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Ch.2: Technical provisions [Table of Contents]

DNV-OS-E303 Offshore Mooring Fibre Ropes

[-] Ch.3: Classification and Certification

CHAPTER 3

Classification and Certification

Ch.3

SECTION 1
Classification and Certification

Ch.3 Sec.1
A. Certification

Ch.3 Sec.1
A 100   General

Ch.3 Sec.1 A
101   The principles, procedures, applicable class notations and technical basis for offshore classification are given in DNV-OSS-101 for Offshore Drilling and Support Units and DNV-OSS-102 for Floating Production and Storage Units.

Ch.3 Sec.1 A
102   The following requirements shall be applied in conjunction with certification according to this standard.

Ch.3 Sec.1
A 200   Main elements in certification

Ch.3 Sec.1 A
201   The main elements in certification of fibre-rope assemblies are approval of Manufacturer, design verification and fabrication survey.

Ch.3 Sec.1
A 300   Approval of Manufacturer

Ch.3 Sec.1 A
301   Load bearing yarn, fibre rope segments and termination hardware shall be manufactured at works which have been approved by DNV.

Ch.3 Sec.1 A
302   In order to be approved, the manufacturer shall demonstrate and submit documentation to the effect that the necessary manufacturing, testing and inspection facilities and procedures are available and are supervised by qualified personnel. The manufacturer shall also carry out a test programme and submit the results.

Ch.3 Sec.1 A
303   Detailed programmes for approval are given in Standards for Certification No.2.9.

Ch.3 Sec.1
A 400   Deviations and test waivers

Ch.3 Sec.1 A
401   If a manufacturer or user wishes to deviate from the requirements of this Offshore Standard, or any reference standard, then thoroughly documented request for waiver of test or deviation shall be submitted for approval by DNV. Any such request should be included in the Request for Certification.

Ch.3 Sec.1 A
402   Any deviations, exceptions and modifications to referenced codes and standards shall be documented and agreed between user, manufacturer and DNV.

Ch.3 Sec.1
A 500   Design Verification

Ch.3 Sec.1 A
501   Design verification covers review of specifications and documentation listed in Ch.2 Sec.2 and issuance of Design Verification Report.

Ch.3 Sec.1
A 600   Survey during manufacture

Ch.3 Sec.1 A
601   Fabrication survey shall be based on attending tests and inspections, monitoring manufacturing, and review of records.

Ch.3 Sec.1 A
602   Follow-up and witness of the production shall be based on the Manufacturing description and the Inspection & Test plan.

Ch.3 Sec.1
B. Certification of yarns

Ch.3 Sec.1
B 100   Load-bearing yarns

Ch.3 Sec.1 B
101   Load-bearing yarns for use in fibre ropes shall be certified by DNV. One certificate will be issued for each delivery.

Ch.3 Sec.1 B
102   Certification of yarn consists of monitoring and witnessing of testing according to an inspection and test plan (ITP).

Ch.3 Sec.1 B
103   Lots for making the yarn shall be delivered with the manufacturers own certificate or a works certificate.

Ch.3 Sec.1 B
104   The following particulars will be listed in the certificate:
—purchasers name, order number
—manufacturers name
—description of products
—grade of yarn, delivery condition (coating etc)
—identification marking
—test results.

The types of testing for production deliveries are given in Ch.2 Sec.3. The extent of survey and testing should be taken as given by the Approval of Manufacturer documentation.

Ch.3 Sec.1
B 200   Non-load bearing components

Ch.3 Sec.1 B
201   Sheathing materials to be ordered with 2.2 certificates.

Ch.3 Sec.1 B
202   In case of a custom-designed jacket for increased cut resistance, materials shall be ordered with 3.2 certificates.

Ch.3 Sec.1
C. Certification of termination hardware

Ch.3 Sec.1
C 100   General

Ch.3 Sec.1 C
101   Thimbles shall be certified by DNV, based on the requirements of this standard. Minimum one certificate will be issued per delivery.

Ch.3 Sec.1 C
102   Other termination elements shall be certified by DNV according to the appropriate standard.

Ch.3 Sec.1
D. Certification of Fibre-Rope Assemblies

Ch.3 Sec.1
D 100   Introduction

Ch.3 Sec.1 D
101   This section describes the work process that shall take place when fibre-rope assemblies are certified according to the requirements of this standard. It is attempted to give this chapter a chronological order such that the prerequisites for certain steps or milestones may be readily determined. The requirements are found in Chapter 2.

Ch.3 Sec.1 D
102   Fibre-rope assemblies shall be certified by DNV. Certification consists of survey according to ITP. The scope of survey shall as a minimum include intervention points as listed in Appendix A.

Ch.3 Sec.1 D
103   For long-term moorings one DNV certificate will normally be issued for the entire delivery. For mobile moorings it may be desirable to issue one certificate per fibre rope assembly.

Ch.3 Sec.1 D
104   Following particulars will be listed in the certificate:
—purchasers name, order number and vessel identification, were known
—manufacturers name
—description of products and dimensions (length and diameter)
—construction
—identification marking
—reference to yarn certificate
—reference to thimble certificate(s)
—MBS
—A reference to repair procedure (applicable only for mobile mooring).

Ch.3 Sec.1
D 200   Special service requirements

Ch.3 Sec.1 D
201   In case of special service requirements such as sea-bed contact during installation, additional qualification activities shall be carried out based on DNV-OSS-401, subject to approval by DNV.

Ch.3 Sec.1
D 300   Recertification of Offshore Mooring Fibre Ropes

Ch.3 Sec.1 D
301   Used fibre-rope assemblies may be re-certified for continued or prolonged service according to the provisions of this standard.

Ch.3 Sec.1 D
302   Cases which may warrant fibre-rope assembly recertification can be:
—rope design life has expired and the service period of the installation shall be extended
—the mooring system has seen excessive loads compared to the design premise
—the fibre-rope assembly has not been previously certified by DNV
—the rope has been damaged and needs repair.


Ch.3 Sec.1 D
303   The requirements for recertification will be determined by DNV's responsible approval centre on a case-by-case basis.

Ch.3

SECTION 2
Work Process for Certification of Fibre-rope Assemblies

Ch.3 Sec.2
A. General

Ch.3 Sec.2
A 100   Introduction

Ch.3 Sec.2 A
101   In the following, the work process is described. The process consists of the following main steps in chronological order:
—request for certification
—pre-production meeting
—submittal of documentation for approval
—design verification
—production and survey
—issuance of certification documents.

Ch.3 Sec.2
A 200   Request for certification

Ch.3 Sec.2 A
201   The request for certification should be sent to DNV by e-mail. The following information should be included:

General:
—manufacturer name, plant location and reference to manufacturer-approval certificate
—production and delivery schedules for fibre-rope segments and termination hardware
—testing facilities, location and foreseen testing schedule
—type of mooring: mobile or long-term
—scope of delivery
—any requests for deviations or test waivers, fully documented
—dimension, breaking strength of the fibre-rope assembly, including type of fibre and rope construction.

Additional information for long term mooring systems:
—in-service condition assessment scheme
—key results from mooring analysis in order to decide the load levels to be used in the certification test program and determine the rope length in production.

Ch.3 Sec.2
A 300   Pre-production Meeting

Ch.3 Sec.2 A
301   A pre-production meeting shall be held at the manufacturer's premises prior to start of the certification process.

Ch.3 Sec.2 A
302   The meeting shall include representatives from the following organisations:
—manufacturer of the fibre ropes
—DNV surveyor from local survey station appointed to follow up production and testing
—representative from DNV's responsible approval centre in case of special service requirements requiring additional qualification activities
—representative from testing facility if the tests are not carried out by the manufacturer or by DNV.


Ch.3 Sec.2 A
303   The presentation made by the manufacturer shall include:
—scope of work
—outline and description of the components to be produced
—content and requirements of purchase orders/specifications
—testing facilities
—any requests for deviations or test waivers
—any elements not directly covered by this standard
—manufacturer's description/specification regarding production, terminations and testing.


Ch.3 Sec.2 A
304   The presentation made by DNV will include:
—presentation of DNV-OS-E303 (this standard)
—outline and explanation of specific requirements regarding class and certification
—scope of design verification and survey to be carried out by DNV:
—status of documentation submitted to DNV
—status approval of rope manufacturer and sub suppliers
—survey during fabrication of fibre-rope segments and termination hardware
—certification of the termination hardware (type of certificate it shall be ordered with, and requirements to materials and testing)
—witnessing during testing.
—final documentation requirements:
—content
—issue and distribution
—review of final documentation.


Ch.3 Sec.2 A
305   Minutes of Meeting from the pre-production meeting should be issued by the QA responsible of the manufacturer and distributed to the involved parties.

Ch.3 Sec.2
B. Design Verification

Ch.3 Sec.2
B 100   General

Ch.3 Sec.2 B
101   The design verification will be carried out based on the required documentation which shall be submitted by this stage in the work process.

Ch.3 Sec.2 B
102   The documentation requirements and the responsibilities of the user and the manufacturer are summarised in Chapter 2. Approved design documentation and procedures will be listed in the Design Verification Report (DVR).

Ch.3 Sec.2
C. Design Verification Report

Ch.3 Sec.2
C 100   General

Ch.3 Sec.2 C
101   DNV will issue a Design Verification report (DVR) for the fibre-rope assemblies. The DVR will state:
—documents which have been reviewed
—complying standards
—assumptions
—conditions and limitations
—a list of all documents from the client/manufacturer will be included together with reference correspondence; any comments which are to be taken into account.

Ch.3 Sec.2
D. Start up of production

Ch.3 Sec.2
D 100   General

Ch.3 Sec.2 D
101   The production of the fibre-rope segments can commence when DNV's responsible approval centre has issued the Design Verification Report.

Ch.3 Sec.2
E. Survey during production and testing

Ch.3 Sec.2
E 100   Scope of survey

Ch.3 Sec.2 E
101   Check certificates for load-bearing yarns.

Ch.3 Sec.2 E
102   Check certificates for yarns and fabrics to be applied in the sheathing process.

Ch.3 Sec.2 E
103   Prior to start of testing, the attending surveyor and the responsible test engineer should review the approved testing specification together.

Ch.3 Sec.2 E
104   Number of rope tests to be witnessed has to be decided by the surveyor based on experience with the product and the testing laboratory. For testing carried out by DNV, the survey is performed by the responsible test engineer.

Ch.3 Sec.2 E
105   Witness that the production is carried out in accordance with the manufacturing specification and associated QA plans regarding the production of subropes, fibre ropes, terminations and sheathing.

Ch.3 Sec.2 E
106   Scope of survey at the rope manufacturer can be found in Appendix A of this standard.

Ch.3 Sec.2
F. Testing

Ch.3 Sec.2
F 100   General

Ch.3 Sec.2 F
101   The testing shall be carried out according to the provisions set forth in the testing specification.

Ch.3 Sec.2 F
102   The testing specification for all tests and reporting is subject to approval by DNV.

Ch.3 Sec.2 F
103   Subject to documentation and approval by DNV, fibre-rope assembly specimen(s) may be used for change-in-length testing for mobile moorings, instead of the three subropes.

Ch.3 Sec.2 F
104   If cyclic endurance testing and subsequent examinations according to approved procedure of an equal-size or larger, but otherwise identical, fibre-rope assembly has been carried out before, then the test can be waved - subject to a documented waiver request and approval by DNV.

Ch.3 Sec.2
G. Certificates

Ch.3 Sec.2
G 100   Certificates for Load-Bearing Yarns

Ch.3 Sec.2 G
101   The load-bearing yarn for the fibre-ropes shall be ordered with DNV certification at the works.

Ch.3 Sec.2
G 200   Certificates for Termination Hardware

Ch.3 Sec.2 G
201   Termination hardware shall be ordered with DNV certification at the works.

Ch.3 Sec.2 G
202   The certificate format and contents for compliance with this standard is shown in Appendix D.

Ch.3 Sec.2
G 300   Certificates for Fibre-Rope Assemblies

Ch.3 Sec.2 G
301   The certificate format and contents for compliance with this standard is shown in Appendix B for Long-Term-Mooring and in Appendix C for Mobile-Mooring.

Ch.3

APPENDIX A
Scope of Survey at Rope Manufacturer

Surveyor shall have access to the manufacture at any time of production.

An ITP shall be issued by the manufacturer. The ITP shall be reviewed and approved by the surveyor prior to start of production.

The DNV intervention points shall as a minimum include following:

Ch.3 App.A (0)
Activity Ref. in OS DNV role Description 
Pre-production meeting Ch.3 Sec.2 H Scope of deliverySchedule/ITPRope manufacturer AoM statusYarn type, AoM statusTermination hardware AoM statusTesting facilitiesDesign documentation status 
Materials Ch.2 Sec.2 M/R Procurement of materials (yarns, filters, sheating)-recipe of goods:Check certificates and traceability for load bearing yarnsCheck certificates and traceability of termination hardwareCertificates and traceability of non-load bearing yarns, filters, etc. 
Manufacturing of subropes  H(W)/M Witness start of production then monitoring-procedure complianceWitness that the production is carried out in accordance with the manufacturing specification and associated QA plans regarding the production of subropes.Hold point on first subrope if next rope is manufactured with same setup. Witness point on remaining subropes. 
Braiding of rope  H(W)/M Witness start of production. Set up of register plates, set up of machines. Then monitoringProcedure complianceWitness that the production is carried out in accordance with the manufacturing specification and associated QA plans regarding the production of ropes.Hold point on first rope if next rope is manufactured with same setup. Witness point on remaining ropes. 
Eye splicing/Coating  H/W Hold point on first splice. For each step in the production process for the soft eye the surveyor will witness compliance to manufacturing description and rope design description,For remaining terminations witnessing will be carried out.Procedure compliance. Including application of PU coating.  
Testing of subropes and fibre rope assembly Ch.2 Sec.4 H Survey of all tests on the subropes and the full ropes. Prior to start of testing, the attending surveyor and the responsible test engineer should review the approved testing specification together.Visual inspection of the finished fibre rope assembly with hardware fitted, marking, splices, how thimbles are sitting and ease of assembly. Testing shall be in accordance with approved testing specification  
Final inspection  H Visual inspection of the finished fibre rope. Inspection on transportation/packing of the rope, shall be within specification for handling and installation. Marking and packing in accordance to approved procedure.Check identification marking of ropes, thimbles etc. Visual inspection of the rope, no cuts and abrasion, eyes thimbles, chafe protection. 
Records (Data book)  R Production and test reportsComplete design documentation 
Issuance of certificate  H  

Definitions:

Hold point (H): A point where DNV shall be present for survey. Advance notification to DNV shall be given in writing or any other agreed system of notification. Work shall not proceed beyond a hold point without DNV present or, in exceptional cases where presence is waved, without first obtaining a written authorisation from DNV.

Witness point (W): A point where DNV may be present for survey, at their discretion. Advance notification to DNV shall be given in writing or any other agreed system of notification. Work may proceed beyond a witness point with or without DNV present.

Monitoring (M): Intermittent survey of any stage of the work in progress including, but not limited to, checking compliance with procedures/instructions for manufacture, testing and inspection, observing workmanship, traceability, etc.

Review (R): Examination of records of activities performed or results achieved.

Ch.3

APPENDIX B
Example of Certificate Format for Long-Term Moorings

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Ch.3

APPENDIX C
Example of Certificate Format for Mobile Moorings

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Ch.3

APPENDIX D
Example of Certificate Format for Termination Hardware

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Ch.2: Technical provisions [Table of Contents]