International convention on load lines 1968 group 2

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International convention on load lines 1968 group 2

  1. 1. INTERNATIONAL CONVENTION ON LOAD LINES 1968 SHIP CONSTRUCTIONS D1MC 34 / GROUP 2 Lecturer : Capt. Siva Vivekanandan Prepared By: 1. Muhammad Fauzee Bin Abd Rahman / D1MC 461 2. Md Mizanur Rahman Parvez / D1MC 468
  2. 2. • The first international agreement for universal application of load line regulations and applied to seagoing ships in international trade and • was based on the principle of reserve buoyancy, although it was recognized then that the freeboard should also ensure adequate stability and avoid excessive stress on the ship's hull as a result of overloading. Introduction and history 1930 Load Line Convention
  3. 3. • The 1930 load Line Convention was an important step in establishing universally applicable rules. • the decades following the adoption of the 1930 Convention saw developments in ship design and methods of construction which began to make the Convention rules look outdated: ships, tankers, grew in size; specialized ship designs to meet different trades; machinery spaces in dry cargo ships being located away from the traditional midships; metal hatchway covers were replacing wooden ones; and welding was replacing riveting. Introduction and history 1930 Load Line Convention
  4. 4. • was held at IMO headquarters in London from 3 March to 5 April 1966 and was attended by delegations from 52 States and observers from 8 States was adopted on 5 April 1966 and entered into force on 21 July 1968. • The terms of the convention stated it would enter into force 12 months after at least 15 countries, 7 of which possessed not less than one million gross tons of shipping had accepted it. These conditions were met in a short time - one reason being that the Convention provided for a general reduction in freeboard allowance for most ships compared to the 1930 Convention. Introduction and history 1968 Load Line Convention
  5. 5. • The 1966 conference agreed that the revision of the 1930 Load Line convention required re- examination of a number of issues, including: • prevention of the entry of water into the hull; • adequate reserve buoyancy; protection of the crew; • adequate structural strength of the hull; •and limitation of water on the deck. Introduction and history 1968 Load Line Convention
  6. 6.  The minimum freeboard was designed to provide a standard of "reserve buoyancy", while the protection of openings in the hull and superstructures, such as hatches, ventilators, air pipes, scuppers, overhead discharges and the access openings in the end bulkhead of superstructures were an important consideration in the assignment of freeboard. Another major concern was protection to the crew by consideration of the strength of gangways, guard rails, lifelines etc.
  7. 7. Load Lines Convention sets out rules for calculation and assignment of freeboard and takes into account the potential hazards present in different zones and different seasons. The technical annex contains several additional safety measures concerning doors, freeing ports, hatchways and other items. Introduction and history 1968 Load Line Convention
  8. 8. The main purpose of these measures is to ensure the watertight integrity of ships' hulls below the freeboard deck. All assigned load lines must be marked amidships on each side of the ship, together with the deck line. Ships intended for the carriage of timber deck cargo are assigned a smaller freeboard as the deck cargo provides protection against the impact of waves. Introduction and history 1968 Load Line Convention
  9. 9. 1966 Load Line Convention The 1966 Convention is made up of: • Articles - cover matters of contract between governments, survey and certification. • Annex I - Regulations for determining load lines, is divided into four chapters. • Chapter I - General -for example, strength of hull, types of ships, definitions, markings. • Chapter II - Conditions of assignment of freeboard;
  10. 10. 1966 Load Line Convention The 1966 Convention is made up of: • Chapter III - Freeboards - evaluation of freeboard in terms of geometrical and physical characteristics of any ship. • Chapter IV - Special requirements for ships assigned timer freeboards. • Annex II defines zones, areas and seasonal periods appropriate to the various load line markings. • Annex III prescribes the form and scope of certificates, including the International Load Line Certificate and the International Load Line Exemption Certificate
  11. 11. Considerations for calculating a ship's freeboard Freeboard The distance between the top of the hull and the waterline. As the ship is loaded, it sinks deeper into the water so the freeboard is reduced. The positioning of the load line mark is aimed at ensuring the freeboard is the minimum necessary for the safety of the ship. Keel Statutory Freeboard Statutory Draught Moulded Depth Extreme Freeboard Extreme Depth Extreme Draught
  12. 12. Structural Strength The deeper the draft of a ship (the amount of the ship that is underwater), the greater are the loads imposed on the ship's structure. So a ship with a deeper draught requires a higher freeboard.
  13. 13. Deck Height Platform height (the height of the weather deck above the waterline) is a measure of how the vessel may be affected by seas which sweep across the deck.
  14. 14. Transverse Stability While freeboard does not directly determine the side to side stability of a ship, higher freeboard will allow a ship to roll further before submerging the deck.
  15. 15. Hull Form Sheer describes the curve between bow and stern. A ship with high freeboard at the bows and stern compared to midships (where freeboard is measured) has more reserve buoyancy.
  16. 16. Fullness The underwater shape of a hull. A rectangular cross section as on a tanker, is described as "full" and has less reserve buoyancy with the same freeboard than a more rounded hull like that of tugboat or liner.
  17. 17. Length A long ship, with only a few feet of freeboard, has less reserve buoyancy than a shorter ship with the same freeboard.
  18. 18. Type of Vessel and Cargo Tankers and timber carrying ships with buoyant cargoes require less freeboard than a passenger liner or containership.
  19. 19. Season and Zone Weather conditions normally encountered along a ship's trade route effects its seaworthiness. Ships sailing the North Atlantic in Winter are exposed to much more severe conditions than one sailing around the South Seas.
  20. 20. LTF - Lumber, Tropical Fresh - This is the draft to which the vessel can load when carrying lumber in the Tropical Fresh designated zone. LF - Lumber, Fresh - This is the draft to which the vessel can load when carrying lumber in the Fresh designated zone. LT - Lumber, Tropical - This is the draft to which the vessel can load when carrying lumber in the Tropical designated zone. LS - Lumber, Summer - This is the draft to which the vessel can load when carrying lumber in the Summer designated zone.
  21. 21. LW - Lumber, Winter - This is the draft to which the vessel can load when carrying lumber in the Winter designated zone. LWNA - Lumber, Winter, North Atlantic - This is the draft to which the vessel can load when carrying lumber in the Winter North Atlantic designated zone. F - Fresh - This is the draft to which the vessel can load when not carrying lumber in the Fresh designated zone. TF - Tropical, Fresh - This is the draft to which the vessel can load when not carrying lumber in the Tropical Fresh designated zone
  22. 22. F - Fresh - This is the draft to which the vessel can load when not carrying lumber in the Fresh designated zone T - Tropical - This is the draft to which the vessel can load when not carrying lumber in the Tropical designated zone S - Summer - This is the draft to which the vessel can load when not carrying lumber in the Summer designated zone W - Winter- This is the draft to which the vessel can load when not carrying lumber in the Winter designated zone
  23. 23. WNA - Winter, North Atlantic - This is the draft to which the vessel can load when not carrying lumber in the Winter North Atlantic designated zone LR - Lloyds Register - The initals of the Classification Society which assigns the marks. Other possible Initials are: BV - Bureau Veritas, GL - Germanischer Lloyd, AB - American Bureau of Shipping, and so on.
  24. 24. Amendments 1971, 1975, 1979, 1983 The 1966 Convention provided for amendments to be made by positive acceptance. Amendments could be considered by the Maritime Safety Committee, the IMO Assembly or by a Conference of Governments. Amendments would then only come into force 12 months after being accepted by two-thirds of Contracting Parties. In practice, amendments adopted between 1971 and 1983 never received enough acceptances to enter into force. These included: · the 1971 amendments - to make certain improvements to the text and to the chart of zones and seasonal areas;
  25. 25. · THE 1975 AMENDMENTS - TO INTRODUCE THE PRINCIPLE OF 'TACIT ACCEPTANCE' INTO THE CONVENTION; · THE 1979 AMENDMENTS - TO MAKE SOME ALTERATIONS TO ZONE BOUNDARIES OFF THE COAST OF AUSTRALIA; AND · THE 1983 AMENDMENTS - TO EXTEND THE SUMMER AND TROPICAL ZONES SOUTHWARD OFF THE COAST OF CHILE.
  26. 26. The 1995 amendments Adopted: 23 November 1995 Entry into force: 12 months after being accepted by two-thirds of Contracting Governments. Status: superseded by 2003 amendments The 2003 amendments Adopted: June 2003 Entry into force: 1 January 2005
  27. 27. The amendments to Annex B to the 1988 Load Lines Protocol include a number of important revisions, in particular to regulations concerning: strength and intact stability of ships; definitions; superstructure and bulkheads; doors; position of hatchways, doorways and ventilators; hatchway coamings; hatch covers; machinery space openings; miscellaneous openings in freeboard and superstructure decks; cargo ports and other similar openings; spurling pipes and cable lockers; side scuttles; windows and skylights; calculation of freeing ports; protection of the crew and means of safe passage for crew; calculation of freeboard; sheer; minimum bow height and reserve buoyancy; and others.
  28. 28. Regulation 27 Types of ships (1) For the purposes of freeboard computation ships shall be divided into Type "A" and Type "B". Type "A" ships (2) A Type "A" ship is one which is designed to carry only liquid cargoes in bulk, and in which cargo tanks have only small access openings closed by watertight gasketed covers of steel or equivalent material. Such a ship necessarily has the following inherent features: (a) high integrity of the exposed deck; and (b) high degree of safety against flooding, resulting from the low permeability of loaded cargo spaces and the degree of subdivision usually provided.
  29. 29. (3) A Type "A" ship, if over 150 metres (492 feet) in length, and designed to have empty compartments when loaded to its summer load waterline, shall be able to withstand the flooding of any one of these empty compartments at an assumed permeability of 0.95, and remain afloat in a condition of equilibrium considered to be satisfactory by the Administration. In such a ship, if over 225 metres (738 feet) in length, the machinery space shall be treated as a floodable compartment but with a permeability of 0.85.
  30. 30. Type "B" ships (5) All ships which do not come within the provisions regarding Type "A" ships in paragraphs (2) and (3) of this Regulation shall be considered as Type "B" ships.

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