Shiphandling Questions Flashcards
Shiphandling
1
Q
- When using an anchor to go alongside a dock with an onshore wind blowing
A
ans: don’t use the lee anchor if vessel is deep draft and there is little bottom clearance.
2
Q
- While turning on an anchor you increase the vessel’s speed. The pivot point ans:
A
does not move forward.
3
Q
- When stopping a vessel the ship falls off from original course. The amount of change is greater in deep water than in shallow water.
A
False
4
Q
- The diameter of a turning circle increases at higher speeds. TRUE
A
True
5
Q
- It is easier for a deep draft vessel to turn around a bend in a narrow channel with a head current than with a fair current.
A
FALSE
6
Q
- Bank cushion is greater than bank suction for a vessel moving ahead in a narrow channel.
A
FALSE
7
Q
- A vessel proceeding close to the bank in a narrow channel will cause the water level between the ship and the far bank to be less.
A
FALSE
8
Q
- Dropping one or two anchors in an emergency would be effective to slow the vessel and assist in controlling direction even when the anchors are used at short scope.
A
True
9
Q
- Transverse thrust is greater from large, slow moving propellor than from a small, fast moving propellor.
A
True
10
Q
- The names used for the three tug lines commonly used in U.S. ports are ans:
A
backing, come ahead, & stern line.
11
Q
- A tug with a quarter line can be capsized.
A
True
12
Q
- A tug is in the most danger of being tripped or capsized when working on a hawser.
A
True
13
Q
- When using standard tug whistle signals for U.S. ports, 1 blast could mean ans:
A
stop coming ahead.
14
Q
- When using standard tug whistle signals for U.S. ports the signal for come ahead full could be ans:
A
1 blast followed by a succession of short blasts.
15
Q
- When turning a vessel that is dead in the water using only the bow thruster and discounting any outside forces such as current where would the pivot point be? Ans:
A
1 X Beam from the stern
16
Q
- When handling a dead tow with a tail boat and a bow tug the bow tug is best used on a hawser led through the bullnose.
A
False
17
Q
- When handling a dead tow with a tug on the hip in a narrow channel where it will be necessary to negotiate sharp right hand turn in the channel, the best position to place the tug would be ans:
A
stbd quarter (inboard side of turn) with bow of tug slightly in towards hull of ship.
18
Q
- When assisting a ship (not a dead tow) in making a right-hand turn in a narrow channel what is the best position for the bow tug? Ans:
A
Tug should be on stbd bow (inboard side of turn) and will assist in slowing the ship down.
19
Q
- When undocking and using the propellor wash to assist in pushing the stern away from the dock the effect is greater when leaving from stbd-side to than from port-side to.
A
True
20
Q
- When docking with the wind blowing off the dock the first line put on the dock should be ans:
A
fwd spring.
21
Q
- A vessel is Dead in the water using tugs of equal power one fwd and one aft to push the vessel laterally. Disregarding current or wind as the vessel comes ahead on the engine and headway is gained ans:
A
the ship turns to stbd and the pivot point moves fwd.
22
Q
- On a ship with limited ballast capacity it is preferable to get the “bow down” to an even or nearly even keel rather than to have the ship with considerable drag.
A
FALSE
23
Q
- Ballasting tanker down by stern will limit amount of twisting. TRUE
A
True
24
Q
- Dropping two anchors on a short scope…a good way to slow the ship? TRUE
A
True
25
25. A vessel docking using an anchor with no tug available and an onshore wind, theoretically the anchor will hold as required with less scope if the lee anchor is used. TRUE
TRUE
26
26. A vessel using an anchor to dock with an onshore wind and no tug available, the anchor which would most benefit the vessel when undocking would be the offshore anchor. TRUE
TRUE
27
27. A vessel moored to a dock with a deep draft vessel passing in the channel. The vessel at the dock will be pushed in towards the dock when the passing vessel is abeam.
FALSE
28
28. In standard U.S. tug signals the signal given for push full ahead would be ans:
one blast followed by a series of short blasts.
29
29. A light vessel in ballast, screw is submerged with a strong wind blowing puts the engines ahead with rudder amidships. The pivot point will move aft from the initial point.
FALSE
30
30. A deep draft vessel starts the engines from dead in the water with rudder hard over and gets underway. As headway increases the pivot point moves aft.
True
31
31. A vessel puts its engines astern in shallow water with rudder amidships to stop the vessel. By the time the vessel is stopped its heading will be 80 to 90 degrees off the original heading.
True
32
32. A vessel is backing in to a slip to dock starboard side to with a fresh breeze blowing off the dock. There is one tug available. The most effective way to use the tug would be ans:
made up on the port bow.
33
33. When making a turn in a narrow channel a buoy located on the point would not be a useful indicator for the turn.
False
34
34. When making a turn in a narrow channel and using a buoy on the point to help position the vessel, if the relative motion of the buoy is towards the bow the vessel will fetch up at a further distance from the buoy. FALSE
False
35
35. A vessel with a controllable pitch propeller will behave like a right-handed propeller ship when backing if the vessel has a ans:
left-handed propeller.
36
36. A controllable pitch propeller is more effective astern than a conventional propeller.
FALSE
37
37. A steam turbine vessel can work against mooring lines more easily than a motor vessel.
TRUE
38
38. A dual mode ITB backing out of a slip will have the same interaction with the bottom as a conventional vessel.
FALSE
39
39. A vessel which increases trim by the stern will decrease the turning diameter.
False
40
40. Bank cushion has a greater effect on a full bodied deep draft vessel than a vessel in ballast.
True
41
41. When turning in to a slip to dock port side to with a tug made up on the stern on a hawser, the tug is more likely to be capsized if the if the towing connection is ans:
high and amidships.
42
42. A twin screw vessel is more likely to take a sheer in a narrow channel than a single screw vessel. TRUE
True
43
43. The three lines commonly used by U.S. tugs are in the order that they would be made fast ans:
backing, come ahead, and stern
44
44. In standard U.S. tug signals one blast could mean stop if the tug is pushing.
TRUE
45
45. Bank cushion and bank suction work together to cause a vessel to sheer away from shoal water.
TRUE
46
46. Bank cushion and bank suction will cause a vessel to sheer away from the near bank.
TRUE
47
47. A vessel making a turn in a narrow channel should have the engine on full ahead when entering the turn and then reduce the revolutions when coming out of the turn.
FALSE
48
48. Docking stern in onshore wind, best placement for tug? A. on the bow on a hawser
B. on the port bow C. midships D. on the stern on a hawser (I put port bow)
49
49. Twin-screw vessel rudder midships going astern you expect to back
a. erractically b. port c. starboard d. fairly straight (I put D)
50
50. Ship with limited ballast capability you want to get the bow down to make it on even keel or almost even keel?
FALSE (I put TRUE credit given)
51
51. Vessel with bow out of water, not underway and drifting, the wind will blow the bow faster than the stern and the stern will go up into the wind.
True
52
52. A twin screw vessel is more likely to shear in a narrow channel then a single screw vessel
TRUE
53
53. Right handed screw varible pitch propeller, if you’re going ahead the stern will go which way? Going astern which way?
Stern will always go to starboard
54
54. Dead in the water, full ahead, full rudder, what you start moving the pivotpoint will shift somewhat aft
TRUE
55
55. A conventional single screw tug is being used to assist a vessel off the berth and is made up on the bow. The tug’s come ahead line will be best used with the line led through the bull nose chock on the bow of the tug.
TRUE
56
56. A deep draft vessel proceeding through a narrow channel that has reached limiting speed increase rpms on the engine. This will not increase the vessels speed but will give better steering control.
False
57
57. A vessel with a block coefficient of 0.77 is making 8 knots and has a squat of 4 feet. If the vessel reduces speed to 4 knots how many feet would the squat decrease to?
ans: 1 foot
58
58. A deep loaded vessel starts its engines while dead in the water with rudder hard over. The pivot point moves to about 1/3 the distance of the vessel from the bow.
False
59
59. A vessel in ballast with the bow high out of the water and the screw submerged with a beam wind starts its engines from dead in the water with the rudder midships, the pivot point will move aft from its initial position.
False
60
60. A deep loaded vessel turning in a bend in a narrow channel that is too close to the bank on the side of the point in the bend, bank suction will adversely affect the vessel in making the turn.
True
61
61. A deep loaded vessel turning in a bend in a narrow channel will likely only need the rudder to check the swing of the turn. TRUE
True
62
62. A dual mode ITB entering restricted waters that must keep the barge on a short tow line should keep the tow line as short as possible to make sure the tug does not become girt or capsize.
False
63
63. A vessel using the lee anchor when docking with no tugs and an offshore wind ans:
theoretically the lee anchor will hold as required with less scope.
64
64. A vessel turning on her anchor at constant speed increases her rpms. The pivot point moves aft.
True
65
65. A full bodied deep draft vessel is likely to squat by the head.
True
66
66. A deep draft vessel coming from deep water to shallow water generally steering will improve unless the vessel goes down by the head.
True
67
67. A vessel that increases its drag will have a tighter turning circle.
False
68
68. When a pilot boards a vessel in order to know what magnetic course to steer he should get from the vessel the ans:
deviation
69
69. A deep draft vessel is proceeding in a narrow channel and passes a vessel moored to a berth. As the deep draft vessel passes the beam of the docked vessel the vessel at the dock will be pushed up against the dock. .
FALSE
70
70. A vessel is overtaking another vessel in a narrow channel. The vessel being overtaken will feel an increase in speed and an increase in bank suction as the overtaking vessel approaches its quarter.
TRUE
71
71. A tugboat assisting a vessel unberthing from a dock working on a hawser. Which placement of the towing hook would be the most dangerous in capsizing the tug? ans: high and midship
72. Shallow water effect becomes significant at a depth 1.5x draft.
True
72
73. The resultant bow thruster force is inversely proportionate to the ship’s speed.
TRUE
73
74. The moment of a force about a point is the product of that force and the perpendicular on its line of action.
TRUE
74
75. A turn in shallow water is wider due to restricted lateral motion of the aft ship and smaller drift angle.
TRUE – restricted bottom clearance impedes water flow
75
76. The rate of turn is about the same whether turning in shallow water or deep water.
TRUE
76
77. Using a bow thruster to turn the ship to port, will result in the center of gravity shifting to starboard.
FALSE –opposite is true
77
78. A ship down by the head will have a wider turning circle because of the reduced steering lever.
FALSE – smaller turning circle, due to increased lateral resistance fwd.
78
79. In shallow water the turning diameter is about the same as in deep water.
FALSE – turning diameter is greater in shallow water
79
80. On smaller ships, a turn to port has a smaller diameter then a turn to starboard.
True
80
81. A ship will have a smaller turning diameter under acceleration.
True
81
82. Momentum is the quantity of motion measured by the product of mass and velocity.
True
82
83. Under sternway in shallow water, a ship changes heading significantly, as much as 80 to 90 deg.
True
83
84. Under sternway in shallow water, much more distance is required to stop a ship then in deep water
False
84
85. For a quicker stop from full ahead, the propeller working slow astern will have a better braking effect than working full astern.
True
85
86. The turning circle in loaded condition in shallow water tends to be larger than in ballast
TRUE – due to smaller rudder ratio, more momentum, less bottom clearance
86
87. Directional stability improves in shallow water, unless ship is down by the head..
TRUE
87
88. Loss of headway with engine stopped, in shallow water, is more than in deep water, due to increased flow restriction under the keel.
FALSE – “ship carries her way longer in shallow water.”
88
89. Twin-screw, single rudder ships steer better at very low speeds when the engines are stopped than when coming ahead.
True
89
90. Under sternway in deep water, ships head will fall off to starboard at a greater rate than in shallow water.
FALSE
90
91. A ship down by the stern has a larger turning circle because of less lateral resistance fwd and more lateral resistance aft of PP.
TRUE
91
92. A complete turn under full rudder and full ahead from DIW takes less than half the room than it does for a ship starting a turn from full speed.
TRUE – due to momentum and longitudinal resistance.
92
93. The turning circle at a constant speed is the same, regardless of the speed.
FALSE – a slower constant speed will result in a smaller turning circle due to less momentum, shorter steering lever, and larger drift angle.
93
94. The vessel will twist more when backed in shallow water.
TRUE
94
95. Directional stability becomes more positive as length increases.
TRUE
95
96. Lateral resistance abaft PP restricts the drift angle AND limits the magnitude of the lateral resistance.
TRUE
96
97. A wider drift angle will result in smaller turning diameter.
TRUE
97
98. A ship under acceleration and turning has a wider drift angle.
TRUE
98
99. Directional stability becomes less positive as drag increases.
FALSE
99
100. A large turbine plant may have as little as 25% of the power astern as she has ahead.
False
100
101. A ship with a wider beam will have a relatively larger turning circle than a ship with a narrower beam.
False
101
102. During acceleration, the PP moves fwd as the resistance fwd is not yet proportionate to the propulsion force.
True
102
103. In order for the anchor to have a significant pivoting effect on a vessel under headway, a large turn must be deliberately initiated using the engine and rudder.
True
103
104. A VLCC loses 5-10% of her headway for every 90 deg. change in heading.
FALSE – “25-30%”
104
105. As depth decreases, the ship’s tactical diameter decreases.
False
105
106. A high-sided ship will feel the wind significantly at 5x the ship’s speed.
false 3x Ships Speed
106
107. A head current in a narrow channel assists large vessels in making turns.
FALSE – “a fair current assists….”
107
108. In the beginning stages of a turn, the imbalance of forces causes the ship to be directionally unstable.
TRUE – All ships
108
109. Disregarding current, if quickwater falls behind the ship when the engine is put astern, the speed could be less than 2 knots.
FALSE
109
110. A ship down by the head, while turning, experiences a relatively larger negative pressure at the quarter, and a relatively smaller positive pressure on the outward bow.
FALSE – just the opposite.
110
111. The PP apparently shifts fwd on a ship down by the head.
TRUE
111
112. During a turn in a narrow channel, a buoy has an opening relative bearing, the ship will end up closer to that buoy.
FALSE – opening = distance increasing
112
113. Squat is directly proportional to speed.
FALSE – “squat varies in proportion to the square of the speed.”
113
114. The windward anchor is preferred in a docking situation because it will hold better in a beam wind.
FALSE
114
115. A ship down by the stern, under sternway, the PP would not move as far aft as if the ship was stopped.
TRUE – transverse thrust and increased directional resistance keep the PP from moving aft.
115
116. Radar is more effective in measuring absolute distances then it is in measuring changes in distance.
False
116
117. In a dead ship movement, it is better to have the tug made up on the inside quarter during a turn, as the tug backing will assist the turn.
True
117
118. A ship at 10 knots has a Cb of .8 and a sinkage of 5.25ft. If speed is reduced to 5 knots, what is the resultant sinkage?
1.3ft (or ¼ the squat at higher speed)
118
119. A ship in shallow water reaches “limiting speed” an increase in RPM will not increase the speed, but the greater flow over the rudder will improve steering.
FALSE – “ship becomes difficult to steer”
119
120. A ship with a large Cb will tend to squat by the stern.
FALSE – by the head.
120
121. The first line sent aboard by the tug is usually the “backing line.”
True
121
122. The “come ahead line” is led from the tugs quarter to a bitt on the ship
.FALSE – the “come ahead line” is lead from the tug’s foredeck, through the bullnose, then up to the ship.
122
123. When using whistle signals when working with a tug, one blast would mean, “stop.”
FALSE – could mean stop if pushing or pulling or if stopped, come ahead normal.
123
124. When working with tugs, on long blast means, “come ahead slow.”
TRUE
124
125. The drag provided by a tug made up aft will improve the effectiveness of the rudder.-
FALSE
125
126. The stern tug tends to set the stern away from the side she is made up on.
TRUE
126
127. The anchor windless brake has three times as much holding power when the wildcat is stopped (static friction) as when it is turning (dynamic friction).
TRUE
127
128. Set and leeway increase in a wind and current situation, causing the turning circle to become more elliptical.
TRUE
128
129. During a stern in docking to a slip, it is important that the stern tug be made up as soon as possible to control the stern.
FALSE – “stern tug stand off until actually needed.”
129
130. A ship under sternway will back into the wind because the PP is fwd.
FALSE – PP is aft
130
131. There is usually a set off the wharf in a current in a direction contrary to the current which is running nearly parallel to the ship’s heading.
TRUE
131
132. The classic Williamson turn using a 60-deg change of heading will apply to all ship types.
FALSE – VLCC’s, directionally unstable, need much less change before shifting helm.
132
133. A 30 knot wind exerts the same force on an equal area as a 1 knot current.
TRUE
133
134. “A ship moves 200 ft per minute at 1 knot”
FALSE – “100 ft per minute @ 1 knot.”
134
135. The quickwater effect is felt first on the starboard side.
TRUE
135
136. A ship in a full speed turning circle will end up inside the original starting point.
TRUE – the first 90 deg. is larger diameter due to momentum and having the PP farther fwd resulting in a smaller drift angle.
136
137. Spring lines are the most effective lines in keeping the ship alongside.
FALSE – breast lines
137
138. When passing a moored ship in a narrow channel, the moored ship is first pushed toward the berth, than sucked away as the ship comes abeam.
TRUE
138
139. The deepest water in turn will be in the bend nearest the point.
FALSE – “deepest water away from the point.”
139
140. Above or below a turn, the deepest water lies on the side nearest the path of the ebb tide as it flows from one bend to the next.
TRUE
140
141. Using an anchor under headway, the bow will be steadied more if the starboard anchor is used on a right-handed propeller ship.
FALSE – “bow steadied regardless of anchor used…”
141
142. A deeper draft ship would have more frictional resistance than a shallower draft ship.
TRUE
142
143. Lateral resistance equals propulsion force when the ship is at a constant speed.
FALSE – “directly proportionate…”
143
144. The position of the PP is determined only by the ship’s shape, motion, and magnitude of the force.
FALSE – also the point of impact
144
145. Frictional drag is one of the elements that determines the PP.
FALSE – happens all along the vessel; no effect on PP.
145
146. The rudder force works at an optimum when the ship is DIW, and full thrust on the rudder has maximal leverage.
TRUE
146
147. As sternway sets in the rotational effect of the transverse rudder force is reduced.
TRUE
147
148. A ship moored in a current are subject to pressure which is directly proportional to the underwater area and also directly proportionate to the current velocity.
FALSE – “proportionate to the square of the current velocity.”
148
149. A current on a freely moving ship, not subject to outside forces, will result in a turning moment.
FALSE
149
150. A ship starting DIW, has the initial PP on ship’s beam from the bow.
TRUE
150
151. As a ship is building up headway, the PP will shift aft proportionally to the magnitude of the underwater resistance force in relation to the propulsion force.
TRUE
151
152. A ship not moving over the ground but subject to a current from astern will have the PP located aft.
TRUE
152
153. Overtaking in narrow channels should be done at moderate speeds as to limit the time the two vessels are alongside.
FALSE – “…with reduced speeds only.”
153
154. The safest way for unberthing a loaded tanker in unfavorable current is to bring the ship parallel to the current as soon as possible.
TRUE
154
155. The lateral resistance forward of the PP does not determine the position of the PP on a ship turning under rudder.
FALSE – “one of the principle forces which determines…”
155
156. The PP shifts aft when a ship is turning at a constant speed.
FALSE – PP stays in the same position
156
157. A ship under headway and turning, the PP lies about 1/3 of the length from fwd.
TRUE
157
158. How bad do you want it?
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
158
159. A ship will turn much tighter when started from DIW with full ahead and full rudder, because it is easier to overcome rotational inertia than longitudinal inertia.
TRUE
159
160. The holding power of an anchor is at best twice its own weight, not including chain.
FALSE – 4x
160
161. Under anchor, the speed must be kept to minimum revs to keep the PP fwd, and allow the desired large swinging moment.TRUE
B
161
162. The relative effectiveness of the rudder is the same regardless of rudder angle. FALSE – “relatively higher in the region of small rudder angles…”
B
162
163. The rate of turn for the first 10 deg. is initially low because the transverse rudder force has to overcome lateral inertia and strong resistance aft of the PP.
TRUE – drift angle opens slowly
163
164. The rate of turn is highest between 5 and 45 deg. of turn.
FALSE – 10 to 90 deg. is the highest rate of turn
164
165. What is the average diameter of a full speed, full rudder turning circle?
3.5 L
165
166. A loaded tanker turning on her anchor, increases RPM’s this will force the PP aft and reduce the leverage of the wind force on the beam.
TRUE
166
167. As the anchor chain becomes slack, the PP moves farther aft.
FALSE – it returns to the fwd position.
