PREVIOUS | TABLE OF CONTENTS | NEXT

1. General

1.0 Multi-use slings are to be manufactured tested, marked and otherwise comply with International Standard ISO 4878; one way slings shall similarly comply with BS1 Standard BS 3481 Part 3. Additional Canadian modifications/requirements are as contained herein and are to be complied with. The owner shall ensure that slings and lifting gear meet the requirements of the Tackle Regulations.

1.1 A batch shall comprise of a maximum of 500 slings.

1.2 At the manufacturing level minimum specified tensile strength of slings shall be determined based on a sufficiently large number of tests to reliably establish the least breaking strength of the sling, which would ensure satisfactory results when representative tests are taken during the production run and for certification purposes.

1.3 A safe working load initially established for a sling before use at the manufacturing level shall prevail throughout the life of that sling. Slings are not to be derated.

2. Certification ^

2.0 A certificate, which identifies and reflects a batch of slings, shall be issued by the manufacturer, or an independent responsible organization for each batch of new slings. All relevant information required in this section shall be under one certificate.

2.1 Slings shall be provided with test certificates which contain the information shown on the example Canadian certificates shown in Appendices 1 or 2. The certificate shall give all relevant descriptions of the tests and shall always be available to the user. Tests shall be carried out by a responsible and competent person and the owner shall ensure this. Further information on the certificate shall be as per ISO.4878, with statement of conformity to Canadian requirements. (See Section 4.10)

3. Marking ^

3.0 Slings shall be properly and durably marked with relevant information which shall be sufficient to identify them to their test certificate and the manufacturers. Each batch with up to 500 slings shall be separately shown on the test certificate together with the break test for the representative slings. Each batch of slings shall have a different mark. All the units in a batch of up to 500 slings, shall have the same mark.

3.1 In addition to the marking on the slings required by the ISO Standard, the batch number shall be included.

4. Testing ^

4.0 To establish the breaking strength applicable to a class of slings at the time of manufacture, at least three representative slings are taken and tested to destruction one after the other, and the value of the lowest break is taken as the representative breaking strength for all of the slings of that manufacture, material and design.

4.1 For multi-use slings, production check tests of at least 1 per 500 slings manufactured, and more where required, shall be carried out to confirm that the required Safety Factor on the rated safe working load for that group is being met.

4.2 Except as provided in Section 4.3 & 4.9(f) all slings shall be tested before use and marked with the rated safe working load using a Safety Factor of not less than 6:1 for repeat use slings, based on the Standard Pin Test. This would allow the sling to be used on straight hooks that are fully radiused on the load bearing area and not more severe than the Standard Pin.

4.3 A Standard pin and/or Standard Hook Test is not required when the manner of use test has been carried out. (See Section 4.9(f)).

4.4 A sling test for establishing the S.W.L. shall be carried out in the straight basic configuration of the sling or manner of use. The breaking load so obtained when divided by the safety factor would yield the rated safe working load. In field use all mode factors such as those related to the sling bridle angle, or hook effect shall be applied to this rated safe working load to obtain the actual load allowed to be lifted to ensure that the required safety factor will be maintained during a lift.

4.5 A "Standard Pin Test" is made with the sling in a basic straight line or eye to eye configuration with at least one end on a 1½" diameter straight pin type anchor. The other end shall be on a larger pin. The 1½" diameter straight pin shall be fully radiused in the load bearing area and shall be referred to as "Standard Pin".

4.6 As an alternative to Manner of Use Test, a Hook Mode Factor may be established so as to permit the use of slings on a curved hook under prescribed conditions. (See Section 4.7)

4.7 A "Standard Hook Test" is made on a hook of 1.5 inches bar thickness, fully radiused in cross section and having a radius of curvature of half the sling width, at least 3 representative slings shall be consecutively tested to destruction and the least value found shall be used in conjunction with the standard pin test value for the same slings, to establish a ratio which will be referred to as the hook mode factor. The hook test described above would be referred to as the Standard Hook Test. The hook shall be referred to as the standard hook and denoted by "R½W 1.5"T".

R = Hooks radius of curvature at the sling bearing area

W = Width of the sling

T = Bar thickness of the cross section in the sling bearing area

4.8 For slings up to 4 inches in width the user may determine the maximum load allowed to be lifted on a curved hook that is not more severe than 1½" bar diameter, and radius of curvature not less than half the width of the sling, by applying the hook mode factor to the safe working load determined by the standard pin test. Where necessary other mode factors shall be applied in addition to the hook mode factor to accommodate bridle angle, choke effect or basket effect etc. to determine the actual load allowed to be lifted so that the appropriate safety factor shall always be maintained during the lift.

4.9 A Manner Of Use test shall be carried out under the following conditions:-

1. Slings of over 4 inches in width.
2. Slings of unusual construction.
3. Unusual sling-hook combination.
4. When hook profile is more severe than the standard pin or standard hook.
5. Slings of questionable quality or suitability.
6. When standard pin test and/or standard hook test have not been carried out.
7. Any other relevant condition.

4.10 For a Manner Of Use test, slings shall be tested to destruction on a hook profile identical to the hook in actual use. This shall be based on the least breaking strength of at least 3 consecutive tests of representative slings. Details including hooks radius of curvature, the bar thickness of the sling bearing surface and the description of the sling bearing surface shall be specified on the hook/sling test certificate. The test description shall also include stress raisers eg. corner effect, bridle effect etc. where required. Slings tested as such shall only be used on hook profiles not more severe than the test hook.

4.11 Mode factors shall be applied where required to the Manner Of Use test to obtain the actual load allowed to be lifted so that the appropriate Safety Factor shall always be maintained.

PREVIOUS | TABLE OF CONTENTS | NEXT