Docks and Harbour Engineering Multiple Choice Questions :-
1. Assertion A : Depth and width required at the entrance to a harbour are more than those required in the channel.
Reason R : The entrance to a harbour is usually more exposed to waves as compared to the harbour itself.
Select your answer based on the coding system given below:
A. Both A and R are true and R is the correct explanation of a.
B. Both A and R are true but R is not the correct explanation of a.
C. A is true but R is false.
D. A is false but R is true.
Answer: A
2. When a ship floats at its designed water line, the vertical distance from water line to the bottom of the ship is known as
A. beam
B. depth
C. freeboard
D. draft
Answer: D
3. 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
A. (i) and (ii) are correct
B. (i) and (iii) are correct
C. (ii) and (iv) are correct
D. (iii) and (iv) are correct
Answer: D
4. The minimum diameter of turning besin, where ships turn by going ahead and without tug assistance should be
A. L
B. 1.5 L
C. 2.0 L
D. 4.0 L
where L is the length of the largest ship to use the port
Answer: D
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
A. i) and ii) are correct
B. ii) and iii) are correct
C. i) and iii) are correct
D. Only iii) is correct
Answer: C
6. In basins subjected to strong winds and tide, the length of the berthing area should not be less than
A. the length of design vessel
B. the length of design vessel + 10% clearance between adjacent vessels
C. the length of design vessel + 20% clearance between adjacent vessels
D. twice the length of design vessel
Answer: C
7. As per Stevenson’s empirical formula, the approximate value of the height of the wave in metres is given by
A. 0.34 VF
B. 0.5 VF
C. 1.5 VF
D. 3.4 VF
where F is the fetch in km.
Answer: A
8. As per Berlin’s formula, the length of wave in metres is given by
A. 1.3412
B. 1.5612
C. 1.7412
D. 1.9412
where ‘t’ is the period in seconds for two successive waves to pass the same section.
Answer: B
9. 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:
A. Both A and R are true and R is correct explanation of A.
B. Both A and R are true but R is not the correct explanation of A.
C. A is true but R is false.
D. A is false but R is true.
Answer: A
10. 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
A. (i) and (ii) are correct
B. (ii) and (iii) are correct
C. (i) and (iii) are correct
D. (i), (ii) and (iii) are correct
Answer: B
11. At a given port, the fetch is 400 nautical miles, the maximum height of storm wave will be
A. 2.073 m
B. 8.169 m
C. 9.144 m
D. 6.8 m
Answer: C
12. In a two lane channel, bottom width of channel is given by
A. Manoeuvring lane + 2 x Bank clearance lane
B. 2 x Manoeuvring lane + 2 x Bank clearance lane
C. 2 x Manoeuvring lane + 2 x Bank clearance lane + ship clearance lane
D. Manoeuvring lane + 2 x Bank clearance lane + ship clearance lane
Answer: C
13. Minimum width of ship clearance shall be
A. B or 30 m
B. 1.5 B or 50 m
C. 1.5 B
D. 50 m
where “B” is beam of the design vessel
Answer: A
14. Select the incorrect statement.
A. The progress of work in low level method of mound construction is very slow.
B. Barge method of mound construction is economical.
C. In low level method of mound construction, the area of working is limited.
D. In staging method of mound cons-truction, the work is not interrupted even during stormy weather.
Answer: B
15. 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:
A. Both A and R are true and R is the correct explanation of A.
B. Both A and R are true but R is not the correct explanation of A.
C. A is true but R is false.
D. A is false but R is true.
Answer: A
16. The most popular method of construction of wall breakwaters is
A. Barge method
B. Staging method
C. Low level method
D. none of the above
Ans:
17. As compared to wall type breakwater, mound type breakwater
A. requires skilled labour
B. requires low maintenance cost
C. requires less material
D. results in less damage due to gradual failure
Answer: D
18. The difference in height between highest high water and lowest low water is called
A. mean range
B. maximum range
C. maximum rise
D. mean rise
Answer: B
19. 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
A. 2.5 m
B. 4 m
C. 5 m
D. 7 m
Answer: D
20. If H is the height of the wave expected, then the height of the breakwater is generally taken as
A. 1.2 H to 1.25 H above the datum
B. 1.2 H to 1.25 H above the low water level
C. 1.2 H to 1.25 H above the high water level
D. 1.2 H to 1.25 H above the mean sea level
Answer: C
Docks and Harbor Engineering Interview Questions ::
21. 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:
A. Both A and R are true and R is the correct explanation of A.
B. Both A and R are true but R is not correct explanation of A.
C. A is true but R is false.
D. A is false but R is true.
Answer: A
22. In multiple point mooring system, vessel is secured to minimum of
A. two points
B. four points
C. six points
D. eight points
Answer: B
23. By increasing the rise of lockgates,
(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
A. (i) and (ii) are correct
B. (i) and (iii) are correct
C. Only (ii) is correct
D. Only (iii) is correct
Answer: A
24. Which of the following is a fixed type mooring accessory ?
A. bollard
B. buoys
C. cables
D. anchors
Answer: A
25. The significant wave height is defined is the average height of the
A. one – third highest waves
B. one – fourth highest waves
C. one – fifth highest waves
D. one – tenth highest waves
Answer: A
26. If Hs is the significant wave height, then the average wave height and highest wave height respectively are given by
A. 0.6 Hs and 1.67 Hs
B. 0.6 Hs and 1.87 Hs
C. 1.27 Hs and 1.87 Hs
D. 1.27 Hs and 1.67 Hs
Answer: B
27. When a wave strikes a vertical breakwater in deep water, it is reflected back and on meeting another advancing wave of similar amplitude merges and rises vertically in a wall of water. This phenomenon is called
A. Surf
B. Clapotis
C. Fetch
D. Swell
Answer: B
28. Which of the following structures are constructed parallel to shore line to develop a demarcating line between land area and water area ?
A. sea walls, bulk heads and groynes
B. sea walls, bulk heads and revetments
C. sea walls, revetments and groynes
D. bulk heads, revetments and groynes
Answer: B
29. Which of the following type of sea walls results in greatest protection of shore structures?
A. vertical sea wall
B. sea wall with batter
C. stepped sea wall
D. sea wall with concave face
Answer: D
30. 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.
A. Both A and R are true and R is the correct explanation of A.
B. Both A and R are true but R is not a correct explanation of A.
C. A is true but R is false.
D. A is false but R is true.
Answer: A
31. Which of the following are repair docks ?
A. marine railways, dry docks, floating docks, wet docks
B. dry docks, wet docks, floating docks, lift docks
C. wet docks, floating docks, lift docks, marine railways
D. wet docks, lift docks, marine railways, dry docks
Answer: C
32. Which of the following structures protects the shore by trapping of littoral drift?
A. groynes
B. sea walls
C. revetments
D. moles
Answer: A
33. Which of the following conditions of loading imposes the greatest load on the foundation in case of dry docks?
A. when the dock is empty
B. when the dock is empty with the ship of maximum tonnage
C. when the dock is full of water
D. when the dock is dry and is under construction
Answer: C
34. For designing the dock, the proportion of ship load assumed to be borne by keel blocks is
A. 5/8
B. 3/8
C. 3/16
D. 5/16
Answer: A
35. A ship strikes the berth generally at an angle
A. 90° with the face of the dock
B. 45° with the face of the dock
C. 30° with the face of the dock
D. 10° with the face of the dock
Answer: D
36. 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 harbour entrance. Of the statements
A. (i) and (ii) are correct
B. (ii) and (iii) are correct
C. (i) and (iii) are correct
D. (i), (ii) and (iii) are correct
Answer: D
37. A ship is berthed in a chamber and lifted by principles of buoyancy Such a chamber is called.
A. Dry dock
B. Wet dock
C. Floating dock
D. Refuge dock
Answer: C
38. For location of soundings a range and one angle from the shore involves the following operations. Which one is correct ?
A. A range line is established
B. The first and the last soundings and every tenth soundings are fixed by angular observations
C. The intermediate soundings are fixed by the time intervals
D. All the above.
Answer: D
39. Pick up the correct statement from the following:
A. the Mediterranean sea is considered to be a huge harbour
B. the Caspean sea is considered to be a big harbour
C. the Red sea is considered to be harbour
D. none of the above.
Answer: A
40. Pick up the correct statement from the following:
A. a harbour without any port complex, is called a refuge harbour
B. a harbour used for fishery, is called fishery harbour
C. the terminal building of a commercial harbour consists of an administrative block, customs clearance and ware-houses.
D. all the above.
Answer: D
41. Pick up the incorrect statement from the following:
A. As a wave of sea water approaches the coast line, it is generally accompanied by a drift of water in the direction of wave advance
B. The on-shore wind helps to produce wave action as well as rise of M.S.L.
C. A falling hydraulic gradient occurs in the direction of the wave
D. The wave while receding carries finer particles out to deep water.
Answer: C
42. In a wet dock system,
A. minimum required depth of water for the vessels is maintained
B. entrance locks are provided with massive gates
C. the locks of dock gate are operated by means of heavy bascule bridges and connected machinery
D. the cost of construction is quite heavy
E. all the above.
Answer: E
43. A roadstead :
A. is a protected area of water where boats can move safely
B. is the end of the road at the harbour
C. may be protected by break water walls
D. none of these.
Answer: A
44. The width of the entrances of the harbours is restricted to
A. 100 m
B. 125 m
C. 150 m
D. 180 m
Answer: D
45. Pick up the correct statement from the following:
A. The tides at any place occur a little less than 1 hour later, each succeeding day
B. The difference in time in solar hours and minutes from any lunar transit to the succeeding transit, is called high water level
C. The influence of the earth’s gravity alone produces level-tidal less sea
D. The spinning force is maximum at the equator and zero at the poles
E. All of the above.
Answer: E
46. Location of soundings by range and one angle is done by the surveyor
A. on the shore
B. on the boat
C. on the shore or on the boat
D. none of the above.
Answer: C
47. The variation of atmospheric potential is caused due to :
A. difference in temperature over the surface of the earth
B. change in the density of air
C. both (A) and (B)
D. neither (A) nor (B).
Answer: C
48. Location of soundings by two angles from the shore requires establishing
A. one range line parallel to shore
B. one range line perpendicular to shore
C. two range lines mutually perpendicular
D. no range line.
Answer: D
49. The floating mooring does not require
A. cables
B. anchors
C. bollard
D. buoy.
Answer: C
50. Pick up the correct statement from the following:
A. The maritime structures should be designed to withstand wave motion of air
B. The wind vortex results in conical depression in the air surface
C. A tube of air rotating at hundreds of kilometres per hour forms a tornado
D. all of the above.
Answer: D
51. In tropical regions,
A. the surface gets heated more effectively than the arctic areas
B. after heating, the air becomes lighter and is displaced by cool air from the polar regions
C. the rising tropical air flows towards the polar region in the upper strata
D. all of the above.
Answer: D
52. For large vessels, the buoys are strengthened by connecting it to a number of anchors having
A. one legged mooring
B. two legged mooring
C. three legged mooring
D. four legged mooring
E. all the types as above.
Answer: E
53. On the sea shore structures, the water wave impact causes
A. direct compressive force due to its horizontal component
B. shear force due to deflected vertical force
C. compressive force due to collapse of the wave
D. suction force due to water returning after striking
E. all of the above.
Answer: E
54. Pick up the correct statement from the following:
A. Spring tides are caused at new and full moon
B. Neap tides are caused when the moon is in her quarters
C. Spring tides are roughly twice the height of neap tides
D. Flood tides and Ebbstides are caused after 24 hours and 50 minutes corresponding to a lunar day
E. All of the above.
Answer: E
55. A dock:
A. is a marine structure for berthing of vessels for loading and unloading cargo and passengers
B. is an artificial basin for vessels where the variation of water in the shore does not affect the level of water
C. is provided with a dock gate
D. is provided with an arrangement to pump out water when required
E. all the above.
Answer: E