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Role of Classification Societies in maintaining cargo ships seaworthiness

A cargo shipper and the underwriter requested to insure a maritime risk require some assurance that any particular vessel is structurally fit to undertake a proposed voyage. To enable the shipper and underwriter to distinguish the good risk from the bad a system of classification has been formulated over a period of some two hundred years. During this period reliable organizations have been created for the initial and continuing inspection of ships so that classification may be assessed and maintained. The principal maritime nations have the following classification societies:

Great Britain—Lloyd’s Register of Shipping
France—Bureau Veritas
Germany—Germanischer Lloyd
Norway—Det Norske Veritas
Italy—Registro Italiano Navale
United States of America—American Bureau of Shipping
Russia—Russian Register of Shipping
Japan—Nippon Kaiji Kyokai

These classification societies publish rules and regulations which are principally concerned with the strength of the ship, the provision of adequate equipment, and the reliability of the machinery. Ships may be built in any country to a particular classification society’s rules, and they are not restricted to classification by the relevant society of the country where they are built. Classification is not compulsory but the shipowner with an unclassed ship will be required to satisfy governmental regulating bodies that it has sufficient structural strength for assignment of a load line and issue of a safety construction certificate.

Steel ships built in accordance with classification societies rules or equivalent standards, are assigned a class in their Register Book, and continue to be classed so long as they are maintained in accordance with the Rules.

Developing Structural Design Programs for use by shipyards

In recent years the principal classification societies have developed software packages for use by shipyards which incorporate dynamic-based criteria for the scantlings, structural arrangements and details of ship structures. This was a response to a perception that the traditional semiempirical published classification rules based on experience could be inadequate for new and larger vessel trends.

The computer programs made available to shipyards incorporate a realistic representation of the dynamic loads likely to be experienced by the ship and are used to determine the scantlings and investigate the structural responses of critical areas of the ship’s structure. They include a program for fatigue design assessment (FDA) which is commonly used to assess the structural design detail of large container ships, tankers and bulk carriers. Evaluation of the structural design by means of these programs can result in the ship being assigned further relevant notations.

42 Ships Detained Due To Structural Safety, Load Lines Deficiencies

The Concentrated Inspection Campaign (CIC) on Structural Safety and the International Convention on Load Lines on Tuesday issued preliminary results carried out in the Paris MoU region between September 1, 2011 and November 30, 2011. The results show - 42 ships were detained as a direct result of the CIC for deficiencies related to structural safety and load lines in the Paris MoU region. Problem areas included stability, strength and loading information, ballast and fuel tanks and water and weather tight conditions.

The CIC questionnaire was completed during 4,386 inspections on 4,250 individual ships. A total of 1,589 CIC-related deficiencies were recorded and 42 ships (1%) were detained for CIC-related deficiencies.

During the campaign most inspections concerned general cargo/multi-purpose ships with 1,563 (36%) inspections, followed by bulk carriers with 795 (18%) inspections, container ships with 495 (11%) inspections, chemical tankers with 433 (10%) inspections and oil tankers with 296 (7%) inspections. 24 (60%) ships, detained for CIC-related deficiencies, were general cargo/multipurpose ships and 5 (12%) were bulk carriers. Among the other detained ships were two container vessels, two offshore supply ships, two passenger ships and two refrigerated cargo ships. 31% of the detained ships were 30 years or older.

Analysis of the recorded deficiencies shows that most deficiencies relate to the freeboard marks (12%), ventilators, air pipes and casings (7%), stability/strength/loading information and instruments (7%) and ballast, fuel and other tanks (5%).

More on general cargo ship :
  1. Rope handling safe procedure

  2. Ropes are made of short fibres that are spun into yarns, which are then made into flat or twisted strands. And the strands are spun or braided to make the finished rope .
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  3. Synthetic man-made ropes and hawsers

  4. Although natural fibre ropes are still widely used throughout the marine industry, they have been superseded by synthetic fibres for a great many purposes. Not only do the majority of synthetic ropes have greater strength than their natural fibre counterparts, but they are more easily obtainable and at present considerably cheaper.
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  5. Natural fibre rope

  6. All natural fibre rope is manufactured from manilla, sisal, hemp, coir, cotton or flax fibres.The process of manufacture consists of twisting the fibres into yarns and turning the yarns in an opposite direction to establish the strands.
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  7. Lay of Ropes and hawsers - Small Stuff descriptions

  8. The lay of rope is a term used to describe the nature of the twist that produces the complete rope .The most common form of rope at sea is known as ‘hawser laid rope’ comprising three strands laid up right- or lefthanded.
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  9. Stresses in ship structures and how to mitigate

  10. Heavy weights tend to cause a downward deflection of the deck area supporting the load .This subsequently produces stresses, with consequent inward and outward deflections of supporting bulkheads, depending on the position of initial loading .
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  11. Anchoring safe practice

  12. Prior approaching an area for anchoring ships master should investigate fully a suitable anchoring position and conduct a planned approach including speed reduction in ample time and orienting the ships head prior anchoring to same as similar sized vessels around or stem the tide or wind whichever is stronger . Final decision to be made on method of anchoring to be used , the number of shackles , the depth of water, expected weather and holding ground. .
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  13. MacGregor single-pull weather-deck hatch cover

  14. Hatch covers are used to close off the hatch opening and make it watertight. Wooden hatch covers, consisting of beams and boards over the opening and covered with tarpaulins, were once used but are no longer fitted. Steel hatch covers, comprising a number of linked steel covers, are now fitted universally. Various designs exist for particular applications, but most offer simple and quick opening and closing, which speed up the cargo handling operation..
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  15. Cargo holds access arrangement

  16. The access shall be separate from the hatchway opening, and shall be by a stairway if possible. A fixed ladder, or a line of fixed rungs, shall have no point where they fill a reverse slope .
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  17. Prepare cargo holds prior loading

  18. Washing is always carried out after the compartment has been swept. Drying time for washed compartments must be allowed for, before loading the next cargo; this time will vary with the climate, but two to three days must be expected.
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  19. Strength and stability of the Lifting appliances

  20. The vessel's structure, crane, derrick or other lifting device and the supporting structure should be of sufficient strength to withstand the loads that will be imposed when operating at its maximum load moment .
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  21. Lifting appliances - Maintenance, testing, controls & safety measures

  22. When there is any suspicion that any appliance or item of equipment may have been subjected to excessive loads, exceeding the Safe Working Load (SWL), or subjected to treatment likely to cause damage, it should be taken out of service until it can be subjected to a thorough examination by a competent person.
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  23. Safe operation of Lifting appliances and gears

  24. All lifting operations must be properly planned, appropriately supervised and carried out to protect the safety of workers.
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  25. Derricks for lifting cargo on board

  26. Derricks for lifting cargo on board is required to be of adequate strength and stability for each load, having regard in particular to the stress induced at its mounting or fixing points , securely anchored, adequately ballasted or counterbalanced and supported by outriggers as necessary to ensure its stability when lifting.
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  27. Deck cranes

  28. Deck cranes have a number of advantages, the rigging time being negligible, and the crane is able to pick up and land permitted loads anywhere within its working radius. The safe working loads of cranes is generally of the order of 10 to 15 tonnes and larger cranes are available capable of lifts from 30 to 40 tonnes..
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  29. Characteristics of Marine paints

  30. Paint consists of pigment dispersed in a liquid referred to as the ‘vehicle’. When spread out thinly the vehicle changes in time to an adherent dry film. The drying may take place through one of the following processes..
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  31. Protection by Means of Paints

  32. It is often assumed that all paint coatings prevent attack on the metal covered simply by excluding the corrosive agency, whether air or water. This is often the main and sometimes the only form of protection; however there are many paints which afford protection even though they present a porous surface or contain various discontinuities. .
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  33. Role classification societies maintaining seaworthiness of vessels

  34. classification societies publish rules and regulations which are principally concerned with the strength of the ship, the provision of adequate equipment, and the reliability of the machinery .
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  35. Periodic survey requirement by classification societies

  36. To maintain the assigned class all steel ships are required to be surveyed and examined by the Society’s surveyors at regular periods. The major hull items to be examined at these surveys only are discussed here..
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