Index Naval architecture

Index Naval architecture.

Question

(a) With reference to the membrane tanks for the carriage of liquefied gas at very low temperatures:

(i) Describe with the aid of a sketch ONE method of building up the insulation;

(ii) State with reasons the alloy which is used for the membrane;

(b) Describe with the aid of a sketch how tanks are located and supported

Explain why a secondary barrier is installed

Question

With reference to dry docking define the responsibility of the 2nd engineer

Prior to dry dock

Whilst the vessel is in DRYDOCK

Prior to flooding and leaving the dock

Question.

With regard to ship construction details for watertight bulkheads

a) State the purpose of this type of bulkhead.

b) State how the bulkhead's are tested for water tightness.

If it is necessary to penetrate the bulkhead, precautions must be taken to ensure that the watertight integrity and strength of the bulkhead are maintained. With this in mind, sketch how the following pass through bulkheads:

Main transmission shaft;

Electric cable.

Question

Sketch a cross section of a bulk carrier with either deep or shallow D.B. showing the types of framing used

Describe the corrosion problem experienced with ballast tanks

State how such tanks are protected against corrosion

Question

Describe the relationship between frictional resistance and

The wetted area

The surface roughness

The length of the vessel

Question

Explain what is meant by permissible length of compartment in passenger ship, Describe how the position of bulkhead is determined

Describe briefly the significance of the factor of subdivision

Question.

Explain how the period of roll varies with

The amplitude of roll

The radius of gyration

The intial metacentric height

The location of masses in the ship

Question

(a) With reference to the underwater surface of the hull:

(i) describe a hull plate roughness analyser system;

(ii) State the significance of the roughness profile and compare the typical roughness values for a new ship and a ship eight years old;

(b) With reference to the application of self polishing paint in dry dock:

(i) describe the plate preparation necessary;

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

Question.

Sketch and describe a collosion bulkhead

Question

Define five of the following, stating how they affect the ship structure and what component parts of the ship structure help to resist the effect of;

Water pressure effect.

Vibration from engine and propellers

Question

Describe the general precaution taken against capsizing

State the recommended criteria for passenger and cargo ship.

Question

Describe the effect on GM of rolling and how bilge keels, anti rolling tanks and stabilizer fins reduce the amplitude of rolling.

Question

What is the effect of centre of gravity of slack tanks?

What is the effect on stability of ice formation on superstructure.

Question

(a) Surface preparation and painting of new ship plates

(b) Design of the ships structure and its maintenance

(c ) Cathodic protection by sacrificial anodes, of the internal and external areas of the ship.

Question

a) State four operational conditions that may lead to vibration of main transmission shafting.

b) Suggest methods to reduce the vibration levels that occur in main transmission shafting.

Question

Describe with detailed Sketch the Arrangement for securing the exhaust gas uptakes in the funnel casing of a steam or motor ship

Question

Explain the reasons why a freeboard less than that usually assigned to a normal ship is permitted under load line rules on a bulk oil carrying vessel

Sketch the load line markings

Question

Sketch a transverse section through the hold of a container ship’ referring to the sketch describes how adequate structural strength is built into the hull

Question

Describe the arrangement of tank top and double bottom in the machinery space making particular reference to the structure and scantlings below the main engine. Show the method adopted in the arrangement of D.B. tanks to avoid contamination of fresh water, fuel oil and lube oil stored in D.B. tanks.

Question

Define the purpose of cofferdams.

State where cofferdams are most likely to be found on :

(i) Dry cargo ships;

(ii) Oil tankers.

(i) State what information is available about danger of entering void spaces?

(ii) Identify, with reasons, the precaution to be observed before and during entry to cofferdams.

QUESTION

W.R.T rotary vane steering gears:

a) Describe, with the aid of a sketch, how such a unit incorporates an integral rudder carrier;

(b) Explain how vertical rudder movement is accommodated.

Question

Transom Floor, Cant Frame, Panting Stringer, Panting Beam.

Question

What is a margin plate?

What is a Margin line? How is the length determined?

What is Floodable length?

What is Subdivision load line?

Question

What is The Effect of wind and waves

What is The Effect of trim on tank sounding?

What is Reserve Buoyancy?

Question

What is the effect of on stability when a tank is partially filled with liquid?

Question

What is Permeability, μ

What is the Effect of bilging on stability

Define Dynamical stability

What is the effect of increasing the beam?

What is the effect of increasing the freeboard?

Question

State why for dry dock she must have a positive initial GM, be upright, and trimmed slightly, usually by the stern.

Question

What is a tender ship.

What factors influence the frictional resistance of a ship and what formulae is used to calculate this resistance.

If resistance ά S V2 and S ά D2/3, derive the Admiralty Coefficient formula.

Effect of GM on rolling

Question

Explain the consideration which governs the size and shape of a rudder.

Question

Damaged Stability

Free surface effect.

The metacentric height (GM)

Question

(a) An M. notice draws attention to the need for adequate support, of engine room gantry cranes.

(i) Sketch sections' through the engine room casing showing how the crane is supported by the ship structure

(ii). State what restricts the forward and aft limits of the crane and what is fitted to prevent the crane damaging the forward and aft bulkheads of the casing

State the Chief Engineers responsibilities for the engine room gantry crane as laid down by the Code of Safe Working Practices for Merchant Seaman.

Question

Describe the In-water survey to classification society requirements of the external underwater structure of a very large crude carrier.

Question

a) Sketch the fwd section of a ship to show the position of the following component parts of the ships anchorage system; hawse pipe, cable stopper, windlass and cable lifter, spurling pipe and chain locker.

b) Describe a chain stopper and state it's purpose.

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

d) Describe how a chain locker is drained of water, sand and mud.

Question

Describe a method for attachment of bilge keel

State 3 reasons for not extending bilge keel to the entire length of the vessel

Explain 2 principle of roll damping that bilge keel exploit

Question

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 bearing surfaces become heavily scored.

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

Question

Explain the purpose of fitting external anodes to a ships hull.

b) i) sketch a method of securing external anodes to the ship hull.

ii) Show, with the aid of a sketch , where external anodes are placed.

iii) Explain how it may be ascertained that anode replacement is necessary.

Question

Which parts of the internal structure of a ship are most liable to corrosion and why

How can the effect of corrosion be reduced.

Question

With reference to statutory certification

State the reason for freeboard requirements

Explain the term conditions of assignments

List the items that may be examined during a related survey

Question

What general effects might continued running at service speed in heavy weather have on marine machinery? What abnormal stresses may be imposed on to the following:-

(a) Intermediate shafting,

(b) Propeller Shaft,

(c) Coupling bolts,

(d) Engine supports &

(e) Thrust Pads.

Question

With reference to Roll-on Roll-off ferries:

Describe the problem of free surface effect;

Explain how it is intended that the water should be cleared from car or cargo decks:

Describe possible methods for improving the stability and survivability of these vessels.

Question

a) State the purpose of cofferdams

b) State where cofferdams are most likely to be found in each of the following;

i) Dry cargo vessels

ii) Oil tankers

c) Identify, with reasons, the general precautions which must be observed before and during entry to cofferdams and state official guidance on entry into void spaces is given;

Question

Foreign going vessels are required to possess a valid safety equipment certificate renewed at intervals after the survey of the safety equipment.

a) Compile a list of items that are contained in the safety equipment survey.

b) From the list compiled in a) above select two ship systems and Explain how they would be examined and identify possible defects.

Question

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

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

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

Question

With ref to rudder state

Why a breached hollow rudder adds to fuel cost

Why excessive pintle clearance should not be tolerated

Why fitted bolts are used

Question

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

b) Describe the preparation necessary before application; of conventional paints to under water surface of; the hull.

Question.

During routine soundings it is found that leakage into a cofferdam is occurring from an adjacent deep cargo oil lank.

(a) As 2nd Engineer state the procedure for directing safe entry by the engine room staff to ascertain the cause of leakage.

(b) If the leakage persists discuss EACH of the following options:

(i) Leave the cofferdam to flood with oil:

(ii) Flood the cofferdam with sea water;

(iii) Seal the cofferdam and pressurize with air pressure:

(iv) Pump the leakage to bunker tanks.

Question.

Describe briefly the tank system in LNG vessel

Question.

Describe the DB and framing arrangement used in the machinery space to cope with concentrated loads and vibration together with shaft and thrust block support

Give reason for choice of thrust block position

Question.

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 freeing ports is as critical to the seaworthiness as watertight-integrity.

Question.

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

Describe how such damage stated in (a) can be made good.

Question

Suggest, with reasons, why EACH of the following courses of action arc appropriate if a ship

a. Begins to wallow in heavy seas:

b. Frequently sound all hold bilges;

c. Frequently sound bilges in chain locker, peak tanks, cofferdams and other void -spaces;

d. Sound all fuel, fresh water and ballast tanks;

If satisfied with Q, (a), (b) and (c) trim ship by the stern and correct any list.

e. Reduce speed of main engine.

Question.

(a) Describe the constructional arrangements for clearing decks of green seas or slack water.

(b) Sketch and describe a double bottom oil fuel tank air ventilator of the automatic float valve type.

(c) State the 'M' notice recommendations relating to the prevention of contamination of fuel oil via air ventilators.

Question

Describe the hull examination that should be carried out on a ship in dry dock. Making special reference to essential maintenance and repairs that can only be carried out in dry dock.

Question

Explain how EACH of the following hull defects should be dealt with:

A cracked weld;

A severe indentation in way of a frame:

Surfaces suffering from general corrosion although the extent of the wastage does not warrant plate replacement;

A bilge keel fractured at the forward end.

Question

The vessel upon which you are serving as Chief Engineer is shortly to be dry-docked;(a)describe the areas on the external hull that should be examined for cracking.(b)the nature of any repairs to be carried out.

Question.

(a) Explain the reasons for the adoption of the following features in propellers:

(i) Six or more blades;

(ii) Highly skewed blades;

(iii) Variable angle to the blades.

(b) Explain with the aid of a sketch how the propeller curve varies from the chosen design curve under the following conditions:

(i) Hull fouling;

(ii) Ballast condition with a clean hull.

Question

(a) Describe how propeller wake occurs.

(b) Explain the influence of wake on:

(i) Propeller efficiency

(ii) Hull induced vibration

Question

With reference to arresting the headway of vessels of considerable mass, give reasoned opinions on EACH of the following statements:

(a) Full power availability for astern running of the propeller is inconsequential; Results have been disappointing in those instances where rudders have been adapted to act as retarders; Discreet use of transverse thrust units may reduce stopping distance.

Question

(a) Outline the manufacturing process for the production of steel suitable for ships shell plating.

(i) Sketch a simple iron-carbon equilibrium diagram and indicate a typical composition of ships steel.

(ii) Sketch the micro-structure of this steel.

Question

(i) Define the'-meaning of the term "conditions of assignment" as applied to ships.

(ii) State how conditions of assignment contribute towards the watertight integrity of ships.

(iii) Give reasons why conditions of assignment need periodic inspection, giving specific instances where they can be found to be less than fully effective.

Question

Describe how a ships structure withstands the forces acting on it:

When in dry dock.

Question

As the Chief Engineer of a RO-RO passenger ferry, detail the operational procedures you would expect both engine room and deck departments to adopt to prevent flooding, loss of buoyancy, loss of stability and loss of power under the following circumstances:

Before departure;

During the voyage in good weather;

During the voyage, when heavy weather is expected;

During the voyage in heavy weather.

Question

Describe, with the aid of a sketch a wire single pull folding hatch cover.

Describe 4 methods that are used to check the weather tightness of hatch covers

Question

When a ship, due to misadventure, rests on a hard bottom, what effect may this produce on the hull of the vessel?

What precaution should be taken by an Engineer when the ship is afloat again?

When in dry dock state which parts should be carefully examined? What is meant by a hogging stress, by a sagging stress?

Is hogging and sagging likely to take place when the ship is afloat?

Question

The ship side has a disc marked on it, make a sketch of this and explain the meaning of the markings. What name is given to the disc and why?

Question

a) With reference to the importance of good design and a high standard of workmanship in the fitting and repair of bilge keels.

(i) Describe how the design and method of attachment reduces the possibility

of damage to the shell plate:

(ii) State the authority the must be afforded the opportunity to inspect the fitting and repair:

(iii) State what non-destructive testing is carried out

(b) Explain why bilge keels do not extend for the full length of the ship:

Question

With reference to the dry-docking of a vessel:

a) Describe how the vessel is prepared for dry-docking;

b) State the pro-docking information that should be given to the dry-dock authority:

(c) Describe the hull inspection and the normal maintenance that should be carried out in dry-dock.

Question

(a) Sketch propeller power curves showing EACH of the following:

ii) The effect of hull fouling:

{ii) Operation in clean hull ballast conditions

b) Explain how the fitting of a light propeller may be beneficial.

(c) Explain how the fitting of a controllable pitch propeller may be beneficial.

Question

(a)State the laboratory tests that may be carried out on specimens of steel for ships' plate giving reasons for the tests.

(b)The basic compositions of two ships' plates are given in Table below One is an example of modem practice whilst the other is a specification of a 1940's tanker that split in two due to brittle fracture. Compare these two specifications critically and explain which of these two steels would be most resistant to brittle fracture.

C M SI S P AI N

Steel 'A' 0.18% 0.70% 0.30% 0.04% 0.04% 0,015% 0,005%

Steal 'B' 0. 19% 0.57% 0.03% 0.029% 0.042% 0.005% 0.008%

Question

With reference to the corrosion of metals, write notes on electrolytic corrosion the precaution necessary when using

(i) Aluminium and steel in the same compartment, (ii) ammonia.

Question

You have been appointed as 2/E on a crude carrier, recently purchased by your shipping company. The company supdt. Requests that you examine the vessel with a view to increase its dead weight capacity without altering the ship's length. Outline the suggestions that you would make justifying your proposals.

Question

A rudder of a vessel requires extensive welding repairs and as second engineer you are requested to supervise:

Suggest a suitable type of welding process

State with reasons four common welding defects

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

Question

Explain why mild steel is used extensively in marine machinery outlining the properties influencing its choice.

State the stresses allowable in crankshafts, piston rods, boilers, and pressure vessels and discuss the type of failures that may occur.

Question

To ensure that a ship remains worthy of its 100 Al classification, annual and special surveys are carried out by classification surveyors. Detail the parts of the ship that should be examined during EACH of the following:

Special survey.

Question

(a) Discuss EACH of the following terms in connection with steel.

(i) Brittle fracture

State, with reasons, where EACH of the mechanisms in (a) may occur in a ship's hull.

Question

A new vessel exhibits severe after end vibration.

(a) As Chief Engineer, outline a procedure to investigate and; identify the source of the vibration

(b) Suggest possible remedies to obviate/reduce aft end vibration

Question

You have been appointed as the Chief Engineer of an older vessel which is in dry dock and has recently been purchased by your shipping company.

Describe in a letter to the engineering superintendent, your inspection to ensure that the conditions of assignment are satisfactorily complied with.

Question

Describe a procedure for the repair of paint damaged areas on a vessel's hull.

State FOUR methods for dealing with surfaces usually inaccessible for painting due to the hull blocks in drydock.

Outline the problem that occur with self polishing copolymer paints when a vessel is at anchor for long periods or proceeding at reduced speed.

Question

With reference to activated fin stabilisers give reasons why:

For large vessels such units are preferred to passive tanks;

These units are preferred for passenger and fast cargo ships;

Partial rather than maximum damping of ship movement in heavy weather is advisable for reasons other than overstressing of fin stocks and activating gear.

Problems

Question

A ship of 9900 tonnes displacement has KM[1]7.3m and KG[1]6.4m. She has yet to load two 50 tonne lifts with her own gear and the first lift is to be placed on deck on the inshore side (KG 9m and centre of gravity 6m out from the centre line). When the derrick plumbs the quay its head is 15m above the keel and 12m out from the centre line. Calculate the maximum list during the operation.

Question

A ship of 8153.75 tonnes displacement has KM8m, KG7. 5m, and has a double bottom tank 15m10m2m which is full of salt water ballast. Find the new GM if this tank is now pumped out till half empty.

Question

A ship of 8000 tonnes displacement has KM 7.5m and KG 7.0m. A double bottom tank is 12m long, 15m wide and 1m deep. The tank is divided longitudinally at the centre line and both sides are full of salt water. Calculate the list if one side is pumped out until it is half empty.

Question

A ship of 3000 tonnes displacement is 100m long, has KM6m, KG5.5m.The centre of flotation is 2m aft of amidships and MCTC40 tonnes m. Find the maximum trim for the ship to enter a dry dock if the metacentric height at the critical instant before the ship takes the blocks forward and aft is to be not less than 0.3m.

Question

A ship of 8000 tones displacement takes the ground on a sand bank on a filing tide at an even keel draft of 5.2 meters. KG 4.0 meters. The predicted depth of water over the sand bank at the low water is 3.2 meters. Calculate the GH at this time assuming that the KM will then be 5.0 meters and that the mean TPC is 15 tone.

Question

A box shaped vessel, 50 meters long X 10 meters wide, floats in salt water on an even keel at a draft of 4 meters. A center line longitudinal watertight bulkhead extends from end to end and for the full depth of the vessel. A compartment amidships on the starboard side is 15 meters long and contains cargo with permeability 30%. Calculate the list if this compartment is bilged. KG = 3 meters.

Question

Explain the use of KN curves.

List the precaution necessary before an inkling experiment is carried out.

Naval architecture Problems. 1

Naval architecture Problems. 2