Seamanship. A braided line comprises a core of braided or stranded threads covered with a sheath. The center or core of the line gives strength.

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1 Seamanship 1. Describe the life boat ropes. On a life boat, we rarely use the word rope but rather lines to describe all of the ropes. Moreover, each line has a specific name, such as the painter, halyard or fender line. Lines can be stranded or braided. A stranded line consists of fibers twisted in one direction to form a rope yarn, which twisted again in the opposite direction, creates the strand. Three strands are then twisted again in the same direction as the fibers to create the final rope. This alternating torsion causes the line to tighten on itself and thus prevents it from unraveling. A braided line comprises a core of braided or stranded threads covered with a sheath. The center or core of the line gives strength. Stranded Braided. 2. Describe rope Storage for life boat. The effects of water, salt, sand and sun on rope fibers cause wear and tear, thereby reducing their strength. All ropes and lines must be protected from wear and tear and to be checked on a regular basis. Ropes that are not used regularly should be uncoiled from time to time to prevent them from losing their flexibility. 1

2 They should be coiled as below ways, 3. What is the use of figure of eight knot? Draw it. The figure of eight knot is useful as a stop knot, to prevent a line from slipping through a pulley. It is preferred to a half-hitch, when a larger stop knot is needed. It is also easier to untie. 4. What is the use of figure of bowline Knot? Draw it. The bowline knot is used to tie a temporary loop in the end of a rope. It can be easily untied, even if placed under extreme tension. 2

3 5. Define clove hitch. The clove hitch is the best knot for tying a line to a ring, a spar, or anything with cylindrical shape. 6. What are the proof loads of derricks? SWL up to 20 tons: SWL + 25%, SWL 20 to 50 tons: SWL + 5 tons, SWL over 50tonnes: SWL + 10%. Here SWL is the Safe Working Load of derrick. 7. What are the Markings on an anchor? 1. Makers name or initials 2. Progressive no. 3. Weigh. 4. No of certificate. 5. Letters indicating the certifying authority. 8. What is choosing an anchorage? 3

4 Choosing an anchorage means choosing for suitable anchoring place. At this time, followings to be take care, Is the anchorage clear of sea traffic? Is the anchorage sheltered from the weather (wind, strong currents, etc.) and will it remain that way? What is the weather forecast? What is the bottom of sea-bed? Is it suitable with good holding for anchor? Is the tide rising or falling? 9. Draw various types of anchors. Danforth Anchor Brydon Anchor Stocked Anchor 4

5 10. Draw various types of metal blocks and identity each parts. 5

6 11. Describe various tackles (1) Gun tackle is two single-sheave blocks about 3 feet apart with the hooks or straps facing outboard. Gun tackle has a 2 to 1 mechanical advantage. (2) Luff tackle is one single- and one double-sheave block in the same manner as with the gun tackle. This tackle offers a 3 to 1 mechanical advantage. (3) Twofold purchase is two double-sheave blocks in the same manner as with the luff tackle. Twofold tackle has a 4 to 1 mechanical advantage. (4) Double luff tackle is group of a double- and a triple-sheave block. Double luff tackle has a 5 to 1 mechanical advantage. (5) Threefold purchase is two triple-sheave blocks 3 feet apart, with the hooks or straps facing outboard, positioning the blocks so one is face down and the other is cheek down. This tackle offers a 6 to 1 mechanical advantage. 6

7 12. Describe the method to measure the size of steel wire Whatever its grade, wire rope is usually measured by its diameter. Figure 6-8 shows the correct method of measuring the diameter of wire rope. 13. What are the common causes of wire rope failures? Using rope of incorrect size, construction, or grade. Allowing rope to drag over obstacles. Operating over sheaves and drums of inadequate size. Over winding or cross winding on drums. Operating over sheaves and drums that are out of alignment. Permitting rope to jump sheaves. Subjecting rope to moisture or acid fumes. Permitting rope to untwist. Using kinked rope. 14. When a wire can be rejected? A wire to be rejected, if any length of eight diameters, the total number of visible broken wires exceeds ten per cent of the total number of wires, or if the wire shows signs of excessive wear or corrosion or other serious defect. 15. Describe the fiber ropes. Fiber rope is made of either vegetable or synthetic fibers. Vegetable fibers include manila, sisal, hemp, cotton, and flax. Synthetic fibers include nylon, polyethylene, polypropylene etc. Descriptions of some types are given as below, Manila is a strong fiber that comes from the leaf stems of the abaca plant. Sisal is made from sisalana. Hemp is a tall plant that has useful fibers for making rope and cloth. 7

8 Nylon made from mineral products, which is waterproof and absorbs shocks, stretches etc. 16. What are the advantages of Synthetic rope? 1. High tensile strength. 2. Does not rot. 3. Does not kink easily. 4. Easy to handle. 5. Does not absorb water. 6. Easily float. 7. Smaller in size, than natural fiber rope of equal strength. 17,What are the disadvantages of Synthetic rope? 1. Do not have audible warning, before break. 2. Low melting point. 3. Can damage by heat and sunlight. 4. Can be effected/damaged by chemical. 5. Have a considerable force to damage if it parted. 6. Damaged, when surged and rendered on winch drum. 18. What are the advantages of Natural fiber rope? 1. Does not melt. 2. Have audible warning, before break. 3. Do not damage by moderate heat and sunlight. 4. Can be surged and rendered on winch drum. 5. Can easily spliced. 19. What are the disadvantages of Natural fiber rope? 1. Lower tensile strength. 2. Can rot. 3. Absorb water. 4. Not easily float. 5. Bigger in size, than synthetic rope of equal strength. 6. If wet, becomes hard, in a very cold weather. 7. Difficult to handle. 8

9 20. Draw all the mooring lines with berthed ship. 1. Head line, 2. Forward spring line, 3. Forward breast line, 4. Stern line, 5. Aft spring line. 6. Aft breast line. 21. What is Open moor? When a ship is anchored with both anchors leading ahead is called the ship is in Open moor. 22. What is Baltic moor? In this moor, a ship is berthed with anchor on opposite side of the berth, where the anchor is staying at the middle, but away from ship with anchor cable leading forward of ship and a wire leading aft of ship. 23. What is Mediterranean moor? In this moor, a ship is berthed at stern to the jetty with both anchors lying ahead on fine of each bow. 24. What are the methods to remove rust? 1. Manual chipping: by chipping-hammer, scupper, wire brush etc. 9

10 2. Chipping machine used onboard for quick chipping operation. 3. Water blasting: water under high pressure directed at ship s hull, used in dry deck. 4. Sand Blasting: Sand under high pressure directed at ship s hull, used in dry deck. 5. Flame (fire) used to burn rust. 5. Acid (Chemical) used to burn rust. 25. What are the painting precautions? 1. Good Surface preparation. 2. Atmosphere- temperature c and Humidity below 85%. 3. Paint not thin (light), nor thick (heavy). 4. Apply enough to cover all surfaces (paint all place equally) 5. Do not mix different packs/boxes of paint from difference manufacturers. 6. Correct paint application methods (brush, roller, spray etc). 7. Follow manufacturer s advice. 10