Ship Construction & Stability

What is the primary purpose of a cofferdam on board a ship?

(a) To act as an empty void space separating two compartments so that leakage from one cannot pass into the other

(b) To stiffen the hull girder against longitudinal bending stresses

(c) To provide extra ballast capacity for trim correction

(d) To provide additional reserve buoyancy in the event of hull damage

Briefly justify. (16)

A ship's metacentric height (GM) is found to be negative while she is upright and floating in calm water. Which of the following best describes the vessel's condition and immediate behavior? (16)

(a) The ship is in stable equilibrium and will return to upright after a small angle of heel.

(b) The ship is in unstable equilibrium, she will heel to some angle of loll and remain there in stable equilibrium at that heel.

(c) The ship is in neutral equilibrium and will float at any angle of heel with no tendency to move.

(d) The ship will capsize immediately and cannot achieve any stable floating condition.

Briefly Justify Your Answer

(a) Draw a labeled sketch of midship section of a double hull oil tanker. (10)

(b) What are Aframax, Suezmax, ULCC and VLCC tankers? (6)

(a) What are the advantages of corrugated bulkheads? (6)

(b) Sketch and describe a corrugated transverse watertight bulkhead. (10)

Sketch a plane bulkhead, showing connections to deck, sides and double bottom and the arrangement of stiffners. (16)

(a) What is the significance of GM-GZ curve? (6)

(b) The pitch of a propeller is measured by means of a batten and cord. The horizontal ordinate is found to be 40 cm while the vertical ordinate 1.15 m at a distance of 2.6 m from the centre of the boss. Calculate the pitch of the propeller, and the blade width at that point. (10)

(a) Explain why the draught of a ship decreases when it passes from fresh water to seawater and vice versa. (6)

(b) A lock gate which is 15m wide has salt water on one side to a depth of 8m and fresh water on the other side to a depth of 9m. Find the resultant thrust on the lock gate and state on which side of the gate it acts. (10)

(a) Describe the function of the stern frame. (6)

(b) The water plane area of a ship at 8.4 m draught is 1670 m². The area of successive water planes at 1.40 m intervals below this are 1600, 1540, 1420, 1270, 1080 and 690 m² respectively. Calculate the displacement in fresh water at 8.4 m draught and the draught at which the ship would lie in sea water with the same displacement. (10)

A vessel about to complete loading in a summer zone is expected to enter a winter zone after steaming from the loading port for 10 days. On passage, fuel consumption is expected to be 30 tonnes per day and water consumption 15 tonnes per day. The ship is at present floating in water of density 1.013 tonnes/m3 at a draft of 9.0m.

(a) The maximum permissible draft on completion of loading.

(b) The amount of cargo which the vessel can load.

(Note: A vessel passing from a summer zone to a winter zone, or from a tropical zone to summer zone, must arrive at the zone boundary at the draft appropriate to that zone.)

Explain in principle, the process of corrosion on the underwater steel plates of the hull. Describe how protection is provided by sacrificial anodes. (16)

What are the main functions of:

(a) fore peak, (4)

(b) after peak, (4)

(c) deep tank, (4)

(d) double bottom (4)

Give examples of liquid carried in these tanks. (4)

(a) Define the six types of ship motions. (6)

(b) In the context of ship stability, what does static stability refer to:

(i) The ships's resistance to rolling in waves.

(ii) The ship's ability to return to equilibrium after a displacement without wave action.

(iii) The dynamic response of a ship in irregular seas.

(iv) The resistance to hull slamming.

Briefly justify your answer. (10)

(a) Sketch a water-tight door and frame showing manner of attachment to bulkhead and the additional reinforcement carried by the bulkhead to compensate for the aperture. (8)

(b) Explain how water-tightness of the door and frame mating surface is ensured with an hydrostatic pressure tending to force the faces apart. (4)

(c) Describe the means of remote closing operation of the door and state how many closing stations there are and their position. (4)

Describe with the aid of sketches how each of the following contribute towards improving the propulsive efficiency of a ship:

(a) Ducted propeller (5)

(b) Costa bulb as fitted to rudder (5)

(c) Grim wheel vane as fitted aft of the propeller (6)

(a) Define Centre of Flotation. What happens to the draught and trim of a ship if a small mass is added to the ship at the Centre of Flotation? (6)

(b) A vessel travelling at 17 knots turns with a radius of 450 m when the rudder is put hard over. The centre of gravity is 7 m above the keel, the transverse metacentre 7.45 m above the keel and the centre of buoyancy 4 m above the keel. If the centripetal force is assumed to act at the centre of buoyancy, calculate the angle of heel while turning, the rudder force may be ignored. (10)

(a) Explain in brief the term 'bulwark' and 'freeing port'. (6)

(b) The pitch of a propeller is measured by means of a batten and cord. The horizontal ordinate is found to be 40 cm while the vertical ordinate 1.15 m at a distance of 2.6 m from the centre of the boss. Calculate the pitch of the propeller and the blade width at that point. (10)

The half-ordinates of a ship's water-plane, which is 80 m long, commencing from forward at equal intervals, are as follows: 0.2, 4.0, 5.0, 5.2, 5.0, 4.0, and 0.2 m respectively. Calculate the area of the water-plane using Simpson's First Rule. (16)

A ship's length at the waterline is 180 meters, with a maximum beam of 30 meters and a draft of 9 meters. If the ship's volume of displacement is 38,880 cubic meters, calculate its block coefficient. (16)

(a) What are the advantages of corrugated bulkheads? (6)

(b) Sketch and describe a corrugated transverse watertight bulkhead. (10)

(a) Describe in detail how brittle fracture is instrumental in causing failure of materials. (6)

(b) Describe how a material is tested to assess the resistance to this type of failure. (4)

(c) Suggest where this type of failure would be likely and explain how the likelihood of failure is reduced. (6)

With reference to hull protection against corrosion and fouling, write a brief explanation of each of the following:

(a) Sacrificial anodes (6)

(b) Impressed Current System (6)

(c) means of preventing marine growth and fouling (4)

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

(a) Racking (4)

(b) Panting (4)

(c) Pounding (4)

(d) Vibration from engine and propellers. (4)

In the absence of external forces, adding weight to one side of a floating vessel, will cause the vessel to __________.

(a) heel until the angle of loll is reached

(b) list until the center of buoyancy is aligned vertically with the center of gravity

(c) trim to the side opposite TCG until all moments are equal

(d) decrease draft at the center of flotation

Briefly Justify Your Answer (16)

(a) With aid of a simple sketch, show the normal positions of centre of gravity of a stable ship relative to keel, centre of buoyancy and meta centre. (6)

(b) A bulkhead 9 m deep is supported by vertical stiffeners 750 mm apart. The bulkhead is flooded to the top edge with sea water on one side only. Calculate:

(i) shearing force at top

(ii) shearing force at bottom

(iii) position of zero shear. (10)

(a) What is the purpose of conducting an inclining experiment on a new vessel? (6)

(b) A ship of displacement 10010 tonnes has KM 6.7m and GM 0.76m. A mass of 10 tonnes having KG 7.6m is shifted transversely. The deflection of a pendulum of length 7.6m is 0.125m. Find the distance through which the mass is shifted. Also find the position of the new centre of gravity above the keel due to the removal of the same mass. (10)

A hopper barge of box form 50 m long and 10 m wide floats at a draught of 2 m in seawater when the hopper, which is 15 m long and 5 m wide, is loaded with mud having relative density twice that of the seawater, to the level of the waterline. Doors in the bottom of the hopper are now opened allowing the mud to be discharged. Calculate the new draught. (16)

(a) Sketch and describe the midship section of a bulk carrier, labelling the structural members. (8)

(b) A vessel 40 m long has a constant cross-section in the form of a trapezoid 10 m wide at the top, 6 m wide at the bottom and 5 m deep. It floats in sea water at a draught of 4 m. Calculate its displacement. (8)

(a) What is the fundamental purpose of a 'Load line' marking on ships? (5)

(b) Sketch and describe the features of a 'Load Line' marking. (6)

(c) Name five conditions that must be met before freeboard is assigned to a ship. (5)

What are the main functions of:

(a) fore peak, (4)

(b) after peak, (4)

(c) deep tank, (4)

(d) double bottom (4)

Give examples of liquid carried in these tanks.

A virtual rise in the center of gravity of a ship may be caused by _______________

(a) filling a partially filled tank

(b) using an onboard crane to lift a freely swinging heavy object

(c) emptying a partially filled tank

(d) transferring pipe from the setback area to the pipe rack

Briefly Justify your Answer (16)

(a) Describe the following and explain their function: (9)

(i) Hawse pipe;

(ii) Spurling pipe;

(iii) Cable stopper.

(b) With the aid of a sketch of a ship bow, show the arrangement of anchor cable, from anchor to chain locker. (7)

Define centre of buoyancy and show with the aid of sketches how a vessel which is stable will return to the upright after being heeled by an external force. (16)

(a) What happens if a neutral equilibrium ship is pushed or acted upon by external forces like a beam wind or wave? Explain with a diagram. (6)

(b) A ship of displacement 10010 tonnes has KM 6.7m and GM 0.76m. A mass of 10 tonnes having KG 7.6m is shifted transversely. The deflection of a pendulum of length 7.6m is 0.125m. Find the distance through which the mass is shifted. Also find the position of the new centre of gravity above the keel due to the removal of the same mass. (10)

(a) What are the SOLAS regulations regarding the location of the collision bulkhead? (6)

(b) A box barge 25 m long and 4 m wide floats in fresh water at a draught of 1.2 m and has an empty mid length compartment 5 m long. The bottom of the barge is lined with teak (rd 0.805) 120 mm thick. After grounding all the teak is torn off and the centre compartment laid open to the sea. Calculate the final draught. (10)

The ½ ordinates of a waterplane 120 m long are as follows:

Calculate: (16)

(a) waterplane area

(b) distance of centroid from midships.

A ballast tank is 15 m long, 12 m wide and 1.4 m deep and is filled with fresh water. Calculate the load on the top and short side, if: (16)

(a) the tank is just completely full

(b) there is a head of 7m of water above the tank top.

(a) What is the purpose of providing air pipes to tanks in the vessel? (5)

(b) Sketch an arrangement of air vent head situated on the weather deck. (6)

(c) What factors are considered in deciding the bore size of air pipe? (5)

(a) What is a right-handed and a left-handed propeller? (5)

(b) With the aid of simple sketches explain Rake, Skew and Pitch of the propeller. (6)

(c) What are the advantages and disadvantages of CPP? (5)

(a) What are various types of tankers for carrying bulk liquids? (6)

(b) Sketch a mid-ship section of a double-hulled crude oil tanker. (10)

Briefly explain the following ship terms used:

(a) LOA (2)

(b) LBP (2)

(c) Breadth Extreme (2)

(d) Breadth Moulded (2)

(e) Depth extreme (2)

(f) Depth Moulded (2)

(g) Draught Extreme (2)

(h) Draught Moulded (2)

What do you understand by 'Free surface effect' and how does it affect the ship's stability? (16)

(a) What is the metric length of one shackle of anchor chain? (4)

(b) A vessel of 10000 t displacement burns 25 t of fuel per day when her speed is 12 knots. Calculate the probable consumption of fuel over a voyage of 3000 nautical miles at a speed of 11 knots with a displacement of 11000 t. (12)

(a) What are the different types of stern used in ship construction? (6)

(b) A ship consumes 360 t of fuel, stores and water when moving from sea water of 1.025 t/m³ into fresh water of 1.000 t/m³ and on arrival it is found that the draught has remained constant. Calculate the displacement in sea water. (10)

(a) What is a 'mast riser' and what is the purpose of it? (6)

(b) A ship 96 m long is floating at 5m fwd draft and 6.4 m aft draft, MCTC 180 tm, TPC 16. COF is 2 m abaft of midships. Find the location where a weight of 50 t should be placed so as to keep the aft draft constant. (10)

A ship 120 meters long at the waterline has equidistantly spaced half-ordinates commencing from forward as follows: 0, 3.7, 5.9, 7.6, 7.5, 4.6, and 0.1 meters respectively: Find the area of the waterplane using Simpson's Second rule and the TPC at this draft. Water density is 1.025 t/m³ . (16)

With regards to the metacentric height, which of the following statements is true? (16)

(a) It is used to indicate the quality of initial stability.

(b) It is measured below the center of buoyancy.

(c) It is measured vertically above the center of buoyancy.

(d) Its determination is the objective of the inclining experiment

Briefly justify your answer to the above statement.

Explain the meaning and purpose of EACH of the following terms: (16)

(a) Bulbous bow

(b) Hawse pipe

(c) Spurling pipe

(d) Cable stopper

Define the main purpose of the following tank and pumping system in detail:

(a) Weighted cocks for tank sounding pipes, (4)

(b) Remote operated gear for bilge valves, (4)

(c) Ventilation pipes for double bottom tanks, (4)

(d) Explain why gauze is sometimes fitted to tank ventilation pipes and explain the effect of mesh size. (4)

Sketch a plane bulkhead, showing connections to deck, sides and double bottom and the arrangement of stiffeners. (16)

Write short notes on each of the following with respect to their contribution to the strength of ships:

(a) Strake (4)

(b) Bracket (4)

(c) Stinger (4)

(d) Girder (4)

(a) Describe the provisions of additional structural strength to withstand pounding. (6)

(b) A vessel travelling at 17 knots turns with a radius of 450 m when the rudder is put hard over. The centre of gravity is 7 m above the keel, the transverse metacentre 7.45 m above the keel and the centre of buoyancy 4 m above the keel. Find the angle of heel when turning. The rudder force may be ignored. (10)

(a) Show by means of diagrams how the center of gravity of the liquid in a partly filled tank moves during rolling. (6)

(b) A box barge is 15 m long, 6 m wide and floats in water of 1.016 t/m³ at a draught of 3m. 150 tonne of cargo now is now added. Calculate the load exerted by the water on the sides, ends and bottom (10)

(a) Explain what is meant by 'assigned summer freeboard'. (6)

(b) A box-shaped vessel 60m long, 10m beam, and 6m deep is floating in salt water at draughts 4m forward and 4.4m aft. Find how far forward of amidships a weight of 30 tonnes must be loaded if the draught aft is to remain at 4.4m. (10)

(a) Explain why the TPC for a given draught will vary with the density of the water in which the ship floats. (6)

(b) A box shaped ship with 12m beam is floating upright at a draft of 6.7 m. Find the increase in draft if the vessel is now listed 18 degrees. (10)

(a) What are the various Static stresses that act on a vessel at rest in still water? Explain with the aid of sketches. (10)

(b) Give examples for dynamic stresses on a vessel? (6)

(a) What is bilging and What are the effects of bilging? (8)

(b) How are bulkheads classified? (3)

(c) What are the advantages of water tight bulkheads? How is the water tight bulkhead tested? (5)

Explain the meaning and purpose of EACH of the following terms:

(a) Flare (3)

(b) Bulwark (3)

(c) Coaming (3)

(d) Freeing port (3)

(e) Scupper (2)

(f) Rise of floor (2)

(a) Sketch a semi balanced rudder showing: (10)

(i) A detail of the hinges or pintels about which rudder turns.

(ii) Details of the rudder carrier bearing, which supports the weight of the rudderstock and rudder.

(b) State advantages of semi balanced rudder over an unbalanced rudder. (3)

(c) What acts as “rudder stops”? What is their purpose and at what angle from mid position would you expect the rudder stops to be set. (3)

(a) What is free surface effect? (6)

(b) Explain the methods used to reduce the free surface effect in ship construction and while operating the ship. (10)

(a) Compare fixed pitch with controllable pitch propellers. (6)

(b) When a mass of 6t is moved transversely through a certain distance on a ship of 4300t displacement, the deflection of an 11m pendulum is found to be 120 mm. The transverse meta-centre is 7.25 m above the keel and KG 5.46 m. Find the distance through which 6t was moved. (10)

(a) What are the various resistances acting against the motion of the ship? (6)

(b) A vessel of 10000 t displacement burns 25 t of fuel per day when her speed is 12 knots. Calculate the probable consumption of fuel over a voyage of 3000 nautical miles at a speed of 11 knots with a displacement of 11000 t. (10)

(a) Explain why the draught of a ship decreases when it passes from fresh water to seawater and vice versa. (6)

(b) A lock gate which is 15m wide has salt water on one side to a depth of 8m and fresh water on the other side to a depth of 9m. Find the resultant thrust on the lock gate and state on which side of the gate it acts. (10)

(a) With aid of a simple sketch, show the normal positions of centre of gravity of a stable ship relative to keel, centre of buoyancy and meta centre. (6)

(b) A ship has 300 t of cargo in the hold, 24 m forward of the midships. The displacement of the vessel is 6000 t and its centre of gravity is 1.2 m forward of midships. Find the new position of the centre of gravity if this cargo is moved to an after hold, 40 m from midships. (10)

For a ship the center of buoyancy and the metacenter are in the line of action of the buoyant force (16)

(a) only when there is positive stability

(b) only when there is negative stability

(c) only when there is neutral stability

(d) at all times Justify your answer.

Explain the meaning and purpose of EACH of the following terms: (16)

(a) Duct keel

(b) Margin line

(c) Sheer

(d) Round of Bilge

With reference to hull protection against corrosion describe how EACH of the following operate:

(a) Sacrificial anodes; (8)

(b) Impressed current system. (8)

With reference to bilge keels:

(a) describe how the design and method of attachment reduces the possibility of damage to the shell plate; (8)

(b) state what testing must be carried out. (4)

(c) Explain why the bilge keels do not extend the full length of the vessel. (4)

With reference to large bulk carriers:

(a) sketch a cross section of a bulk carrier through the mid-ship; (8)

(b) explain the design features that have evolved to minimise the possibility of failure. (8)

(a) Define angle of loll. (6)

(b) A box barge 60 m long and 10m wide floats at an even keel draught of 4 m. It has a compartment amidships 12 m long. Calculate the new draught if this compartment is laid open to the sea when: (10)

(i) µ is 100%

(ii) µ is 85%

(iii) µ is 60%

(a) What do you understand by 'coffin' plate? (6)

(b) A ship displacing 10000 tonne and travelling at 16 knots has a fuel consumption of 41 tonne per day. Calculate the consumption per day if the displacement is increased to 13750 tonne and the speed is increased to 17 knots. Within this speed range, fuel consumption per day varies as (speed)^3.8. (10)

A ship with a displacement of 8,200 tonnes and a length of 90 m is floating in sea water with a density of 1.024 t/m³. The half-ordinates of the waterplane area at equal intervals are: 0, 2.61, 3.68, 4.74, 5.84, 7.00, 7.30, 6.47, 5.35, 4.26, 3.16, 1.88, and 0 m. Calculate: (16)

(i) Calculate the Waterplane Area using Simpson's First Rule.

(ii) Calculate the TPC (Tonnes per Centimetre Immersion) in sea water.

(iii) Find the change in mean draught when the ship moves from sea water of density 1.024 t/m³ into river water with a density of 1.005 t/m³.

(a) What are the water pressure loads on the ship's hull? (6)

(b) A ship of 5,000 tonnes displacement has a KM of 6.2 m and a KG of 5.5 m. It has a rectangular double-bottom tank of length 16 m and breadth 10 m, which is partially filled with diesel oil (Relative Density = 0.88). Calculate (10)

(i) The Free Surface Correction (FSC) or virtual rise in KG.

(ii) The final GM of the ship.

Explain the following:

(a) sub division; (4)

(b) margin line (4)

(c) floodable length; (4)

(d) watertight bulkhead penetration (4)

(a) Define any six types of ship motions. (6)

(b) In the context of ship stability, what does static stability refer to: (10)

(i) The ship's resistance to rolling in waves.

(ii) The ship's ability to return to equilibrium after a displacement without wave action.

(iii) The dynamic response of a ship in irregular seas.

(iv) The resistance to hull slamming.

Briefly justify your answer.

(a) Explain why a Spectacle Frame and Boss Plates are fitted to twin screw ships. (8)

(b) Make a simple sketch of a Spectacle Frame showing how it is attached to the ship structure and to the Boss Plates. (8)

(a) Sketch the arrangement of rudder stock, bearings, glands and method of suspension of a pintless rudder, labeling the components parts. (8)

(b) State how the bearing wear down is measured and what prevents the rudder from jumping? (8)

Describe the construction of chain lockers and how cables are secured in the lockers? Explain how to secure anchors in preparation for sea passage. (16)

(a) Explain in brief the term 'bulwark' and 'freeing port'. (6)

(b) A ship has 300 t of cargo in the hold, 24 m forward of the midships. The displacement of the vessel is 6000 t and its centre of gravity is 1.2 m forward of midships. Find the new position of the centre of gravity if this cargo is moved to an after hold, 40 m from midships. (10)

(a) What is Freeboard of a Ship? Why oil tankers have less freeboard? (6)

(b) A ship's length at the waterline is 180 meters, with a maximum beam of 30 meters and a draft of 9 meters. If the ship's volume of displacement is 38,880 cubic meters, calculate its block coefficient. (10)

The half-ordinates of a ship's water-plane, which is 80 m long, commencing from forward at equal intervals, are as follows: 0.2, 4.0, 5.0, 5.2, 5.0, 4.0, and 0.2 m respectively. Calculate the area of the water-plane using Simpson's First Rule. (16)

(a) What is the purpose of conducting inclining experiment on a new vessel? (6)

(b) A ship of 12400 tonne displacement is 120 m long, 17.5 m beam and floats at a draught of 7.5 m. The propeller has a pitch ratio of 0.75 and, when turning at 100 rev/min, produces a ship speed of 12 knots with a real slip of 30%. Calculate the apparent slip, pitch and diameter of the propeller. The wake fraction w may be found from the expression, w = 0.5Cb – 0.05 (10)

(a) Explain what is meant by longitudinal framing and transverse framing? (8)

(b) Which types of ships would have these methods of construction? Give reasons (8)

What are the main functions of:

(a) fore peak (4)

(b) after peak (4)

(c) deep tank (4)

(d) double bottom (4)

Give examples of liquid carried in these tanks.

With regards to the metacentric height, which of the following statements is true?

(a) It is used to indicate the quality of initial stability.

(b) It is located below the center of buoyancy.

(c) It is measured vertically above the center of buoyancy.

(d) Its determination is the objective of the inclining experiment.

Briefly justify your answer. (16)

(a) Sketch a semi balanced rudder of your choice showing: (10)

(i) A detail of the hinges or pintles about which rudder turns.

(ii) Details of the rudder carrier bearing, which supports the weight of the rudder stock and rudder.

(b) State advantages of semi balanced rudder over an unbalanced rudder. (6)

Define centre of buoyancy and show with the aid of sketches how a vessel which is stable will return to the upright after being heeled by an external force. (16)

(a) Define Centre of Flotation. What happens to the draught and trim of a ship if a small mass is added to the ship at the Centre of Flotation? (6)

(b) A ship of displacement 10010 tonnes has KM 6.7m and GM 0.76m. A mass of 10 tonnes having KG 7.6m is shifted transversely. The deflection of a pendulum of length 7.6m is 0.125m. Find the distance through which the mass is shifted. Also find the position of the new centre of gravity above the keel due to the removal of the same mass. (10)

(a) What is meant by 'statical stability'? What are the factors that influence stability? (6)

(b) A box barge 25 m long and 4 m wide floats in fresh water at a draught of 1.2 m and has an empty mid length compartment 5 m long. The bottom of the barge is lined with teak (rd 0.805) 120 mm thick. After grounding all the teak is torn off and the centre compartment laid open to the sea. Calculate the final draught. (10)

The ½ ordinates of a waterplane 120 m long are as follows:

Calculate: (16)

(a) waterplane area

(b) distance of centroid from midships.

A ballast tank is 15 m long, 12 m wide and 1.4 m deep and is filled with fresh water. Calculate the load on the top and short side, if: (16)

(a) the tank is just completely full

(b) there is a head of 7m of water above the tank top.

(a) Describe the following, and explain their function: (8)

(i) Hawse pipe

(ii) Spurling pipe

(iii) Cable stopper

(iv) Bitter end

(b) With the aid of a sketch of a ship’s bow show the arrangement of anchor cable, from anchor to chain locker. (8)

In the absence of external forces, adding weight to one side of a floating vessel, will cause the vessel to

(a) heel until the angle of loll is reached

(b) list until the center of buoyancy is aligned vertically with the center of gravity

(c) trim to the side opposite TCG until all moments are equal

(d) decrease draft at the center of flotation

Briefly Justify Your Answer (16)

(a) Draw a labeled sketch of midship section of a double hull oil tanker. (10)

(b) What are Aframax, Suezmax, ULCC and VLCC tankers? (6)

(a) What are the advantages of corrugated bulkheads? (6)

(b) Sketch and describe a corrugated transverse watertight bulkhead. (10)

(a) What is free surface effect ? (6)

(b) Explain the methods used to reduce the free surface effect in ship construction and while operating the ship. (10)

(a) What is the significance of GM-GZ curve? (6)

(b) The pitch of a propeller is measured by means of a batten and cord. The horizontal ordinate is found to be 40 cm while the vertical ordinate 1.15 m at a distance of 2.6 m from the centre of the boss. Calculate the pitch of the propeller and the blade width at that point. (10)

(a) Explain why the draught of a ship decreases when it passes from fresh water to seawater and vice versa. (6)

(b) A lock gate which is 15m wide has salt water on one side to a depth of 8m and fresh water on the other side to a depth of 9m. Find the resultant thrust on the lock gate and state on which side of the gate it acts. (10)

(a) Describe the function of the stern frame. (6)

(b) The water plane area of a ship at 8.4 m draught is 1670 m². The area of successive water planes at 1.40 m intervals below this are 1600, 1540, 1420, 1270, 1080 and 690 m² respectively. Calculate the displacement in fresh water at 8.4 m draught and the draught at which the ship would lie in sea water with the same displacement. (10)

(a) Explain why an unstable ship is dangerous. (6)

(b) A vessel travelling at 17 knots turns with a radius of 450 m when the rudder is put hard over. The centre of gravity is 7 m above the keel, the transverse metacentre 7.45 m above the keel and the centre of buoyancy 4 m above the keel. If the centripetal force is assumed to act at the centre of buoyancy, calculate the angle of heel when turning. The rudder force may be ignored. (10)

(a) What are the advantages of corrugated bulkheads? (6)

(b) Sketch and describe a corrugated transverse watertight bulkhead. (10)

(a) Describe in detail how brittle fracture is instrumental in causing failure of materials. (6)

(b) Describe how a material is tested to assess the resistance to this type of failure. (4)

(c) Suggest where this type of failure would be likely and explain how the likelihood of failure is reduced. (6)

With reference to hull protection against corrosion and fouling, write a brief explanation of each of the following:

(a) Sacrificial anodes (6)

(b) Impressed Current System (6)

(c) Means of preventing marine growth and fouling (4)

Define the following stating how they affect the ship structure and what component parts of the ship structure help to resist the effect (4)

(a) Racking (4)

(b) Pounding (4)

(c) Panting (4)

(d) Vibration in engine and propellers. (4)

(a) What is the fundamental purpose of a 'Load line' marking on ships? (5)

(b) Sketch and describe the features of a 'Load line' marking. (6)

(c) Name five conditions that must be met before freeboard is assigned to a ship. (5)

(a) Explains why the draught of a ship decreases when it passes from fresh water to seawater and vice versa. (6)

(b) A bulkhead 9 m deep is supported by vertical stiffeners 750 mm apart. The bulkhead is flooded to the top edge with sea water on one side only. Calculate: (10)

(i) shearing force at top

(ii) shearing force at bottom

(iii) position of zero shear.

(a) What is the purpose of conducting an inclining experiment on a new vessel? (6)

(b) A mass of 6 t is moved transversely through a certain distance on a ship of 4300 t displacement, when the deflection of an 11 m pendulum is found to be 120 mm. The transverse meta-centre is 7.25 m above the keel and KG 5.46 m. Find the distance through which the mass of 6 t was moved. (10)

A hopper barge of box form 50 m long and 10 m wide floats at a draught of 2 m in seawater when the hopper, which is 15 m long and 5 m wide, is loaded with mud having relative density twice that of the seawater, to the level of the waterline. Doors in the bottom of the hopper are now opened allowing the mud to be discharged. Calculate the new draught. (16)

(a) Sketch and describe the midship section of a bulk carrier, labelling the structural members. (8)

(b) A vessel 40 m long has a constant cross-section in the form of a trapezoid 10 m wide at the top, 6 m wide at the bottom and 5 m deep. It floats in sea water at a draught of 4 m. Calculate its displacement. (8)

(a) What is the purpose of providing air pipes to tanks in the vessel? (6)

(b) Sketch an arrangement of air vent head situated on the weather deck. (5)

(c) What factors are considered in deciding the bore size of air pipe? (5)

(a) What is a right-handed and a left-handed propeller? (5)

(b) With the aid of simple sketches explain Rake, Skew and Pitch of the propeller. (6)

(c) What are the advantages and disadvantages of CPP? (5)

(a) What are various types of tankers for carrying bulk liquids? (6)

(b) Sketch a mid-ship section of a double-hulled crude oil tanker. (10)

Briefly explain the following ship terms used:

(a) LOA (2)

(b) LBP (2)

(c) Breadth Extreme (2)

(d) Breadth Moulded (2)

(e) Depth Extreme (2)

(f) Depth Moulded (2)

(g) Draught Extreme (2)

(h) Draught Moulded (2)

What do you understand by 'Free surface effect' and how does it affect the ship's stability? (16)

(a) What is the metric length of one shackle of an anchor chain? (4)

(b) A vessel of 10,000 t displacement consumes 25 t of fuel per day when her speed is 12 knots. Calculate the probable consumption of fuel over a voyage of 3000 nautical miles at a speed of 11 knots with a displacement of 11000t (12)

(a) What are the different types of stern used in ship construction? (6)

(b) A ship consumes 360 t of fuel, stores and water when moving from sea water of 1.025 t/m3 into fresh water of 1.000t/m3and on arrival it is found that the draught has remained constant. Calculate the displacement in sea water (10)

(a) What is a 'mast raiser' and what is the purpose of it? (6)

(b) A ship 96 m long is floating at 5m fwd draft and 6.4m aft draft. MCTC 180tm, TPC 16. COF is 2m abaft of midships. Find the location where a weight of 50t should be placed so as to keep the at draft constant (10)

A ship 120 meters long at the waterline has equidistantly spaced half-ordinates commencing from forward as follows: 0, 3.7, 5.9, 7.6, 7.5, 4.6 and 0.1 meters respectively. Find the area of the waterplane using Simpson's Second rule and the TPC at this draft. Water density is 1.025 t/m3. (16)

For a ship the center of buoyancy and the metacenter are in the line of action of the buoyant force

(a) only when there is positive stability

(b) only when there is negative stability

(c) only when there is neutral stability

(d) at all times

Justify your answer. (16)

Explain the meaning and purpose of EACH of the following terms:

(a) Duct keel (4)

(b) Margin line (4)

(c) Sheer (4)

(d) Round of Bilge (4)

With reference to hull protection against corrosion describe how EACH of the following operate:

(a) Sacrificial anodes; (8)

(b) Impressed current system. (8)

With reference to bilge keels:

(a) describe how the design and method of attachment reduces the possibility of damage to the shell plate; (8)

(b) state what testing must be carried out. (4)

(c) Explain why the bilge keels do not extend the full length of the vessel. (4)

With reference to large bulk carriers:

(a) sketch a cross section of a bulk carrier through the mid-ship; (8)

(b) explain the design features that have evolved to minimise the possibility of failure. (8)

(a) Define angle of loll (6)

(b) A box barge 60 m long and 10m wide floats at an even keel draught of 4 m. It has a compartment amidships 12 m long.

Calculate the new draught if this compartment is laid open to the sea when: (10)

(i) µ is 100%

(iii) µ is 85%

(iii) µ is 60%

(a) What do you understand by 'coffin' plate? (6)

(b) A ship displacing 10000 tonne and travelling at 16 knots has a fuel consumption of 41 tonne per day. Calculate the consumption per day if the displacement is increased to 13750 tonne and the speed is increased to 17 knots. Within this speed range, fuel consumption per day varies as (speed)^3.8 (10)

(a) Compare fixed pitch with controllable pitch propellers. (6)

(b) A ship of 12400 tonne displacement is 120 m long, 17.5 m beam and floats at a draught of 7.5 m. The propeller has a pitch ratio of 0.75 and, when turning at 100 rev/min, produces a ship speed of 12 knots with a real slip of 30%. Calculate the apparent slip, pitch and diameter of the propeller. The wake fraction w may be found from the expression. w 0.5Cb -0.05 (10)

(a) What are the water pressure loads on the ship's hull? (6)

(b) The water plane area of a ship at 8.4 m draught is 1670 m². The area of successive water planes at 1.40 m intervals below this are 1600, 1540, 1420, 1270, 1080 and 690 m² respectively. Calculate the displacement in fresh water at 8.4 m draught and the draught at which the ship would lie in sea water with the same displacement. (10)

With regards to the metacentric height, which of the following statements is true?

(a) It is used to indicate the quality of initial stability.

(b) It is located below the centre of buoyancy

(b) It is measured vertically above the centre of buoyancy

(c) Its determination is the objective of the inclining experiment.

Briefly justify your answer. (16)

Explain the meaning and purpose of EACH of the following terms:

(a) Bulbous bow (4)

(b) Hawse pipe (4)

(c) Spurling pipe (4)

(d) Cable stopper (4)

Define the main purpose of the following tank and pumping system in detail:

(a) Weighted cocks on tank sounding pipes; (4)

(b) Remote operated gear for bilge valves (4)

(b) Venting arrangements for double bottom tanks; (4)

(c) Explain why gauze is sometimes fitted to tank ventilation pipes and explain the effect of mesh size. (4)

Sketch a plane bulkhead, showing connections to deck, sides and double bottom and the arrangement of stiffeners. (16)

Write short notes on each of the following with respect to their contribution to the strength of ships:

(a) Strake

(b) Bracket

(c) Stinger

(d) Girder

(a) Describe the provisions of additional structural strength to withstand pounding. (6)

(b) A vessel trawling at 17 knots turns with a radius of 450 m. When the rudder is put hard over. The centre of gravity is 7 m above the keel and the transverse metacentre 7.45 m above the keel and the centre of buoyancy 4 m above the keel. If the centripetal force is assumed to act at the centre of buoyancy, calculate the angle of heel when turning. The rudder force may be ignored. (10)

(a) Show by means of diagrams how the center of gravity of the liquid in a partly filled tank moves during rolling. (6)

(b) A box barge is 15 m long, 6 m wide and floats in water of 1.016 t/m³ at a draught of 3 m. 150 tonne of cargo is now added. Calculate the load exerted by the water on the sides, ends and bottom. (10)

(a) Explain what is meant by 'assigned summer freeboard'. (6)

(b) A box-shaped vessel 60m long, 10m beam, and 6m deep, is floating in salt water at drafts 4m, Forward and 4.4 m. Aft. Find how far forward of amidships a weight of 30 tonnes must be loaded if the draft aft is to remain at 4.4m. (10)

(a) Explain why the TPC for a given draught will vary with the density of the water in which the ship floats. (6)

(b) A box shaped ship with 12m beam is floating upright at a draft of 6.7 m. Find the increase in draft if the vessel is now listed 18 degrees. (10)

State with reasons, the main purpose of the following:

(a) Bulbous Bow (4)

(b) Collision Bulkhead (4)

(c) Bilge Keel (4)

(d) Sheer (4)

A virtual rise in the center of gravity of a ship may be caused by (16)

(a) filling a partially filled tank

(b) using an onboard crane to lift a freely swinging heavy object

(c) emptying a partially filled tank

(d) transferring pipe from the setback area to the pipe rack

Briefly justify your Answer.

(a) Sketch a water-tight door showing manner of attachment to bulkhead and the additional reinforcement carried by the bulkhead to compensate for the aperture. (8)

(b) Explain how water-tightness of the door and frame mating surface is ensured with an hydrostatic pressure tending to force the faces apart.

(c) Describe the means of remote closing operation of the door and state how many closing stations are there and their position

(a) Sketch the arrangement of rudder stock, bearings, glands and method of suspension of a pintleless rudder, labeling the components parts. (8)

(b) State how the bearing wear down is measured and what prevents the rudder from jumping (8)

Describe the construction of chain lockers and how cables are secured in the lockers? Explain how to secure anchors in preparation for a sea passage. (16)

(a) Explain in brief the term 'bulwark' and 'freeing port'. (6)

(b) A ballast tank is 1.5m long, 12m wide and 1.4m deep and is filled with fresh water.

Calculate the load on the top and short side, if:

(i) the tank is just completely full.

(ii) there is a head of 7m of water above the tank top

(a) What is Freeboard of a Ship? Why oil tankers have less freeboard? (6)

(b) A ship's length in the waterline is 180 meters, with a maximum beam of 30 meters and a draft of 9 meters. If the ship's volume of displacement is 38,880 cubic meters, calculate its block coefficient. (10)

The half-ordinates of a ship's waterplane, which is 80m long, commencing from forward at equal intervals are as follows 0.2, 4.0, 5.0, 5.2, 5.0, 4.0 and 0.2 m respectively. Calculate the area of the water-plane using Simpson's First Rule. (16)

(a) Explain why the draught of a ship decreases when it passes from fresh water to seawater and vice versa. (6)

(b) A lock gate which is 15m. wide has salt water on one side to a depth of 8m. and fresh water on the other side to a depth of 9m. Find the resultant thrust on the lock gate and the state on which side of the gate it acts. (10)

Describe with the aid of sketches how each of the following contribute towards improving the propulsive efficiency of a ship: (16)

(a) Ducted propeller

(b) Costa bulb as fitted aft of the propeller

(c) Grim wheel vane as fitted aft of the propeller

A virtual rise in the center of gravity of a ship may be caused by (16)

(a) Filling a partially filled tank

(b) Using an onboard crane to lift a freely swinging heavy object

(c) Emptying a partially filled tank

(d) Transferring pipe from the setback area to the pipe rack

Briefly Justify your Answer

(a) Sketch a water-tight door and frame showing manner of attachment to bulkhead and the additional reinforcement carried by the bulkhead to compensate for the aperture. (8)

(b) Explain how water tightness of the door and frame mating surface is ensured with an hydrostatic pressure tending to force the faces apart. (4)

(c) Describe the means of remote closing operation of the door and state how many closing stations there are and their position. (4)

(a) Sketch the arrangement of rudder stock, bearings, glands and method of suspension of a pintleless rudder, labeling the components parts. (8)

(b) State how the bearing wear down is measured and what prevents the rudder from jumping? (8)

Describe the construction of chain lockers and how cables are secured in the lockers?

Explain how to secure anchors in preparation for a sea passage. (16)

(a) Explain in brief the term 'bulwark' and 'freeing port'. (6)

(b) A ballast tank is 15 m long, 1.2 m wide and 1.4 m deep and is filled with fresh water.

Calculate the load on the top and short side, if: (10)

(a) The tank is just completely full

(b) There is a head of 7m of water above the tank top.

(a) What is 'freeboard of a Ship'? Why oil tankers have less freeboard?

(b) A box barge 25 m long and 4 m wide floats in fresh water at a draught of 1.2 m and has an empty mid length compartment 5 m long. The bottom of the barge is lined with teak (rd 0.805) 120 mm thick. After grounding all the teak is torn off and the centre compartment laid open to the sea. Calculate the final draught.

The ½ ordinates of a waterplane 120 m long are as follows:

Calculate: (16)

(a) Waterplane area

(b) Distance of centroid from midships.

A vessel about to complete loading in a summer zone is expected to enter a winter zone after steaming from the loading port for 10 days. On passage, fuel consumption is expected to be 30 tonnes per day and water consumption 15 tonnes per day. The ship is at present floating in water of density 1.013 tonnes/m3 at a draft of 9.0m.

(a) The maximum permissible draft on completion of loading.

(b) The amount of cargo which the vessel can load.

(Note: A vessel passing from a summer zone to a winter zone, or from a tropical zone to summer zone, must arrive at the zone boundary at the draft appropriate to that zone.)

(a) What are the various Static stresses that act on a vessel at rest in still water? Explain with the aid of sketches. (10)

(b) Give examples for dynamic stresses on a vessel? (6)

(a) What is bilging and What are the effects of bilging? (8)

(b) How are bulkheads classified? (3)

(c) What are the advantages of water tight bulkheads? How is the water tight bulkhead tested? (5)

Explain the meaning and purpose of EACH of the following terms:

(a) Flare (3)

(b) Bulwark (3)

(c) Coaming (3)

(d) Freeing port (3)

(e) Scupper (2)

(f) Rise of floor (2)

(a) Sketch a semi balanced rudder showing: (10)

(i) A detail of the hinges or pintles about which rudder turns

(ii) Details of the rudder carrier bearing, which supports the weight of the rudderstock and rudder

(b) State advantages of semi balanced rudder over an unbalanced rudder (3)

(c) What acts as "rudder stops"? What is their purpose and at what angle from mid position would you expect the rudder stops to be set (3)

(a) What is free surface effect. (6)

(b) Explain the methods used to reduce the free surface effect in ship construction and while operating the ship. (10)

(a) What is the purpose of conducting an inclining experiment on a new vessel? (6)

(b) A mass of 6t is moved transversely through a certain distance on a ship of 4300t displacement, when the deflection of an 11m pendulum is found to be 120mm. The transverse meta-centre is 7.25 m above the keel and KG 5.46m. Find the distance through which the mass of 6t was moved. (10)

(a) What are the various resistances acting against the motion of the ship? (6)

(b) A vessel of 10000 t displacement burns 25 t of fuel per day when her speed is 12 knots. Calculate the probable consumption of fuel over a voyage of 3000 nautical miles at a speed of 11 knots with a displacement of 11000t. (10)

(a) Explain why the draught of a ship decreases when it passes from fresh water to seawater and vice versa (6)

(b) A bulkhead 9 m deep is supported by vertical stiffeners 750 mm apart. The bulkhead is flooded to the top edge with sea water on one side only. Calculate: (10)

(i) Shearing force at top

(ii) Shearing force at bottom

(iii) Position of zero shear

(a) With aid of a simple sketch, show the normal positions of centre of gravity of a stable ship relative to keel, centre of buoyancy and meta centre. (6)

(b) A ship has 300 t of cargo in the hold, 24 m forward of the midships. The displacement of the vessel is 6000 t and its centre of gravity is 1.2 m forward of midships. Find the new position of the centre of gravity if this cargo is moved to an after hold, 40 m from midships. (10)

(a) Explain what is meant by longitudinal framing and transverse framing? (8)

(b) Which types of ships would have these methods of construction? Give reasons (8)

What are the main functions of:

(a) Fore peak (4)

(b) After peak (4)

(c) Deep tank (4)

(d) Double bottom (4)

Give examples of liquid carried in these tanks.

With regards to the metacentric height, which of the following statements is true?

(a) It is used to indicate the quality of initial stability.

(b) It is located below the center of buoyancy.

(c) It is measured vertically above the center of buoyancy.

(d) Its determination is the objective of the inclining experiment.

Briefly justify your answer. (16)

(a) Sketch a semi balanced rudder of your choice showing: (10)

(i) A detail of the hinges or pintels about which rudder turns.

(ii) Details of the rudder carrier bearing which supports the weight of the rudderstock and rudder.

(b) State the advantages of semi balanced rudder over an unbalanced rudder (6)

(a) Describe the following and explain their function: (9)

(i) Hawse pipe.

(ii) Spurling pipe.

(iii) Cable stopper.

(b) With the aid of a sketch of a ship bow show the arrangement of anchor cable, from anchor to chain locker. (7)

(a) Define Centre of Flotation. What happens to the draught and trim of a ship if a small mass is added to the ship at the centre of Flotation? (6)

(b) A ship of displacement 10010 tonnes has KM 6.7m and GM 0.76m. A mass of 10 tonnes having KG 7.6m is shifted transversely. The deflection of a pendulum length 7.6m is 0.125m. Find the distance through which the mass is shifted. Also find the metacentric of the new centre of gravity above the keel due to the removal of the same mass. (10)

(a) What is meant by 'statical stability'? What are the factors that influence stability? (6)

(b) A box barge 25 m long and 4 m wide floats in fresh water at a draught of 1.2 m and has an empty mid length compartment 5 m long. The bottom of the barge is lined with teak (rd 0.805) 120 mm thick. After grounding all the teak is torn off and the centre compartment laid open to the sea. Calculate the final draught. (10)

The ½ ordinates of a waterplane 120 m long are as follows:

Calculate: (16)

(a) waterplane area

(b) distance of centroid from midships.

A ballast tank is 15 m long, 12 m wide and 1.4 m deep and is filled with fresh water.

Calculate the load on the top and short side, if: (16)

(a) The tank is just completely full

(b) There is a head of 7m of water above the tank top.

(a) What is the purpose of providing air pipes to tanks in the vessel? (5)

(b) Sketch an arrangement of air vent head situated on the weather deck. (6)

(c) What factors are considered in deciding the bore size of air pipe? (5)

(a) What is a right-handed and a left-handed propeller? (5)

(b) With the aid of simple sketches explain Rake, Skew and Pitch of the propeller. (6)

(c) What are the advantages and disadvantages of CPP? (5)

(a) What are various types of tankers for carrying bulk liquids? (6)

(b) Sketch a mid-ship section of a double-hulled crude oil tanker. (10)

Briefly explain the following ship terms used:

(a) LOA (2)

(b) LBP (2)

(c) Breadth Extreme (2)

(d) Breadth Moulded (2)

(e) Depth extreme (2)

(f) Depth Moulded (2)

(g) Draught Extreme (2)

(h) Draught Moulded (2)

What do you understand by 'Free surface effect' and how does it affect the ship's stability? (16)

(a) What is the metric length of one shackle of an anchor chain? (4)

(b) A vessel of 10000 t displacement burns 25 t of fuel per day when her speed is 12 knots. Calculate the probable consumption of fuel over a voyage of 3000 nautical miles at a speed of 11 knots with a displacement of 11000 t. (12)

(a) What are the different types of stern used in ship construction? (6)

(b) A ship consumes 360 t of fuel, stores and water when moving from sea water of 1.025 t/m3 into fresh water of 1.000 t/m3 and on arrival it is found that the draught has remained constant. Calculate the displacement in sea water. (10)

(a) What is a 'mast riser' and what is the purpose of it? (6)

(b) A ship 96 m long is floating at 5m fwd draft and 6.4 m aft draft, MCTC 180 tm, TPC 16. COF is 2 m abaft of midships. Find the location where a weight of 50 t should be placed so as to keep the aft draft constant. (10)

A ship 120 meters long at the waterline has equidistantly spaced half-ordinates commencing from forward as follows: 0, 3.7, 5.9, 7.6, 7.5, 4.6, and 0.1 meters respectively. Find the area of the waterplane using Simpson's Second rule and the TPC at this draft. Water density is 1.025 t/m3. (16)

A virtual rise in the centre of gravity of a ship may be caused by

(a) Filling a partially filled tank

(b) Using an onboard crane to lift a freely swinging heavy object

(c) Emptying a partially filled tank

(d) Transferring pipe from the setback area to the pipe rack

Briefly Justify your Answer. (16)

Explain the meaning and purpose of EACH of the following terms:

(a) Bulbous bow (4)

(b) Sparring pipe (4)

(c) Hawse pipe (4)

(d) Cable stopper (4)

Define the main purpose of the following tank and pumping system in detail:

(a) Weighted cocks on tank sounding pipes. (4)

(b) Remote operated gear for bilge valves. (4)

(c) Ventilation pipes for double bottom tanks. (4)

(d) Explain why gauze is sometimes fitted to tank ventilation pipes and explain the effect of mesh size. (4)

Sketch a plane bulkhead, showing connections to deck, sides and double bottom and the arrangement of stiffeners. (16)

Write short notes on each of the following with respect to their contribution to the strength of ships:

(a) Strake (4)

(b) Bracket (4)

(c) Stringer (4)

(d) Girder (4)

(a) Describe the provisions of additional structural strength to withstand pounding. (6)

(b) A ship is turning at 17 knots turns with a radius of 450 m when the rudder is put hard over. The centre of gravity is 7 m above the keel, the transverse metacentre 7.45 m above the keel and the centre of buoyancy 4 m above the keel. If the centripetal force is assumed to act at the centre of buoyancy, calculate the angle of heel when turning. The rudder force may be ignored. (10)

(a) Show by means of diagrams how the centre of gravity of the liquid in a partly filled tank moves during rolling. (6)

(b) A box barge is 15 m long, 6 m wide and floats in water of 1.016 t/m³ at a draught of 3 m. 150 tonne of cargo is now added. Calculate the load exerted by the water on the sides, ends and bottom. (10)

(a) Explain what is meant by 'assigned summer freeboard'. (6)

(b) A box-shaped vessel 60m long, 10m beam, and 6m deep, is floating in salt water at drafts 4m. Forward and 4.4 m Aft. Find how far forward of amidships a weight of 30 tonnes must be loaded if the draft aft is to remain at 4.4m. (10)

(a) Explain why the TPC for a given draught will vary with the density of the water in which the ship floats. (6)

(b) A box-shaped ship with 12m beam is floating upright at a draft of 6.7 m. Find the increase in draft if the vessel is now listed 18 degrees. (10)

(a) What are the advantages of corrugated bulkheads? (6)

(b) Sketch and describe a corrugated transverse watertight bulkhead. (10)

(a) Describe in detail how brittle fracture is instrumental in causing failure of materials. (6)

(b) Describe how a material is tested to assess the resistance to this type of failure. (4)

(c) Suggest where this type of failure would be likely and explain how the likelihood of failure is reduced. (6)

With reference to hull protection against corrosion and fouling, write a brief explanation of each of the following:

(a) Sacrificial anodes (6)

(b) Impressed Current System (6)

(c) means of preventing marine growth and fouling (4)

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

(a) Racking (4)

(b) Panting (4)

(c) Pounding (4)

(d) Vibration from engine and propellers. (4)

(a) What is the fundamental purpose of a 'Load Line' marking on ships? (5)

(b) Sketch and describe the features of a 'Load Line' marking. (6)

(c) Name five conditions that must be met before freeboard is assigned to a ship. (5)

(a) Explains why the draught of a ship decreases when it passes from fresh water to seawater and vice versa. (6)

(b) A bulkhead 9 m deep is supported by vertical stiffeners 750 mm apart. The bulkhead is plated to the top edge with sea water on one side only. Calculate: (10)

(a) Shearing force at top

(b) Shearing force at bottom

(c) Position of zero shear

(a) What is the purpose of conducting an inclining experiment on a new vessel? (6)

(b) A mass of 6 t is moved transversely through a certain distance on a ship of 4300 t displacement. When the deflection of a 11 m pendulum is found to be 120 mm. The transverse meta-centre is 7.25 m above the keel and KG 5.46 m. Find the distance through which the mass of 6 t was moved. (10)

A hopper barge of box form 50 m long and 10 m wide floats at a draught of 2 m in seawater when the hopper, which is 15 m long and 5 m wide, is loaded with mud having relative density twice that of the seawater, to the level of the waterline. Doors in the bottom of the hopper are now opened allowing the mud to be discharged. Calculate the new draught. (16)

(a) Sketch and describe the midship section of a bulk carrier, labelling the structural members. (8)

(b) A vessel 40 m long has a constant cross-section in the form of a trapezoid 10 m wide at the top, 6 m wide at the bottom and 5 m deep. It floats in sea water at a draught of 4 m. Calculate its displacement. (8)

(a) Describe the following and explain their function: (8)

(i) Hawse pipe

(ii) Spurling pipe

(iii) Cable stopper

(iv) Bitter end

(b) With the aid of a sketch of a ship's bow show the arrangement of anchor cable, from anchor to chain locker. (8)

In the absence of external forces, adding weight to one side of a floating vessel, will cause the vessel to (16)

(a) Heel until the angle of loll is reached

(b) List until the centre of buoyancy is aligned vertically with the centre of gravity

(c) Trim to the side opposite TCG until all moments are equal

(d) Decrease draft at the centre of flotation

Briefly Justify Your Answer

(a) Draw a labeled sketch of midship section of a double hull oil tanker. (10)

(b) What are Aframax, Suezmax, ULCC and VLCC tankers? (6)

(a) What are the advantages of corrugated bulkheads? (6)

(b) Sketch and describe a corrugated transverse watertight bulkhead. (10)

(a) What is free surface effect? (6)

(b) Explain the methods used to reduce the free surface effect in ship construction and while operating the ship. (10)

(a) What is the significance of GM-GZ curve? (6)

(b) The pitch of a propeller is measured by means of a batten and cord. The horizontal ordinate is found to be 40 cm while the vertical ordinate 1.15 m at a distance of 2.6 m from the centre of the boss. Calculate the pitch of the propeller and the blade width at that point. (10)

(a) Explain why the draught of a ship decreases when it passes from fresh water to seawater and vice versa. (6)

(b) A lock gate which is 15m wide has salt water on one side to a depth of 8m and fresh water on the other side to a depth of 9m. Find the resultant thrust on the lock gate and state on which side of the gate it acts. (10)

(a) Describe the function of stern frame (6)

(b) The water plane area of a ship at 8.4 m draught is 1670 m2 The area of successive water planes at 1.40 m intervals below this are 1600, 1540, 1420, 1270, 1080 and 690 m2 respectively. Calculate the displacement in fresh water at 8.4 m draught and the draught at which the ship would lie in sea water with the same displacement. (10)

(a) Explain why an unstable ship is dangerous. (6)

(b) A vessel travelling at 17 knots turns with a radius of 450 m when the rudder is put hard over. The centre of gravity is 7m above the keel, the transverse metacentre 7.45 m above the keel and the centre of buoyancy 4 m above the keel. If the centripetal force is assumed to act at the centre of buoyancy, calculate the angle of heel when turning. The rudder force may be ignored. (10)

For a ship the center of buoyancy and the metacenter are in the line of action of the buoyant force

(a) Only when there is positive stability

(b) Only when there is negative stability

(c) Only when there is neutral stability

(d) At all times

Justify your answer.

Explain the meaning and purpose of EACH of the following terms:

(a) Duct keel (4)

(b) Margin line (4)

(e) Sheer (4)

(d) Round of Bilge (4)

With reference to hull protection against corrosion describe how EACH of the following operate:

(a) Sacrificial anodes (8)

(b) Impressed current system. (8)

With reference to bilge keels:

(a) Describe how the design and method of attachment reduces the possibility of damage to the shell plate. (8)

(b) State what testing must be carried out. (4)

(c) Explain why the bilge keels do not extend the full length of the vessel. (8)

With reference to large bulk carriers:

(a) Sketch a cross section of a bulk carrier through the mid-ship (8)

(b) Explain the design features that have evolved to minimise the possibility of failure. (8)

(a) Define angle of loll.

(b) A box barge 60 m long and 10m wide floats at an even keel draught of 4 m. It has a compartment amidships 12 m long.

Calculate the new draught if this compartment is laid open to the sea when:

(i) µ is 100%

(ii) µ is 85%

(iii) µ is 60%

(a) What do you understand by 'coffin' plate? (6)

(b) A ship displacing 10000 tonne and travelling at 16 knots has a fuel consumption of 41 tonne per day. Calculate the consumption per day if the displacement is increased to 13750 tonne and the speed is increased to 17 knots. Within this speed range, fuel consumption per day varies as (speed)^3.8? (10)

(a) Compare fixed pitch with controllable pitch propellers. (6)

(b) A ship of 12400 tonne displacement is 120 m long, 17.5 m beam and floats at a draught of 7.5 m. The propeller has a pitch ratio of 0.75 and, when turning at 100 rev/min, produces a ship speed of 12 knots with a real slip of 30%. Calculate the apparent slip, pitch and diameter of the propeller. (10)

The wake fraction w may be found from the expression. w = 0.5Cb - 0.05

(a) Describe water pressure loads on the ship's hull. (6)

(b) The ½ ordinates of a waterplane 120 m long are as follows:

Calculate: (10)

(a) Waterplane area

(b) Distance of centroid from midships.

(a) What is a right-handed and a left-handed propeller? (4)

(b) With the aid of simple sketches explain Rake, Skew and Pitch of the propeller. (6)

(c) What are the advantages and disadvantages of CPP? (6)

Define the main purpose of the following with respect to tank and pumping system.

(a) Weighted cocks on tank sounding pipes (4)

(b) Remote operated gear for bilge valves (4)

(c) Ventilation pipes for double bottom tanks (4)

(d) Explain why gauze is sometimes fitted to tank ventilation pipes and explain the effect of mesh size. (4)

Briefly explain the following ship terms used:

(a) LOA (2)

(b) LBP (2)

(c) Breadth Extreme (2)

(d) Breadth Moulded (2)

(e) Depth extreme (2)

(f) Depth Moulded (2)

(g) Draught Extreme (2)

(h) Draught Moulded (2)

Define centre of buoyancy and show with the aid of sketches how a vessel which is stable will return to the upright after being heeled by an external force. (16)

(a) State why cargo ships must have a collision bulkhead. (6)

(b) A bilge holding tank of 5 m length, 3 m width and 1.8 m depth has water of density 1.020 t/m3 upto a sounding of 1.3 m and oil of density 0.86 t/m3 is floating on top of water upto an ullage of 0.3 m. Calculate the mass of water and oil in the tank. (10)

(a) Define TPC. Explain why TPC for a given draught will vary with the density of the water in which the ship floats. (6)

(b) The pitch angle, measured at a distance of 2 m from the centre of the boss, was found to be 21.5°. Calculate the pitch of the propeller. (10)

(a) Explain clearly the meaning of the term 'reserve buoyancy' (6)

(b) When a mass of 10 tonnes is shifted 12 m transversely across the deck of a ship with a GM of 0.6 m, it causes 0.25 m deflection in a 10 m plumb line. Calculate the ship's displacement. (10)

(a) Explain various powers and efficiencies in the Propulsion plant of a ship. (6)

(b) A vessel with a displacement of 12250 t burns 290 t of fuel while travelling at a speed of 15 knots on a voyage of 2850 nautical miles. On a voyage of 1800 nautical miles at a speed of 13 knots and a displacement of 14200 t, estimate the quantity of fuel that will be burnt. (10)

(a) What are the effects of adding mass to draught and trim of a ship? (6)

(b) A ship of 7000 t displacement has a water plane area of 1500 m2. In passing from sea water into river water of 1005 kg/m2 there is an increase in draught of 10 cm.

Find the density of the sea water. (10)

(a) Sketch a transverse section through a duct keel labeling its component parts. Indicate the duct keel’s position in the ship structure. (8)

(b) Explain why duct keels are fitted. (8)

(a) Write short notes on Panting, Pounding, Racking. (8)

(b) Explain with the aid of simple sketches hogging and sagging of a vessel. (8)

(a) What are the 3 Classes of bulkheads? (4)

(b) What are the advantages of water tight bulkheads? (4)

(c) How is the water tight bulkhead tested? (4)

(d) What is the purpose of providing air pipes to tanks in the vessel? (4)

(a) What is the fundamental purpose of a 'Load line' marking on ships? (5)

(b) Sketch and describe the features of a 'Load Line' marking. (6)

(c) Name five conditions that must be met before freeboard is assigned to a ship. (5)

(a) Name the different types of rudders. (6)

(b) Draw a labeled sketch of an unbalanced rudder fitted onto a rudder post. (10)

(a) Sketch and describe the midship section of a bulk carrier, labeling the structural members.

(b) A vessel 40 m long has a constant cross-section in the form of a trapezoid 10 m wide at the top, 6 m wide at the bottom, and 5 m deep. It floats in sea water at a draught of 4 m. Calculate its displacement.

Briefly explain the following ship terms commonly used:

(a) Gross Tonnage (2)

(b) Deadweight (2)

(c) Displacement (3)

(d) Strakes (3)

(e) Deck Beams (3)

(f) Girders (3)

(a) Derive the formula for Admiralty Coefficient. (6)

(b) A ship travels 900 nautical miles at a speed of 12.5 knots and burns 150 t of fuel over the voyage. Estimate the distance the ship could travel at a speed of 13.5 knots on 250 t of fuel. (10)

A hopper barge of box form 50 m long and 10 m wide floats at a draught of 2 m in seawater when the hopper, which is 15 m long and 5 m wide, is loaded with mud having relative density twice that of the seawater, to the level of the waterline. Doors in the bottom of the hopper are now opened allowing the mud to be discharged. Calculate the new draught. (16)

(a) What are the various Static stresses that act on a vessel at rest in still water? Explain with the aid of sketches. (10)

(b) Give examples for dynamic stresses on a vessel? (6)

(a) What is bilging and What are the effects of bilging? (8)

(b) How are bulkheads classified? (3)

(c) What are the advantages of water tight bulkheads? How is the water tight bulkhead tested? (5)

Explain the meaning and purpose of EACH of the following terms:

(a) Flare (3)

(b) Bulwark (3)

(c) Coaming (3)

(d) Freeing port (3)

(e) Scupper (2)

(f) Rise of floor (2)

(a) Sketch a semi balanced rudder showing: (10)

(i) A detail of the hinges or pintels about which rudder turns.

(ii) Details of the rudder carrier bearing, which supports the weight of the rudderstock and rudder.

(b) State advantages of semi balanced rudder over an unbalanced rudder. (3)

(c) What acts as "rudder stops"? What is their purpose and at what angle from mid position would you expect the rudder stops to be set. (3)

(a) What is free surface effect? (6)

(b) Explain the methods used to reduce the free surface effect in ship construction and while operating the ship. (10)