Hi Andrés,

For a 161-m Mariner class cargo ship, the following parameters can be found in 1965 publication by Chislett and Strøm-Tejsen:

• K = 0.185
• T1 = 118
• T2 = 7.8
• T3 = 18.5

Article Planar motion mechanism tests and full-scale steering and ma...

Other Question Mr. Chak. The Nomoto's model has a few limitation because it is a linear model and one of this limitation is the rudder angle. What is the maximun rudder angle that accepted the model?

Other thing, the k value would be -0.1.85 because I just read a thesis with the same dimension and they put k = -0.185

Hi Mr. Gómez,

For small angle approximation, I'd say ±10°.

I'm unclear about your 2nd post. So the thesis came from the original authors? Or, are you implying that the original authors made a minor mistake in the 1965 paper because someone else used K = − 0.185 in his/her thesis? Please clarify.

Would you show the simulation results for both K = 0.185 and K = − 0.185? It is easier to make a comparison from the visuals. From the physical interpretation of the model (in thesis), the minus sign could mean reverse maneuvering.

Hi Mr. Chak.

You are right about the value of K, because later that I send you the message about my doubt I realize that  it doesn't matter if K=0.185 or K=-0.185, since the minus sign could mean reverse maneuvering as you said previously.

I'm very gratefull for the answers and the help that you have given me.

Hi Mr. Gómez,

Thank you for your clarification.

I wish you success in this endeavor.