benefits from a fully implemented solution, in which precision, craftsmanship and reliability are central.
