Rules for Classification and Construction Ship Technology

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1 I Rules for Classification and Construction Ship Technology 4 Rigging Technology 3 Guidelines for the Type Approval of Carbon Strand and PBO Cable Rigging for Sailing Yachts Edition 2008

2 The following Guidelines come into force on March 1 st, 2008 Germanischer Lloyd Aktiengesellschaft Head Office Vorsetzen 35, Hamburg, Germany Phone: Fax: headoffice@gl-group.com "General Terms and Conditions" of the respective latest edition will be applicable (see Rules for Classification and Construction, I - Ship Technology, Part 0 - Classification and Surveys). Reproduction by printing or photostatic means is only permissible with the consent of Germanischer Lloyd Aktiengesellschaft. Published by: Germanischer Lloyd Aktiengesellschaft, Hamburg Printed by: Gebrüder Braasch GmbH, Hamburg

3 I - Part 4 Table of Contents Chapter 3 Page 3 Table of Contents Section 1 Type Approval of Carbon Strand and PBO Cable Rigging A. General B. Materials, Quality Measures C. Design, Construction, Assembly D. Performance E. Operational Instructions F. Testing G. Pre-Delivery Tests and Documentation H. Monitoring

I - Part 4 Section 1 C Type Approval of Carbon Strand and PBO Cable Rigging Chapter 3 Page 1 1 Section 1 Type Approval of Carbon Strand and PBO Cable Rigging A. General 1.

5 I - Part 4 Section 1 C Type Approval of Carbon Strand and PBO Cable Rigging Chapter 3 Page 1 1 Section 1 Type Approval of Carbon Strand and PBO Cable Rigging A. General 1. These Guidelines address issues associated with unidirectional fibre strand cables intended for sail boat rigging. These cables may be intended for different purposes in staying a rig. 2. In the following, conditions are outlined under which these types of cables can be accepted by GL to be of an approved type of rigging for sailing yachts under the premises of Chapter 2 Guidelines for the Design and Construction of Large Modern Yacht Rigs. A "Type Approval" Certificate would be issued. 3. Issues listed below especially address particular characteristics of the fibre types themselves as well as characteristics of the completed cable made of a strand of dry fibres (PBO) 1 or of impregnated strands of carbon fibres, including their typical end fittings. Optionally, other cable materials or configurations may be dealt with upon special agreement with GL. 4. The following is considered to be standard basic requirements of what is necessary to be described / discussed/ tested. Unusual design, unexpected intermediate findings or test results may make deviating considerations and assessments necessary. 5. The approval is only valid for products alike the ones tested, described and documented. In case of doubt, GL reserves the right to evaluate whether products are alike or not in the understanding of these Guidelines. 6. Provided the required documentation is conclusive in the sense of these Guidelines and the required tests were passed successfully, a type approval certificate would be issued naming particular sizes or size categories of cables and confirming nominal static ultimate tensile load, maximum working load and corresponding tensile stiffness. A reference note will be given to follow manufacturer's instructions, maintenance and replacement schedules. The GL type approval logo may be displayed on the product: 1 PBO: Poly p-phenylene-2,6-benzobisoxazole B. Materials, Quality Measures 1. Material specifications shall be submitted to GL for: a) PBO fibre type; fibre, roving or strand tex b) Carbon fibre type, type of resin c) End fittings, including technical drawings d) Chafe, UV and humidity protection cover materials 2. For the storage of PBO fibres intended for use, a complete history of storing conditions shall be part of quality measures of the cable manufacturer and any third company involved in the construction of a cable. A description of quality measures in this respect shall be given. Instructions for third companies shall be defined. 3. Batches of fibres received from the fibre manufacturer shall always be accompanied by a product technical data sheet, confirming that relevant data is appropriate for its intended use. The same is required for pre-fabricated cable ware from a subsupplier. 4. PBO fibres may not be exposed to direct sunlight at all and not to visible light for more than 48 hours (cumulative). C. Design, Construction, Assembly 1. A description of the cable construction/ manufacturing process shall be given, including relevant issues such as: a) PBO fibres: Winding procedure b) Carbon fibres: Production method c) Order of assembly, description of how a repeatability of the assembly process is ensured d) Specification of chafe-, UV- and humidity protection cover including their relevant mechanical characteristics e) Special design features such as forestay bearing seats, different terminal types, etc.

6 Chapter 3 Page 1 2 Section 1 E Type Approval of Carbon Strand and PBO Cable Rigging I - Part 4 f) If the end fitting is of a spool thimble type, an argumentation for an appropriate ratio of spool thimble diameter vs. cable size shall be given. Similar argumentation is to be provided for different type end fittings. This is because testing may be limited to representative sizes. 2. Fibres must be assembled dry. Recording of ambient temperature and relative humidity shall be carried out during construction. 3. The protection cover shall protect PBO fibres from ingress of water, also in-service. 4. Free articulation of end fittings: A "free articulation" is understood to be an unconstrained movement in a way that no bending moment is implied on the cable and its terminal within an angle of 2,5 relative to the cable s longitudinal axis for fixed standing rigging purposes. 4.1 A "free articulation" can be provided by e.g.: An eye fitting on a fixed barrel pin, if geometry allows for this assumption An eye fitting on a toggle or turnbuckle An eye fitting on a rope strop A ring or swivel bail fitting on a rope strop A "T"-Terminal, if bearing point is in line with cable axis 4.2 The following items/combinations are by default not considered "free articulating": An eye fitting on a fixed pin (free articulation provided about only one axis) "Ball"-type termination, e.g. in a spreader "tipcup" fitting. (Free articulation may be constrained under high tensile forces) 5. If cables will be assembled by a third company, a detailed instruction manual shall be prepared. A list of these companies shall be submitted, including a confirmation of their qualifications. 6. A list shall be provided including the following specifications of characteristic properties of all cables: a) Cable designation b) Nominal static break load "NBL" (see F.2.3) c) Maximum working load "MWL" d) Yarn count in dtex of cable e) Distinct specification of end fitting A similar description is required for cables with customized sizing. D. Performance 1. The following performance characteristics shall be described: a) General explanation of difference between theoretical roving (strand) strength given by fibre manufacturer and cable strength (e.g. reduction due to friction or stress concentration effects in loop or cone termination etc.) b) Fatigue properties, life time expectation (Estimation of load cycles at different load levels) c) Maximum exploitation of ultimate capacity in service, recommended service load or maximum working load d) Sensibility to UV, impact and chafe e) Recommendations about appropriate additional protection covers for forestay or side stay applications E. Operational Instructions 1. The instructions for customers shall include: 1.1 Installation instructions, covering Alignment, suitable attachments (e.g. pin, loop, etc.) Rolling of cable for storage or transport 1.2 Operational Instructions, covering: Recommendation for maximum service load, avoiding of twist, etc. Handling, etc. Recommendations for appropriate cable chafe protection for relevant applications 1.3 Maintenance instructions, covering: General maintenance measures in service Special instructions for inspections on abrasion and chafe, depending on sheath or cover type Expected life span, service intervals and replacement intervals 1.4 Further operational instructions, if deemed necessary

7 I - Part 4 Section 1 F Type Approval of Carbon Strand and PBO Cable Rigging Chapter 3 Page 1 3 F. Testing Table 1.1 Cable sizes and number of samples 1. General 1.1 Testing of relevant properties shall be performed to achieve assurance about the structural behaviour, covering tensile strength, fatigue effects and service loads. This all shall be performed prior to the acceptance. If not explicitly mentioned differently within these Guidelines, cables shall be tested in their "delivery" condition, representing typical design, construction and assembly methods and conditions. In the following paragraphs the terms "size of cables" and "range of cables" will be referred to. This is provided that sizes are not customized. In the latter case a range of cables will be defined by the graduation in typical sizes, each of which may not differ from the next smaller size more than 40 % of their break load. 1.2 For ultimate strength and fatigue testing, the length of the test cable may affect results, because a short cable may not bridge e.g. uneven fibre lengths as good as long cables. A reasonable sample length for normal standing rigging components is considered to be 3 m to 5 m, however may not be longer than for usual applications. It shall be evaluated whether short strops offered in the range of products may fall short of the tested values and thus may need to be handled differently. 1.3 Closer inspections and interpretation of failure modes shall be carried out after tests. All test results and all required documentation has to be submitted for review/approval to GL Head office. 1.4 Testing facilities need to be appropriately accredited in accordance with ISO or EN or equivalent. Alternatively, a GL Surveyor will have to witness tests at appropriate intervals. In any case, the testing jigs including their measurement and recording devices have to be calibrated by an authorised institution. 1.5 Alternative testing methods or measures can be accepted as long as it is ensured that those provide similar overall results. GL reserves the right to assess alternative methods. 2. Static tensile testing 2.1 Choice of test samples Tensile strength and tensile stiffness values shall be determined by static tensile testing. The following static tensile testing is required to be carried out on all sizes of cables. For a range of cables including "X" different sizes, each size shall be tested with "Y" samples according to Table 1.1: Different sizes "X" Samples to be tested "Y" > Testing strategy Quasi-static tensile tests up to failure shall be carried out for samples as defined in 2.1 at slow ramp. The test shall be accompanied by perpetual recording of tensile force / elongation. 2.3 Evaluation of test results An evaluation of the test results will be carried out by GL in order to find whether tested data is furnishing sufficient consistency of the curve given by axial stiffness / tensile break load ratios over the tensile break load each. The relevant value of the break load will be calculated following a statistical analysis of test results and be called "NBL". 3. Fatigue testing 3.1 General Fatigue testing is required to be carried out in order to find an indication about the long-term dynamic behaviour. The proposed fatigue testing program shall give rise to possible fatigue failure or degradation assisted by residual tensile strength (and tensile stiffness) measurements after each fatigue run. 3.2 Force level The applied force level shall be specified by the manufacturer. Following satisfactory test results, this level chosen will be called "maximum working load MWL" and be included in the approval documentation. 3.3 Choice of samples If the design of cable terminations is typical over the whole range of sizes, not all sizes will need to be tested for fatigue. GL reserves the right to determine sizes to be tested out of a given range of production. Samples of at least 3 different sizes will be chosen, representing the full range of products. 3.4 Fatigue test 1 The fatigue testing shall be carried out with alternating load (sinusoidal or triangular) between slack and MWL. Magnitude of frequencies of oscillations is free

8 Chapter 3 Page 1 4 Section 1 F Type Approval of Carbon Strand and PBO Cable Rigging I - Part 4 of choice. The term "slack" indicates a condition under which a cable will/would "sag" ca. 5 % of its length. Some cables could be too stiff to measure this sag; if so, the "slack" is to be achieved by moving the terminal fix points 0,7 % of its initial length closer to each other than at zero load condition (see Fig. 1.1). L o 5 % L o 0.7 % L o Fig. 1.1 Alternating loads Unloaded "Slack" Loaded Due to a possible loss of tensile stiffness of a cable, the fatigue testing machine shall be able to ensure maintaining of target forces over the full amount of cycles Testing strategy The cycling strategy shall be as follows, for each chosen cable size a number of samples as indicated has to be tested: Sample 1: Initial tensile stiffness measurement at recommended working load level, 100 cycles, unload, residual tensile stiffness measurement at MWL, length measurement (creep), ultimate tensile test to destruction with measurement of force and strain. Sample 2: 1000 cycles, unload, residual tensile stiffness measurement at MWL, length measurement (creep), ultimate tensile test to destruction with measurement of force and strain. Sample 3: cycles, unload, residual tensile stiffness measurement at MWL, length measurement (creep), ultimate tensile test to destruction with measurement of force and strain. Sample 4: cycles, unload, residual tensile stiffness measurement at MWL, length measurement (creep), ultimate tensile test to destruction with measurement of force and strain. The order of testing is free. If sample 4 shows no noticeable degradations in stiffness and strength, testing of samples 3, 2, and 1 need not to be carried out Criteria The residual tensile strength may not be less than 2,0 times MWL. After the tests are finished, consequences of potential degradations shall be analysed and described. All results shall be submitted to GL for review. 3.5 Fatigue test General Fatigue test 2 is required additionally, if end fittings are not of "free articulation" type as defined in C Testing strategy A fatigue test shall be carried out with a forced change in lead angle about the axis perpendicular to the terminal pin axis of ± 2,5 at a constant tensile load (MWL or 30 % of NBL). As a minimum cycles are to be accomplished. Test of residual strength is recommended. Three samples each are to be tested from three selected cable sizes Criteria Cables tested shall not break under the conditions described. After the tests are finished, consequences of potential degradations shall be analysed and described. All results shall be submitted to GL for review. 4. Chafe impact testing 4.1 General In comparison with steel wire or rod rigging a special focus is put on the abrasion and impact resistance of fibre cables. The requirements defined within these Guidelines are intended to cover occasional and little or slight contact or chafe occurring during normal operation. Cables will be subdivided in two groups, each of which are to undergo different levels of testing (see ). The categorization of the cables is done according to their application in a rig: Category A: Occasional and slight chafe, e.g. lower diagonal shroud (D1), all vertical shrouds and the upper diagonal shroud. Category B: Low risk of chafe or little chafe, e.g. all intermediate diagonal shrouds (except D1 and upper diagonal), generally all standing and running aft stays (backstays, running backstays, checkstays). Specific additional protection is required for different components of the rig (such as lower vertical shroud (V1), upper diagonal shroud and forestay) due to exceptional severe chafe such as fast easing of a gennaker sheet in preparation of a jibe, the fast ease of a spinnaker aft guy during an accidental broach, the sliding of a genoa sheet during tacking, etc. This additional cover shall be designed so that the cable itself will not be effected or be abrasion-proof.

9 I - Part 4 Section 1 F Type Approval of Carbon Strand and PBO Cable Rigging Chapter 3 Page 1 5 The following test shall be carried out on standard supplied (covered) cables. End fittings do not need to be fitted necessarily: 4.2 Chafe test Sample choice If the thickness and type of coating and/or protection is identical over the range of cable sizes, the test shall be carried out on a mid size sample Testing strategy A test shall be carried out pulling a tight rope over a tight cable by means of a drop test. The rope shall be of normal running rigging braided type and be of ca. ½ of the diameter of the cable. The cable shall be tensioned appropriately and the rope shall be deflected by 10 over the cable. The arrangement is described in Fig The free drop height of the heavier weight shall be at least 5 m. The deflection sheaves shall be of low friction type (with ball bearings). The mass of the drop weight shall be calculated according to the following formula: Category A: m D = 30 + NBL / 30 Category B: m D m D = 10 + NBL / 100 = mass of drop weight [kg] NBL = nominal break load of cable [kn] The counter weight shall be of 25 % of the mass of the drop weight. The test shall be performed at least: once for Category A cables 5 times for Category B cables Criteria The cover of the cable shall not be penetrated after this test. 4.3 Impact testing General Impact testing shall give rise to the effects caused by objects hitting standing rigging or by high local offaxis impact forces. The following tests shall be carried out on standard supplied (covered) cables. End fittings do not need to be fitted necessarily. Under the configurations described below, the cable must not be longer than for normal applications Choice of samples The test shall be carried out for one sample each of a small size and a large size out of the cable range Testing strategy Initial conditions: Test cables shall be tested in tensioned (ca. 30 % of NBL) and subsequently in slack condition (cable sag in the middle of the cable shall be ca. 2,5 % of its straight length or cable end points shall be moved towards each other by ca. 1,5 % of the cable's straight length). The end points of the cable shall be non-flexible. A pendulum is to be set up with a mass of m i being fixed to the end of a rigid bar or truss according to Fig The mass m i is to be calculated according to the following formula: m i = 10 + NBL / 100 m i = mass of drop weight [kg] NBL = nominal break load of cable [kn] r = 1 m m i Braided rope "sheet" type 5 m Drop drop weight Tensioned stay 10 deg deflection Counter weight Fiber cable Impact contour cylindical Retrieval rope Fig. 1.2 Chafe test arrangement Fig. 1.3 Impact test arrangement

10 Chapter 3 Page 1 6 Section 1 H Type Approval of Carbon Strand and PBO Cable Rigging I - Part 4 The length of the pendulum shall be 1m (between axis of articulation and centre of gravity of weight). The axis of the pendulum shall be positioned 1m above and in line with the cable, half way along the cable. The pendulum shall be dropped 10 times from its horizontal position. The likely area of contact between weight and cable shall be of a cylindrical contour, where the axis between cable and contour shall be perpendicular; the diameter of the contour shall be the same as the cables nominal diameter; the contact surface shall be of rigid material, preferably be of metal Criteria Subsequent ultimate residual tensile test shall be carried out determining possible reduction of tensile capacity. The tensile capacity must not be reduced due to this test. G. Pre-Delivery Tests and Documentation It is required to have each cable loaded to recommended working load level prior to delivery. Also, it is strongly recommended to issue a force/strain curve with each cable intended for side staying of a rig (shrouds). This curve shall be recorded during a second loading to compensate settling effects. Each cable or terminal shall be marked in a unique way, so that production, manufacturing conditions, fibre batches and other relevant data and documentation in the sense of these Guidelines can be traced back. H. Monitoring The criteria specified above are intended to assess whether composite cables in general are suitable structural elements for staying a sail boat rig. Note Due to aging effects, certain monitoring measures are required in order to set appropriate maintenance and replacement schedules. Respective specifications of the manufacturer are to be observed.

CHAPTER 4 EXPERIMENTAL ANALYSIS FOR A 2 IN, SCHEDULE 10 PIPE

CHAPTER 4 EXPERIMENTAL ANALYSIS FOR A 2 IN, SCHEDULE 10 PIPE To validate the results of theoretical and numerical analysis, three cases of experimental analysis were conducted. Two types of pipe-bend test