© Cordage Institute 2007. All rights reserved. No part of this
standard/guideline may be reproduced in any way or by any
means (electronic or mechanical) without permission in
writing from the Cordage Institute.
Approved for use.
Cordage Institute
International Standard
POLYPROPYLENE FIBER ROPE
3-Strand Laid and 8-Strand Plaited Constructions
CI 1301-07
May 2007
Supersedes CI 1301-96, V.2 April 1999
1. Scope
1.1 This standard covers 3-strand laid and 8-strand plaited polypropylene rope for general and
industrial use and should be used in conjunction with CI 1201.
1.2 This standard does not purport to address all of the safety problems associated with its use. It
is the responsibility of the user of this standard to select a size to meet working load
requirements, establish appropriate safety and health practices, and determine the applicability
of regulatory limitations prior to its use. The working load limits and design factors are provided
as guidelines only.
1.3 In the event of any conflict between the text of this document and any references cited, the text
of this document takes preference.
2. Referenced Documents
2.1 CI 1201: Fiber Rope – General Standard. This standard contains requirements for ordering,
materials, manufacturing, product identification, physical properties, performance, testing,
packaging, labeling, quality assurance, end item inspection and certification that are applicable
to this standard, unless otherwise specified.
2.2 CI 1202: Terminology. This standard contains definitions of terms used in Cordage Institute
standards and guidelines.
2.3
2.4
CI 1203: Hardness Values. This standard provides hardness values for stranded rope.
CI 1401: Safe Use Guidelines. This document provides important information regarding
working load limits for specific applications.
2.5 CI 1500: Test Methods for Fiber Ropes. This standard provides both the general and special
test methods to determine rope physical properties.
2.6 CI 1501: Hardness Test Method for 3-strand and 8-strand Fiber Ropes. This standard defines
the procedure for determining hardness values.
2.7 CI 2100: Procedure for 3-strand eye splice.
2.8 CI 2101: Procedure for 8-strand eye splice.
3. Terminology
3.1
3.2
3.3
Definitions – for definitions of terms used in this and other standards, refer to CI 1202.
Polypropylene Fibers: Monofilament or fibrillated film fibers having a tenacity, sufficient to meet
the requirements of this standard.
Units: The values stated in SI are to be regarded as standard. The values in inch-pound units
are provided for use where required.
Cordage Institute, 994 Old Eagle School Rd., Suite 1019, Wayne, PA 19087-1866
Phone: 610-971-4854 • Fax: 610-971-4859 • E-mail: [email protected] • Web: www.ropecord.com
International Standard: CI 1301-07 Polypropylene Fiber Rope
3-Strand Hawser and 8-Strand Plaited Constructions
May 2007
4. Ordering Information
4.1 Unless otherwise stated or included in a purchase order, ordering information shall meet the
requirements of CI 1201.
5. Materials
5.1
5.2
The rope may be fabricated from monofilament or fibrillated film fibers.
No extraneous materials shall be added for the purpose of weighting the rope. Extractable
matter of the finished rope shall not exceed 2%.
5.3 Fiber finish: when specified, an overlay finish shall be applied to all yarns used to make the
rope, either by the yarn producer or the ropemaker. The finish shall improve the resistance to
internal fiber-to-fiber abrasion and external abrasion when a rope rubs against other surfaces.
The total finish content shall not be less than 0.35% and not over 5%.
5.4 When specified, the rope fibers shall be stabilized against deterioration due to ultraviolet light
(sun) light.
6. Manufacturing
6.1 The rope shall be either 3-strand laid or 8-strand plaited construction.
6.1.1 3-strand laid rope shall be made with 3 strands, each strand having an identical structure and
number of yarns. The strands shall be formed and the rope laid to produce a torque-balanced
product.
6.1.2 8-strand plaited rope shall be made of 2 pairs of right-twisted strands and 2 pairs of left-twisted
strands plaited together such that pairs of strands of the opposite twist alternately pass one
over the other, with all strands having identical structure and the same number of yarns.
6.2 The use of an internal marker or a surface yarn maker shall be the only exception to the strandto-strand uniformity requirement.
7. Product Identification
7.1 The manufacturer may use colored synthetic yarn(s), in accordance with CI 1201, to identify his
product.
7.2 When required, a printed, marker tape shall be used in accordance with CI 1201.
8. Physical Properties
8.1 The physical properties of the ropes shall meet or exceed those listed in Table 1.
9. Performance Requirements
9.1 Elongation of the ropes shall not exceed 45% at breaking point when tested according to
Cordage Institute Standard Test Method CI 1500.
9.2 The finished rope shall be easily spliced using the Cordage Institute splicing procedures for 3
and 8-strand rope (CI 2100 and CI 2101).
9.3 When a Hardness Value is required, the finished rope shall meet the requirements of CI 1203
Hardness Values, when tested according to the test method CI 1501.
10. Packaging and Labeling
10.1 Unless otherwise stated or included in a purchase order, the packaging and labeling of the
products shall meet the requirements of CI 1201.
11. Quality Assurance
11.1 Unless otherwise specified, Quality Assurance of the product including sampling, end
item inspection, performance testing, and certification shall meet the requirements of CI 1201.
2
International Standard: CI 1301-07 Polypropylene Fiber Rope
3-Strand Hawser and 8-Strand Plaited Constructions
May 2007
12. Special Requirements
12.1 Requirements beyond the scope of this document shall be established by a mutual agreement
between the buyer and the seller.
13. Key Words
13.1 Polypropylene rope, rope, 3-strand laid rope, 8-strand plaited rope, laid rope, plaited rope.
The use of rope and cordage products has inherent safety risks which are subject to highly variable
conditions and which may change over time. Compliance with standards and guidelines of the
Cordage Institute does not guarantee safe use under all circumstances, and the Institute disclaims
any responsibility for accidents which may occur. If the user has any questions or uncertainties about
the proper use of rope or cordage or about safe practices, consult a professional engineer or other
qualified individual.
3
International Standard: CI 1301-07 Polypropylene Fiber Rope
3-Strand Hawser and 8-Strand Plaited Constructions
May 2007
Table 1: Physical Properties
Nominal
Diameter (1)
mm
inch
5
3/16
6
1/4
8
5/16
10
3/8
11
7/16
12
1/2
14
9/16
16
5/8
18
3/4
22
7/8
24
1
26
1-1/16
28
1-1/8
30
1-1/4
32
1-5/16
36
1-1/2
40
1-5/8
44
1-3/4
48
2
52
2-1/8
56
2-1/4
60
2-1/2
64
2-5/8
68
2-3/4
72
3
80
3-1/4
88
3-1/2
96
4
104
4-1/4
112
4-1/2
120
5
128
5-5/16
136
5-5/8
144
6
Size
No. (2)
5/8
3/4
1
1-1/8
1-1/4
1-1/2
1-3/4
2
2-1/4
2-3/4
3
3-1/4
3-1/2
3-3/4
4
4-1/2
5
5-1/2
6
6-1/2
7
7-1/2
8
8-1/2
9
10
11
12
13
14
15
16
17
18
Linear
Density (3)
Pounds per
kilotex
100 feet
9.70
0.65
17.2
1.15
26.9
1.8
38.8
2.6
52.2
3.5
68.6
4.6
88.0
5.9
107
7.2
155
10.4
212
14.2
269
18
304
20.4
340
22.8
412
27.6
454
30.4
588
39.4
686
46
791
53
1029
69
1164
78
1313
88
1596
107
1790
120
2104
141
2283
153
2775
186
3327
223
4058
272
4700
315
5371
360
6266
420
7072
474
7923
531
8997
603
Minimum Breaking Strength (MBS)(4) (5) and Working Load Limit (6)
(WLL) for Two Design Factors
KiloNewtons
Pounds
MBS
WLL
MBS
WLL
Design Factor
Design Factor
12
5
12
5
3.2
0.27
0.65
730
61
146
5.6
0.47
1.12
1260
105
252
8.5
0.71
1.70
1915
160
383
12.1
1.0
2.4
2720
227
544
15.7
1.3
3.1
3525
294
705
18.8
1.6
3.8
4235
353
847
22.9
1.9
4.6
5140
428
1028
27.8
2.3
5.6
6250
521
1250
38.1
3.2
7.6
8570
714
1714
51.6
4.3
10.3
11600
967
2320
64.1
5.3
12.8
14400
1200
2880
71.6
6.0
14.3
16100
1342
3220
79.6
6.6
15.9
17900
1492
3580
96.5
8.0
19.3
21700
1808
4340
105
8.8
21.1
23700
1975
4740
136
11.3
27.2
30600
2550
6120
159
13.3
31.8
35800
2983
7160
184
15.3
36.7
41300
3442
8260
233
19.4
46.6
52400
4367
10480
262
21.9
52.5
59000
4917
11800
296
24.6
59.2
66500
5542
13300
359
29.9
71.7
80600
6717
16120
401
33.4
80.2
90200
7517
18040
471
39.2
94.1
105800
8817
21160
511
42.6
102.2
114900
9575
22980
605
50.4
121.0
136000
11333
27200
717
59.8
143.5
161300
13442
32260
856
71.4
171.2
192500
16042
38500
987
82.2
197.3
221800
18483
44360
1112
92.7
222.4
250000
20833
50000
1278
106.5
255.6
287300
23942
57460
1430
119.2
286.1
321600
26800
64320
1591
132.6
318.3
357800
29817
71560
1785
148.7
356.9
401200
33433
80240
Important Notes:
(1) Diameters are approximate. The reference for rope size is its linear density or weight per unit length.
(2) Size No. is the approximate rope circumference in inches.
(3) Linear Density is considered standard. Tolerances are: ±10% for diameters below 8 mm inclusive; ±8% for diameters 10-14
mm inch inclusive; ±5% for 16 mm diameter and larger.
(4) Minimum Breaking Strength (MBS) values in individual rope standards are based on data from a number of rope
manufacturers and the result of computation by regression analysis.
(5) The MBS values are based on ropes tested with Eye Splices, making the values approximately 10% lower than ropes
tested without splices.
(6) Working Load Limit (WLL) is determined by dividing the new rope MBS by a selected Design Factor. Examples of WLL,
based on a DF of 12 and 5, are given above. For actual Design Factor selection for a specific application, refer to "CI 1401:
Safe Use Guidelines" included as page 5 of this standard.
4
Cordage Institute International Guideline CI 1401-06 • Safer Use of Fiber Rope • May 2006
Purpose
This Guideline is provided to help in the selection and safer use of
cordage products. Compliance with Cordage Institute Standards and
Guidelines does not guarantee safe use under all circumstances, and the
Institute disclaims any responsibility for any accidents that may occur.
1. Overview
There are inherent risks in the use of rope and cordage because such
products are subject to highly variable conditions that change over time.
Therefore, Design Factor selections and Working Load Limits must be
calculated with consideration of exposure to risk and actual conditions of
use for each application. If in doubt, consult an experienced engineer or
other qualified individual regarding the design, application and selection
of a rope product.
2. Minimum Breaking Strength
The Minimum Breaking Strength (MBS) is the force that a given
rope is required to meet or exceed in a laboratory test when it is new and
unused. MBS values are given in Cordage Institute Standards and
individual manufacturers’ specifications.
3. Working Load / Working Load Limit
The Working Load (WL) is the weight or force applied to rope or
cordage in a given application.
The Working Load Limit (WLL) is a guideline for the maximum
allowable capacity of a rope product and should not be exceeded.
Applied loads higher than a specified WLL can overstress and
damage fibers, resulting in premature rope failure. The Working Load of
an application should not exceed the WLL of the rope for optimal product
performance and the safety of personnel and property.
4. Design Factors
The Design Factor (DF) is the ratio between the MBS and WL. This
value is the margin of safety for an application. For a particular
application, the factors affecting rope behavior and the degrees of risk to
life, personnel and property must be considered when setting a DF.
Commercial and industrial users must determine a DF based on
actual service conditions and establish operating procedures for a specific
application. A “general use” consumer must also assess his application
and determine conditions of use and hazards that may apply.
As a rule, the more severe the application, the higher the DF needs to
be. Selection of a DF in the general range between 5:1 and 12:1 is
recommended. A design factor at the low end of this range should only
be selected with expert knowledge of conditions and professional estimate
of risk. DF at or above the high end of the range should be used for more
severe conditions of use. When in doubt, always select the highest
practical DF, or contact the manufacturer for additional guidance.
Engineering assistance may be necessary to determine the service loads
and risks and to set the appropriate DF.
Considerations in the Selection of a Design Factor
• Experience is the best guide for determining a DF. Select a DF value
used in a similar application that proved successful.
• Consider increasing the Design Factor if:
- Problems have previously been observed in similar applications
- Injury, death or loss of property may result if rope fails
- Loads are not accurately known
- High or continuous dynamic loads are anticipated (See Section 6)
- Shock loads are anticipated
- Extensive cyclic loads are likely to occur
- Tension is on the rope for long periods
- Knots are used, as knots can reduce strength by as much as 50%
- Operators are not well trained
- Operation/use procedures are not well defined and/or controlled.
- Severe abrasion is likely to occur from exposure to rough surfaces or
cutting edges, or by contamination from dirt and grit.
Expert Guidance is Strongly Suggested for the Following Situations
• Rope is used constantly over pulleys or around a small bend.
• Rope is used at elevated temperature that may glaze, weaken or melt the
fibers.
• Rope is used in the presence of hazardous chemicals.
• Rope is not new and is of unknown properties and/or prior use.
• Rope is not inspected frequently or adequately.
• Rope will be in service for long periods that may lose strength due to
fatigue.
CI Guideline 2003 Fibers for Cable, Cordage, Rope and Twine explains
some of the effects of elevated temperature and chemicals on synthetic
fibers.
5. Calculation of Values
After the WL has been estimated and the DF for an application has
been determined, a rope can be selected by calculating the necessary new
rope Minimum Breaking Strength. The required MBS is determined by
multiplying the Working Load by Design Factor. WL*DF=MBS. For
example, an application with a Working Load of 3 tons and a Design
Factor of 10 would require an rope with MBS = 3*10 = 30 tons.
Similarly, the Working Load Limit of a new rope is determined by
dividing the Minimum Breaking Strength by the Design Factor for a
given application. MBS÷DF=WLL. Examples of WLL, based on a DF of
5:1 and 12:1, are given in individual Cordage Institute Standards. The
WLL in CI standards are for new ropes with standard terminations.
6. Dynamic Loading
Nearly all rope in use is subject to Dynamic Loading to some degree.
Whenever a load is picked up, stopped, moved or swung there is an
increased force due to the acceleration or dynamics of the movement. The
more rapidly or suddenly such actions occur, the greater the forces. In
extreme cases, the force sustained by the rope may be two, three, or even
more times the static load. (e.g., when picking up a tow on a slack line or
using a rope to stop a falling object) Therefore, in applications such as
towing lines, lifelines, safety lines, climbing ropes, etc., the DF must
reflect the added risk involved. If significant dynamic load is foreseen, a
DF at or above the high end of the range should be considered. Loads
should be handled slowly and smoothly to minimize dynamic effects.
Users should also be aware that dynamic effects are greater on a lowelongation rope, such as manila, than a high-elongation rope, such as
nylon. Also note that dynamic effects are more significant on short
segments of rope as opposed to longer ones.
Excessive dynamic loading will shorten the life of a line and/or cause
premature failure.
7. Recoil/Snapback Safety Warning
When a tensioned rope breaks, an attachment fails, or either are
suddenly released, the energy in the rope will cause it or the attachment to
recoil back in unpredictable directions with great force, resulting in
possible injury or death to persons in its path. Persons should never stand
in line with or in the general path of rope under tension to avoid snapback
injuries.
8. Special Applications
The DF ranges can be lower or higher than recommended in
applications where actual field experience has proven successful, where a
recognized standard or specification exists, where qualified professionals
have made a thorough engineering analysis of all conditions of use and/or
a regulatory agency has granted specific permission. In such controlled
cases, breaking strength, elongation, energy absorption, and other factors,
including operating procedures, must be evaluated during the selection of
the Design Factor.
In addition to the above, more specific guidelines should be
considered for applications such as life safety and marine use.
© Cordage Institute 2006. All rights reserved. No part of this standard/guideline may be reproduced or utilized in any way or by any means (electronic or mechanical)
without permission in writing from the Cordage Institute.
Cordage Institute, 994 Old Eagle School Rd., Suite 1019, Wayne, PA 19087-1866
Tel: 610-971-4854; Fax: 610-971-4859; E-mail: [email protected]; Web: www.ropecord.com