DAMAGE STABILITY QUESTIONNAIRE FOR SHIP'S MASTERS AND SENIOR OFFICERS

This questionnaire forms the basis for the development of an IMO Model Course „Damage Stability and Survivability“. The aim is to detect knowledge gaps which would be addressed in the model course. The questionnaire is anonymous and will not be forwarded to any third party. However, the statistical analysis may be made public at a later stage. It is developed for ship masters and chief officers as the responsible persons on board in a damage case.

1. Please enter your data

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On which type of vessel have you sailed during your career?







Please indicate your rank on your last ship(s).





Please state how long you have been sailing as deck officer:

Approximately years.

 

My age is:

years.

 



1.Subdivision and other shipbuilding measures to mitigate the adverse effects of a damaged ship

Question 1:

How would you define a 2-compartment ship?

a) A 2-compartment ship must be able to withstand the flooding of two adjacent main compartments.
b) A 2-compartment ship must be able to withstand the flooding of two main compartments.
c) A 2-compartment ship must be able to withstand the flooding of all possible damages as long as these damages leave two main compartments intact.
d) I don't know.

Answer:



Question 2:

Is a 1-compartment ship non-compliant if it does not sustain a bulkhead-damage which separates two main compartments?


a) It is not compliant as it must sustain the damage of a bulkhead without flooding two compartments.
b) It is still compliant but unfortunate.
c) That depends upon the location of the bulkhead as only certain bulkheads are able to prevent the flooding of 2 compartments (e.g. engine-room bulkhead).
d) I don't know.


Answer:



Question 3:

In order to limit the consequences for a damaged ship cross-flooding valves are fitted. What is their main purpose?

a) These valves lead to the ship’s hull, so that the water of a flooded compartment can flow outboard.
b) The valves are located on the ship’s hull and are designed to let seawater in to reduce a list.
c) Cross-flooding valves link two tanks or compartments in order to reduce the list.
d) I don't know.

Answer:



Question 4:

As per SOLAS ’90 watertight subdivision bulkheads shall be capable of supporting at least

a) the pressure due to a head of water as high as the entire compartment.
b) the pressure due to a head of water up to the margin line including the dynamic portion caused by the free surface moment.
c) the pressure due to a head of water up to the margin line, i.e. up to 76mm below the the bulkhead deck.
d) I don't know.

Note: Since 2009 the text is as follows: In all cases, watertight subdivision bulkheads shall be capable of supporting at least the pressure due to a head of water up to the bulkhead deck.

Answer:


2.On-board measures to assess a ships’ stability and survivability




Question 5:

Please select an action to be taken if your ship has a negative GM and is heavily inclined (ship intact).

a) Ballast the DB-tank which is on the inclination side to lower the GM.
b) Reduce the list by ballasting the DB-tanks opposite of the inclined side.
c) It does not matter as the stability of the ship will be increased in any case, either by ballasting the inclined or the opposite side.
d) I don't know.

Answer:



Question 6:

You have detected a leakage on the ship’s hull. In which case do you need to immediately evacuate the ship when progressive flooding of the adjacent compartments can not be prevented?

a) When the leakage area is >= 0.5m2 ist.
b) When the leakage area is >= 0.15m2 ist.
c) When the leakage area is >= 1.5m2 ist.
d) I don’t know.

Answer:



Question 7:

Does the volume of the floodwater entering the ship over a period of time depend upon the depth of the damage below the waterline, and is this considered when calculating the volume of floodwater entering the ship?

a) yes it does, but it is negligible and therefore not considered in the calculation.
b) Yes.
c) No.
d) I don't know.

Answer:



Question 8:

What methods of calculating the damaged ships’ stability are scientifically recognized?

a) The methods of "added buoyancy" and "lost weight".
b) The methods of "lost buoyancy" and "added weight".
c) The methods of "constant loading" and "total buoyancy".
d) I don't know.

Answer:



Question 9:

Why might intermediate stages of flooding be more dangerous to a ship than the final stage of flooding?

a) Because of the free surface moment effects and subsequent reduction of GM.
b) Because of the dynamic alteration of the ship’s floating state which must impact the ability to properly launch life saving appliances.
c) Because during flooding the water intake has an adverse dynamic effect which causes extra pressure on the compartment walls ("hammering").
d) I don't know.

Answer:



Question 10:

The BM (BM = I/V ) of the damaged ship is compared to the BM of the intact ship

a) greater.
b) smaller.
c) the same (no change).
d) I don’t know.

Answer:



Question 11:

What is the "permeability" of a compartment?

a) Permeability of a damaged compartment is the amount of water flooding the adjacent compartments in a 1 hour-period.
b) Permeability of a space is the proportion of the immersed volume of that space which can be occupied by water.
c) Permeability describes the amount of water in a compartment and thus, inter alia, the value of the free surface moment. Permeability is only applicable to compartments containing fluids.
d) I don't know.

Answer:



Question 12:

You want to calculate the new draught of your damaged ship by the method of constant displacement. Assume a midship damage on your ship which was floating on an even keel before the damage. The damaged compartment is not entirely flooded. the calculation of the draught increase would be:

a) delta T = lost buoyancy / damaged water-plane-area
b) delta T = lost weight / intact water-plane-area
c) delta T = gained buoyancy / intact water-plane-area
d) I don't know.

Answer:



Question 13:

One of the difficulties of calculating the final stage of flooding of a ship (ignoring the cases when the damaged compartment is entirely below the intact waterline) is that the exact amount of floodwater is not known. It is therefore sufficiently correct for the master to:

a) calculate the amount of floodwater up to the intact waterline because draught calculated by this method in the final stage of flooding does not differ significantly from the exact mathematical solution.
b) calculate the amount of floodwater under the assumption that the entire damaged compartment/space is flooded. Making that assumption considers an extra safety margin.
c) calculate the final stage of flooding by using the 2 methods as described above and monitor the results through the mathematical method of iteration until the draughts do not change noticeably.
d) I don't know.

Answer:


3.Maßnahmen zur Leckabwehr


Question 14:

What method is more effective to mitigate floodwater entering a ship?

a) securing the outer hull with damage control kit.
b) securing the inner hull with damage control kit.
c) it depends upon the training, skill and physical fitness of the damage control crew. If they are able to withstand the physical and psyhological pressure securing the inner hull is generally more efficient.
d) I don't know.

Answer:



Question 15:

To prevent your ship from capsizing or foundering you should:

a) before initiating other measures first try to seal the hull and prevent any further water intake.
b) deballast all tanks possible in order to get extra buoyancy.
c) prevent progressive flooding to adjacent compartments.
d) I don't know.

Answer: