Ship Manoeuvring and Motions - Naval Architecture and Ocean Engineering - Naval Architecture & Marine Engineering Previous Year Questions

1

2022 · Naval Architecture & Marine Engineering · Naval Architecture and Ocean Engineering · Ship Manoeuvring and Motions

Naval Architecture & Marine Engineering (NM) 2022

Assume that a ship has length \(L = 200\) m and operates at a design speed \(U = 12\) m/s. If in a turning circle maneuver, the ship exhibits a steady turning diameter of \(6L\), then the yaw rate of the ship is ______ rad/s (correct to two decimal places).

Check answer

Open complete paper

2

2022 · Naval Architecture & Marine Engineering · Naval Architecture and Ocean Engineering · Ship Manoeuvring and Motions

Naval Architecture & Marine Engineering (NM) 2022

Consider the wave elevation spectrum \(S_{\eta\eta}(\omega)\) as shown in the figure. Then, the significant wave height is ______ m.

A

2

B

4

C

6

D

8

Open complete paper

3

2022 · Naval Architecture & Marine Engineering · Naval Architecture and Ocean Engineering · Ship Manoeuvring and Motions

Naval Architecture & Marine Engineering (NM) 2022

An autonomous underwater vehicle is made of a long cylinder with a semi-ellipsoid at the forward end and a hemisphere at the aft end as shown in the figure. The origin of the reference frame is located at the centroid of the cylinder.
The positive x, y and z axes, respectively, are pointing towards forward, port and upward directions. The surge, sway and heave motions are represented by indices 1-2-3 and roll, pitch and yaw motions are represented by indices 4-5-6, respectively.
If \(A = [A_{ij}]\) is the added mass matrix, then which of the following are NOT zero?

A

\(A_{15}\)

B

\(A_{35}\)

C

\(A_{46}\)

D

\(A_{26}\)

Check answer

Open complete paper

4

2022 · Naval Architecture & Marine Engineering · Naval Architecture and Ocean Engineering · Ship Manoeuvring and Motions

Naval Architecture & Marine Engineering (NM) 2022

Consider a ship with a forward speed \( U \) of 9.81 m/s moving in deep waters. A wave is incident at an angle \( \beta = 120^{\circ} \) to the longitudinal axis of the ship as shown in figure. Assume acceleration due to gravity \( g = 9.81 \, \text{m/s}^2 \). If a person onboard the ship observes the encounter period of the incident wave to be 4.187 s, then the actual period of the wave is ______ s (rounded off to one decimal place).

Check answer

Open complete paper

5

2023 · Naval Architecture & Marine Engineering · Naval Architecture and Ocean Engineering · Ship Manoeuvring and Motions

Naval Architecture & Marine Engineering (NM) 2023

The time series of rudder angle (δ) and heading angle (ψ) during a ship’s maneuver are shown in the following figure. Identify the maneuver and the associated parameters (p, q, r and s)

A

turning maneuver
p: heading angle, q: rudder angle, r: 1^st overshoot angle, s: 2^nd overshoot angle

B

spiral maneuver
p: heading angle, q: rudder angle, r: 1^st overshoot angle, s: 2^nd overshoot angle

C

zig-zag maneuver
p: rudder angle, q: heading angle, r: 1^st overshoot angle, s: 2^nd overshoot angle

D

zig-zag maneuver
p: heading angle, q: rudder angle, r: 1^st overshoot angle, s: 2^nd overshoot angle

Check answer

Open complete paper

6

2023 · Naval Architecture & Marine Engineering · Naval Architecture and Ocean Engineering · Ship Manoeuvring and Motions

Naval Architecture & Marine Engineering (NM) 2023

The trajectory of a model ship during a pure sway PMM test is shown below. The steady forward speed, u is 2.0 m/s. The maximum amplitude of sway motion, \(y_{max}\) is 0.5 m and its period is 8 s. The magnitude of maximum drift angle, in degrees (round off to the nearest integer), and the magnitude of maximum sway acceleration, in m/s² (round off to one decimal place), of the model respectively are

A

11 and 0.3

B

13 and 0.5

C

15 and 0.2

D

9 and 0.1

Open complete paper

7

2024 · Naval Architecture & Marine Engineering · Naval Architecture and Ocean Engineering · Ship Manoeuvring and Motions

Naval Architecture & Marine Engineering (NM) 2024

A ship with a standard right-handed coordinate system has positive x, y and z axes respectively pointing towards bow, starboard and down as shown in the figure. If the ship takes a starboard turn, then the drift angle, sway velocity and the heel angle of the ship for a steady yaw rate respectively are

A

positive, negative and positive

B

negative, positive and positive

C

negative, positive and negative

D

positive, negative and negative

Open complete paper

8

2024 · Naval Architecture & Marine Engineering · Naval Architecture and Ocean Engineering · Ship Manoeuvring and Motions

Naval Architecture & Marine Engineering (NM) 2024

A ship with controls fixed, is modeled as a two degrees of freedom system. For the linear maneuvering equations of motion for coupled sway and yaw, if the derived eigenvalues are real and negative, then the ship must possess

A

positional motion stability

B

directional stability

C

straight line stability

D

both directional and positional motion stabilities

Open complete paper

9

2024 · Naval Architecture & Marine Engineering · Naval Architecture and Ocean Engineering · Ship Manoeuvring and Motions

Naval Architecture & Marine Engineering (NM) 2024

Which of the following statement(s) is/are correct about strip theory?

A

It can be used to calculate the surge added mass

B

It is a two-dimensional theory

C

It can be used to calculate the pitch added mass

D

It can be used to calculate the coupled sway, roll and yaw added mass

Check answer

Open complete paper

10

2024 · Naval Architecture & Marine Engineering · Naval Architecture and Ocean Engineering · Ship Manoeuvring and Motions

Naval Architecture & Marine Engineering (NM) 2024

Consider a two-dimensional ship section as shown in the figure. About the point O, let the sway added mass components be \(a_{22}\) and \(a_{24}\) and roll added moment of inertia be \(a_{44}\). The clockwise roll angle is considered positive. The roll added mass due to roll, about P which is at a distance \(z_P\) above O is given by

A

\(a_{44} - a_{24}z_P\)

B

\(a_{44} - a_{22}z_P - a_{24}z_P\)

C

\(a_{44} - a_{22}z_P + a_{24}z_P\)

D

\(a_{22} + a_{24} + a_{44}\)

Open complete paper

11

2024 · Naval Architecture & Marine Engineering · Naval Architecture and Ocean Engineering · Ship Manoeuvring and Motions

Naval Architecture & Marine Engineering (NM) 2024

The wave spectrum and the ship heave Response Amplitude Operator (RAO) are shown in the figure. The variance of the heave motion is _______ m² (rounded off to three decimal places).

Check answer

Open complete paper

12

2025 · Naval Architecture & Marine Engineering · Naval Architecture and Ocean Engineering · Ship Manoeuvring and Motions

Naval Architecture & Marine Engineering (NM) 2025

Consider a Planar Motion Mechanism (PMM) test of a ship model in a towing tank. The transverse motion of the model from the centerline of the tank is described by \( y = a_0 \cos(\omega t) \), where \( \omega \) is the angular frequency. The carriage speed is 3 m/s, \( \omega = \frac{\sqrt{3}}{2} \) rad/s and the maximum drift angle during the test is 30°. The amplitude of oscillation \( a_0 \) lies between ______.

A

0.2 m and 0.4 m

B

0.5 m and 0.7 m

C

1.0 m and 1.2 m

D

1.9 m and 2.1 m

Open complete paper

13

2025 · Naval Architecture & Marine Engineering · Naval Architecture and Ocean Engineering · Ship Manoeuvring and Motions

Naval Architecture & Marine Engineering (NM) 2025

The dynamics of a 90 m long ship are governed by the non-dimensional Nomoto equation. The magnitude of Nomoto gain \(|K'| = \frac{72}{35\pi}\) and that of Nomoto time constant \(|T'| = \frac{288}{35\pi}\).
The steady turning radius of the ship for a 35° turning circle maneuver is _____ m (answer in integer).

Check answer

Open complete paper

14

2025 · Naval Architecture & Marine Engineering · Naval Architecture and Ocean Engineering · Ship Manoeuvring and Motions

Naval Architecture & Marine Engineering (NM) 2025

Consider a rectangular barge of length (L) 100 m, breadth 25 m and draught 10 m. The barge has the following non-dimensional hydrodynamic derivatives with respect to a coordinate system whose origin is at the center of gravity.
\(Y'_v = -1000 \times 10^{-5}, N'_r = -800 \times 10^{-5},\)
\(N'_v = -200 \times 10^{-5}, Y'_r = 100 \times 10^{-5}\)
The stability criterion \(C'\) is given by
\(C' = Y'_v(N'_r - m' x'_G) - (Y'_r - m') N'_v\)
where \(m' = \frac{m}{\frac{1}{2} \rho L^3}\), m is the mass of the barge, \(\rho\) is the density of seawater, and \(x_G\) is the distance of the center of gravity from the origin.
Which one of the following is correct regarding the controls-fixed straight-line stability?

A

Unstable with \(C' = -1.8 \times 10^{-5}\)

B

Stable with \(C' = 3.2 \times 10^{-5}\)

C

Stable with \(C' = -1.8 \times 10^{-5}\)

D

Unstable with \(C' = 3.2 \times 10^{-5}\)

Open complete paper

15

2026 · Naval Architecture & Marine Engineering · Naval Architecture and Ocean Engineering · Ship Manoeuvring and Motions

Naval Architecture and Marine Engineering (NM) 2026

The RAO (Response Amplitude Operator) of a floating body with no forward speed is denoted by \(H(\omega)\).
If it encounters a wave spectrum \(S(\omega)\), then its response spectrum is ____.

A

\(H(\omega)S(\omega)\)

B

\(|H(\omega)|^2 S(\omega)\)

C

\(|H(\omega)|^3 S(\omega)\)

D

\(|H(\omega)| S(\omega)\)

Open complete paper

16

2026 · Naval Architecture & Marine Engineering · Naval Architecture and Ocean Engineering · Ship Manoeuvring and Motions

Naval Architecture and Marine Engineering (NM) 2026

The sway-yaw coupled maneuvering equation of motion for a ship is
\[\begin{bmatrix} M - Y_{\dot{v}} & -Y_{\dot{r}} \\ -N_{\dot{v}} & I_z - N_{\dot{r}} \end{bmatrix} \begin{bmatrix} \dot{v} \\ \dot{r} \end{bmatrix} = \begin{bmatrix} Y_v & Y_r \\ N_v & N_r \end{bmatrix} \begin{bmatrix} v \\ r \end{bmatrix} + \begin{bmatrix} Y_\delta \\ N_\delta \end{bmatrix} \delta_R\]
For a control-fixed straight-line stability, the eigenvalues of the function should be ____.

A

real and negative

B

real and positive

C

complex numbers with positive real part and negative imaginary part

D

zero

Open complete paper

17

2026 · Naval Architecture & Marine Engineering · Naval Architecture and Ocean Engineering · Ship Manoeuvring and Motions

Naval Architecture and Marine Engineering (NM) 2026

During a captive maneuvering model test of a ship with a rudder, which ONE or MORE of the following coefficients can be calculated using an oblique towing test (straight line test with a drift angle)?

A

\(Y_v\) and \(Y_{vvv}\)

B

\(N_v\) and \(N_{vvv}\)

C

\(Y_{v\delta\delta}\) and \(N_{v\delta\delta}\)

D

\(N_{r\delta\delta}\) and \(N_{vr\delta}\)

Check answer

Open complete paper