QUESTION BANK NAVAL ARCHITECTURE PART-1

0
1120

Q a) Describe the arrangement made in a main structural bulkhead for a watertight door aperture.

b) Explain the procedure for assuring that sliding watertight doors are operated safely.

c) Differentiate between the categories of the watertight door & state the regulation pertaining to each type.

Q With regard to ship construction details for transverse watertight bulkheads:

a) State the purpose of this type of the bulkhead.

b) State how the bulkheads are tested for the water tightness.

c) If it is necessary to penetrate the bulkhead, precaution must be taken to ensure that the watertight integrity & the strength of the bulkhead are maintained. With this in the mind, describe, using simple sketches, how the following pass through bulkheads.

i. Main transmission shaft

ii. Electrical cables

iii. Fuel oil transfer pipes

iv. Air and sounding pipes

Q a) Sketch the cross-section of a bulk carrier with either deep or shallow double bottom showing the type of framing used.

b) i. Describe the corrosion problems experienced with ballast tanks.

ii. State how such tanks are protected against extensive corrosion.

Q a) Explain what is meant by “permissible length” of compartments in passenger ships.

b) Describe how the position of bulkheads is determined.

c) Describe briefly the significance of the factor of subdivision

Q a) Sketch a transverse section through the hold space of a container ship hull.

b) Referring to the sketch in (a) describe how adequate structural strength is built into the hull.

Q a) Draw a simple line diagram of the bow of a ship to show the position of the following component parts of the ships anchoring system: Hawse pipe, Cable stopper, Windlass & Cable lifter, Spurling pipe & Chain locker.

b) Describe the cable stopper & state its purpose.

c) Show by means of a sketch how the anchor cable is attached to the ship.

d) Describe how the chain locker is drained of water, sand & mud.

Q Describe the double bottom and framing arrangement used in the machinery space to cope up with the concentrated loads and vibration, together with shaft and thrust block support. Give reasons for the choice of thrust block position.

Q a) Discuss the need for adequate support of engine room gantry cranes, detailing the following:

i. Sketch section through the engine room casing showing how the crane is supported by ship structure.

ii. State what restricts the forward & aft limits of the crane & what is fitted to prevent the crane damaging the forward & aft bulkheads or casing.

b) State the 2/E responsibility for the engine room gantry crane.

Q What is sub-division? Why is it necessary?

What is margin line? How is the length of a compartment determined?

Q Describe a forced ventilation system for the machinery spaces and a natural ventilation system for a lower hold. Why hold ventilation is considered necessary?

Q Give a reasoned opinion as to the validity of the following assertions concerning ship structure:

a) Crack propagation in propeller shaft ‘A’ brackets or spectacle frames is indicative of inadequate scantlings and strength.

b) The adequate provision of deck scuppers and freeing ports is as critical to seaworthiness as watertight integrity.

Q Describe the following parts of a vessel and state the purposes for which they are fitted. Illustrate by means of sketches.

a) Cant frames

b) Transom floor

c) Panting beams

d) Panting stringer

Q Define five of the following, starting how they affect the ship structure and what component part of the ship structure help to resist their effect:

a) Racking

b) Water pressure effect

c) Panting

d) Pounding

e) Local weights

f) Vibration from engine and propellers

Q Sketch and describe the construction of collision bulkhead of a large tanker. Include principal dimensions in the sketch.

Q With reference to dry docking define the responsibility of the 2nd engineer and instructions for Junior Engineer:

a) Prior to docking

b) Whilst the vessel is in drydock

c) Prior to flooding and leaving the dock

d) Between leaving the dock & full ahead of main propulsion

Q Describe the preparation required before the application (in dry dock) of sophisticated or approved long life coating to the underwater surface of the hull.

a) State the significance of the roughness profile.

b) List the different sophisticated coatings which are available.

Q a) Describe a method of the attachment of bilge keels.

b) State 3 reasons for not extending bilge keels the entire length of the vessel.

c) Explain 2 principles of roll damping that bilge keels exploit.

Q a) With the help of a sketch describe the method of attachment for a bilge keel & hence explain what protection is made to reduce the possibility of the shell being punctured in the event of the damage to the keel.

b) State why the keel does not extend for the length of the ship.

c) Evaluate the effectiveness of the bilge keels for large wall sided vessels.

Q State how & why the following machinery items are affected when the maximum service speed of a Vessel is consistently maintained in heavy weather.

a) Intermediate shafting

b) Propeller shafting

c) Shafting coupling bolts

d) Main thrust pads

Q a) With reference to the underwater surface of a ship’s hull

i. Describe a hull plate roughness analyzer system

ii. State the significance of the roughness profile & compare the typical roughness values for a new ship & a ship eight years old.

b) Which parts of the internal structure of a ship are most liable to corrosion & why? How can the effects of corrosion be reduced?

c) With reference to the application of the self-polishing paint in the drydock:

i. Describe the plate preparation necessary.

ii. State the defects that may occur in the paint coating if it is not correctly applied.

Q a) With reference to fatigue of engineering components explain the influence of stress level and cyclical frequency on expected operating life.

b) Explain the influence of material defects on the safe operating life of an engineering component.

c) State the factors which influence the possibility of the fatigue cracking of a bedplate transverse girder and explain how the risk of such cracking can be minimized.

Q Describe the relationship between frictional resistance &:

a) Ship speed

b) The wetted area

c) The surface roughness

d) The length of the vessel.

Q a) State 4 sources of excitation that may induce vibration into the main hull girder.

b) Suggest methods for reducing the vibration levels induced by each of the exciting forces in (a).

Q a) Explain the causes of the formation of mill scale on the steel plate.

b) Describe the preparation required before the application of conventional paints to the underwater surface of the hull.

c) Describe a coating scheme for the underwater hull using conventional paints.

Q a) State, with reasons, the locality & extent of damage, which may be sustained by the hull structure of a ship being driven hard through heavy seas.

b) Describe how the damage stated in (a) may be repaired.

Q If a ship is seriously damaged under water in way of a large fuel oil side bunker tank what is the immediate effect & what may ultimately happen? What features in the ship would improve safety?

Q a) With reference to fatigue of hull structures explain in the influence of stress level and cyclical frequency on expected operating life.

b) Explain the influence of material defects on the safe operating life of the forged components of stern fittings.

Q Discuss the importance of the following to be examined for meeting EEDI limitations:-

a) Slimmer vessels with lower block coefficients

b) Long-stroke engines

c) Low revolution large diameter propellers

Q During routine soundings it is found that leakage into a cofferdam is occurring from an adjacent deep cargo oil tank. As 2/E state the procedure for directing safe entry by the engine room staff to ascertain the cause of the leakage. If the leakage persists discuss each of the following options as a possible remedy:

i. Leave the cofferdam to flood with oil

ii. Flood the cofferdam with sea water

iii. Seal the Cofferdam and pressurize with air

iv. Pump the leakage to bunker tanks.

Q a) i. Explain the purpose of fitting external anodes to a ship’s hull.

ii. Sketch a method of securing external anodes to the ship’s hull.

b) Show, with the aid of a sketch, where external anodes are placed. Explain how it may be ascertained that anode replacement is necessary.

Q A rudder (or palm of the rudder) of vessel requires extensive welding repairs & as 2/E /Chief Engineer you are requested to supervise:

a) Suggest a suitable type of welding process.

b) State, with reasons, 4 common welding defects.

c) State what tests may be carried out before returning the rudder to service.

Q a) Explain how the flow of water around the propeller can result in inducing vibration?

b) What are the possible options to reduce the effects?

Q a) Sketch a bearing designed to transfer the full weight of the rudder to the ships structure.

b) Describe the consequences if the rudder carrier hearing surfaces become heavily scored.

c) Describe the consequences of & the action to be taken, if the carrier shatters.