AB. The International Marine Contractors Association. Guidance on. The Use of Cable Laid Slings and Grommets. IMCA M August AB The International Marine Contractors Association Guidance on The Use of Cable Laid Slings and Grommets IMCA M Franklin Grommet Slings. CGBL. Sling Diameter / mm. Reference: IMCA M Table Reference: MCLT/01 Rev Franklin Cable Laid Grommet Table.
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Guidance document on t Guidance of Solder Pas IMCA promotes improvements in quality, health, safety, environmental and technical standards through the publication of information notes, codes of practice and by other appropriate means.
Members are self-regulating through the adoption of Imac guidelines as appropriate. They commit to act as responsible members by following relevant guidelines and being willing to be audited against compliance with them by their clients. There are two core activities that relate to all members: HSE has advised that, although it no longer issues this type of imfa, it would not be adverse to operational practices which followed the guidelines formerly available in PM Iimca guidance was originally prepared by a working group of experts in and was intended to be mainly of assistance to those concerned with the use of cable laid slings and grommets in very heavy lifting operations.
Such operations often use cable laid slings and grommets of mm diameter and over, as developed for use in the offshore oil industry. These are generally too large for existing test equipment to be used to test the rope sample to destruction. This note, therefore, gives advice on their construction, rating, testing, certification, examination and use.
The original working group membership for PM20 was as follows: The lay length of the cable laid rope should be a minimum of six times and a maximum of seven-and-ahalf times its nominal diameter. Cable laid ropes should be manufactured right or left hand lay in accordance with one of the combinations of unit rope constructions and cable lay factors, as specified in Appendix 6.
Dimension w should be in accordance with Table 1 with h at least 2w.
The difference in imcq between slings of matched pairs should not exceed 0. Diameter of cable laid rope Pin diameter mm mm mm mm Table 1 — Pin Diameters mm mm mm mm If measurement under conditions different from the above is required, the customer should state the requirements on the order and the details should be shown on the Certificate of Dimensional Conformity Appendix 3A. For core unit ropes also seven strands can be used.
All unit ropes should have a steel core. Compacted or deformed unit ropes are not allowed to be used. The breaking load of unit ropes up to 60mm diameter should be calculated in accordance with the method given in ISO and for larger ropes EN will be applicable see Appendix 1 for method of calculation. For these purposes, this is taken as 9.
This is calculated as follows: CSBL f is as defined in paragraph 3. This bending factor will also be applicable for the bend of the sling eye, although this will often not be governing as the sling load will be divided over the two legs of the eye. The bending factor EB shall be calculated according to the formula: WLL will thus be: Under no circumstances should the sling body contact any surface where iimca radius is less than 0. The eyes of a sling leg should be formed by the use of hand splices made in one of the following ways, or by another method which can be demonstrated to be as efficient.
The core imcaa be worked in with the splice and not cut out. The length of tails of outer ropes after the last tuck should be at least three times the diameter of the cable laid rope and the tails should be seized to the main body of the sling. The method of splicing must be mentioned on the consolidation test certificate see Appendix 2. These tucks should be over and under against the lay of the rope, except that the first tuck only of any one unit rope may be with the lay.
The sixth tuck can be made with one half of the strands from the outer unit ropes. All tucks umca be over one and under two. The minimum remainingsling length between the splices of both sling ends shall, in all cases, be at least 15d, where d is the nominal diameter of the cable laid rope forming the sling.
If the sling body is to be doubled then this minimum length must be agreed by the interested parties, but should not be less than 15d. A grommet contains one tuck splice diametrically opposite the core imcs position.
This core butt and tuck position should be clearly marked by red paint and should be positioned at approximately 0. The grommet must never be bent at this marked position. Dimension h should be at imcw 2w. The difference in circumferential length between grommets of matched pairs should not exceed 1. The length mica the circumference should be at least five times the cable lay length. Unless specified otherwise, when measuring actual grommet lengths, if pins are used, the pin diameter should be as per Table 2.
Diameter of cable laid rope Pin diameter mm mm mm mm Table 2 — Pin Diameters mm mm mm mm If measurement under conditions different from the above is required, the customer should state the requirements on the order and imcs details should be shown on the certificate of dimensional conformity Appendix 3B.
For these purposes this is taken as 9. Although the cross icma of the grommet comprises a total of 14 ropes, the core section of the unit rope should be discounted in the calculation of the 719 load because the joint is butted and not spliced.
For these applications, f is taken as not less than 2. Bending factor for the bend of a grommet at its ends or when used as a doubled grommet at the grommet body.
Under no circumstances should the grommet contact any surface where the radius is less than 0. The actual unit rope breaking load imcca be equal to or greater than the calculated breaking load in accordance with paragraphs 2.
The following certificates should be issued for each sling or grommet and should be available to all interested parties on request: Each cable laid sling should also be marked with a longitudinal line to show its alignment when originally measured see paragraph 2. For a grommet, the core butt position and the tuck position should be marked by red paint see paragraph 5. Competent person Designated person, suitably trained, ijca by knowledge and practical experience, and in possession of the necessary instructions to enable the required calculation of WLL and examination to be carried out.
An inspection or thorough examination is carried out to identify damage or deterioration which affects fitness for use, such as: A thorough examination should be carried out: Appendix 5 gives guidance on the assessment of the condition of the sling or grommet and on discard.
A certificate of examination see Appendix 4 should be renewed after each thorough examination. The record of lifts should be kept together with the certificates and made available on demand to the independent competent person and to the statutory authorities. K factors omca the various classes are: Consolidation certificate number Sling number Customer Measured length L? Items 5 to 13 may be illustrated in a sketch. Items 5 to 9 may be illustrated in a sketch. Sketches can be enclosed I, the undersigned, thoroughly examined the above and certify that they showed no apparent defects or damage which could affect the strength or safe use.
IMCA publishes guidance on the manufacture and safe use of cable-laid slings and grommets – IMCA
For and on behalf of: This certificate is valid for a maximum of six months or such imac period as stated. The appearance of a few well distributed broken wires may have no marked effect on the strength of the sling, but it might be indicative of mechanical or corrosive damage. Generally, the loss of strength caused by the mechanical or corrosive action on the rope as a whole is more critical than the loss in strength resulting from the actual wire breaks. Localised breaks If there are three or more broken wires closely grouped, the effect on 1779 sling or grommet should be assessed by an independent competent person.
Corrosion The sling should be withdrawn from service and referred to an independent competent person for thorough examination where corrosion detrimental to the strength of the sling is suspected. Significant distortion of the rope The sling should be discarded when distortion due to kinking, crushing, core collapse or knotting is inca. In cases where it is difficult to distinguish between detrimental distortion and acceptable deformation, the sling should be imc from service and referred to an independent competent person for opinion or thorough examination.
IMCA publishes guidance on the manufacture and safe use of cable-laid slings and grommets
Damage due to weld arcing, etc. The sling should be withdrawn from service and referred to an independent competent person for thorough examination, where pitting, arcing imfa marked discoloration due to overheating are identified. Damaged or defective terminations Particular attention should be paid to signs of: The competent person should consider measuring the actual length of the sling or grommet and the length of the splice tails, as this can give an ijca indication of serious deterioration.
In addition, the actual length of the sling is critical if it is used as part of a matched set. The core unit rope should be right or left hand ordinary lay; The outer unit ropes should be rightleft hand ordinary lay; The cable laid ropes should be laid right or left hand.
Lay Factors For core unit and outer unit ropes: