1、 GUIDE FOR BUILDING AND CLASSING LIFTBOATS 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 Guide for Building and Classing Liftboats 201
2、7, 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 of the ABS Rules for Conditions of Classification Offshore Uni
3、ts and Structures (Part 1).) PART 3 HULL CONSTRUCTION AND EQUIPMENT CHAPTER 2 HULL STRUCTURES AND ARRANGEMENTS SECTION 13 RUDDERS AND STEERING EQUIPMENT 17 Double Plate Rudder (Revise Paragraph 3-2-13/17.1 and add new 3-2-13/Figures 5, 6, and 7, as follows:) 17.1 Strength (1 July 2017) The section m
4、odulus and web area of the rudder mainpiece are to be such that the stresses indicated in the following Subparagraphs are not exceeded. In calculating the section modulus of the rudder, the effective width of side plating is to be taken as not greater than twice the athwartship dimension of the rudd
5、er. Bolted cover plates on access openings to pintles are not to be considered effective in determining the section modulus of the rudder. In order for a cover plate to be considered effective, it is to be closed using a full penetration weld and confirmed suitable by non-destructive testing method.
6、 Generous radii are to be provided at abrupt changes in section where there are stress concentrations, including in way of openings and cover plates. When inspection windows are located in the panel below the rudder hub, the stress is to be as permitted in way of cutouts. Moments, shear forces and r
7、eaction forces are to be as given in 3-2-13/7.5 and 3-2-13/13.5. For spade rudders and rudders with horns, the section modulus at the bottom of the rudder is not to be less than one-third the required section modulus of the rudder at the top of the rudder or at the center of the lowest pintle. Speci
8、al attention is to be paid in design and construction of rudders with slender foil sections in the vicinity of their trailing edge (e.g., hollow foil sections, fishtail foil sections). Where the width of the rudder blade at the aftermost vertical diaphragm, w, is equal or less than 1/6of the trailin
9、g edge length measured between the diaphragm and the trailing edge, , finite element vibration analysis of the rudder blade is also to be submitted for review. See 3-2-13/Figure 5. ABSGUIDE FOR BUILDING AND CLASSING LIFTBOATS .2016 1 Notice No. 1 July 2017 FIGURE 5 (1 July 2017) wSpade rudders with
10、an embedded rudder trunk are to have a trailing edge with dimensions that satisfy the following requirements: i) For a rudder trailing edge having a monotonous transition to a rounded end with a finite thickness or diameter (see 3-2-13/Figure 6), the vortex shedding frequency calculated using the eq
11、uation given below is to be higher than 35 Hz. fs= TDUSTDt +where fs= vortex shedding frequency, in Hz U = flow velocity, in m/s (ft/s), which is taken as liftboats design speed with liftboat running ahead at the maximum continuous rated shaft rpm and at the summer load waterline St= nominal Strouha
12、l number = 0.18 D= 0.27 C = minimal chord length of rudder cross section profile, in m (ft) D = nominal boundary layer thickness at trailing edge = 0.01C T= 0.77 T = thickness or diameter of rounded end, in m (ft) FIGURE 6 (1 July 2017) Thickness or Diameter of Rounded End2 ABSGUIDE FOR BUILDING AND
13、 CLASSING LIFTBOATS .2017 Notice No. 1 July 2017 ii) For a rudder trailing edge with a flat insert plate (see 3-2-13/Figure 7), the insert plate thickness, t0, is to be no larger than 1.5Vdin mm, where Vdis the design speed in ahead condition, in knots, as defined in 3-2-13/3.1. The extension beyond
14、 the weld to rudder plate, , is to satisfy the following 3-2-13/Figure 7 and with consideration of possible local vibratory bending of the insert plate. FIGURE 7 (1 July 2017) Insert Plate Thicknesst0Rudder Plate Thicknesst1 (t0+ 2t1)Alternatively, a vibration analysis is to be carried out to confir
15、m that the natural frequency of the rudder is to be at least 20% away from the vortex shedding frequency preferably determined using either a detailed numerical analysis method such as CFD or testing for ballast and full draft at 85% and 100% Vdas defined in 3-2-13/3.1. (Renumber existing 3-2-13/Fig
16、ures 5 through 8 as 3-2-13/Figures 8 through 11.) (Revise Subparagraph 3-2-13/17.1.2, as follows:) 17.1.2 In way of Cut-outs Allowable stresses for determining the rudder strength in way of cutouts (see 3-2-13/Figure 8) are as follows: Bending stress b= K/Q N/mm2(kgf /mm2, psi) Shear stress = K/Q N/
17、mm2(kgf /mm2, psi) Equivalent stress e= 223 +b= Ke/Q N/mm2(kgf/mm2, psi) where SI units MKS units US units K75 7.65 10,900 K50 5.1 7,300 Ke100 10.2 14,500 Q = 1.0 for ordinary strength hull steel = as defined in 3-2-1/9.5 for higher strength steel plate ABSGUIDE FOR BUILDING AND CLASSING LIFTBOATS .
18、2017 3 Notice No. 1 July 2017 FIGURE 8 (2009) Z6r26r16r1r26r2XNote:r1= corner radius of rudder plate in way ofportable bolted inspection holer2= corner radius of rudder plateIn way ofcutoutsr1The mainpiece of the rudder is to be formed by the rudder side plating (but not more than the effective widt
19、h indicated above) and vertical diaphragms extending the length of the rudder or the extension of the rudder stock or a combination of both. PART 4 VESSEL SYSTEMS AND MACHINERY CHAPTER 3 PROPULSION AND MANEUVERING MACHINERY SECTION 3 STEERING GEAR 11 Steering Gear Control System 11.3 General (1 July
20、 2011) (Add new Subparagraph 4-3-3/11.3.5, as follows:) 11.3.5 System Response Under Failure (1 July 2017) The failures (as listed, but not limited to items in 4-3-3/11.9) likely to cause uncontrolled movements of rudder are to be clearly identified. In the event of detection of such failure, the ru
21、dder should stop in the current position. Alternatively, the rudder may be set to return to the midship/neutral position. Failure Mode and Effect Analysis methodology may be used to identify the failures. 11.9 Instrumentation and Alarms (Revise Subparagraph 4-3-3/11.9.7, as follows:) 11.9.7 Low Oil
22、Level Alarm (1 July 2017) A visual and audible alarm is to be given on the navigation bridge and engine room control station to indicate a low oil level in any power unit reservoir. The operation of this alarm is not to interrupt the power supply circuit. 4 ABSGUIDE FOR BUILDING AND CLASSING LIFTBOA
23、TS .2017 Notice No. 1 July 2017 (Add new Subparagraph 4-3-3/11.9.12, as follows:) 11.9.12 Earth Fault (1 July 2017) A visual and audible alarm is to be given on the navigation bridge to indicate an earth fault on AC and DC circuits (Add new Subparagraph 4-3-3/11.9.13, as follows:) 11.9.13 Deviation
24、(1 July 2017) Where arrangements discussed in 4-3-3/11.9.8, 4-3-3/11.9.9, 4-3-3/11.9.10 and 4-3-3/11.9.11 can lead to reduced or erroneous system performance of the commanded change in rudder angle, a deviation alarm visible and audible at the navigating bridge shall be initiated if the rudders actu
25、al position does not reach the set point within acceptable time limits for the closed loop control systems (e.g., follow-up control, computer based systems, and autopilot). Deviation alarm may be caused by mechanical, hydraulic or electrical failures. See 4-3-3/11.9.8, 4-3-3/11.9.9, 4-3-3/11.9.10 an
26、d 4-3-3/11.9.11 for acceptable time limits or angle deviations, as applicable. PART 4 VESSEL SYSTEMS AND MACHINERY CHAPTER 5 PUMPS AND PIPING SYSTEMS SECTION 1 GENERAL 9 General Installation Details 9.19 Flexible Hoses (2006) 9.19.3 Design and Construction (Revise Item 4-5-1/9.19.3(c), as follows:)
27、9.19.3(c) Fire Resistance (1 July 2017). Flexible hose assemblies constructed of non-metallic materials intended for installation in piping systems for flammable media and sea water systems where failure may result in flooding are to be of a fire-resistant type*, except in cases where such hoses are
28、 installed on open decks having no fire risk, and not used for fuel oil lines. Fire resistance is to be demonstrated by testing to ISO 15540 and ISO 15541. * Note: The installation of a shutoff valve immediately upstream of a sea water hose does not satisfy the requirement for fire resistant type ho
29、se. ABSGUIDE FOR BUILDING AND CLASSING LIFTBOATS .2017 5 Notice No. 1 July 2017 PART 4 MACHINERY AND SYSTEMS CHAPTER 7 ELECTRICAL INSTALLATIONS SECTION 2 SHIPBOARD SYSTEMS 7 Distribution System (Revise Paragraph 4-7-2/7.9, as follows:) 7.9 Harmonics (1 July 2017) The total harmonic distortion (THD)
30、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 document
31、ed (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 an
32、d monitoring systems are to be considered. See also 4-7-2/9.18 and 4-7-2/9.19. 9 Circuit Protection System (Add new Paragraph 4-6-2/9.18, as follows:) 9.18 Harmonic Distortion for Liftboat Electrical Distribution System including Harmonic Filters (1 July 2017) 9.18.1 Monitoring Where the electrical
33、distribution system on board a liftboat includes harmonic filters, such liftboats 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.
34、 Where the 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
35、 excluded from the requirements of this section. 9.18.2 Measurement As a minimum, harmonic distortion levels of main bus bar on board such existing liftboats are to be measured annually under seagoing conditions as close to the periodical machinery survey as possible so as to give a clear representa
36、tion of the condition 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 ca
37、n be replicated for the next periodical survey. Harmonic distortion levels are also to be measured following any modification to the liftboats electrical distribution system or associated consumers by suitably trained liftboats personnel or from a qualified outside source. Records of all the above m
38、easurements are to be made available to the surveyor at each periodical survey in accordance with the ABS Rules for Survey After Construction (Part 7). 9.18.3 Validation of Calculated Harmonic Where the electrical distribution system on board a liftboat includes harmonic filters, the system integrat
39、or of the distribution system is to show, by calculation, the 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 liftboat owner with guidance documenting permitted modes of operation of the elec
40、trical distribution system while maintaining harmonic distortion levels within acceptable limits during normal operation as well as following the failure of any combination of harmonic filters. 6 ABSGUIDE FOR BUILDING AND CLASSING LIFTBOATS .2017 Notice No. 1 July 2017 The calculation results and va
41、lidity of the guidance provided are to be verified 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
42、with individual protection of each phase. The 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
43、crew in case of current unbalance. Consideration 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
44、. (Revise first paragraph of Paragraph 4-6-2/9.19, as follows:) 9.19 Protection of Harmonic Filter Circuits (1 July 2017) Notwithstanding the requirements of 4-6-2/9.18 above, harmonic filters circuits shall be protected against overload and short-circuit. An alarm is to be initiated in a continuous
45、ly manned location in the event of an activation of overload or short-circuit protection. (Following text remains unchanged.) PART 4 VESSEL SYSTEMS AND MACHINERY CHAPTER 7 ELECTRICAL INSTALLATIONS SECTION 4 MACHINERY AND EQUIPMENT 13 Cables and Wires 13.1 Cable Construction (Revise first paragraph o
46、f Subparagraph 4-7-4/13.1.1, as follows:) 13.1.1 General (1 July 2017) Electric 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, or IEEE Std. 45. Other recognized
47、marine standards of an equivalent or higher safety level, will also be considered. 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 suc
48、h as flexible cable, fiber-optic cable, etc., used for special purposes may be accepted 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: (Following text remains unchanged.) ABSGUIDE FOR BUILDING AND CLASSING LIFTBOATS .2017 7
