Verification of Shaft Alignment, SHAFT

Purpose

Shaft alignment has in recent years become a bigger challenge due to increased power, lower shaft speeds and heavier propellers in combination with a shorter propulsion shaft. Consequently, these effects should be carefully considered when designing an optimal shaft line in order to avoid problems in operation.

Benefits

Proper shaft alignment analyses during the design phase help to avoid both delays in delivery and alignment problems in operation, thereby reducing expensive off-hire.

DNV has experience from several research projects studying the interaction between hull deflections and the shaft line.

DNV have in-house multidisciplinary technical knowledge and experience and is therefore a preferred active partner for finding the true reason for damage caused by shaft alignment and for providing assistance in shaft design.

Features

Knowledge and experience of the parameters that affect shaft alignment are important to avoid shafting problems. A DNV shaft alignment report for a new design may include:

• Shaft alignment and whirling analyses

• Analysis of propeller excitation forces

• Alignment procedure

• Verification of the alignment

For a conversion project, DNV may:

• Measure alignment during and after the conversion process

• Propose a new alignment for the shaft line