Improper Methods for Uncoiling Wire Rope

Engineering Data

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NOTE: Avoid unreeling and uncoiling methods that are likely to provide kinks. Such IMPROPER procedures should be strenuously avoided in order to prevent the occurrence of loops. These loops, when pulled taut, will inevitably result in kinks. No matter how a kink develops, it will damage strands and wires, resulting in a kinked section that must be cut out. Proper and careful handling will keep the wire rope free from kinks.

Improper Methods for Uncoiling Wire Rope

BI011160

Engineering Data

Seizing Wire Rope

While there are numerous ways to cut wire rope, in every case, certain precautions must be observed. It is critical that before any cut is made proper seizings must be applied on both sides of the location where the cut is to be made. Carelessly or inadequately seized, ends may become distorted and flattened. This will also prevent the strands at the ends from loosening or fraying. Subsequently, when the rope is installed there may be an uneven load distribution to the strands. This will create a condition that will significantly shorten the life of the rope.

There are two widely accepted methods of applying a seizing, which are illustrated. The seizing material itself should be soft, or an annealed wire or strand. Seizing wire diameter, and the length of the seize, will be dependant on the diameter of the wire rope. But the length of the seize should never be less than the diameter of the rope in use. Normally, for a preformed rope, one seize on each side of the cut is sufficient. For ropes that are not preformed, a minimum of two seizings on each side is recommended; and these should be spaced six rope diameters apart.

For larger wire ropes: lay one end of the seizing wire in the groove between two strands; wrap the other end tightly in a close helix over a position of the groove using a seizing iron (a round bar 1/2" to 5/8" dia. x 18" long) as shown. Both ends of the seizing wire should be twisted together tightly, and the completed seize should appear as shown. Seizing widths should not be less than the rope diameter.

The procedure illustrated below is the second of the two accepted methods for placing seizing on wire rope. This method is normally used on smaller ropes.

Engineering Data

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Engineering Data

End Preparations/Terminations

There may arise a need for special end preparations in order to compensate for certain applications such as tight drum openings, or other complicated reeving systems. When these situations are encountered a number of basic designs (and combinations) are available to choose from. Whenever possible end preparations should be removed after final installation.

“Beckets” are what is referred to when we discuss a termination utilized to pull the operating rope into place. The rope end must be fastened to a mechanism so that force and motion are transferred efficiently without distortion of the wire rope. End terminations become items of great importance for transferring these forces. Each basic type of termination has its own individual characteristic. Hence, one type will usually fit the needs of a given installation better than others. It should be noted that not all end terminations will develop the full strength of the wire rope being utilized. To lessen the possibility of error, the wire rope industry has determined terminal efficiencies for various types of end terminations. Four commonly used beckets are illustrated.

Engineering Data

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Wire Rope Clips

Wire rope clips are widely used for making end terminations. Clips are available in two basic designs; the U-BOLT and FIST GRIP. The efficiency of both types is approximately the same.

NOTE: When using U-BOLT clips, extreme care must be exercised to make certain that they are positioned correctly. The important factor is that the U-BOLT clip be applied in order that the “U” section is in contact with the dead end of the rope. Also, the tightening and re-tightening of the nuts must be accomplished as required.

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Engineering Data

Wire Rope Clip Application

The following is the recommended method of applying U-Bolt clips in order to get the maximum holding power from the installation:

1. Turn back the specified amount of rope from the thimble. Apply the first clip a distance of one base width from the dead end of the wire rope (U-bolt over the dead end - live end rests in the clip saddle). Tighten nuts diametrically and evenly to recommended torque. 2. Apply the next clip as near the loop as possible. Snug down the nuts, but do not tighten. 3. Space additional clips (if required) equally between the first two. Turn on nuts evenly to take up rope slack. Continue to tighten all nuts evenly (on all clips) until recommended torque is reached.

NOTE: Apply the initial load to the strand of rope, and then re-tighten nuts to the recommended torque. This is accomplished because the rope will stretch and be reduced in diameter when loads are applied. Inspect periodically and tighten to recommended torque each time.

A termination complying with the above instructions, using the number of clips shown, has approximately an 80% efficiency rating. This rating is based upon the nominal strength of the wire rope. If a pulley is used in place of a thimble where the rope turns back, add one additional clip.

The number of clips shown is based upon using right regular or lang lay wire rope, 6 x 19 class or 6 x 37 class, fiber core or IWRC, IPS or EIP. If Seale construction is to be used for sizes 1 inch and larger, or similar large outer wire type construction in the 6 x 19 class, add one additional clip.

The number of clips shown also applies to right regular lay wire rope, 8 x 19 class, fiber core, IPS,

Engineering Data

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sizes 1-1/2 inch and smaller; and right regular lay wire rope, 18 x 7 class, fiber core, IPS or EIP, size 1-3/4 inch and smaller.

For other classes of wire rope not mentioned, it may be necessary to add additional clips to the number shown. If a greater number of clips are used than shown in the table, the amount of rope turn-back should be increased proportionately. THE ABOVE IS BASED ON THE USE OF CLIPS

ON A NEW ROPE.

Failure to make a termination in accordance with the aforementioned instructions, or failure to periodically check and re-tighten to recommended torque, will cause a reduction in the efficiency rating.

The correct spacing and number of clips is shown above.

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Engineering Data

Wedge Sockets

One of the more popular field end attachments for wire rope is the wedge socket. Attachment and the dismantling of this device is both easy and simple.

1. Inspect the wedge and socket; remove all rough edges/ burrs that might damage the rope.

2. Welded ends of the rope should be cut off prior to assembly. This will allow the rope strands to distort slightly as they bend sharply around the wedge. If the welded end were not removed the minimal sliding of the strands would be restricted and evidenced further up the rope. This may result in the development of high strands, wavy rope and uneven loading. 3. Place the socket in an upright position and bring the rope around it in a large, easy to handle loop. Care must be taken to make certain that the live-loaded-side of the rope is in line with the ears.

4. The dead end of the rope should extend from the socket for a distance of six to nine times the rope diameter. The wedge is now placed in the socket. 5. Secure the socket and carefully apply a gradually increasing load to the live side of the rope in order to pull the wedge into position. Only tension sufficiently to hold the pieces in place.