The Use of Swivels with Wire Rope.

Under certain circumstances it may be necessary to use a swivel in a lifting system to prevent rotation of the load. This is typically done for employee safety considerations. It is possible however, that the use of a swivel will have an adverse affect on rope performance and may in some cases damage the wire rope.

There are many types of accessories available that incorporate different types and degrees of rotation preventing swivels. The swivel may be either an independent accessory or an integral part of a lifting device such as a crane block with a swivel hook. A typical independent accessory is a ball bearing anti- friction swivel. There are also headache balls with swivel hooks.

The type of swivel that causes the most concern from the standpoint of the wire rope is the independent anti-friction swivel that attaches directly to the rope. The purpose of using a swivel in a lifting system is to prevent rotation of the load. This then allows the wire rope to rotate. Excessive rope rotation can damage a wire rope.

To assist in determining whether or not a swivel should be used in the lifting system, the following recommendations should be considered. It must also be recognized that the rotation characteristics of different types and constructions of wire rope vary considerably. The following types and constructions of wire rope are grouped according to their rotation characteristics.

Group 1
Wire rope constructions having very high rotation characteristics should not be used with a swivel under any circumstances. These rope constructions will rotate excessively with one end free to rotate and the rope will unlay and distort and be easily damaged with a loss of rope breaking force.
Blue Strand 6x19 Class Lang lay Blue Strand 6x36 Class Lang lay All constructions of Triangular (flattened) Strand Lang Lay	Endurance Dyform 8 Lang Lay Constructex

Group 2
Wire rope constructions having high rotation characteristics when used in single part reeving may require a swivel in the system to prevent rotation in certain operating conditions. However, this should be done only when employee safety is the issue. These rope constructions when used in a reeving system with one end free to rotate will have a high level of rotation. This will cause the rope to unlay and to some degree and distortion of the rope will occur.
Blue Strand 6x19 Class Blue Strand 6x36 Class Regular lay	Endurance Dyform 6 Regular lay Endurance Dyform 8 Regular lay

Group 3a and 3b
The ropes in this Group are designed with an inner rope that is laid in the opposite direction to the outer strands to provide a medium resistance to rotation. Ropes with medium rotation characteristics are used with a swivel in single part reeving applications. However, a swivel is not recommended for multiple part hoisting applications or in any application where the swivel is not necessary for safety reasons. If it is necessary to use a swivel the rope must be operating within the design factor of 5, must not be shock loaded and must be inspected daily by a qualified person for distortion. It should be noted that if a swivel is used on conjunction with Group 3a ropes, rope service life might be reduced due to increased internal wear between the outer strands and the inner rope.
Endurance 8RR Rotation Resistant	Endurance 19 Rotation Resistant	Endurance Dyform 18 Rotation Resistant

Group 4
Wire ropes having low rotation characteristics used in either single or multiple part reeving may be used with a swivel. The reason for this is that the ropes will exhibit very little, if any, rotation when used at the proper design factor. Application parameters such as a fleet angle may induce turn into a wire rope that can be relieved by the use of a swivel. However, if the application does not induce any turn into the rope or if a swivel is not beneficial to the performance of the rope the swivel may not be necessary.
Endurance 35 LS	Endurance Dyform 34LR/PI/MAX

NOTE: When using a swivel with any wire rope, frequent inspection of the rope is necessary. The rope should not be shock loaded or overloaded.