Nomoto K and T from Zig-zag

First-order Nomoto response coefficients K (yaw-rate sensitivity) and T (yaw time constant) from zig-zag trial data. K/T characterises how responsive a ship is to rudder.

Manoeuvring

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This calculator requires JavaScript to compute its result. The formula, symbols, and regulatory sources are shown in the Formula section below.

Formula, assumptions, and limits

T \dot{\psi} + \dot \psi = K \delta, \quad K = \frac{\dot\psi_\text{steady}}{\delta}, \quad T = t_{63\%}

Symbol	Meaning	Unit
$δ$	Rudder angle	°
$\dot\psi$	Yaw rate	°/s
$K$	Yaw-rate gain	(°/s)/°
$T$	Yaw time constant	s

Source: Nomoto et al. - On the Steering Qualities of Ships (1957)

In short

First-order Nomoto response coefficients K (yaw-rate sensitivity) and T (yaw time constant) from zig-zag trial data.

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