DNVGL-CP-0413 Carbon and PBO cable rigging for sailing yachts · 1 PBO: Poly p-phenylene-2,6-benzobisoxazole. Section 2 Class programme — DNVGL-CP-0413. Edition November 2016 Page

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DNV GL AS

CLASS PROGRAMME

Type approval

DNVGL-CP-0413 Edition November 2016

Carbon and PBO cable rigging for sailingyachts

FOREWORD

DNV GL class programmes contain procedural and technical requirements including acceptancecriteria for obtaining and retaining certificates for objects and organisations related toclassification.

© DNV GL AS November 2016

Any comments may be sent by e-mail to [email protected]

This service document has been prepared based on available knowledge, technology and/or information at the time of issuance of thisdocument. The use of this document by others than DNV GL is at the user's sole risk. DNV GL does not accept any liability or responsibilityfor loss or damages resulting from any use of this document.

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Class programme — DNVGL-CP-0413. Edition November 2016 Page 3Carbon and PBO cable rigging for sailing yachts

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CONTENTS

Changes – current.................................................................................................. 3

Section 1 General....................................................................................................51 Objective..............................................................................................52 Scope................................................................................................... 53 Application...........................................................................................5

Section 2 Carbon and PBO cable rigging.................................................................61 General................................................................................................ 62 Documentation.....................................................................................63 Materials, quality measures.................................................................74 Design, construction, assembly........................................................... 75 Performance........................................................................................ 86 Operational instructions...................................................................... 87 Testing requirements...........................................................................88 Pre-delivery test and documentation.................................................149 Monitoring..........................................................................................1410 Requirements for marking of product..............................................14

Section 3 Continuous style fibre rigging............................................................... 151 General.............................................................................................. 152 Testing requirements.........................................................................16

Changes – historic................................................................................................23

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SECTION 1 GENERAL

1 ObjectiveThe objective of this class programme is to describe the type approval (TA) scheme for carbon strand andPBO cable rigging intended for sail boat rigging.The general requirements for obtaining type approval is given in class programme DNVGL-CP-0338 DNV GLtype approval scheme.The procedures described in this CP are applicable for obtaining TA certificate based on Society's rules andstandards, including other standards as listed below, e.g.:

— DNVGL-ST-0412 Large modern rigs.

2 ScopeThis CP describes how to document compliance with the requirements in order to obtain a TA certificatefor the equipment. This includes, where relevant, technical requirements for how the type tests shall beperformed.

3 Application

3.1 This CP covers basic requirements of what is necessary to be documented and tested. Requirements for fibrerigging of unusual designs/properties will be agreed on a case-by-case basis with the Society.

3.2 The TA certificate is only valid for products alike the ones tested, described and documented according thisCP.In case of doubt, the Society reserves the right to evaluate wether products are alike or not in theunderstanding of this CP.

3.3 A TA certificate will be issued and sent to the TA applicant when compliance with the requirements to theproduct is confirmed. The type approval certificate will include particular sizes or size categories of cables andconfirming nominal static ultimate tensile load, maximum working load and corresponding tensile stiffness. Areference note will be given to follow manufacturer's instructions, maintenance and replacement schedules.

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SECTION 2 CARBON AND PBO CABLE RIGGING

1 GeneralDocumentation shall include particular characteristics of the fibre types themselves as well as characteristicsof the completed discontinuous cable made of a strand of dry fibres (PBO)1 or of impregnated strand/strandsof carbon fibres, including their typical end fittings.Optionally, other cable materials or configurations may be dealt with upon special agreement with theSociety.

2 DocumentationThe documentation shall be submitted by the manufacturer at initial type approval. The documentation shall,to the extent possible, be submitted as electronic files.The documentation that forms the basis for the TA shall be easily available for surveyors at the TA applicant’spremises.The manufacturer shall keep one (1) copy of type approval documentation for their own records.The documentation shall be in the English language if not otherwise agreed. (Please number documentationaccording to below list to facilitate review).

2.1 MaterialMaterial specifications shall be submitted to the Society:

a) PBO fibre type; fibre, roving or strand texb) carbon fibre type, type of resinc) end fittings, including technical drawingsd) chafe, UV and humidity protection cover materials.

2.2 Design, construction, assemblyA description of the cable construction/ manufacturing process shall be given, including:

a) PBO fibres: Winding procedureb) carbon fibres: Production methodc) order of assembly, description of how a repeatability of the assembly process is ensuredd) specification of chafe-, UV- and humidity protection cover including their relevant mechanical

characteristicse) special design features such as forestay bearing seats, different terminal types, etc.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 shall be provided for different type endfittings, as testing may be limited to representative sizes.

2.3 SpecificationA list shall be provided including the following specifications of characteristic properties of all cables:

a) cable designationb) nominal static break load "NBL" (see Sec.2 [1.2.3])c) maximum working load "MWL"d) yarn count in dTex of cable

1 PBO: Poly p-phenylene-2,6-benzobisoxazole

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e) distinct specification of end fitting.

3 Materials, quality measures

3.1 For the storage of PBO fibres, a complete history of storing conditions shall be part of quality measures of thecable manufacturer. A description of quality measures in this respect shall be given.

3.2 Batches of fibres received from the fibre manufacturer shall always be accompanied by a product technicaldata sheet, confirming that relevant data is appropriate for its intended use. The same is required for pre-fabricated cable ware from a sub-supplier.

3.3 PBO fibres shall not be exposed to direct sunlight at all and not to visible light for more than 48 hours(cumulative).

4 Design, construction, assembly

4.1 Fibres shall be assembled dry. Recording of ambient temperature and relative humidity shall be carried outduring construction.

4.2 A protection cover shall protect PBO fibres from ingress of water, also in-service.

4.3 Free articulation of end fittings shall be assured.

Guidance note:A free articulation is understood to be an unconstrained movement in a way that no bending moment is implied on the cable andits terminal within an angle of 2.5° relative to the cable’s longitudinal axis for fixed standing rigging purposes.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.

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 "tip-cup" fitting. (Free articulation may be constrained under high tensile forces).

---e-n-d---o-f---g-u-i-d-a-n-c-e---n-o-t-e---

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4.4 If cables will be assembled by a third company, a detailed instruction manual shall be prepared. A list ofthese companies shall be submitted, including a confirmation of their qualifications.

5 PerformanceThe following performance characteristics shall be described:

a) general explanation of difference between theoretical roving (strand) strength given by fibremanufacturer and cable strength (e.g. reduction due to friction or stress concentration effects in loop orcone termination etc.)

b) fatigue properties, life time expectation (estimation of load cycles at different load levels)c) maximum utilisation of ultimate capacity in service, recommended service load or maximum working

loadd) sensitivity to UV, impact and chafee) recommendations for appropriate additional protection covers for forestay or side stay applications.

6 Operational instructions

6.1 GeneralThe instructions for customers shall include:

6.1.1 Installation instructions, covering:

— alignment, suitable attachments (e.g. pin, loop, etc.)— rolling of cable for storage or transport.

6.1.2 Operational instructions, covering:

— recommendation for maximum service load, avoiding of twist, etc.— handling, etc.— recommendations for appropriate cable chafe protection for relevant applications.

6.1.3 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.

6.1.4 Further operational instructions, if deemed necessary.

7 Testing requirements

7.1 General

7.1.1 Testing of relevant properties shall be performed to achieve assurance about the structural behaviour,covering tensile strength, fatigue effects and service loads. This shall be performed prior to the acceptance.If not explicitly mentioned otherwise, cables shall be tested in their "delivery" condition, representing typicaldesign, construction and assembly methods and conditions.

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In the following paragraphs the terms "size of cables" and "range of cables" will be referred to. This isprovided that sizes are not customized. In the latter case a range of cables will be defined by the graduationin typical sizes, each of which may not differ from the next smaller size more than 40% of their break load.

7.1.2 For ultimate strength and fatigue testing, the length of the test cable may affect results, because ashort cable may not bridge e.g. uneven fibre lengths as good as long cables. A reasonable sample length fornormal standing rigging components is considered to be 3 m to 5 m, but shall not be longer than for usualapplications. It shall be evaluated whether short strops offered in the range of products may fall short of thetested values and thus may need to be handled differently.

7.1.3 Closer inspections and interpretation of failure modes shall be carried out after tests.All test results and all required documentation shall be submitted to the Society.

7.1.4 Testing facilities shall be appropriately accredited in accordance with ISO 17025 or EN 45001 orequivalent. Alternatively, a DNV GL surveyor shall witness the testing (according to DNVGL-CP-0338 DNV GLtype approval scheme).The testing jigs including their measurement and recording devices shall be calibrated by an organisationrecognized by the Society.

7.1.5 Alternative testing methods or measures can be accepted as long as it is ensured that these providesimilar overall results. The Society reserves the right to assess alternative methods.

Guidance note:Large capacity cables that can only be tested to destruction in very few test labs in the world:For few cables out of a given range, it might be sufficient to prove the ultimate strength by reaching a proof load, possibly withoutdestruction. This value will be considered as nominal break load (NBL), if in line with a statistical evaluation of other test results.


7.2 Static tensile testing7.2.1 Choice of test samplesTensile strength and tensile stiffness values shall be determined by static tensile testing. The following statictensile testing shall be carried out on all sizes of cables. For a range of cables including X different sizes, eachsize shall be tested with Y samples according to Table 1:

Table 1 Cable sizes and number of samples

Different sizes X Samples to be tested Y

3 4

4 3

5 2

6 2

> 6 1

7.2.2 Testing strategyQuasi-static tensile tests up to failure shall be carried out for samples as defined in [7.2.1] at slow ramp. Thetest shall be accompanied by perpetual recording of tensile force/elongation.

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7.2.3 Evaluation of test resultsAn evaluation of the test results will be carried out by the Society in order to find whether tested data isconsistent . A statistical analysis of test results will derive the "NBL".

7.3 Fatigue testing7.3.1 GeneralFatigue testing shall be carried out.The proposed fatigue testing program shall give rise to possible fatigue failure or degradation assisted byresidual tensile strength (and tensile stiffness) measurements after each fatigue run.

7.3.2 Force levelThe applied force level shall be specified by the manufacturer. Following satisfactory test results, this levelchosen will be called maximum working load (MWL) and be included in the approval documentation.

7.3.3 Choice of samplesIf the design of cable terminations is typical over the whole range of sizes, not all sizes will need to be testedfor fatigue. The Society 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 selected, representing the full range of products.

7.3.4 Fatigue test 1The fatigue testing shall be carried out with alternating load (sinusoidal or triangular) between slack andMWL. Magnitude of frequencies of oscillations is free of choice. The term slack indicates a condition underwhich a cable will/would sag approximately 5% of its length. Some cables could be too stiff to measure thissag; if so, the slack shall be achieved by moving the terminal fix points 0.7% of its initial length closer toeach other than at unloaded condition (see Figure 1).

Figure 1 Alternating loads

Due to a possible loss of tensile stiffness of a cable, the fatigue testing machine shall be able to maintaintarget forces over the full amount of cycles.

Guidance note:The intention with the provisions mentioned under this paragraph is to simulate the behaviour of leeward diagonal shrouds ofsailing yachts or other relatively short cables prone to possible slackening in service:It has been found difficult to realise the "slack-condition", particularly for short test samples of very large capacity cables. As analternative measure, a minimum uniaxial compressive force should be applied to the cable as a lower limit fatigue load level. Themagnitude of this compressive force should be determined by the theoretical buckling force of the tested cable using a length of 9m. This measure is considered to provide an appropriate amount of compression for a typical cable length on superyachts:

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F = compressive load in test

EI = bending stiffness of cable

L = 9 m

Cables as mentioned in this guidance may waive with the mentioned provision to achieve slackness or compression during thefatigue test. Those cables may be fatigue cycled with a lower tension value of 5% MWL.Those cables will be designated with their restrictions of use in the certificate.


7.3.4.1 Testing strategyThe cycling strategy shall be as follows:

sample 1: Initial tensile stiffness measurement at recommended working load level, 100 cycles, unload,residual tensile stiffness measurement at MWL, length measurement (creep), ultimate tensiletest 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: 10 000 cycles, unload, residual tensile stiffness measurement at MWL, length measurement(creep), ultimate tensile test to destruction with measurement of force and strain.

sample 4: 100 000 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 ofsamples 3, 2, and 1 need not to be carried out.

7.3.4.2 CriteriaThe residual tensile strength shall not be less than 2.0 times MWL. After completion of testing, consequencesof potential degradations shall be analysed and described. All results shall be submitted to the Society forreview.

7.3.5 Fatigue test 2

7.3.5.1 GeneralFatigue test 2 is required where end fittings are not of free articulation type as defined in Sec.1 [4.3].

7.3.5.2 Testing strategyA fatigue test shall be carried out with a forced change in lead angle about the axis perpendicular to theterminal pin axis of ±2.5° at a constant tensile load (MWL or 30% of NBL). As a minimum, 100 000 cyclesshall be accomplished. Test of residual strength is recommended. Three samples each shall to be tested fromthree selected cable sizes.

7.3.5.3 CriteriaCables tested shall not break under the conditions described. After completion of testing, consequencesof potential degradations shall be analysed and described. All results shall be submitted to the Society forreview.

7.4 Chafe impact testing7.4.1 GeneralIn comparison with steel wire or rod rigging a special focus is put on the abrasion and impact resistance offibre cables.The requirements defined in this programme are intended to cover occasional and little or slight contact orchafe occurring during normal operation.

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Cables will be subdivided in two groups, each of which shall undergo different levels of testing (see[7.4.2.2]). 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 theupper diagonal shroud.

category B: Low risk of chafe or little chafe, e.g. all intermediate diagonal shrouds (except D1 andupper 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 gennakersheet in preparation of a jibe, the fast ease of a spinnaker aft guy during an accidental broach, the sliding ofa genoa sheet during tacking, etc. This additional cover shall be designed so that the cable itself will not beeffected or be abrasion-proof.The following test shall be carried out on standard supplied (covered) cables. End fittings do not need to befitted necessarily:

7.4.2 Chafe test

7.4.2.1 Sample choiceThe thickness and type of coating and/or protection is identical over the range of cable sizes, the test shall becarried out on a mid size sample.

7.4.2.2 Testing strategyA test shall be carried out by pulling a tight rope over a tight cable by means of a drop test. The rope shallbe of normal running rigging braided type and be approximately 50% of the diameter of the cable. The cableshall be tensioned appropriately and the rope shall be deflected by 10° over the cable. The arrangement isdescribed in Figure 2. The free drop height of the heavier weight shall be at least 5 m. The deflection sheavesshall be of low friction type (with ball bearings). The mass of the drop weight shall be calculated according tothe following equation:

category A:

mD = 30 + NBL / 30

category B:

mD = 10 + NBL / 100

mD = mass of drop weight [kg]NBL = nominal break load of cable [kN].

The counter weight shall be 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.

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Figure 2 Chafe test arrangement

7.4.2.3 CriteriaThe cover of the cable shall not be penetrated after this test.

7.4.3 Impact testing

7.4.3.1 GeneralImpact testing shall give rise to the effects caused by objects hitting standing rigging or by high local off-axisimpact forces.The following tests shall be carried out on standard supplied (covered) cables. End fittings do not need to befitted necessarily. Under the configurations described below, the cable shall not be longer than for normalapplications.

7.4.3.2 Choice of samplesThe test shall be carried out for one sample each of a small size and a large size out of the cable range.

7.4.3.3 Testing strategyInitial conditions: Test cables shall be tested in tensioned (approx. 30% of NBL) and subsequently in slackcondition (cable sag in the middle of the cable shall be ca. 2.5% of its straight length or cable end pointsshall be moved towards each other by ca. 1.5% of the cable's straight length). The end points of the cableshall be non-flexible.

A pendulum is to be set up with a mass of mi being fixed to the end of a rigid bar or truss according to Figure3.

The mass mi shall be calculated according to the following equation:

mi = 10 + NBL / 100

mi = mass of drop weight [kg]NBL = nominal break load of cable [kN].

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Figure 3 Impact test arrangement

The length of the pendulum shall be 1 m (between axis of articulation and centre of gravity of weight). Theaxis of the pendulum shall be positioned 1m above and in line with the cable, half way along the cable. Thependulum shall be dropped 10 times from its horizontal position. The likely area of contact between weightand 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 ofrigid material, preferably of metal.

7.4.3.4 CriteriaSubsequent ultimate residual tensile test shall be carried out determining possible reduction of tensilecapacity.The NBL shall not be reduced due to this test.

8 Pre-delivery test and documentationIt is required to have each cable loaded to recommended working load level prior to delivery. Also, it isrecommended to issue a force/strain curve with each cable intended for side staying of a rig (shrouds). Thiscurve shall be recorded during a second loading to compensate settling effects.

9 MonitoringGuidance note:Due to aging effects, certain monitoring measures are required in order to set appropriate maintenance and replacementschedules.Respective specifications of the manufacturer are to be observed.


10 Requirements for marking of productEach cable or terminal shall be marked in a unique way, so that production, manufacturing conditions, fibrebatches and other relevant data and documentation in the sense of this program can be traced back.

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SECTION 3 CONTINUOUS STYLE FIBRE RIGGING

1 General

1.1 DefinitionContinuous style rigging is standing rigging of sailing yachts which is by intention lead and deflected over astrong point, usually a spreader, jumper or diamond strut outboard end.This section is valid for cables having congeneric basic constitution as cables that have been TA according toSec.2. The term constitution is understood to be a common expression for all relevant design, constructionand manufacturing characteristics outside the proximity of the strong point. If in doubt, it is up to the Societyto assess this congeneric constitution.The expression cable describes a structural unit usually consisting of an assembly of unidirectional structuralfibres, occurring as compacted dry state tows or as a single or a bundle of epoxy resin consolidated rods.Cables may split in multiple at strong points. A split is understood to be a divergence of the cable, where thebundle of structural fibres splits in two or more (cables).Sec.2 [1] - Sec.2 [5] and Sec.2 [7] - Sec.2 [8] shall be considered.

1.2 TypesIt shall be distinguished between continuous and split types:

— C-Type: A continuous cable which is solely lead and deflected over a strong point.— Y-type: This split is common for conventional transverse rigging set-up where a lower vertical shroud

(Vlower) splits into an upper vertical shroud (Vupper) and an upper diagonal shroud (Dupper) over a strongpoint.

— K-type: This split is a split arrangement seen on "Millennium"-styled transverse rigging, with an additionalinverse lower diagonal shroud (Dlower). The particular split method shall be reviewed by DNVGL in order toconfirm the validity of the following provisions.

— Other types: Other splits or splits without being lead over a strong point, such as a backstay split, will betreated case-by-case, following a similar philosophy as presented in this class program.

1.3 CharacteristicsParticular issues of continuous rigging (as opposed to non-continuous or discontinuous fibre rigging cables asdescribed in Sec.2) are:

— loading fractions will vary between the split legs and cause uneven loading in the joint cable to a certainphysical extent and over a certain length

— depending on the design and building process of the cable, a cable will have to cope with uneven fibrelengths (e.g. when it is built straight)

— a deflection over a strong point is always causing a reaction force perpendicular to the cable. This reactionforce will cause the occurrence of transverse bearing loads/pressures, both internally and externally

— depending on the different fibre arrangement scenarios (e.g. dry fibres, consolidated fibre strand bundlesor consolidated fibre rod), different contact effects (friction, peeling, splitting, cutting, bearing etc.) occurin the split region

— K-type and Y-type splits and also C-type rigging may in service be deflected out of their initial plane.Thus, bending in the cables or other structurally relevant effects due to the change from the originalalignment angles may occur

— cables might be structurally tapered in size.

This list has only indicative character and does not intend to be complete.

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1.4 DocumentationThe following documentation shall be submitted by the manufacturer at initial type approval. Thedocumentation shall, to the extent possible, be submitted as electronic files. The manufacturer shall keep one(1) copy of type approval documentation for their own records.The documentation that forms the basis for the TA shall be easily available for surveyors at the TA applicant’spremises.The documentation shall be in the English language if not otherwise agreed. (Please number documentationaccording to below list to facilitate review).Relevant design and construction characteristics shall be described, if applicable.

1.4.1 General

— range and limitations of possible deflection and/or split angles— range and/or variations of split sizes— other characteristics— structural design philosophy of split.

1.4.2 Split technology

— description on where in the section the split' leg cable bundle or fibres are taken from the Vlower(internally, externally, sectorial, segment-wise etc.) in detail

— minimum deflection radii and seat geometries (length, sectorial width and radius)— strong point attachment and interlocking— measures, precautions, particulars addressing points listed in [1.3]— other particulars.

2 Testing requirements

2.1 GeneralProvided that split effects such as listed in [1.3] are confined to the proximate split area, it is consideredsufficient that (if the non-continuous cables from a manufacturer have been certified by the Society) afatigue test and a post-fatigue strength test will be carried out on only one typical mid-range cable sizeassembly. This provides that the effects occurring with continuous rigging are considered similar throughout arange of sizes.It is very likely that both Y-type and C-type or K- type and C-type rigging occur in one set of continuousrigging. It is sufficient to cover the C-type rigging by testing Y-type or K-type, but only if the relevant designcharacteristics of the split (of K- or Y-type) are considered similar with the deflection over a strong point onC-type. Otherwise a separate test shall be set up.

2.2 Geometry and cable sizes2.2.1 Y-Split cables

2.2.1.1 Cable sizeReference is made towards the size chosen to be the Vlower, as being 100% capacity. The Vupper has to bea cable with ca. 75% of the capacity of Vlower and Dupper has to be a cable with ca. 30% of the capacity ofVlower.

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2.2.1.2 Cable anglesIn-plane deflection angles: Vupper has to be deflected by a = 4° and the Dupper has to be deflected by b = 30°in reference to Vlower. These angles are assumed to be at the upper limit of common deflections. See Figure1.

The length of each cable leg should be at least 3 m.

Figure 1 Plan view in-plane set-up and in-plane cycling test of Y-type rigging

α = 4° in x/y-planeβ = 30° in x/y planeδ = angle acc. to force vector resultant, in x/y-planeε = 35° in x/y-planeφ = 35° or 20° in x/y-planeA = lower end of Vlower

B = upper end of Vupper

B' = upper end of Vupper under pretension

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C = inboard end of "spreader strut"D = upper end of Dupper

D' = upper end of Dupper under pretension.

2.2.2 K-Split cables

2.2.2.1 Cables sizes and anglesSee Y-split [2.2.1], with the addition that Dlower shall have ca. 40% of the capacity of Vlower and be set at anangle of 35° off the Vlower. See Figure 2.

Figure 2 Plan view in-plane set up and in-plane cycling testing of K-type rigging

2.2.3 C-Split cables

2.2.3.1 Cable sizeSee Y-split [2.2.1].

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2.2.3.2 Cable anglesIn order to cover jumper configuration C-type rigging, the deflection angle shall be 35°. Otherwise, an angleof 20° suffices. See Figure 3.

Figure 3 Plan view in-plane cycling testing of C-type rigging

2.2.4 Test assemblyThe strong point should be designed in a way it behaves like a pivoting spreader. The spreader needs to beable to articulate freely in order to allow movements of the point in all directions except allowing the strongpoint move in the spreaders longitudinal axis. The spreader's axis shall be pointing in the direction of theoverall resulting force vector (resulting with all shrouds tensioned according to their capacity, see Figure 1,angle δ). All cables and the strut shall be in the same plane initially. See Figure 1.

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2.3 Fatigue testing strategy2.3.1 Setting a referenceDepending on the outcome of testing it might be required that an uncycled sample undergoes a staticstrength test under conditions and set-ups similar to the residual test described in [2.4].

2.3.2 In-plane cyclingK and Y-type: The load path Vlower / Vupper shall be set under an initial pretension of 80% of nominalmaximum predicted or certified working load (MWL, see [7.3.2]) of Vupper. This pre-strain shall be locked andmaintained during the fatigue test.For K-type rigging, Dlower shall be slack. The definition of "slack" is given in [7.3.4].Dupper shall be cycled between slack and its MWL axially 100 000 times (Consider that the lead angle mightchange due to pulling out of plane).

2.3.3 Out of plane cyclingFor common design of Bermudian rigs with spreaders and jumpers, the out of axis deflection of cables (whichare lead over a strong point) is anticipated to stay well below 1°. These greatest deflections are commonlyseen on shrouds on leeward spreader tips. For some fibre cables or fibre rods this deflection under a reducedload (leeward rigging) is considered uncritical. See Figure 4.

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Figure 4 Perspective view out-of-plane set-up and out-of-plane cycling test

Out of plane testing as defined in this paragraph has to be accomplished if one or more of the followingprovisions are met:

1) out of axis deflections of cables lead over a strong point are predicted to be greater than 1° under staticsailing conditions

2) particular design of cables or their fittings in way of strong points suggest that an out of axisdeflection of less than 1° might be critical for the integrity of the cable or fitting. A proof by calculation(geometrically non-linear FEA, reflecting a similar situation like defined by the test set up defined belowis appropriate) is requested by DNV GL in order to assess the situation.

The Society reserves the right to decide whether a condition is met.After cycling according to [2.3.2] is finished, all cables shall be tensioned to 25% of their MWL and be locked.Then, cycling is requested to be carried out at the strong point, perpendicular to the frame plane. Theperpendicular push on the strong point shall cause the verticals to be deflected out of the plane by:

— 2.0° if condition 2) is considered to apply— to twice the predicted angle under condition 1) if condition 1) applies.

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100 000 cycles are requested.

2.4 Residual strength testThe residual strength test is performed to assess the possible aging effects of the tested arrangement. Thepretension set-up from [2.3.2] shall be maintained. The residual strength test will require pulling the Dupperto destruction after being cycled.

2.5 CriteriaThe residual tensile strength may not be less than 2.0 times MWL of the failed cable. After the tests arefinished, failure modes, reasons and consequences of potential degradations shall be analysed and describedwith reference also to the results from [2.3.1]. All results shall be submitted to the Society for review.

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DNV GL AS

CHANGES – HISTORICThere are currently no historical changes for this document.

DNV GLDriven by our purpose of safeguarding life, property and the environment, DNV GL enablesorganizations to advance the safety and sustainability of their business. We provide classification andtechnical assurance along with software and independent expert advisory services to the maritime,oil and gas, and energy industries. We also provide certification services to customers across a widerange of industries. Operating in more than 100 countries, our 16 000 professionals are dedicated tohelping our customers make the world safer, smarter and greener.

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Documents

DNVGL-CP-0413 Carbon and PBO cable rigging for sailing yachts · 1 PBO: Poly p-phenylene-2,6-benzobisoxazole. Section 2 Class programme — DNVGL-CP-0413. Edition November 2016 Page