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32 Cards in this Set
- Front
- Back
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Describe the checks carried out on a Rudder in dry dock? |
1. visual inspection for any damage, distortion, cracking. 2. water leakage, drain plug removed, seal can be pressure tested 3. check anode security and wastage. The paintwork near the anodes should be inspected for deterioration. 4. check security of all connections, coupling bolts and pintle nut etc. 5. measure pintle or bearing clearences and ensure within tolerance. 6. check paintwork for condition, renew as necessary 7. rudder movement can be checked full swing and timed. |
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what are the constructional details of a watertight door? |
1. watertight doors are fitted below the bulkhead deck to allow access through watertight compartments for watch keeping or emergency escape. 2. The doors are heavy, thick, steel and of a sliding type. Penetration in the bulkhead would be suitable stiffened to reinstate strength and have a running rail for the door to into. 3. The doors are power operated using an electro-hydraulic system. 4. brass facing strips are used at the sale areas, avoiding seizure due to dissimilar metal. |
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what regulations pertain to watertight doors? |
SOLAS, LOADLINE 1. Doors need to be of the vertical or horizontal sliding type 2. They can be operated locally and remotely from a position above the bulkhead deck and from a control station on the bridge. 3. They should be powered from the emergency supply and have an independent means of closing. 4. They should occupy an audible alarm that will sound for 5 minutes before movement commences should the door be operated remotely. 5. The door can be closed with a list of up to 15 degrees. 6. The bridge control station should be able to close all doors simultaneously in 60 seconds 7. The emergency means of pumping should be able to closed the door in 90 seconds, and 3 times in total at 15 degrees 8. the door should closed in no less than 20 seconds but no more than 40 seconds. 9. The bulkhead should be suitably stiffened to maintain strength and integrity. 10. position indicator at remote locations |
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What is the routine maintenance carried out to weathertight doors? |
1. regular operation 2. inspection of NEOPRENE seal 3. greasing of hinges and toggles 4. HOSE TEST 2 BAR <1M |
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describe with the aid of a sketch an engine room gantry crane showing how it is supported |
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Describe checks that should be made to an engine room gantry crane before use |
1. chek general condition of crane, securing arrangements 2. check SWL and load to be lifted 3. check condition of lifting arrangement, should be greased and in good condition. 4. check the crane operates in all directions before applying load |
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Describe/sketch braking arrangements for lifeboats and how they're tested |
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How are lifeboats protected from falling back into descent if the power fails during housing? |
The design of the gravity brake incorporates an ECCENTRIC PIVOT that allows the brake to be release during housing. As soon as the drum rotates in opposite direction, the gravity brake will engage |
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Define an A Class bulkhead |
- made from steel - suitably stiffened - must withstand the passage of smoke and flame until the end of a one hour standard fire test - should have sufficient insulation of non combustible material such that the average temperature does that go above 140 degrees on top of original temperature and at no point/ joint will the temperature exceed 180 degrees. 60/30/15/0 |
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Define B Class bulkhead |
Constructed of various approved materials Must withstand the passage of smoke for the first half hour of a standard Fire test Should be insulated with approved non combustible material such that the average temperature doesn't rise above 140 degrees on top of normal temp or at any one point/joint above 225 degrees. B-15/B-0 |
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Describe the door penetration arrangement through an A60 bulkhead |
Constructed of A60 material Can be closed manually, either side of door Can be closed simualtaneoualy or in groups from control centre with accompanied alarm |
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Describe a trunking penetration arrangement through an A60 deck |
Normally a steel flap held open by a weight hinge secured by a fusable plug that will melt at 70 degrees and close automatically. Trunking made of A60 material. Can be manually closed and position indicator given |
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Describe the constructional differences between unbalanced/ semi/ balanced rudders |
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Sketch an unbalanced rudder |
Back (Definition) |
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Sketch a balanced rudder |
Upper lower bearings |
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Explain why scuppers are fitted in close proximity to the superstructure whereas freeing ports are generally fitter to open areas of the weather deck Why is it essential that the scuppers and freeing ports are kept fully operational at all times? |
Scuppers are fitted to allow small amounts of water thats accumulated near the superstructure, to drain overboard. Freeing ports are of a much larger design and allow for the rapid drainage of green seas form the open deck 1. Additional mass, rise in COG, loss of Stab 2. Free surface effect, loss of Stab 3. SW corrosive effect on materials, loss of strength 4. Bending stresses on hull due to force at distance from centreline. |
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Sketch a midship section of a ship, labelling each of the following: 1. Camber 2. Bilge Radius 3. Bilge Keel 4. Flat of Bottom 5. Rise of floor |
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State FIVE terms used to describe the conditions that relate to the distortion a hull undergoes, stating in EACH case, the stresses involved |
1. Static stressing due to weight of ship acting downwards against upwards buoyancy force 2. Hogging and sagging of the hull due to waveforms cause longitudinal bending stresses 3. Racking and water pressure cause transverse stressing 4. Panting and pounding due to to heavy seas cause dynamic stressing on the hull plating 5. Dry docking causes both longitudinal and transverse bending stresses as the ship is lowered and then sat on the blocks |
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Sketch a method of attaching an anchor cable to the ships hull, stating how the cable can be released in an emergency. |
Spindle and handle up on forecastle deck, guide ring to guide cable, bitter end. Turning handle on forecastle deck is turned on an UN-TENSIONED anchor and final link is released |
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Sketch an anchor cable stopper, explaining its purpose. |
Designed to hold the anchor in place when at anchor or when stowed. This isolates the windlass from any shocks and vibration. It is not designed to stop a moving cable. |
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Sketch the top and bottom connection of a fully balanced axle type rudder. What are the advantages of a fully balanced rudder? |
top connection: axle with bolted palm to stern frame. cast steel bearing housing. bronze bush and bronze shrunk fit liner. jumper bard bottom connection: axle bolted to stern frame with lock nut. Gliding bearing hard/mild steel top/bottom. Bronze bush and braze shrunk liner advantage: reduction in torque on rudder stock due to certain amount of balanced water force on fwd and aft of rudder, meaning smaller/lighter steering gear required. |
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Sketch a sea chest suitable for the connection of a main sea water inlet valve, labelling all of the fittings. |
sea chest-anodes-grid bars longitudinal- isolation valves- strainer box with drain and vent |
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explain why a bilge injection valve is incorporated into the main sea water system describe how it is tested |
Sea water pumps are normally one of the latest capacity water pumps onboard and will be able to remove large amounts of water in the event of a flood. To test the bilge injection valve, ensure the sea water consumers are fed from an alternative pump. Close the main suction and open the bilge injection valve. A bag filled with fresh water can be attached to the injection line and pump start stopped to prove there is suction. |
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sketch a lifeboat braking system. state the safety features incorporated in the breaker should the operator: 1. let go of the brake handle during lowering 2. attempt to lower the boat to quickly 3. loose power during hoisting Maximum rate of decent? |
Two brakes acting on common shaft. Gravity break, eccentric pivot, spring loaded shoes, brake liners. Centrifgual break 1. break drops cut to gravity and engages 2. cent. break engages and slows decent 3. eccentric pivot disengages during hoist but engages as soon as boat falls. 0.6 m/s |
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State the advantages and disadvantages of the following materials in ship building: 1. Mild Steel 2. High Tensile Steel 3. Aluminium |
1. advantages- cheap, ductile, easily welded, hot worked without treating, corrosion resistant. Disadvatanges- heavy, magnetic, SW corrosive, poor durability 2. advantages- increased strength over mild steel. disadvantages- hydrogen embrittlement SW corrosive 3. advantages- much lighter, non magnetic, more corrosion resistant, tough, cryogenic properties disadvantages- cost, harder to weld, galvanic cell with steel,needs alloying. |
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Describe the circumstance sunder which each of the following tests are carried out in dry dock. State with reasons which part of the external plating require most attention during dry dock. |
Hose test: Carried out to demonstrate the structural tightness of watertight and weathertight items that cannot be subjected to hydrostatic or leak testing. Hose test is approved by IACS and is normally conducted during construction or after a major repair, in the presence of a surveyor. Ultrasonic testing: An IACS approved method of testing the thickness/condition of plating, piping, welds etc. Can also be used as a leak testing method on weather/watetight items. An example of UT would be during a 5 year special hull survey, to measure thickness of hull plating, ensuring its within limits. Hammer test; it is an accepted practise to carry out controlled impact testing on any abnormality such as rust, scale, pitting and to test the continuity of cracks in materials. Lloyds refer to hammer testing under visual testing during hull continuous surveys. The structure forward of the collision bulkhead is further supported as it is subject to a lot of dynamic stressing when the ship is making headway, especially during heavy weather. The fluctuation in water pressure can cause the plating to pant and the slamming of the bow into the waves as the ship pitches (pounding) can cause deformation. Also, plating near suction and discharge piping should be carefully monitored due to the turbulent flow and chances of cavitation, which can erode the material. |
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Explain the purpose of transverse watertight bulkheads (TWB) |
The use of TWB subdivides the ship into watertight compartments, the number of which is governed by class and dictated by the ship type and size etc. The purpose of transverse subdivision and bulkhead spacing is to provide damage stability; an arrangement that will maintain the ship afloat should one or a number of the watertight compartments flood. They extended at least up to the freeboard deck and also provide transverse strength, fire zone/cargo separation, and reduce free surface effect. |
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Describe with the aid of a sketch how each of the following are sealed when passing though a water tight bulkhead; (i) electoral cables (ii) transmission shaft. |
cable glands: rubber sleeves for seperation and adhesive surface, silicon based, fire/waterproof sealant. Welded frame Transmission shaft; various designs from stuffing box to self activated air seals. Stuffing box; shaft, follower, packing, frame, bulkhead. |
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with reference to the construction of refridegarted spaces (a) state the materials used for insulation (b) state the properties that an insulating material should possess (c) sketch a section through a wall of cold storage space detailing how the insulation is attached to the ships structure. |
(a) granulated polymer or foamed; mineral wool; wood boxes filled with perlite; rolled fibre glass (b) low thermal conductivity; moisture resistant; fire resistant; low density; lightweight; non hazardous; cheap (c) bulkhead; frames; steel lugs welded to frame heels; ground wood blocks screwed to lugs; aluminium sheet metal, sealing strips at joints. |
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with reference to double bottom fuel tanks: (a) state why weighted cocks are fitted to tank sounding pipes (b) state the purpose of air pipes (c) state the design features of air pipes in respect to heavy weather, fire and bunkerin |
(a) weight cocks are fitted on sounding pipes to ensure positive closing once the handle has been released. This ensures the sounding pipe is sealed from the compartment where otherwise flammable vapours could escape to or even an overflow should the sounding cock be left open (b) air pipes are fitted to extended up from the bottom of the tank to prevent overpressure or vacuum conditions in the tank when it is being filled or pumped out. Any air at the bottom of the tank will be vented rather than being trapped and compressed by the filling. Overpressure may cause deformation of the tank (c) heavy weather; air pipes will have a heavy weather flap that can be closed in the event of bad weather. It may also have a non return element such as a floating ball, along with a gooseneck design to prevent any water from entering. Fire; the pipe will have a copper gauze inside to prevent the passage of any flame, by dissipating the heat, copper good thermal conductivity (c) air pipes are led to open deck areas where vapours given off will not cause a hazard. They will also in a save all to contain any fuel in the event of an overflow. |
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Skecth a weathertight door, showing how the edges are sealed. State the routine maintenance Describe how the function of the door may be tested |
1. frequent operation 2. visual check on steel condition, framing for corrosion. 3. check condition of rubber seal for wear, cracks 4. grease hinges, toggles, springs 5. hose test as per PMS Hose test; 2bar hose pressure max 1m away chalk the rubber seal, close the door. hose test, you should still have a chalk max around the seal. If rubbed off the seal is faulty. |
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Explain the purpose of cofferdams State the locations where they may be used state the procedure to be undertaken when entering a cofferdam |
Cofferdams are void or empty spaces that provide segregation between different compartments and tanks and prevent leakage from one to another. They are used to segregate various cargos from each other or another compartment. They also provide a means for inspection Between double bottom fuel tank and water tank between deep tanks and dry cargo holds around main engine sump for inspection Enclose space entry |
