Pivot Point Location
Approximate pivot point location forward of amidships as a function of propeller thrust direction. Ahead motion: pivot ~ 1/4 L forward of amidships; astern: ~ 1/4 L aft.
Pivot-point offset from amidships
50.0m
Formula, assumptions, and limits
$$x_\text{pivot} \approx \pm 0.25 L$$
Rule-of-thumb location; true pivot depends on rudder angle, trim, water depth and momentum. Bank suction and bow-cushion effects shift it several metres further. Used for estimating turning moments in confined waters.
Symbol legend
| Symbol | Meaning | Unit | Source |
|---|---|---|---|
| $L$ | LBP | m | particulars |
| $x_\text{pivot}$ | Distance from amidships (+ fwd) | m | result |
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