SPEC 377N.pdf

UNITED STATES COAST GUARD

OCEAN ENGINEERING DIVISION

WASHINGTON, D.C.

SEPTEMBER 2016

SPECIFICATION FOR THE MANUFACTURE

OF

OPEN LINK, WELDED STEEL CHAIN AND BRIDLES

SPECIFICATION NO. 377

REVISION N

1. SCOPE

1.1 Purpose. This specification describes the requirements for the manufacture of open link, welded steel chain and bridles used for mooring aids to navigation buoys in the coastal and inland waters of the United States.

1.2 Precedence. In the event of a conflict between the requirements of this specification, the drawings, the contract, and the applicable documents, the order of precedence is as follows:

a. The contract

b. This specification

c. The drawings listed in paragraph 2.2

d. The applicable documents listed in paragraph 2.1

1.3 Classification. Chain and bridles are classified by size as indicated in Tables I and II below.

Chain and bridle dimensions shall be either U.S. Customary sizes (inches/feet) or metric sizes

(millimeters/meters). These two measurement standards shall not be combined.

1.3.1 Chain. Chain size is defined as the bar diameter in inches or millimeters of the common links used in the chain. Chain is furnished in 90ft (27.4m) lengths (called "shots"), in 45ft

(13.7m) lengths (called "half shots"), and in 540ft (164.4m) lengths.

Table I

U.S. Customary Sizes

(inches)

Metric Sizes

(millimeters)

U.S. Customary Sizes

(inches)

Metric Sizes

(millimeters)

1/2 12.7 1-3/4 44

3/4 19 1-7/8 48

1 25 2 51

1-1/8 28 2-1/8 54

1-1/4 32 2-1/4 57

1-1/2 38

1.3.2 Bridles. Bridle size is defined as the bar diameter in inches or millimeters of the common links used in bridle, combined with the respective length of the bridle in feet or meters.

Table II

(in x feet)

Metric Sizes

(mm x meters)

7/8 x 10 22 x 3.1

1 x 12 25 x 3.6

1-1/4 x 15 32 x 4.5

1-1/2 x 18 38 x 5.5

1-1/2 x 20 38 x 6.1

1-1/2 x 26 38 x 7.9

2. APPLICABLE DOCUMENTS

2.1 Industry publication. The following document forms a part of this specification to the extent referenced herein. The suffix denoting the specific issue of the document will be omitted from future references to the document in this specification.

AMERICAN SOCIETY FOR QUALITY (ASQ)

ANSI/ASQ/ISO

Q9001-2015

Quality Management Systems -- Requirements

American Society for Quality/International Org. for

Standardization (Sep-2015)

2.1.1 Source of document. The document may be obtained from the following source:

American Society for Quality

Web: http://asq.org/

Phone: (800) 248-1946

Mail: 600 North Plankinton Avenue

Milwaukee, WI 53203

Order: http://asq.org/iso9001/

2.2 Drawings. The latest revisions of the following United States Coast Guard Ocean

Engineering Drawings form a part of this specification, and are hereafter referred to as “the drawings."

Number Title

121031 Buoy Bridles

121032 Buoy Chain http://asq.org/ http://asq.org/iso9001/

3. REQUIREMENTS

3.1 General. The chain and bridles shall be manufactured in accordance with the drawings and shall meet the requirements of this specification.

3.2 Material. The chain and bridles shall be manufactured of carbon steel of uniform quality and shall be resistance welded. The chemical composition of the steel shall be determined at the steel mill for each heat of steel and shall conform to the following values:

Element Weight % (Max.)

Carbon (C) 0.36

Manganese (Mn) 1.90

Silicon (Si) 0.55

Phosphorus (P) 0.05

Sulfur (S) 0.05

3.2.1 Material certificates. The Contractor shall furnish material certificates from the steel mill for each heat of steel used. The certificates shall indicate the heat number, steel designation, chemical composition, and quantity of steel represented by the certificate.

3.3 Traceability. The Contractor shall maintain the traceability of steel throughout the production, testing, and inspection processes. Each shot and each bridle offered shall be traceable to the heat of steel from which it was made through the batch number and trace code described below.

3.3.1 Batch number. A batch is defined as all chain and bridles of the same size manufactured from the same heat of steel. The Contractor shall assign a unique number to each batch of chain and bridles. The Contractor may use the heat number assigned by the steel mill as the batch number provided it meets the requirements of this paragraph.

3.3.2 Trace code. The Contractor shall assign a trace code to each shot and each bridle submitted under this specification. The purpose of this trace code is to identify the batch of steel from which the shot or bridle was manufactured. The type of trace code used is at the Contractor's discretion: it may be the batch number itself, a unique sequential number, or any other alphanumeric designation. The only requirement is that the trace code clearly identifies the batch of steel from which the shot or bridle was manufactured.

3.4 Design.

3.4.1 Chain. Chain shall be furnished in shots of at least 90ft (27.4m) length, half shots of at least

45ft (13.7m) length, and 540ft (164.4m) lengths (tolerance for all = +3%, -0%). The common links and end links shall conform to the shapes, dimensions, and tolerances shown on the drawings. End links are only required on designated 1/2-inch (12.7 mm) and 3/4-inch (19 mm) chain, as specified on the delivery order.

3.4.2 Bridles. Bridles shall be constructed of a specific number of common links and shall be the applicable length within the specified tolerances shown in Table III and on the drawings. The common links, end links, and center rings shall conform to the shapes, dimensions, and tolerances shown on the drawings. End links are required on all bridles.

Table III

(inches x feet)

T o ta l

C o m m o n

L in k s

Metric Sizes

(millimeters x meters)

Bridle

Size

Minimum

Length

Maximum

Length

Bridle

Size

Minimum

Length

Maximum

Length

7/8 x 10 10ft 10ft 7in 28 22 x 3.1 3.00m 3.20m

1 x 12 11ft 3in 12ft 3in 28 25 x 3.6 3.38m 3.65m

1-1/4 x 15 14ft 15ft 3in 28 32 x 4.5 4.24m 4.57m

1-1/2 x 18 17ft 18ft 3in 28 38 x 5.5 5.12m 5.50m

1-1/2 x 20 19ft 20ft 3in 32 38 x 6.1 5.70m 6.12m

1-1/2 x 26 25ft 26ft 3in 44 38 x 7.9 7.46m 8.00m

3.4.3 Inside curvature of links. The common links and end links of chain and bridles shall be made such that the inside curvature shall allow a round bar, of the diameter listed in Table IV, to pass through the link at either end. When the bar is held perpendicular to the link, it shall not be restricted from making contact with, or coming within 1/32in (0.8 mm) of, all points along the curvature, or from freely passing between both ends of the link.

Table IV

Minimum Inside Curvature Mating

Chain Size Minimum Bar

Diameter inch millimeter inch millimeter

1/2 12.7 5/8 15.9

3/4 19 1 25.4

1 25 1-5/16 33.3

1-1/8 28 1-1/2 38.1

1-1/4 32 1-11/16 42.9

1-1/2 38 2 50.8

1-3/4 44 2-3/8 60.3

1-7/8 48 2-9/16 65.1

2 51 2-3/4 69.9

2-1/8 54 3 76.2

2-1/4 57 3-1/8 79.5

3.5 Welding. Welding shall be performed by resistance welding.

3.5.1 Weld defects. The welds shall not contain craters, undercutting, overlap, or porosity.

3.5.2 Weld Diameter. The diameter of the weld at any one point shall not be less than the bar diameter, nor shall it exceed the bar diameter by more than 10 percent.

3.5.3 Bar end misalignment. Bar end misalignment shall not exceed 5 percent of the bar diameter.

3.6 Proof load. Every shot of chain and every bridle offered for acceptance shall have successfully withstood the proof load specified in Table V without rupture, deformation, cold welding, or stretching beyond the tolerances shown on the drawings. A horizontal test bed or an incremental calibrator shall be used to apply the proof load. This process shall be recorded in the documentation of inspections and tests required by paragraph 4.1.2. The Contractor shall certify conformance with this requirement by submitting a Certificate of Performance (Appendix A) for each batch of chain or bridles offered.

3.7 Breaking load. Chain and bridles shall be capable of withstanding the applicable breaking load specified in Table V for a minimum of 15 seconds without rupture.

Table V

Proof and Breaking Loads

Chain/Bridle

Link Diameter

Proof Load

Breaking Load inch millimeter lb kg lb kg

1/2 12.7 7,500 3,402 15,000 6,804

3/4 19 16,000 7,257 32,000 14,515

7/8 22 22,000 9,979 44,000 19,958

1 25 29,000 13,154 58,000 26,308

1-1/8 28 38,500 17,463 77,000 34,927

1-1/4 32 45,500 20,638 91,000 41,277

1-1/2 38 65,500 29,710 131,000 59,421

1-3/4 44 86,500 39,236 173,000 78,472

1-7/8 48 100,000 45,360 200,000 90,720

2 51 116,000 52,616 232,000 105,232

2-1/8 54 131,000 59,420 262,000 118,841

2-1/4 57 147,000 66,678 294,000 133,355

3.8 Elongation. The elongation of the chain and bridles shall be at least 15 percent before rupture. The elongation shall be determined in accordance with paragraph 4.2.4.6.

3.9 Cracks. A crack is defined as a linear defect that has a length of more than three (3) times its width. Chain and bridles shall be free from cracks in the interior link radius and weld fusion zone.

3.10 Surfaces. Each link shall be free from mill defects, burrs, slag, weld spatter, or rough surfaces which might present a safety hazard or cause kinking of the chain or bridle in service.

3.11 Finish. Chain and bridles shall be submitted in natural color and finish. Varnish or other coatings shall not be used.

3.12 Marking. The last link on both ends of each shot of chain and one end link on each bridle shall be legibly and permanently stamped or engraved with the manufacturer’s name or trademark, the trace code per paragraph 3.3.2, and the year of manufacture. For 1/2-inch chain supplied without end links, only the trace code is required and shall be applied at a maximum rate of once every ten links.

4. INSPECTION AND ACCEPTANCE

4.1 General. The Contractor shall have a quality assurance program in place prior to beginning the manufacture of the chain and bridles. This quality assurance program shall meet the minimum requirements of ANSI/ASQ/ISO Q9001. However, the Contractor does not have to be

Q9001 certified. The Contractor shall ensure that every shot and bridle submitted to the Coast

Guard meets the requirements of this specification.

4.1.1 Test equipment calibration system. The Contractor shall maintain a calibration and maintenance system to control the accuracy of measurement and test equipment used in the fulfillment of the requirements of this specification. The system shall include, as a minimum, prescribed calibration intervals, source of calibration, and a monitoring system to ensure adherence to calibration schedules. All testing equipment shall have been calibrated traceable to the International Standards within 12 months prior to the testing. At the time of final inspection, documentation in support of this requirement shall be made available to the Contracting

Officer’s Representative (COR).

4.1.2 Documentation of inspections and tests. The Contractor shall maintain, and make available to the COR, documentation of all inspections and tests performed throughout the entire manufacturing process and during the final inspection.

4.2 Coast Guard final inspection. The following inspections and tests are not intended to limit or supplant any inspections or tests normally performed by the Contractor to ensure product quality.

4.2.1 Sampling. Samples for inspections and tests performed during the final inspection will be randomly selected from batches by the COR. The actual number of samples selected for testing will be at the discretion of the COR.

4.2.2 Units of inspection.

4.2.2.1 Overall shot and bridle length requirement. The unit of inspection for the overall length requirement in paragraphs 3.4.1 and 3.4.2 will be one shot or one bridle.

4.2.2.2 Proof load, breaking load, and elongation test requirements. The unit of inspection for the requirements in paragraphs 3.6, 3.7, and 3.8 will be one shot or one bridle.

4.2.2.3 Other requirements. The unit of inspection for the requirements in paragraphs 3.4.3, 3.5.1, 3.5.2, 3.5.3, 3.9, 3.10, 3.11, and 3.12 will be one link.

4.2.3 Rejection Criteria.

4.2.3.1 Rejection criteria for material composition defects. Failure to comply with the requirements of paragraphs 3.2 and 3.2.1 will result in rejection of the entire batch. A batch thus rejected shall not be resubmitted.

4.2.3.2 Rejection criteria for visual defects. Failure to comply with the requirements in paragraphs 3.4.1, 3.4.2 (except for bridle length – see paragraph 4.2.3.3), 3.4.3, 3.5.1, 3.5.2, 3.5.3, 3.10, 3.11, and 3.12 will result in rejection of the entire batch in accordance with the rejection criteria in Tables VI and VII. The rejected batch may, at the discretion of the COR, be reworked and resubmitted for inspection when it complies with this specification.

Table VI

Overall Length Rejection Criteria

Number of shots or half-shots per batch

Defective shots or half-shots

Accept Reject

2 to 15 0 1

16 to 50 1 2

51 to 90 2 3

91 to 150 3 4

151 to 280 5 6

281 and above 7 8

Table VII

Rejection Criteria for Visual Defects

(other than overall length)

Number of links in batch

Defective links

Accept Reject up to 500 2 3

501 to 1,200 3 4

1,201 to 3,200 5 6

3,201 to 10,000 7 8

10,001 to 35,000 10 11

35,001 and above 14 15

4.2.3.3 Rejection criteria for bridle length defects. Failure of any sample to comply with the bridle length requirements of paragraph 3.4.2, Table III will result in rejection of the entire batch.

The rejected batch may, at the discretion of the COR, be reworked and resubmitted for inspection.

4.2.3.4 Rejection criteria for welds. Links shall not rupture at the weld when subjected to the tests outlined in paragraphs 4.2.4.4, 4.2.4.5, and 4.2.4.6. Any link that ruptures at the weld will result in rejection of the entire batch. A batch thus rejected shall not be reworked or resubmitted.

4.2.3.5 Rejection criteria for strength and elongation defects. Failure of any sample to comply with the requirements of paragraphs 3.6, 3.7, and 3.8 will result in rejection of the entire batch.

A batch thus rejected shall not be reworked or resubmitted.

4.2.3.6 Rejection criteria for cracks. Failure of any sample to comply with the requirement of paragraphs 3.9 will result in rejection of the entire batch. A batch thus rejected shall not be reworked or resubmitted.

4.2.4 Inspections and tests.

4.2.4.1 Material conformance inspection. The COR will review the material certificates required by paragraph 3.2.1 to verify conformance with paragraph 3.2. In addition, the COR will review the Contractor's traceability system to verify conformance with paragraph 3.3. Rejection criteria for the material conformance inspection will be in accordance with paragraph 4.2.3.1.

4.2.4.2 Visual inspection. The Contractor shall perform all visual inspections necessary to ensure compliance with the requirements of paragraphs 3.4.1, 3.4.2, 3.4.3, 3.5.1, 3.5.2, 3.5.3, 3.10, 3.11, and 3.12. At the time of final inspection, the COR will verify compliance by performing visual inspections on selected samples. Rejection criteria for visual inspections will be in accordance with paragraphs 4.2.3.2 and 4.2.3.3.

4.2.4.3 Proof load test. The COR will review the Certificates of Performance required by paragraph 3.6. In addition, the COR will witness proof load tests performed on selected samples.

Rejection criteria for the proof load test will be in accordance with paragraph 4.2.3.5.

4.2.4.4 Breaking load test. The breaking load tests shall be performed in the presence of the

COR. Samples for these tests shall be cut from the ends of the sample shots or bridles chosen by the COR. Samples shall consist of 3 to 7 links (excluding the end links) as required by the testing machine being used, or as determined by the COR. Samples shall be free from twist, and shall be secured to the testing machine with a bar, pin, or half link having a diameter no greater than the "minimum bar diameter" listed in Table IV for the diameter of the sample links being tested. All stresses bearing on the terminal links shall be the same as those applied to every link in the sample. The samples shall be brought to the breaking load and held for 15 seconds. The highest load applied to each sample shall be recorded on the documentation of inspections and tests as required by paragraph 4.1.2. Rejection criteria for the breaking load test will be in accordance with paragraph 4.2.3.5.

4.2.4.5 Weld strength testing. During the breaking load test, the COR may require that the load be increased until the sample ruptures. Samples that break at the weld will result in rejection of the batch in accordance with paragraph 4.2.3.4. The highest load applied to each sample shall be recorded on the documentation of inspections and tests as required by paragraph 4.1.2.

4.2.4.6 Elongation test. The elongation test shall be performed in the presence of the COR.

Samples for these tests may be the same as those used for the breaking load tests at the discretion of the COR. The setup criteria shall be as specified in paragraph 4.2.4.4. Elongation shall be determined using an autographic recorder, or by measuring the sample manually before and after the test. When performing manual measurements, ten percent of the applicable proof load shall be applied to each sample for the initial measurement to ensure that the links are properly set.

Subsequent measurements of each sample shall be taken with the load reduced to ten percent of the proof load. The elongation for each sample shall be recorded on the documentation of inspections and tests as required by paragraph 4.1.2. Rejection criteria for the elongation test will be in accordance with paragraph 4.2.3.5.

4.2.4.7 Testing for cracks. The COR will test selected samples for cracks using magnetic particle or dye penetrate inspection procedures. Rejection criteria for cracks will be in accordance with paragraph 4.2.3.6.

4.3 Disposition of shot and bridle remains.

4.3.1 Shots. Shots which have had no more than 9 links (including the end link) cut from one end for purposes of the breaking load and elongation tests may be submitted as deliverables.

Although the shots may not meet the overall length requirements of paragraph 3.4.1, they shall meet all other requirements of this specification. The marking required by paragraph 3.12 shall be located on the last common link.

4.3.2 Bridles. Bridles which have had sample links cut out for the breaking load and elongation tests shall be reworked to replace the sample links (including the end link) and proof tested again. If they successfully pass the proof test (and all other requirements of this specification), then they may be submitted as deliverables. The Contractor shall certify conformance of the proof load test by submitting a Certificate of Performance (Appendix A) for each batch of bridles that have been reworked.

5. PACKAGING AND MARKING

5.1 Preservation, Packaging, Packing. and bridles shall be bundled with wire rope or bundling chain of sufficient size and strength to ensure safe handling and delivery, or shall be contained in barrels. Bundling chain and barrels, as used, shall become the property of the Coast Guard. The maximum number of shots per bundle and the maximum number of bridles per bundle are listed in Tables VIII. The shipment shall be packaged in a manner that will facilitate unloading at destination by standard lifting equipment (i.e., forklift or crane).

Table VIII

Chain Bundling

Bridle Bundling

Chain Size Shots per

Bundle/Drums

Bridle Size Bridles per

Bundle inch x feet millimeter x meter inch x feet millimeter x meter

1/2 x 45 12.7 x 13.7 10 7/8 x 10 22 x 3.1 10

1/2 x 90 12.7 x 27.4 10 1 x 12 25 x 3.6 10

3/4 x 90 19 x 27.4 5 1-1/4 x 15 32 x 4.5 8

1 x 90 25 x 27.4 3 1-1/2 x 18 38 x 5.5 5

1-1/8 x 90 28 x 27.4 1 1-1/2 x 20 38 x 6.1 4

1-1/4 x 90 32 x 27.4 1 1-1/2 x 26 38 x 7.9 4

1-1/2 x 90 38 x 27.4 1

1-3/4 x 90 44 x 27.4 1

1-7/8 x 90 48 x 27.4 1

2 x 90 51 x 27.4 1

2-1/8 x 90 54 x 27.4 1

2-1/4 x 90 57 x 27.4 1

1/2"X540 12.7 x 164.4 1 Drum

5.2 Marking. Each barrel or bundle shall be tagged with metal shipping tags indicating the complete name and address of consignee, contract number, contract item number, lot number, quantity contained, size, National Stock Number (NSN - see Table IX), and name of manufacturer.

Table IX

Item NSN ½"x45' Buoy Chain (with End Links) 2050-01-620-4710

½"x90' Buoy Chain (with End Links) 2050-01-620-4724

¾"x90' Buoy Chain (with End Links) 2050-01-620-4614

½" x 90' Buoy Chain (no End Links) 2050-01-620-4624

½"x540' Buoy Chain (no End Links) 2050-01-620-4754

1" x 90' Buoy Chain 2050-01-620-4867

1-1/8" x 90' Buoy Chain 2050-01-620-4880

1-1/4" x 90' Buoy Chain 2050-01-620-4888

1-1/2" x 90' Buoy Chain 2050-01-620-4902

1-3/4” x 90' Buoy Chain 2050-01-620-4915

1-7/8" x 90' Buoy Chain 2050-01-620-4950

2" x 90' Buoy Chain 2050-01-620-4961

2-1/8" x 90' Buoy Chain 2050-01-620-4969

2-1/4" x 90' Buoy Chain 2050-01-620-4970

7/8" x 10' Bridle 2050-01-620-6092

1" x 12' Bridle 2050-01-620-6103

1-1/4" x 15' Bridle 2050-01-620-6115

1-1/2" x 18' Bridle 2050-01-620-5102

1-1/2" x 20' Bridle 2050-01-620-5099

1-1/2”X26’ Bridle No current NSN

5.3 Material Inspection and Receiving Report (DD-250 Form). Material Inspection and Receiving Report

(DD Form 250). A form DD-250 shall be used as a certification of product quality assurance, as a packing list, and as a certification of acceptance. A separate DD-250 shall be prepared by the

Contractor for each shipping lot. Prior to shipment, the DD-250 must be signed by the COR.

SPECIFICATION FOR THE MANUFACTURE OF OPEN LINK, WELDED STEEL CHAIN

AND BRIDLES

SPECIFICATION NO. 377 REVISION N

September 2016

PREPARED BY: REVIEWED BY:

Signature on file Signature on file

Robert Melin, CWO4 Wayne Danzik

Project Officer Deputy Product line Manager

APPENDIX A

CERTIFICATE OF PERFORMANCE

Contract No.

Chain/Bridle Size_____________ Batch/Heat No. _____________

I hereby certify that _____ shots and/or _____ bridles produced from the above numbered batch, submitted for Coast Guard inspection on the date shown below, have successfully passed the proof load test as specified in paragraph 3.6 and Table V of U.S. Coast Guard Specification No.

377N.

Signed________________________ Date__________________

Title__________________________