Latest Docks & Harbour Engineering Objective Questions

1.In multiple point mooring system, vessel is secured to minimum of

two points
four points
six points
eight points

ANSWER : : four points

2.As compared to wall type breakwater, mound type breakwater

requires skilled labour
requires low maintenance cost
requires less material
results in less damage due to gradual failure

ANSWER : : results in less damage due to gradual failure

3.Assertion A : Intervention of undulations in the sea bed reduces the depth of wave at the section. Reason R : No wave can have a height greater than the depth of water through which it passes. Select your answer based on the coding system given below:

Both A and R are true and R is correct explanation of A.
Both A and R are true but R is not the correct explanation of A.
A is true but R is false.
A is false but R is true.

ANSWER : : Both A and R are true and R is correct explanation of A.

4.If the maximum spring rise is 2 m and height of the waves expected is 4 m , then the breakwater height above the datum will be

2.5 m
4 m
5 m
7 m

ANSWER : : 7 m

5.Dead weight tonnage of a ship i) varies with latitude and season ii) is more than displacement tonnage iii) is the difference between displacement load and displacement light Of these statements

i) and ii) are correct
ii) and iii) are correct
i) and iii) are correct
Only iii) is correct

ANSWER : : i) and iii) are correct

6.When a ship floats at its designed water line, the vertical distance from water line to the bottom of the ship is known as

beam
depth
freeboard
draft

ANSWER : : draft

7.By increasing the rise of lock gates, (i) the length of the lock gate will increase (ii) transverse stress due to water pressure on the gate will increase (iii) compressive force on the gate will increase Of these statements

(i) and (ii) are correct
(i) and (iii) are correct
Only (ii) is correct
Only (iii) is correct

ANSWER : : (i) and (ii) are correct

8.The difference in height between highest high water and lowest low water is called

mean range
maximum range
maximum rise
mean rise

ANSWER : : maximum range

9.At a given port, the fetch is 400 nautical miles, the maximum height of storm wave will be

2.073 m
8.169 m
9.144 m
6.8 m

ANSWER : : 9.144 m

10.Assertion A : Basin walls have to be of much grater height than dock walls. Reason R : Tidal basins are subject to fluctuations of levels due to tidal variations. Select your answer based on the coding system given below:

Both A and R are true and R is the correct explanation of A.
Both A and R are true but R is not correct explanation of A.
A is true but R is false.
A is false but R is true.

ANSWER : : Both A and R are true and R is the correct explanation of A.

11.The maximum harbour depth below lowest low water is generally equal to (i) loaded draft + 1.2 m when bottom is rock (ii) loaded draft + 1.8 m when bottom is soft (iii) loaded draft + 1.2 m when bottom is soft (iv) loaded draft + 1.8 m when bottom is rock Of these statements

(i) and (ii) are correct
(i) and (iii) are correct
(ii) and (iv) are correct
(iii) and (iv) are correct

ANSWER : : (iii) and (iv) are correct

12.Consider the following statements in regard to Beaufort scale for wind speeds, (i) The Beaufort number ranges from 1 to 12. (ii) Higher Beaufort number indicates higher speed of wind, (iii) Beaufort number for calm is smallest and for hurricane is highest Of these statements

(i) and (ii) are correct
(ii) and (iii) are correct
(i) and (iii) are correct
(i), (ii) and (iii) are correct

ANSWER : : (ii) and (iii) are correct

13.Select the incorrect statement.

The progress of work in low level method of mound construction is very slow.
Barge method of mound construction is economical.
In low level method of mound construction, the area of working is limited.
In staging method of mound cons-truction, the work is not interrupted even during stormy weather.

ANSWER : : Barge method of mound construction is economical.

14.Minimum width of ship clearance shall be

B or 30 m
1.5 B or 50 m
1.5 B
50 m

ANSWER : re “B” is beam of the design vessel

15.In basins subjected to strong winds and tide, the length of the berthing area should not be less than

the length of design vessel
the length of design vessel + 10% clearance between adjacent vessels
the length of design vessel + 20% clearance between adjacent vessels
twice the length of design vessel

ANSWER : : the length of design vessel + 20% clearance between adjacent vessels

16.If H is the height of the wave expected, then the height of the breakwater is generally taken as

1.2 H to 1.25 H above the datum
1.2 H to 1.25 H above the low water level
1.2 H to 1.25 H above the high water level
1.2 H to 1.25 H above the mean sea level

ANSWER : : 1.2 H to 1.25 H above the high water level

17.The significant wave height is defined is the average height of the

one – third highest waves
one – fourth highest waves
one – fifth highest waves
one – tenth highest waves

ANSWER : : one – third highest waves

18.Assertion A : Marine structures are made specially bulky and strong. Reason R : Sea insects result in undermining of the hardest and the soundest building material. Select your answer based on the coding system given below:

Both A and R are true and R is the correct explanation of A.
Both A and R are true but R is not the correct explanation of A.
A is true but R is false.
A is false but R is true.

ANSWER : : Both A and R are true and R is the correct explanation of A.

19.As per Berlin’s formula, the length of wave in metres is given by

1.3412
1.5612
1.7412
1.9412

ANSWER : re ‘t’ is the period in seconds for two successive waves to pass the same section.

20.If Hs is the significant wave height, then the average wave height and highest wave height respectively are given by

0.6 Hs and 1.67 Hs
0.6 Hs and 1.87 Hs
1.27 Hs and 1.87 Hs
1.27 Hs and 1.67 Hs

ANSWER : : 0.6 Hs and 1.87 Hs

21.In a two lane channel, bottom width of channel is given by

Manoeuvring lane + 2 x Bank clearance lane
2 x Manoeuvring lane + 2 x Bank clearance lane
2 x Manoeuvring lane + 2 x Bank clearance lane + ship clearance lane
Manoeuvring lane + 2 x Bank clearance lane + ship clearance lane

ANSWER : : 2 x Manoeuvring lane + 2 x Bank clearance lane + ship clearance lane

22.As per Stevenson’s empirical formula, the approximate value of the height of the wave in metres is given by

0.34 VF
0.5 VF
1.5 VF
3.4 VF

ANSWER : re F is the fetch in km.

23.The minimum diameter of turning besin, where ships turn by going ahead and without tug assistance should be

L
1.5 L
2.0 L
4.0 L

ANSWER : re L is the length of the largest ship to use the port

24.Which of the following is a fixed type mooring accessory ?

bollard
buoys
cables
anchors

ANSWER : : bollard

25.A ship strikes the berth generally at an angle

90� with the face of the dock
45� with the face of the dock
30� with the face of the dock
10� with the face of the dock

ANSWER : : 10� with the face of the dock

26.Which of the following are repair docks ?

marine railways, dry docks, floating docks, wet docks
dry docks, wet docks, floating docks, lift docks
wet docks, floating docks, lift docks, marine railways
wet docks, lift docks, marine railways, dry docks

ANSWER : : wet docks, floating docks, lift docks, marine railways

27.Which of the following structures are constructed parallel to shore line to develop a demarcating line between land area and water area ?

sea walls, bulk heads and groynes
sea walls, bulk heads and revetments
sea walls, revetments and groynes
bulk heads, revetments and groynes

ANSWER : : sea walls, bulk heads and revetments

28.Which of the following structures protects the shore by trapping of littoral drift?

groynes
sea walls
revetments
moles

ANSWER : : groynes

29.Assertion A : Large size stones are required in stone revetment in shore protection. Reason R : Resistance of stone to wave force is proportional to its volume and wave force is proportional to the exposed area of the stone. Select your answer based on the coding system given below.

Both A and R are true and R is the correct explanation of A.
Both A and R are true but R is not a correct explanation of A.
A is true but R is false.
A is false but R is true.

ANSWER : : Both A and R are true and R is the correct explanation of A.

30.Consider the following statements. (i) Fender is the cushion provided on the face of the jetty for ships to come in contact, (ii) Slip is the space of water area between two adjacent piers where ships are berthed, (iii) Pier head is a structure constructed near the tip of a break water near the harbor entrance. Of the statements

(i) and (ii) are correct
(ii) and (iii) are correct
(i) and (iii) are correct
(i), (ii) and (iii) are correct

ANSWER : : (i), (ii) and (iii) are correct

31.A ship is berthed in a chamber and lifted by principles of buoyancy Such a chamber is called.

Dry dock
Wet dock
Floating dock
Refuge dock

ANSWER : : Floating dock

32.Which of the following conditions of loading imposes the greatest load on the foundation in case of dry docks?

when the dock is empty
when the dock is empty with the ship of maximum tonnage
when the dock is full of water
when the dock is dry and is under construction

ANSWER : : when the dock is full of water

33.For designing the dock, the proportion of ship load assumed to be borne by keel blocks is

5/8
3/8
3/16
5/16

ANSWER : : 5/8

34.Which of the following type of sea walls results in greatest protection of shore structures?

vertical sea wall
sea wall with batter
stepped sea wall
sea wall with concave face

ANSWER : : sea wall with concave face