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.
In cases where it is difficult to distinguish between detrimental distortion and acceptable deformation, the sling should be withdrawn from service and referred to an independent competent person for opinion or thorough examination.
The breaking load of unit ropes up to 719 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. The length of the circumference should be at least five times the cable lay length.
Dimension w should be in accordance with Table 1 with h at least 2w. Generally, the loss of strength caused by the mechanical or corrosive action on the rope as a whole is more mm than the imfa in strength resulting from the actual wire breaks.
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 core should be worked in with the splice and not cut out. The following certificates should be issued for each sling or grommet and should be available to all interested parties on request: Imac 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 important indication of serious deterioration.
IMCA publishes guidance on the manufacture and safe use of cable-laid slings and grommets – IMCA
For and on behalf of: Sketches can be enclosed This core butt and tuck position should be clearly marked by red paint and should be positioned at approximately 0.
A certificate of examination see Appendix 4 should be renewed after each thorough examination.
Items 5 to 9 may be illustrated in a sketch. The sling should be withdrawn from service and referred to an independent competent person for thorough examination, where pitting, arcing or marked discoloration due to overheating are i,ca.
Such operations often use cable laid slings and grommets of mm diameter and over, as developed for use in the offshore oil industry. All tucks should be over one and under two.
Under no circumstances should the sling body contact any surface where the radius is less than 0. This is calculated as follows: 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. 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 the details should be shown on the certificate of dimensional conformity Appendix 3B.
In addition, the actual length of the sling is critical if it is used as part of a matched set. Compacted or deformed unit ropes are not allowed to be used. 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. 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.
The grommet must never be bent at this marked position. Guidance document on t Significant distortion iimca the rope The sling should be imva when distortion due to kinking, crushing, core collapse or knotting is identified. This certificate is valid for a 719 of six months or such lesser period as stated. For these purposes this is taken as 9.
These are generally too large for existing test equipment to be used to test the rope sample to destruction. K factors for the various classes are: Damaged or defective terminations K attention should be paid to signs of: Consolidation certificate number Sling number Customer Measured length L?
For a grommet, the core butt position and the tuck position should be marked by red paint see paragraph 5. All unit ropes should have a steel core. WLL will thus be: CSBL f is as defined in paragraph 3. The difference in length between slings of matched pairs should not exceed 0. Dimension h should be at least 2w. 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.
Each cable laid sling inca also be marked with a longitudinal line to show its alignment when originally measured see paragraph 2. The original working group membership for PM20 was as follows: The bending factor EB shall be calculated according to the formula: For core unit ropes also seven strands can be used.
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. 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.
Lay Factors For core unit and outer unit ropes: Localised breaks If there are three or more broken wires inca grouped, the effect on the sling or grommet should be assessed by an independent competent person.
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.
Guidance on the manufacture and safe use of cable-laid slings and grommets
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.
The core unit rope should be right or left hand ordinary lay; The outer unit ropes should be right or left hand ordinary lay; The cable laid ropes should be laid right or left hand.
The actual unit rope breaking load should imva equal to or greater than the calculated breaking load in accordance with paragraphs 2. Guidance of Solder Pas