NA & Ship Co Quiz I

1. After transferring a weight forward on a vessel, the draft at the center of flotation will :________

change, depending on the location of the LCG

increase

decrease

remain constant

2. The pillar shape that gives the greatest strength for the least weight is the :_______

octagonal pillar

"H" Beam pillar

"I" Beam pillar

circular type pillar

3. by using which of the tank we can change the draft but not changing trim of the ship?

peak tank

DB tank

deep tank

top side tank

4. A tank 36 ft. by 36 ft. by 6 ft. is filled with water to a depth of 5 ft. If a bulkhead is placed in the center of the tank running fore-and-aft along the 36-foot axis, how will the value of the moment of inertia of the free surface be affected?

The moment of inertia would remain unchanged.

The moment of inertia would be 1/4 its original value

The moment of inertia would be 1/2 the original value

None of the above

5. The average of the forward and after drafts is the __________.

mean draft

true mean draft

mean of the calculated drafts

draft at the center of flotation

6. The GM of the ship will change with_______

shifting of weight longitudinally

shifting of weight transversely

shifting of weight vertically

all the above

7. Which statement about the free surface correction is TRUE

It is added to the uncorrected GM to arrive at the corrected available GM

It is obtained by dividing the free surface moments by 12 times the
volume of displacement

It is obtained by dividing the total free surface by the total vertical moments

It is subtracted from the total longitudinal moments before dividing by displacement to find LCG

8. a section of standard weight seamless steel pipe has an external diameter of 4.0 inches .when the pipe is bent into 90 degree turn ,the length of the outside edge of the curve A-B will exceed the length of the inside edge curve C-D by _______ inch.

1.05

1.25

2.67

6.28

9. The lower and the upper stools are provided for bulk carriers

with plate type of transverse watertight bulkheads and they normally extend athwartship from ship side to ship side

with corrugated type of transverse watertight bulkheads and they normally extend athwartship from ship side to ship side

with plate type of transverse watertight bulkheads and they normally extend athwartship from one side lower hopper to other side lower hopper

with corrugated type of transverse watertight bulkheads and they normally extend athwartship from one side lower hopper to other side lower hopper

10. Better freeing arrangements on tanker decks inform of open rails for 50% of length are provided

To ensure no seawater gets into the tanks.

Because tankers have less freeboard.

Both A and B

None of the above

Show Answers:

1-remain constant;
2-circular type pillar;
3-DB tank;
4-The moment of inertia would be 1/4 its original value;
5-mean draft;
6-all the above;
7-It is obtained by dividing the free surface moments by 12 times the volume of displacement;
8-6.28;
9-with corrugated type of transverse watertight bulkheads and they normally extend athwartship from one side lower hopper to other side lower hopper;
10-Because tankers have less freeboard.