OFFSHORE SUPPORT VESSELS 2013

Transcription

1 RULES FOR BUILDING AND CLASSING OFFSHORE SUPPORT VESSELS 2013 NOTICE NO. 2 JULY 2013 The following Rule Changes were approved by the ABS Rules Committee on 31 May 2013 and become EFFECTIVE AS OF 1 JULY (See for the consolidated version of the Rules for Building and Classing Offshore Support Vessels 2013, with all Notices and Corrigenda incorporated.) Notes - The date in the parentheses means the date that the Rule becomes effective for new construction based on the contract date for construction, unless otherwise noted. (See 1-1-4/3.3.) PART 3 CHAPTER 3 APPENDIX 2 VESSEL SYSTEMS AND MACHINERY SUBDIVISION AND STABILITY DAMAGE STABILITY REQUIREMENTS FOR OFFSHORE SUPPLY VESSELS (Revise Subsection 3-3-A2/3, as follows:) 3 Damage Assumptions (1 July 2013) The following damage assumptions are to be applied: i) Damage is to be assumed to occur anywhere in the vessel s length between transverse watertight bulkheads. The longitudinal extent of damage is: a) For a vessel the keel of which is laid or which is at a similar stage of construction* before 22 November 2012: **) not greater than 43 m (141 ft): 10% of L f ; and ) greater than 43 m (141 ft): 3 m (10 ft) plus 3% of L f ; b) For a vessel the keel of which is laid or which is at a similar stage of construction on or after 22 November 2012: ) not greater than 43 m (141 ft): 10% of L f ; ) greater than 43 m (141 ft) and less than 80 m (262.5 ft): 3 m (10 ft) plus 3% of L f ; and ) from 80 m (262.5 ft) to 100 m (328 ft): 1/3L f 2/3 ; * A similar stage of construction means the stage at which: 1 construction identifiable with a specific ship begins; and 2 assembly of that ship has commenced comprising at least 50 tonnes (49 Long tons) or one per cent of the estimated mass of all structural material, whichever is less. ** L f is the freeboard length, as defined in 3-1-1/3.3. ABS RULES FOR BUILDING AND CLASSING OFFSHORE SUPPORT VESSELS

2 ii) iii) The vertical extent of damage is to be assumed from the underside of the cargo deck, or the continuation thereof, for the full depth of the vessel. The transverse extent of damage is: a) For a vessel the keel of which is laid or which is at a similar stage of construction before 22 November 2012: 760 mm (30 in.) measured inboard from the side of the vessel perpendicularly to the centerline at the level of the summer load waterline; b) For a vessel the keel of which is laid or which is at a similar stage of construction on or after 22 November 2012: ) less than 80 m (262.5 ft): 760 mm (30 in.); and ) from 80 m to 100 m (262.5 ft to 328 ft): B/20, but not less than 760 mm (30 in.); Notes: 1 (1 July 2013) For a vessel the keel of which is laid or which is at a similar stage of construction: 1.1 Before 22 November 2012: A transverse watertight bulkhead extending from the vessel s side to a distance inboard of 760 mm (30 in.) or more at the level of the summer load line joining longitudinal watertight bulkheads is to be considered as a transverse watertight bulkhead for the purpose of the damage calculations. 1.2 On or after 22 November 2012: For a vessel ) less than 80 m (262.5 ft), a transverse watertight bulkhead extending from the vessel s side to a distance inboard of 760 mm (30 in.) or more at the level of the summer load line joining longitudinal watertight bulkheads is to be considered as a transverse watertight bulkhead for the purpose of the damage calculations. For a vessel ) from 80 m to 100 m (262.5 ft to 328 ft), a transverse watertight bulkhead extending from the vessel s side to a distance inboard of B/20 or more but not less than 760 mm (30 in.) at the level of the summer load line joining longitudinal watertight bulkheads is to be considered as a transverse watertight bulkhead for the purpose of the damage calculations. 2 If pipes, ducts or tunnels are situated within the assumed extent of damage, arrangements are to be made to ensure that progressive flooding cannot thereby extend to compartments other than those assumed to be floodable for each case of damage. 3 If damage of a lesser extent than that specified in 3-3-A2/3i), 3-3-A2/3ii), and 3-3-A2/3iii) results in a more severe condition, such lesser extent is to be assumed. 4 Where a transverse watertight bulkhead is located within the transverse extent of assumed damage and is stepped in way of a double bottom or side tank by more than 3.05 m (10 ft), the double bottom or side tanks adjacent to the stepped portion of the transverse watertight bulkhead is to be considered as flooded simultaneously. 5 If the distance between adjacent transverse watertight bulkheads or the distance between the transverse planes passing through the nearest stepped portions of the bulkheads is less than the longitudinal extent of damage given in i), only one of these bulkheads should be regarded as effective. 6 The forecastle space need not be assumed damaged if the continuation of the cargo deck forward is capable of being secured watertight. 7 For a vessel operating in well stimulation service, the assumed damage occurs anywhere in the vessel s length at any transverse watertight bulkhead. 2 ABS RULES FOR BUILDING AND CLASSING OFFSHORE SUPPORT VESSELS. 2013

3 PART 3 CHAPTER 7 SECTION 1 HULL CONSTRUCTION AND EQUIPMENT TESTING, TRIALS AND SURVEYS DURING CONSTRUCTION HULL TANK, BULKHEAD AND RUDDER TIGHTNESS TESTING 1 General (1 July 2013) (Revise Subsection 3-7-1/1, as follows:) Test procedures are to confirm the watertightness of tanks and watertight boundaries, the structural adequacy of tanks and the weathertightness of structures/shipboard outfitting. The tightness of tanks and tight boundaries is to be confirmed by test procedures for: New ships, prior to delivery, and Structures involved in or affected by major conversions or repairs affecting structural integrity 1.1 Application All gravity tanks which are subjected to vapor pressure not greater than 0.7 bars (0.7 kgf/cm 2, 10 psi) and other boundaries required to be watertight or weathertight are to be tested in accordance with this Subsection and proven tight or structurally adequate as follows: Gravity Tanks for their structural adequacy and tightness, Watertight Boundaries Other Than Tank Boundaries for their watertightness, and Weathertight Boundaries for their weathertightness. Testing of structures not listed in 3-7-1/Table 1 and 3-7-1/Table 2 is to be specially considered. 1.3 Types and Definitions of Test Structural Testing is a test to verify the structural adequacy of the construction of the tank. This may be hydropneumatic testing or hydrostatic testing as specified in 3-7-1/5.1 and 3-7-1/ Leak Testing is a test to verify the tightness of the boundary. Unless specific testing is indicated, this may be hydrostatic/hydropneumatic testing or air testing as specified in 3-7-1/5.1, 3-7-1/5.3 and 3-7-1/5.5. Leak testing in items 14 to 17 as specified in 3-7-1/Table 1 includes hose test as an acceptable medium of the test. 3 Test Procedures 3.3 Structural Testing (1 July 2013) (Revise Paragraph 3-7-1/3.3, as follows:) Test Type and Time Where structural testing is specified by 3-7-1/Table 1 or 3-7-1/Table 2, hydrostatic testing in accordance Where structural testing is specified by 3-7-1/Table 1 or 3-7-1/Table 2, hydrostatic testing in accordance with 3-7-1/5.1 will be acceptable, except where practical limitations (strength of building berth, density of liquid, etc.) prevent it or where air testing is permitted by Note 1 to /Table 1. Hydropneumatic testing, in accordance with 3-7-1/5.3, may be approved in lieu of hydrostatic testing. Structural testing may be carried out after the vessel is launched. ABS RULES FOR BUILDING AND CLASSING OFFSHORE SUPPORT VESSELS

4 Tank boundaries are to be tested at least from one side. Tanks to be tested for structural adequacy (see Note 1 to 3-7-1/Table 1) are to be selected so that all representative structural members are tested for the expected tension and compression Number of Structural Testing i) Structural testing is to be carried out for at least one tank of the same construction (i.e. tanks of the same structural design and configuration and same general workmanship as determined by the attending Surveyor) on each vessel provided all subsequent tanks are tested for leaks by an air test. The relaxation to accept leak testing using an air test instead of a structural test does not apply to cargo space boundaries in tankers and combination carriers and tanks for segregated cargoes or pollutants. ii) iii) iv) However, where structural adequacy of a tank was verified by structural testing required in 3-7-1/Table 1, the subsequent vessels in the series (i.e. sister ships built in the same shipyard) may be exempted from such testing for other tanks which have the structural similarity to the tested tank, provided that the water-tightness in all boundaries of exempted tanks are verified by leak tests and thorough inspection. For sister ships built several years after the last ship of the series, such exemption may be reconsidered. In any case, structural testing is to be carried out for at least one tank for each vessel in order to verify structural fabrication adequacy. The relaxation to accept leak testing and thorough inspections instead of a structural test on subsequent vessels in the series does not apply to cargo space boundaries in tankers and combination carriers and tanks for segregated cargoes or pollutants. For watertight boundaries of spaces other than tanks (excluding chain lockers), structural testing may be exempted, provided that the watertightness in all boundaries of exempted spaces are verified by leak tests and thorough inspection. These subsequent tanks may require structural testing if found necessary after the structural testing of the first tank. Tanks for structural test are to be selected so that all representative structural members are tested for the expected tension and compression. (Replace existing Paragraphs 3-7-1/3.5 and 3-7-1/3.7 with the following:) 3.5 Leak Testing (1 July 2013) For leak testing specified in 3-7-1/Table 1, air testing, compressed air fillet weld testing, vacuum box testing in accordance with 3-7-1/5.5, 3-7-1/5.9, and 3-7-1/5.11, or their combination will be acceptable. Hydrostatic or hydropneumatic testing may also be accepted as leak testing provided 3-7-1/5.1 and 3-7-1/5.3 are complied with. Hose testing is applied to structures not subjected to structural or air testing but required to be watertight or weathertight as specified in 3-7-1/Table 1. For the details of hose testing, see 3-7-1/5.7. Air testing or structural testing may be accepted in lieu of hose testing. Joint air testing may be carried out in the block stage provided all work on the block that may affect the tightness of the joint is completed before the test. See also 3-7-1/7.1 for the application of final coating and 3-7-1/7.5 for safe access to the joint and their summary in 3-7-1/Table 3. 4 ABS RULES FOR BUILDING AND CLASSING OFFSHORE SUPPORT VESSELS. 2013

5 5 Details of Testing (1 July 2013) (Revise Subsection 3-7-1/5, as follows:) 5.1 Hydrostatic Testing Hydrostatic Testing is a test to verify the structural adequacy of the design and the tightness of the tank s structure by means of water pressure. Hydrostatic testing is the normal means for structural testing with exception as per 3-7-1/3.3. Hydrostatic testing is to consist of a head of water to the level specified in 3-7-1/Table 1 or 3-7-1/Table Hydropneumatic Testing Hydropneumatic Testing is a combined hydrostatic and air testing wherein a tank is filled by water with air pressure applied on top. When approved, the combined water level and air pressure used for hydropneumatic testing is to simulate the actual loading as far as practicable. The requirements and recommendations in 3-7-1/5.5 relative to air pressure will also apply. 5.5 Air Testing Air Testing is a test to verify the tightness of the structure by means of air pressure difference. All boundary welds, erection joints, and penetrations including pipe connections are to be examined in accordance with the approved procedure and under a pressure differential not less than 0.15 bar (0.15 kgf/cm 2, 2.2 psi) with a leak indicating solution. It is recommended that the air pressure in the tank be raised to and maintained at 0.20 bar (0.20 kgf/cm 2, 2.9 psi) for approximately one hour, with a minimum number of personnel around the tank, before being lowered to the test pressure. A U-tube with a height sufficient to hold a head of water corresponding to the required test pressure is to be arranged. The cross sectional area of the U-tube is to be not less than that of the pipe supplying air. In addition to the U-tube, a master gauge or other approved means is to be provided to verify the pressure. Other effective methods of air testing, including compressed air fillet weld testing or vacuum testing, may be considered in accordance with 3-7-1/ Hose Testing Hose Testing is a test to verify the tightness of the joint by a jet of water. Hose testing is to be carried out with the pressure in the hose of at least 2 bar (2 kgf/cm 2, 30 psi) during test. The nozzle is to have minimum inside diameter of 12 mm (0.5 in.) and is to be located at a distance to the joint not exceeding 1.5 m (5 ft). For structural welds, where hose testing is not practical because of possible damage to machinery, electrical equipment insulation or outfitting items, it may be replaced by a careful visual examination of welded connections, supported where necessary by means such as penetration testing, ultrasonic testing, or an equivalent. For cable penetrations, where hose testing is not practical because of possible damage to machinery, electrical equipment insulation or outfitting items, other methods of testing may be considered upon submission of full particulars to the attending Surveyor. 5.9 Compressed Air Fillet Weld Testing Compressed Air Fillet Weld Testing is an air test of a fillet welded tee joint with a leak indicating solution applied on the fillet welds. In this air testing, compressed air is injected from one end of fillet welded joint and the pressure verified at the other end of the joint by a pressure gauge on the opposite side. Pressure gauges are to be arranged so that an air pressure of at least 0.15 bar (0.15 kgf/cm 2, 2.2 psi) can be verified at each end of all passages within the portion being tested. Where a leaking test of partial penetration welding is required and the root face is sufficiently large such as 6-8 mm ( inch), the compressed air test is to be applied in the same manner as for a fillet weld. ABS RULES FOR BUILDING AND CLASSING OFFSHORE SUPPORT VESSELS

6 5.11 Vacuum Box Testing Vacuum Box Testing is a test to detect any leaks on the structure. A box over a joint with leak indicating solution applied on the fillet or full penetration welds. A vacuum is created inside the box to detect any leaks. A box (vacuum tester) with air connections, gauges and inspection window is placed over the joint with leak indicator applied. The air within the box is removed by an ejector to create a vacuum of 0.20 bar (0.20 kgf/cm 2, 2.9 psi) 0.26 bar (0.27 kgf/cm 2, 3.8 psi) inside the box Ultrasonic Testing Ultrasonic Testing is a test to verify the tightness of a sealing by means of ultrasound. An arrangement of an ultrasonic echoes transmitter placed inside a compartment and a receiver outside. A location where the sound is detectable by the receiver displays a leakage in the sealing of the compartment Penetration Testing Penetration Testing is a test to verify that no leakage exist in the boundaries of a compartment by the application of low surface tension liquids. A test of butt welds by applying a low surface tension liquid to one side of a compartment boundary. When no liquid is detected on the opposite side of the boundary after expiration of a definite time, verification of the tightness of the compartment boundary can be assumed Other Methods of Testing Other methods of testing may be considered upon submission of full particulars. 7 Application of Coating 7.1 Final Coating (1 July 2013) (Revise Paragraph 3-7-1/7.1, as follows:) Structural Testing For all weld joint types excluding butt joints by automatic process, final coating may be applied prior to the structural testing. See 3-7-1/Table Leak Testing For all manual or semi-automatic erection welds and all fillet weld tank boundary connections including penetrations, the final coating is to be applied after leak testing. For other welds, the final coating may be applied prior to leak testing provided the Surveyor, after examination prior to the application of the coating, is satisfied with the weld. The Surveyor reserves a right to require leak testing prior to the final coating of automatic erection welds and manual or automatic preerection welds. See 3-7-1/Table 3. (Add new Paragraph 3-7-1/7.5, as follows:) 7.5 Safe Access to Joints (1 July 2013) For leak testing, a safe access to all joints under examination is to be provided. See 3-7-1/Table 3. 6 ABS RULES FOR BUILDING AND CLASSING OFFSHORE SUPPORT VESSELS. 2013

7 (Replace existing 3-7-1/Table 1 with the following:) TABLE 1 Testing Requirements for Tanks and Boundaries (1 July 2013) Tank or Boundary to be Tested Test Type Test Head or Pressure Remarks 1 Double bottom tanks (4) - top of the overflow, tank (2), or - to bulkhead deck 2 Double bottom voids (5) Leak See 3-7-1/5.5, 3-7-1/.5.9, and 3-7-1/ 5.11, 3 Double side tanks 4 Double side voids Leak 5 Deep tanks other than those listed elsewhere in this table 6 Cargo oil tanks 7 Ballast hold of bulk carriers 8 Peak tanks 9 a. Fore peak voids Leak b. Aft peak voids Leak - top of the overflow, tank (2), or - to bulkhead deck See 3-7-1/5.5, 3-7-1/.5.9, and 3-7-1/ 5.11, - top of the overflow, or tank (2) - top of the overflow, tank (2), or - to top of tank (2) plus setting of any pressure relief valve - top of the overflow, or - top of cargo hatch coaming - top of the overflow, or tank (2) See 3-7-1/5.5, 3-7-1/.5.9, and 3-7-1/ 5.11, See 3-7-1/5.5, 3-7-1/.5.9, and 3-7-1/ 5.11, 10 Cofferdams Leak See 3-7-1/5.5, 3-7-1/.5.9, and 3-7-1/ 5.11, a. Watertight bulkheads Leak See 3-7-1/5.5 through 3-7-1/5.11 (7) 11 See 3-7-1/5.5 through 3-7-1/5.11 b. Superstructure end bulkhead Leak c. Cable penetrations in watertight bulkheads Hose See 3-7-1/ Watertight doors below freeboard or bulkhead deck 13 Double plate rudder blade Leak Leak (6, 8) See 3-7-1/5.5 through 3-7-1/5.11 See 3-7-1/5.5 through 3-7-1/5.11 See item 16 for hatch covers. After peak to be tested after installation of stern tube After peak to be tested after installation of stern tube See 3-2-9/9.11 of the Steel Vessel Rules for additional test at the manufacturer. ABS RULES FOR BUILDING AND CLASSING OFFSHORE SUPPORT VESSELS

8 14 Shaft tunnel clear of deep tanks Leak (3) See 3-7-1/5.5 through 3-7-1/ Shell doors Leak (3) See 3-7-1/5.5 through 3-7-1/ Weathertight hatch covers and closing appliances Leak (3, 8) See 3-7-1/5.5 through 3-7-1/ Dual purpose tank/dry cargo hatch cover Leak (3, 8) See 3-7-1/5.5 through 3-7-1/ Chain locker Structural Top of chain pipe 19 Independent tanks 20 Ballast ducts - top of the overflow, or - to 0.9 m (3 ft) above top of tank - ballast pump maximum pressure, or - setting of any pressure relief valve Hatch covers closed by tarpaulins and battens excluded In addition to structural test in item 6 or 7 Notes: 1 Provided the structural similarity of a group of tanks is recognized by ABS and a representative tank as selected by ABS is structurally tested based on the design approval, all subsequent tanks on each vessel are tested for leaks by an air testing in accordance with 3-7-1/5.5. However, where structural adequacy of a tank was verified by structural testing, the subsequent vessels of a series of identical new buildings may be exempted from such testing for other tanks which have the structural similarity to the tested tank, provided that the water-tightness in all boundaries of exempted tanks are verified by leak tests and thorough inspection are to be carried out. In any case, structural testing is to be carried out for at least one tank for each vessel in order to assure structural fabrication adequacy. These relaxations do not apply to cargo space boundaries in tankers and combination carriers and tanks for segregated cargoes or pollutants. (See 3-7-1/3.3.2i).) 2 Top of tank is deck forming the top of the tank, excluding any hatchways. 3 Hose Testing may also be considered as a medium of the test. See 3-7-1/ Including tanks arranged in accordance with the provisions of SOLAS regulation II-1/9.4 5 Including duct keels and dry compartments arranged in accordance with the provisions of SOLAS regulation II-1/9.4 6 Where water tightness of watertight door has not confirmed by prototype test, testing by filling watertight spaces with water is to be carried out. See SOLAS regulation II-1/16.2 and MSC/Circ Where a hose test is not practicable, other testing methods listed in 3-7-1/5.13 through 3-7-1/5.17 may be applicable subject to adequacy of such testing methods being verified. See SOLAS regulation II-1/ As an alternative to the hose testing, other testing methods listed in 3-7-1/5.13 through 3-7-1/5.17 may be applicable subject to adequacy of such testing methods being verified. See SOLAS regulation II-1/ ABS RULES FOR BUILDING AND CLASSING OFFSHORE SUPPORT VESSELS. 2013

9 (Revise 3-7-1/Table 2, as follows:) TABLE 2 Additional Testing Requirements for Tanks of Special Service (1 July 2013) Type of Vessels or Tanks 1 Liquefied Gas Carriers 3 Chemical Carriers Notes: Structures to be Tested Ballast or Fuel Oil Tanks adjacent to or between the Tank Holding Spaces Integral or Independent Tanks Type of Testing Structural & Leak Structural & Leak Hydrostatic Testing Head water head - to the top of overflow, or tank (1) water head tank (1), or - to top of tank (1) plus setting of any pressure relief valve 1 (1 July 2013) Top of tank is deck forming the top of the tank, excluding any hatchways. Remarks Gas such as liquefied Nitrogen Chemicals such as: Hydrochloric, Hydrofluoric and Acetic Acid etc. Butt Fillet Notes: (Add new 3-7-1/Table 3, as follows:) TABLE 3 Application of Leak Testing, Coating and Provision of Safe Access for Type of Welded Joints (1 July 2013) Type of Welded Joints Leak Testing Before Leak Testing Coating (1) Safe Access (2) After Leak Testing & Before Structural Test Leak Testing Structural Test Automatic Not required Allowed (3) N/A Not required Not required Manual or Semi-automatic (4) Required Not allowed Allowed Required Not required Boundary including Required Not allowed Allowed Required Not required penetrations 1 Coating refers to internal (tank/hold coating), where applied, and external (shell/deck) painting. It does not refer to shop primer. 2 Temporary means of access for verification of the leak testing. 3 The condition applies provided that the welds have been carefully inspected visually to the satisfaction of the Surveyor. 4 Flux Core Arc Welding (FCAW) semiautomatic butt welds need not be tested provided that careful visual inspections show continuous uniform weld profile shape, free from repairs, and the results of NDE testing show no significant defects. ABS RULES FOR BUILDING AND CLASSING OFFSHORE SUPPORT VESSELS

10 PART 4 CHAPTER 8 SECTION 4 VESSEL SYSTEMS AND MACHINERY ELECTRICAL SYSTEMS SHIPBOARD INSTALLATION AND TESTS 21 Cable Installation Deck and Bulkhead Penetrations (Revise Subparagraph 4-8-4/ , as follows:) General (1 July 2013) Where cables pass through watertight or fire-rated bulkheads or decks, the penetrations are to be made through the use of approved stuffing tubes, transit devices or pourable materials installed in accordance with manufacturer s installation procedures to maintain the watertight integrity or firerating of the bulkheads or decks. These devices or materials are not to cause damage to the cable and are to be examined and tested as specified in 3-7-1/Table 1 and 4-8-4/ Where cable conduit pipe or equivalent is carried through decks or bulkheads, arrangements are to be made to maintain the integrity of the water or gas tightness of the structure. 31 Shipboard Tests (Add new Paragraph 4-8-4/31.15, as follows:) Watertight and Fire-rated Deck and Bulkhead Cable Penetrations (1 July 2013) During installation of deck and bulkhead watertight and fire-rated cable penetrations, the attending Surveyor is to confirm that the installer is familiar with and has access to the manufacturer s installation procedures for stuffing tubes, transit devices or pourable materials. After installation, all watertight and fire-rated cable penetrations are to be visually examined. Watertight cable penetrations are to be tested as required by 3-7-1/Table ABS RULES FOR BUILDING AND CLASSING OFFSHORE SUPPORT VESSELS. 2013