Wire Rope Clamps - Which is better?
Wire Rope Clamps - Which is better?
(OP)
Can anyone provide some insight as to which wire rope clamp is better - saddle or fist? We had a major safety incident with the wire rope hoists we use to move around 3-ton rolls of paper. The dead-end of the wire rope pulled out and dropped the roll to the floor, almost landing on the operator. The saddle clamps we were using were properly oriented (never saddle a dead horse) and properly torqued. The hoist manufacturer suggested fist clamps as an alternative since they do not deform the dead-end of the cable as much, which sparked the debate as to which clamp is better. I've checked the Crosby website, but I can't find any data that tells me if one is better than the other. Can anyone provide me additional resources or insights? Thanks!





RE: Wire Rope Clamps - Which is better?
It does not mention fist clamps. Swaging will give 100% of cable strength if you can use that.
RE: Wire Rope Clamps - Which is better?
Presumably, the objective is to keep the free end from slipping. Counting on a single point of constraint sounds difficult to me as a starting point.
Are there alternate configurations that can be used? What if you made it a slip knot with the clamp?
TTFN
RE: Wire Rope Clamps - Which is better?
What I'm looking for is more in terms of general design practices. I know saddle clamps are very widely used, but they deform the dead-end of the rope. Fist clamps may be more expensive and take up a little more space, but are they better, worse, or the same as saddle clamps in general?
Thanks again for your responses!
RE: Wire Rope Clamps - Which is better?
RE: Wire Rope Clamps - Which is better?
RE: Wire Rope Clamps - Which is better?
of efficiency (where efficiency = actual breaking strength
spliced termination divided by actual breaking strength of
the rope). The efficiency will change from splice to splice
because of the many variable factors involved in producing
the splice.
See termination efficiencies at:
http://www.safetysling.com/wrs1.htm
RE: Wire Rope Clamps - Which is better?
ruble3, we looked into the lay of the cable, and according to Crosby, the one we're using is the appropriate one for the clip. I'm glad to hear that you decided not to file any ridges off!
boo1, that website you gave is a huge help. It looks like from a strength standpoint, there's really no difference between the two clamps.
Thanks a bunch for all your information!!
knooper
RE: Wire Rope Clamps - Which is better?
RE: Wire Rope Clamps - Which is better?
RE: Wire Rope Clamps - Which is better?
U-Bolt clips must have the U-Bolt section on the dead or short end of the rope and the saddle on the live or long end of the rope. The wrong application, U-Bolt on live instead of dead end, of even one clip can reduce the efficiency of the connection to 40%.
Never use fewer than the number of clips recommended by the manufacture. Turn back the correct amount of rope for dead ending to permit proper spacing of the clips. Always use new clips; re-used clips will not develop the proper efficiency. It is equally important to always use a thimble to prevent the rope from wearing in the eye and to provide a safer connection.
Apply the first clip one base width from the dead end of the wire rope. Tighten the nuts. Apply the second clip adjacent to the thimble, but don't tighten the nuts. Apply all the other clips, leaving equal space between each. For maximum holding power they should be installed 6-7 diameters apart. Take up the rope slack by applying tension to the eye and cable and tighten all the nuts evenly on all the clips to the recommended torque.
After the rope has been in operation for an hour or so, all nuts on the clip bolts will have to be retightened and they should be checked for tightness at frequent intervals thereafter. This is necessary because the rope will stretch slightly causing a reduction in diameter which will slacken the clips.
see:
http://www.jameswalker.com/restsite/crosbyhardware/1.htm
note
Oshaa requires inspection of the rope and related equipment at the beginning of every work period at least daily in most instances and particularly following any incident which could have damaged the rope or installation.
RE: Wire Rope Clamps - Which is better?
(a)(6) Inspections. Each day before being used, the sling and all fastenings and attachments shall be inspected for damage or defects by a competent person designated by the employer. Additional inspections shall be performed during sling use, where service conditions warrant. Damaged or defective slings shall be immediately removed from service.
(c)(1) Tables H-3 through H-14 shall be used to determine the safe working loads of various sizes and classifications of improved plow steel wire rope and wire rope slings with various types of terminals. For sizes, classifications, and grades not included in these tables, the safe working load recommended by the manufacturer for specific, identifiable products shall be followed, provided that a safety factor of not less than 5 is maintained.
c)(5) When U-bolt wire rope clips are used to form eyes, Table H-20 shall be used to determine the number and spacing of clips.
BE SAFE review your plant safety plans, sling proof testing proceedures (yearly), rigging training, and record keeping proceedures. Lawer's love this kind of stuff........
RE: Wire Rope Clamps - Which is better?
The result will be more safe and secure than any rope fixing device that you will be able to put in use.
This more an art than a science, so first try it with several scrap pieces of wire rope, and you will master it in very short time.
SACEM1
RE: Wire Rope Clamps - Which is better?
RE: Wire Rope Clamps - Which is better?
In http://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=FEDERAL_REGISTER&p_id=13573 search for "fist" and find an interesting discussion.
Check out http://www.osha.gov/doc/outreachtraining/htmlfiles/slings.html for some general sling info.
More detailed info is at http://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=STANDARDS&p_id=9834