Specification NDBC-5109 Rev.docx

NDBC-5109 Rev. -

Procurement Specification for 12-Strand HMPE Rope

CHAIR, ENGINEERING REVIEW BOARD DATE

NATIONAL DATA BUOY CENTER

JOHN C. STENNIS SPACE CENTER

STENNIS SPACE CENTER, MISSISSIPPI 39529-6000

REVISION HISTORY

Revision

Date

Description

NDBC-5109 Rev. -

ACRONYMS AND ABBREVIATIONS

TERM DEFINITION

1.0 PURPOSE

This procurement specification establishes the requirements for 12-strand High Modulus Polyethylene rope for use in the mooring of buoys in the ocean environment. The HMPE rope will be deployed in salt and fresh water ranging from warm tropical waters to cold artic waters.

2.0 APPLICATION

This procurement specification applies to all 12-strand HMPE rope purchased for operational use on NDBC stations.

The following documents were used in developing this specification

a) Cordage Institute, CI-1201-00, Fiber Ropes, General Standard

b) Cordage Institute, CI-1500-99, Test Methods for Fiber Rope

c) Cordage Institute, CI-2003 Fibers for Cable, Cordage, Rope and Twine Subsequent revisions of the above specifications may be substituted unless specified otherwise in the contract. Any ambiguity or conflict between this specification and other applicable documents shall be resolved in the following precedence:

4.0 DISCUSSION

The NDBC uses 12-HMPE rope in operational stations moorings throughout the earth’s oceans. These moorings exist in harsh conditions and are exposed to many hazards such as fish bite, vandalism from long-line fishing vessels, and the general rigors of deploying moorings off the decks of marine vessels. The loss of a single mooring can cost the NDBC $100,000s in the recovery and/or replacement of the lost station. This specification was developed through years of research and operational lesson learned to try and minimize these losses. This specification is intended to ensure the NDBC receives high quality rope regardless of the vendor.

5.0 MATERIALS REQUIRED

The rope shall be fabricated using a polyolefin fiber produced by gel spinning of an Ultra High Molecular Weight Polyethylene (UHMWPE) feedstock to produced extremely high tenacity fibers. The fibers are also called extended-chain PE (Polyethylene) or HPPE (High Performance Polyethylene). The rope shall be constructed using Dyneema® SK-75/90 (DSM Dyneema Corporation) or Spectra® 900/1000 (Honeywell Corporation) fibers. The mixing of HMPE fiber types and grades of different manufacturers shall not be permitted.

6.0 SAFETY

Since it is the burden of the vendor to provide the testing described in this procedure there are no specific safety concerns. However, if the Government should choose to do lot or sample testing the personnel performing the tests shall comply with the safe practices of NWSM 50-1115 Occupational Safety and Health Manual, the NASA SSP-8715-0001 Safety and Health Handbook, and shall follow whatever specific safety practices are required by the specific test procedures.

The rope shall be made of 12 strands arranged in a twill pattern. One half of the strands shall be the “Z” twist while the remaining half shall be the “S” twist. The twist and lay characteristics shall be optimal to maximize the rope’s tenacity while maintaining ease of splice ability by standard hollow braid techniques or alternatively with a tuck splice method.

7.2 Performance

The finished rope shall conform, as a minimum, to the physical and performance properties in the following table. Physical properties may exceed the required minimums.

HMPE 12 STRAND PHYSICAL PROPERTIES

Nominal Size (1)

lbs.

(1) Diameter is approximate and determined by linear density.

(2) New rope Minimum Breaking Strength is based on data from several manufacturers.

(3) Min. Working Load Limit is determined by dividing the new rope Minimum Breaking Strength by the selected Design Factor.

7.3 Put-Up

The rope shall be provided on reels meeting either the Fixed Length criteria (7.3.1) or the Minimum Length criteria (7.3.2). This length scenario shall be specified at the time of purchase.

7.3.1 Fixed Length

Each reel shall contain a fixed length depending upon the nominal diameter of the rope:

The rope shall be furnished on non-returnable wooden reels meeting the following criteria:

a) Flange diameter of 36” (30” for ½” and 5/16”).

b) Barrel diameter of 12” for ½” and 5/16” (18” for all other sizes).

c) Barrel width of 23”for ½” and 5/16” (25 1/5 for all other sizes).

d) The reel drive pinhole diameter shall be 1” and located 5” from the center.

e) The reel head shall be constructed from 5/4” boards x 2 ply laid perpendicular to each other and securely nailed. The nail heads shall be countersunk below the surface of the wood.

f) The headboards shall have a center arbor hole of 3” diameter.

g) The barrel shall consist of ¾” thick wood staves mortised into the reel head.

h) The reel shall be assembled using 3/8” or ½” diameter steel bolts with cup washers on both ends.

7.3.2 Minimum Length

Each reel shall contain a variable length of rope with the combined total equaling the amount of the purchase request. The minimum continuous quantity on a single reel is dependent upon the diameter and is shown in the following table:

7.3.3 Packaging

The rope shall be furnished on non-returnable wooden reels meeting the following criteria:

a) For 5/8”diameter to 1” diameter rope, a flange diameter of 30”. For 1-1/8” diameter and larger rope, flange diameter shall not exceed 8 ft (2.44 m).

b) Barrel diameter of 12” min.

c) Barrel width of 23”min.

d) The reel drive pinhole diameter shall be 1” and located 5” from the center.

e) The reel head shall be constructed from 5/4” boards x 2 ply laid perpendicular to each other and securely nailed. The nail heads shall be countersunk below the surface of the wood.

f) The headboards shall have a center arbor hole of 3” diameter min.

g) The barrel shall consist of ¾” thick wood staves mortised into the reel head.

h) The reel shall be assembled using 3/8” or ½” diameter steel bolts with cup washers on both ends.

Each reel shall be identified with the following information on both reel flanges:

a) Name of manufacturer.

b) Month and year of fabrication.

c) Sequential number of the reel.

d) Type and nominal diameter of the rope.

e) Length of rope on the reel.

f) Contract number.

The supplier is responsible for having all inspections and tests completed by a Government certified laboratory. The Government reserves the right to repeat any and all inspections listed herein for purposes of acceptance testing.

7.4.2 Testing and Inspections

At least one sample from each mill run lot shall be tested to provide the following data. The samples used shall be free of braider splices.

a) Circumference: A rope sample 12’-15’ long must be attached to one end to a solid fixture and tension must be applied to the other end. The tension applied is to be 200d2 lbs. The circumference is to be measured and recorded according to CI-1500. From these results calculate the diameter.

b) Linear Density: Using the same sample above, while under tension, mark off a 10’ section in the middle of the sample. Remove the tension and then cut out the 10’ section. Weigh this section and calculate the linear density according to CI-1500.

c) Performance: Determine the cycled break strength and extension in accordance with CI-1500. From this test determine the following data: tensile strength, and stress/strain curves for the 1st and 11th cycles.

The manufacturer shall provide copies of the following documentation:

Contract documents should specify the following:

The following deliverables shall be provided at least 7 days prior to shipment of the rope. The manufacturer shall provide to NDBC 3 copies of the documentation required in section 7.4.3a-c. This shall be delivered to:

National Data Buoy Center Attention: Contracting Officer Building 3205 Stennis Space Center, MS 39529-6000 Upon approval of the above documentation the manufacturer shall submit documentation in 7.4.3d and proceed with delivery of the rope.

APPENDIX A

CERTIFICATE OF CONFORMANCE

NDBC-5109, 12-Strand HMPE Rope

Contract #

Nominal Diameter (in)

Linear Density (lbs/100 ft)

Tensile Strength (lbs)

Lot Number

I hereby certify that all the information contained above and in exhibits and attachments hereto is true and complete.

Signature:

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