Tug Line Force - Pivot Moment
Turning moment generated by a tug pulling at a given position - used to evaluate effectiveness of stern / bow tugs during manoeuvring.
Turning moment
37,588kN·m
Formula, assumptions, and limits
$$M = F \cdot d \cdot \cos\alpha$$
Maximum moment when tug pulls perpendicular to hull. Pivot point shifts with ship motion - see pivot-point calculator. Twin-tug at bow + stern equal pulls maximise couple.
Symbol legend
| Symbol | Meaning | Unit | Source |
|---|---|---|---|
| $F$ | Tug pulling force | kN | bollard pull |
| $d$ | Distance from pivot | m | tug configuration |
| $\alpha$ | Line angle from perpendicular | deg | ship-handling |
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