Turning Circle - Advance & Tactical Diameter
Advance and tactical diameter of a ship's 35° turning circle given length and speed, with IMO A.751 pass criteria check.
Advance / L
3.55 -
TD / L
4.05 -
Status
Pass - within IMO A.751 limits
Formula, assumptions, and limits
$$\text{Advance} \leq 4.5 L, \quad \text{TD} \leq 5 L$$
IMO A.751 limits at 35° rudder. Advance measured at 90° heading change; tactical diameter at 180° heading change. Published in manoeuvring booklet and wheelhouse poster.
Symbol legend
| Symbol | Meaning | Unit | Source |
|---|---|---|---|
| $Advance$ | Forward distance from track to 90° heading | m | sea trial |
| $TD$ | Tactical diameter at 180° heading | m | sea trial |
Spotted an error in this calculation? . We acknowledge editorial corrections within two working days.