Minimum intermediate shaft diameter per IACS UR M68 from rated power, rpm and material UTS.
Formula
$$ d = 100 \cdot \sqrt[3]{\frac{P \cdot k}{N}} \cdot \frac{560}{\sigma_\text{UTS} + 160} $$
Symbol legend
| Symbol | Meaning | Unit | Source |
|---|---|---|---|
| $P$ | Rated shaft power | kW | engine/plant spec |
| $N$ | Shaft rpm at rated power | rpm | engine/plant spec |
| $\sigma_\text{UTS}$ | Material ultimate tensile strength | N/mm² | material certificate |
| $k$ | Installation factor | - | IACS UR M68 |
| $d$ | Shaft diameter | mm | result |
Sources
- IACS UR M68 - Shaft Design.