1、 RULES FOR BUILDING AND CLASSING MOBILE OFFSHORE DRILLING UNITS 2017 NOTICE NO. 1 JULY 2017 The following Rule Changes were approved by the ABS Rules Committee on 30 May 2017 and become EFFECTIVE AS OF 1 JULY 2017. (See http:/www.eagle.org for the consolidated version of the Rules for Building and C
2、lassing Mobile Offshore Drilling Units 2017, 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. (See 1-1-4/3.3 of the ABS Rules for Conditions of Classific
3、ation Offshore Units and Structures (Part 1).) PART 3 HULL CONSTRUCTION AND EQUIPMENT CHAPTER 2 HULL STRUCTURES AND ARRANGEMENTS SECTION 1 STRUCTURAL ANALYSIS 1 Structural Analysis (Add new first paragraph in Subsection 3-2-1/1, as follows:) (1 July 2017) The structural design criteria specified in
4、this Chapter is presented in the Working Stress Design (WSD) format, also known as the Allowable Stress (or Strength) Design (ASD) format. Alternative structural design criteria for self-elevating drilling units and column-stabilized drilling units in a Load and Resistance Factor Design (LRFD) forma
5、t are provided in the ABS Guide for Load and Resistance Factor Design (LRFD) Criteria for Offshore Structures. In general, WSD and LRFD criteria are not to be mixed within the analysis. PART 4 MACHINERY AND SYSTEMS CHAPTER 2 PUMPS AND PIPING SYSTEMS SECTION 1 GENERAL 11 General Installation Details
6、11.29 Flexible Hoses (1 July 2017) Flexible hoses are to comply with the requirements of 4-6-2/5.7 of the Steel Vessel Rules. Hose connections utilized in cooling systems for engines with cylinder bores equal to or less than 300 mm (12 in.) will be subject to special consideration. ABSRULES FOR BUIL
7、DING AND CLASSING MOBILE OFFSHORE DRILLING UNITS .2017 1 Notice No. 1 July 2017 PART 4 MACHINERY AND SYSTEMS CHAPTER 3 ELECTRICAL INSTALLATIONS SECTION 2 ELECTRICAL SYSTEMS 7 Distribution System (Revise Paragraph 4-3-2/7.9, as follows:) 7.9 Harmonics (1 July 2017) The total harmonic distortion (THD)
8、 in the voltage waveform in the distribution systems is not to exceed 8% and any single order harmonics not to exceed 5%. Other higher values may be accepted provided the distribution equipment and consumers are designed to operate at the higher limits. This relaxation on THD limits is to be documen
9、ted (harmonic distortion calculation report) and made available on board as a reference for the Surveyor at each periodical survey. Where higher values of harmonic distortion are expected, any other possible effects, such as additional heat losses in machines, network resonances, errors in control a
10、nd monitoring systems are to be considered. See also 4-3-2/9.18 and 4-3-2/9.19. 9 Circuit Protection System (Add new Paragraph 4-3-2/9.18, as follows:) 9.18 Harmonic Distortion for Unit Electrical Distribution System including Harmonic Filters (1 July 2017) 9.18.1 Monitoring Where the electrical dis
11、tribution system on board a unit includes harmonic filters, such units are to be fitted with facilities to continuously monitor the levels of harmonic distortion experienced on the main bus bar as well as alert the crew should the level of harmonic distortion exceed the acceptable limits. Where the
12、engine room is provided with automation systems, this reading is to be logged electronically, otherwise it is to be recorded in the engine log book for future inspection by the Surveyor. However, harmonic filters installed for single application frequency drives such as pump motors may be excluded f
13、rom the requirements of this section. 9.18.2 Measurement As a minimum, harmonic distortion levels of main bus bar on board such existing ships are to be measured annually under seagoing conditions as close to the periodical machinery survey as possible so as to give a clear representation of the con
14、dition of the entire plant to the Surveyor. Harmonic distortion readings are to be carried out when the greatest amount of distortion is indicated by the measuring equipment. An entry showing which equipment was running and/or filters in service is to be recorded in the log so this can be replicated
15、 for the next periodical survey. Harmonic distortion levels are also to be measured following any modification to the ships electrical distribution system or associated consumers by suitably trained ships personnel or from a qualified outside source. Records of all the above measurements are to be m
16、ade available to the surveyor at each periodical survey in accordance with Part 7 of the Rules. 9.18.3 Validation of Calculated Harmonic Where the electrical distribution system on board a unit includes harmonic filters, the system integrator of the distribution system is to show, by calculation, th
17、e effect of a failure of a harmonic filter on the level of harmonic distortion experienced. The system integrator of the distribution system is to provide the unit owner with guidance documenting permitted modes of operation of the electrical distribution system while maintaining harmonic distortion
18、 levels within acceptable limits during normal operation as well as following the failure of any combination of harmonic filters. 2 ABSRULES FOR BUILDING AND CLASSING MOBILE OFFSHORE DRILLING UNITS .2017 Notice No. 1 July 2017 The calculation results and validity of the guidance provided are to be v
19、erified by the Surveyor during sea trials. 9.18.4 Filter Protection Alarm Arrangements are to be provided to alert the crew in the event of activation of the protection of a harmonic filter circuit. A harmonic filter is to be arranged as a three-phase unit with individual protection of each phase. T
20、he activation of the protection arrangement in a single phase is to result in automatic disconnection of the complete filter. Additionally, there is to be installed a current unbalance detection system independent of the overcurrent protection alerting the crew in case of current unbalance. Consider
21、ation is to be given to additional protection for the individual capacitor element as (e.g., relief valve or overpressure disconnector) in order to protect against damage from rupturing. This consideration is to take into account the type of capacitors used. (Revise first paragraph of Paragraph 4-3-
22、2/9.19, as follows:) 9.19 Protection of Harmonic Filter Circuits (1 July 2017) Notwithstanding the requirements of 4-3-2/9.18 above, harmonic filters circuits shall be protected against overload and short-circuit. An alarm is to be initiated in a continuously manned location in the event of an activ
23、ation of overload or short-circuit protection. (Following text remains unchanged.) PART 4 MACHINERY AND SYSTEMS CHAPTER 3 ELECTRICAL INSTALLATIONS SECTION 3 ONBOARD INSTALLATION 7 Cables and Wires 7.1 Cable Construction (Revise Subparagraph 4-3-3/7.1.1, as follows:) 7.1.1 General (1 July 2017) Elect
24、ric cables are to have conductors, insulation and moisture-resistant jackets in accordance with IEC Publication 60092-350, 60092-352, 60092-353, 60092-354, 60092-360, 60092-370, 60092-376, IEEE Std-45. Other recognized marine standards of an equivalent or higher safety level, will also be considered
25、. The tests may be carried out by the manufacturer whose certificate of tests will be acceptable and is to be submitted upon request from ABS. Network cables are to comply with a recognized industry standard. Cables such as flexible cable, fiber-optic cable, etc. used for special purposes may be acc
26、epted provided they are manufactured and tested in accordance with recognized standards accepted by ABS. Conductors are to be of copper and stranded in all sizes. Conductors are not to be less than the following in cross sectional size: ABSRULES FOR BUILDING AND CLASSING MOBILE OFFSHORE DRILLING UNI
27、TS .2017 3 Notice No. 1 July 2017 PART 7 SURVEYS CHAPTER 2 SURVEYS AFTER CONSTRUCTION SECTION 1 CONDITIONS FOR SURVEYS AFTER CONSTRUCTION 7 Damage, Failure and Repair (1996) (Add new Paragraph 7-2-1/7.9, as follows:) 7.9 Prompt and Thorough Repairs (1 July 2017) Notwithstanding 7-2-1/7.1 and 7-2-1/7
28、.3, any damage in association with wastage over the allowable limits (including buckling, detachment or fracture), or extensive areas of wastage over the allowable limits, which affects or may affect the units structural, watertight or weathertight integrity, is to be promptly and thoroughly repaire
29、d. Areas to be considered include: Side shell frames, their end attachments and adjacent shell plating Deck structure and deck plating Bottom structure and bottom plating Inner bottom structure and inner bottom plating Watertight and oil tight bulkheads Hatch covers and hatch coamings, where fitted
30、Weld connection between air pipes and deck plating Air pipe heads installed on the exposed decks Ventilators including closing devices, if any Bunker and vent piping systems Legs, spud can and mat connections Jackhouse/Jackcase to deck connections Columns pontoons and bracings, including their conne
31、ctions Any Special Application Structure For instances where the unit is currently on location and drilling, special consideration may be given to allow the unit to carry out repairs on site. When this is allowed the Owner is to submit a repair plan that includes a time line for completion of the re
32、pairs and where necessary an Engineering Analysis and/or changes to the approved operating mode to justify continued operation. Additionally, when a survey results in the identification of structural defects or corrosion, either of which, in the opinion of the Surveyor, will impair the units fitness
33、 for continued service, remedial measures are to be implemented before the unit continues in service. Where damage found on structure is isolated and of a localized nature which does not affect the units structural integrity, consideration may be given by the Surveyor to allow an appropriate tempora
34、ry repair to restore watertight or weather tight integrity and impose a Recommendation with a specific time limit. 4 ABSRULES FOR BUILDING AND CLASSING MOBILE OFFSHORE DRILLING UNITS .2017 Notice No. 1 July 2017 PART 7 SURVEYS CHAPTER 2 SURVEYS AFTER CONSTRUCTION SECTION 5 SPECIAL PERIODICAL SURVEYS
35、 13 Special Periodical Survey Special Features (All Types) (2010) (Revise Paragraph 7-2-5/13.15, as follows:) 13.15 Self-Elevating Drilling Units Leg Jacking Systems (1 July 2017) On self-elevating type drilling units, the following components of leg jacking and rack fixation systems are to be exami
36、ned and reported on. Pinions, gears, bearings and brakes throughout the climbing pinion gear train of rack and pinion systems Racks, chocks and positioning equipment of leg rack fixation systems Leg pins, yokes and associated components of moving yoke type jacking systems The extent of the examinati
37、on is to consider the age of the unit, the records of previous examinations, and the usage of the jacking system. For detailed requirements of rack and pinion systems, refer to the ABS Guide for Survey and Inspection of Jacking Systems. At Special Survey No. 1, the items listed above are to be exami
38、ned as far as practicable to the Surveyors satisfaction. If considered necessary, any items in question are to be examined by an effective crack detection method. At Special Periodical Survey No. 2 and subsequent Special Periodical Surveys, the leg jacking system is to be examined in the presence of
39、 the Surveyor by the original equipment manufacturer or other third party inspector mutually agreeable to the owner and the Surveyor. 15 Thrusters and Dynamic Position Systems (2016) 15.3 Units Classed with DPS-1, DPS-2, or DPS-3 Notations (Revise Subparagraph 7-2-5/15.3.1, as follows:) 15.3.1 DP Th
40、rusters (1 July 2017) On units with a DP system, component parts of oil-lubricated thrusters are to be opened for examination at least every five years. Internal examination of oil-lubricated thrusters may be specially considered by the Surveyor if the thrusters are maintained under an ABS approved
41、Condition Monitoring (CM) plan and results recorded have proven satisfactory performance. As a minimum, CM plan is to include daily unit observations; periodic lubrication oil sampling; and periodic vibration analysis or alternative dynamic analysis technique as described in the ABS Guidance Notes o
42、n Equipment Condition Monitoring Techniques. Where the thrusters are maintained under an ABS approved CM plan, the frequency for opening up thrusters for internal examination may be longer than five years, provided this is indicated in the CM plan. No Preventative Maintenance Program with CM superse
43、des the judgment of the Surveyor nor does the Program waive the attendance for damage, overhaul, functional testing or verification of safety devices as required by Appendix 7-2-A4. ABSRULES FOR BUILDING AND CLASSING MOBILE OFFSHORE DRILLING UNITS .2017 5 Notice No. 1 July 2017 PART 7 SURVEYS CHAPTE
44、R 2 SURVEYS AFTER CONSTRUCTION SECTION 6 DRYDOCKING SURVEYS OR EQUIVALENT 1 Parts to be Examined 1.5 Self-Elevating Units (2017) (Revise fourth paragraph and Item i) of Paragraph 7-2-6/1.5, as follows:) (1 July 2017) The following is an outline of some of the areas that will be subjected to close vi
45、sual examination and extensive NDE at each Drydocking Survey/UWILD not associated with Special Surveys: i) Leg-to-spudcan connections (1 July 2017) Units with a low operational risk qualify for the following examination regime: Units less than five years old require no NDE of the spud can or leg con
46、nections. Units with low operational risks require designated areas of the leg to can connections to be cleaned to the extent necessary to conduct a General Visual Examination and confirm that there are no visual indications. Age of the Unit Number of Spudcan(s) to be Examined Up to 10 Years 1 11 to
47、 15 Years 2 16 to 20 Years 3 21 and above All Low operational risk factors are considered to be as noted below: a) No history of eccentric spud can loading or scour since last spud can examination associated with Special Survey b) Rig/Unit designs that meet the 2008 and newer MODU Rules for spud can
48、 design. c) Operational history of unit is clear of structural indications d) No substantial corrosion in the spud can and leg connections A UWILD request submitted for a vessel with low operational risk shall include confirmation of the risk factors above, and include the extent of cleaning and exa
49、mination proposed. 6 ABSRULES FOR BUILDING AND CLASSING MOBILE OFFSHORE DRILLING UNITS .2017 Notice No. 1 July 2017 PART 7 SURVEYS CHAPTER 2 SURVEYS AFTER CONSTRUCTION APPENDIX 2 SURVEY OF PORTABLE MODULES (Revise Subsection 7-2-A2/3, as follows:) 3 Survey of Portable Accommodation Modules (1 July 2017) The Survey of portable accommodation modules is to be carried out in accordance with Section 5 of the ABS Guide for Portable Accommodation Modules to verify satisfactory condition of the structure, piping, electrical, fire-fightin
