1、 RULES FOR BUILDING AND CLASSING OFFSHORE SUPPORT VESSELS 2016 NOTICE NO. 1 JULY 2016 The following Rule Changes were approved by the ABS Rules Committee on 23 May 2016 and become EFFECTIVE AS OF 1 JULY 2016. (See http:/www.eagle.org for the consolidated version of the Rules for Building and Classin
2、g Offshore Support Vessels 2016, 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 HULL CONSTRUCTION AND E
3、QUIPMENT CHAPTER 2 HULL STRUCTURES AND ARRANGEMENTS SECTION 13 STEMS, STERN FRAMES, RUDDER HORNS, AND PROPELLER NOZZLES 5 Rudder Horns (Add new Paragraphs 3-2-13/5.5 and 3-2-13/5.7, as follows:) 5.5 Rudder Horn Plating (1 July 2016) The thickness of the rudder horn side plating is not to be less tha
4、n: t = 2.4 Lk mm t = 0.522 Lk in. where L = length of vessel, as defined in 3-1-1/3.1 k = K as defined in 3-2-14/1.3 for castings = 1.0 for ordinary strength hull steel plate = Q as defined in 3-2-1/5.5 for higher strength steel plate 5.7 Welding and Connection to Hull Structure (1 July 2016) The fo
5、llowing requirements are to apply: i) The rudder horn plating is to be effectively connected to the aft ship structure (e.g., by connecting the plating to side shell and transverse/longitudinal girders) in order to achieve a proper transmission of forces, see 3-2-13/Figure 4. When the connection bet
6、ween the rudder horn and the hull structure is designed as a curved transition into the hull plating, special consideration should be given to the effectiveness of the rudder horn plate in bending and to the stresses in the transverse web plates ii) Where the rudder horn does not have curved transit
7、ions into the shell plating, brackets or stringer are to be fitted internally in horn, in line with outside shell plate, as shown in 3-2-13/Figure 4. ABSRULES FOR BUILDING AND CLASSING OFFSHORE SUPPORT VESSELS .2016 1 Notice No. 1 July 2016 iii) Transverse webs of the rudder horn are to be led into
8、the hull up to the next deck or flat in a sufficient number. iv) Strengthened plate floors are to be fitted in line with the transverse webs in order to achieve a sufficient connection with the hull. v) Where a centerline bulkhead (wash-bulkhead) is fitted in the after peak, it is to be connected to
9、 the rudder horn. vi) Scallops are to be avoided in way of the connection between shell plating and transverse webs in line with the aft face of the rudder horn and the webs in the rudder horn. vii) The weld at the connection between the rudder horn plating and the side shell is to be full penetrati
10、on. The welding radius is to be as large as practicable and may be obtained by grinding. (Renumber Paragraphs 3-2-13/5.5 through 3-2-13/5.9 as 3-2-13/5.9 through 3-2-13/5.13.) (Add new 3-2-13/Figure 4, as follows:) FIGURE 4 Connection of Rudder Horn to Aft Ship Structure (1 July 2016) (Renumber exis
11、ting 3-2-13/Figure 4 as 3-2-13/Figure 5.) 2 ABSRULES FOR BUILDING AND CLASSING OFFSHORE SUPPORT VESSELS .2016 Notice No. 1 July 2016 PART 3 HULL CONSTRUCTION AND EQUIPMENT CHAPTER 2 HULL STRUCTURES AND ARRANGEMENTS SECTION 14 RUDDERS AND STEERING EQUIPMENT 1 General (Revise Paragraph 3-2-14/1.1, as
12、follows:) 1.1 Application (1 July 2016) Requirements specified in this Section are applicable to: i) Ordinary profile rudders described in 3-2-14/Table 1A with rudder operating angle range from 35 to +35. ii) High-lift rudders described in 3-2-14/Table 1B, the rudder operating angle of which might b
13、e exceeding 35 on each side at maximum design speed. iii) Other steering equipment other than rudders identified in Section 3-2-14. Rudders not covered in 3-2-14/Table 1A nor in 3-2-14/Table 1B are subject to special consideration, provided that all the required calculations are prepared and submitt
14、ed for review in full compliance with the requirements in this Section. Where direct analyses adopted to justify an alternative design are to take into consideration all relevant modes of failure, on a case by case basis. These failure modes may include, amongst others: yielding, fatigue, buckling a
15、nd fracture. Possible damages caused by cavitation are also to be considered. Validation by laboratory tests or full scale tests may be required for alternative design approaches. Rudders and other steering equipment provided on Ice Classed vessels are subject to additional requirements specified in
16、 6-1-4/31 or 6-1-5/41 of the ABS Rules for Building and Classing Steel Vessels (Steel Vessel Rules). (Revise 3-2-14/Table 1B, as follows:) TABLE 1B Coefficient kc for High-Lift/Performance Rudders (1 July 2016) Profile Type kcAhead Condition Astern Condition 1 Fish tail (e.g., Schilling high-lift ru
17、dder) 1.4 0.8 2 Flap rudder (or Twisted rudder of Cat. 3) 1.7 1.3 (if not provided) 3 Rudder with steering nozzle 1.9 1.5 (Renumber 3-2-14/Figure 1 as 3-2-14/Figure 1A.) FIGURE 1A Rudder Blade without Cutouts (2009) ABSRULES FOR BUILDING AND CLASSING OFFSHORE SUPPORT VESSELS .2016 3 Notice No. 1 Jul
18、y 2016 (Renumber 3-2-14/Figure 2 as 3-2-14/Figure 1B.) FIGURE 1B Rudder Blade with Cutouts (2009) 7 Rudder Stocks (2012) (Revise Paragraph 3-2-14/7.5, as follows:) 7.5 Rudder Trunk and Rudder Stock Sealing (1 July 2016) i) In rudder trunks which are open to the sea, a seal or stuffing box is to be f
19、itted above the deepest load waterline, to prevent water from entering the steering gear compartment and the lubricant from being washed away from the rudder carrier. ii) Where the top of the rudder trunk is below the deepest waterline two separate stuffing boxes are to be provided. iii) Materials.
20、The steel used for the rudder trunk is to be of weldable quality, with a carbon content not exceeding 0.23% on ladle analysis and a carbon equivalent (Ceq) not exceeding 0.41. Plating materials for rudder trunks are in general not to be of lower grades than corresponding to class II as defined in 3-
21、1-2/Table 1. Rudder trunks comprising of materials other than steel are to be specially considered. iv) Scantlings. Where the rudder stock is arranged in a trunk in such a way that the trunk is stressed by forces due to rudder action, the scantlings of the trunk are to be such that the equivalent st
22、ress due to bending and shear does not exceed 0.35F, and the bending stress on welded rudder trunk is to be in compliance with the following formula: 80/k N/mm2 8.17/k kgf/mm2 11,600/k psi where = bending stress in the rudder trunk k = K as defined in 3-2-14/1.3 for castings = 1.0 for ordinary stren
23、gth hull steel plate = Q as defined in 3-2-1/5.5 for higher strength steel plate k is not to be taken less than 0.7 F= specified minimum yield strength of the material used, in N/mm2(kgf/mm2, psi) For calculation of bending stress, the span to be considered is the distance between the mid-height of
24、the lower rudder stock bearing and the point where the trunk is clamped into the shell or the bottom of the skeg. v) Welding at the Connection to the Hull. The weld at the connection between the rudder trunk and the shell or the bottom of the skeg is to be full penetration and fillet shoulder is to
25、be applied in way of the weld. The fillet shoulder radius r, in mm (in.) (see 3-2-14/Figure 2) is to be as large as practicable and to comply with the following: r = 60 mm when 40/k N/mm260 mm when 4.09/k kgf/mm22.4 in. when 5800/k psi 4 ABSRULES FOR BUILDING AND CLASSING OFFSHORE SUPPORT VESSELS .2
26、016 Notice No. 1 July 2016 r = 0.1S, without being less than 30 mm when a/b 1/5D(Renumber existing 3-2-14/Figures 3 and 4 as 3-2-14/Figures 4 and 5.) 9.5 Vertical Couplings (Revise Subparagraph 3-2-14/9.5.1, as follows:) 9.5.1 Coupling Bolts (1 July 2016) There are to be at least eight coupling bolt
27、s in vertical couplings and the diameter of each bolt is not to be less than obtained from the following equation: db= 0.81ds( )sbnKK / mm (in.) where n = total number of bolts in the vertical coupling, which is not to be less than 8 (Following text remains unchanged.) (Add new Subparagraph 3-2-14/9
28、.5.3, as follows:) 9.5.3 Joint between Rudder Stock and Coupling Flange (1 July 2016) The welded joint between the rudder stock and the flange is to be made in accordance with 3-2-14/Figure 3 or equivalent. 6 ABSRULES FOR BUILDING AND CLASSING OFFSHORE SUPPORT VESSELS .2016 Notice No. 1 July 2016 11
29、 Tapered Stock Couplings (Revise Paragraph 3-2-14/11.1, as follows:) 11.1 Coupling Taper (1 July 2016) Tapered stock couplings are to comply with the following general requirements in addition to type-specific requirements given in 3-2-14/11.3 or 3-2-14/11.5 as applicable: i) Tapered stocks, as show
30、n in 3-2-14/Figure 4, are to be effectively secured to the rudder casting by a nut on the end. ii) The cone shapes are to fit exactly. iii) Taper length () in the casting is generally not to be less than 1.5 times the stock diameter (do) as shown in 3-2-14/Figure 4. iv) The taper on diameter (c) is
31、to be 1/12 to 1/8 for keyed taper couplings and 1/20 to 1/12 for couplings with hydraulic mounting/dismounting arrangements, as shown in the following table. v) Where mounting with an oil injection and hydraulic nut, the push-up oil pressure and the push-up length are to be specially considered upon
32、 submission of calculations. vi) Means of effective sealing are to be provided to protect against sea water ingress. (Table remains unchanged.) (Revise Paragraph 3-2-14/11.3, as follows:) 11.3 Keyed Fitting (1 July 2016) Where the stock is keyed, the key is to be fitted in accordance with the follow
33、ing: i) The top of the keyway is to be located well below the top of the rudder. ii) Torsional strength of the key equivalent to that of the required upper stock is to be provided. iii) For the couplings between stock and rudder the shear area* of the key is not to be less than: as= 155.17FkFdQcm2as
34、= 120.27FkFdQin2where QF= design yield moment of rudder stock, in N-m (kg-m, lbf-ft) = 0.02664kdt3N-m = 0.002717kdt3kgf-m = 0.01965kdt3lbf-ft Where the actual rudder stock diameter dtais greater than the calculated diameter dt, the diameter dtais to be used. However, dtaapplied to the above formula
35、need not be taken greater than 1.145dt. dt= stock diameter, in mm (in.), according to 3-2-14/7.1 k = material factor for stock as given in 3-2-14/1.3 dk= mean diameter of the conical part of the rudder stock, in mm (in.), at the key F1= minimum yield stress of the key material, in N/mm2(kgf/mm2, psi
36、) ABSRULES FOR BUILDING AND CLASSING OFFSHORE SUPPORT VESSELS .2016 7 Notice No. 1 July 2016 The effective surface area of the key (without rounded edges) between key and rudder stock or cone coupling is not to be less than: ak= 25FkFdQcm2ak= 2749.7FkFdQin2where F2= minimum yield stress of the key,
37、stock or coupling material, in N/mm2(kgf/mm2, psi), whichever is less. iv) In general, the key material is to be at least of equal strength to the keyway material. For keys of higher strength materials, shear and bearing areas of keys and keyways may be based on the respective material properties of
38、 the keys and the keyways, provided that compatibilities in mechanical properties of both components are fully considered. In no case, is the bearing stress of the key on the keyway to exceed 90% of the specified minimum yield strength of the keyway material. v) Push up. It is to be proved that 50%
39、of the design yield moment is solely transmitted by friction in the cone couplings. This can be done by calculating the required push-up pressure and push-up length according to 3-2-14/11.5v) and 3-2-14/11.5vi) for a torsional moment FQ = 0.5QF. Notwithstanding the requirements in 3-2-14/11.5iii) an
40、d 3-2-14/11.5v), where a key is fitted to the coupling between stock and rudder and it is considered that the entire rudder torque is transmitted by the key at the couplings. * Note: The effective area is to be the gross area reduced by any area removed by saw cuts, set screw holes, chamfer, etc., a
41、nd is to exclude the portion of the key in way of spooning of the key way. (Revise Paragraph 3-2-14/11.5, as follows:) 11.5 Keyless Fitting (1 July 2016) Hydraulic and shrink fit keyless couplings are to be fitted in accordance with the following: i) Detailed preloading stress calculations and fitti
42、ng instructions are to be submitted; ii) Preload stress is not to exceed 70% of the minimum yield strength of either the stock or the bore; iii) Prior to applying hydraulic pressure, at least 75% of theoretical contact area of rudder stock and rudder bore is to be achieved in an evenly distributed m
43、anner; iv) The upper edge of the upper main piece bore is to have a slight radius; v) Push-up Pressure. The push-up pressure is not to be less than the greater of the two following values: preq1= omFdQ22103N/mm (kgf/mm2) preq1= omFdQ2901.2108psi preq2= mmbddM26103N/mm2(kgf/mm2) preq2= mmbddM2702.810
44、8psi where QF= design yield moment of rudder stock, as defined in 3-2-14/11.3iii) dm= mean cone diameter, in mm (in.) = cone length, in mm (in.) 0= frictional coefficient, equal to 0.15 Mb= bending moment in the cone coupling (e.g., in case of spade rudders), in N-m (kg-m, lbf-ft) 8 ABSRULES FOR BUI
45、LDING AND CLASSING OFFSHORE SUPPORT VESSELS .2016 Notice No. 1 July 2016 It has to be proved by the designer that the push-up pressure does not exceed the permissible surface pressure in the cone. The permissible surface pressure is to be determined by the following formula: pperm= ( )42318.0+GYN/mm
46、2(kgf/mm2, psi) where YG= specified minimum yield strength of the material of the gudgeon, in N/mm2(kgf/mm2, psi) = dm/dadm= mean cone diameter, in mm (in.) da= outer diameter of the gudgeon to be not less than 1.5dm, in mm (in.) vi) Push-up Length. The push-up length , in mm (in.), is to comply wit
47、h the following formula: 1 2where 1= cRcEdptmmreq8.02-12+mm (0.0394+ cRcEdptmmreq8.02-12in.) 2= cREcdYtmmG8.036.14+mm (0.0394+cREcdYtmmG8.036.14in.) Rtm= mean roughness, in mm (in.) taken equal to 0.01 c = taper on diameter according to 3-2-14/11.1iv) YG= specified minimum yield strength of the mate
48、rial of the gudgeon, in N/mm2(kgf/mm2, psi) E = Youngs modulus of the material of the gudgeon, in N/mm2(kgf/mm2, psi) YG, , and dmare as defined in 3-2-14/11.5v). Notwithstanding the above, the push up length is not to be less than 2 mm (0.8 in.). Note: In case of hydraulic pressure connections the
49、required push-up force Pefor the cone may be determined by the following formula: Pe= preqdm + 02.02cN (0.102 preqdm + 02.02ckgf, 0.225preqdm + 02.02clbf) The value 0.02 is a reference for the friction coefficient using oil pressure. It varies and depends on the mechanical treatment and roughness of the details to be fixed. Where due to the fitting procedure a partial push-up effect caused by the rudder weight is given, th
