Propeller Slip

Slip = (V_t − V_s) / V_t. Theoretical speed from pitch × RPM.

Theoretical speed V_t: — kn

Slip: — %

Classification: —

V_t = P × RPM × 60 / 1852. Slip is positive when the ship advances less than theoretical.

Report: Propeller Slip

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Notes

Theoretical speed: \( V_t(\mathrm{kn}) = \dfrac{P \cdot \mathrm{RPM} \cdot 60}{1852} \).

Slip (%): \( \dfrac{V_t - V_s}{V_t} \times 100 \).

Typical ranges: 0–10% excellent, 10–25% normal, >25% high (check propeller loading/cavitation).