It is the rotation characteristics of the wire rope that determines whether you can use a swivel with steel wire ropes on cranes. These rotation characteristics also determine the kind of swivel that can be used with the particular kind of rope. Namely the steel wire rope can belong to three categories including non-rotation resistant, semi rotation resistant and rotation resistant wire ropes.
Let’s take a look at the different types of swivels that can be used for a particular kind of stainless steel wire rope.
1. Free Spinning Swivel
This is the most commonly used type of swivel and is only used with rotation resistant ropes. It has been designed for maximum wire rope force transmission and also limits the transmission of torque as much as possible. There is a chance of some twisting when this type of swivel is used and therefore a mechanism that lets out such twists should always be a part of your system. Although, only used in the case of rotation resistance ropes, certain amount of tweaking and the addition of available mechanisms can also ensure it can be used for semi or
non-rotation resistant steel wire ropes as well.
2. The Lockable Swivel
This is the type of free spinning swivel, which can be used for non-rotation resistant or semi rotation resistant ropes. It is called a lockable swivel because it can be locked by hand and when it is locked it will stop rotating. Now you might wonder what will happen if and when a twist builds up in the reeving system. Well, in that case all you need to do is unlock the swivel, get rid of the wire rope twist and lock it again.
3. Self-Locking Swivel
As the name suggests, this is an automated version of the lockable swivel and operates like free spinning swivel till it reaches the predefined level of line pull. Once it crosses this level it has been designed in a way such that its two rotating halves will interlock. And the swivel will stop rotating. This swivel can be used in combination with all three types of ropes. The one thing that you have to take care of in the case of this swivel is that wire ropes can only be de-twisted in their unloaded state and not in their loaded state.
Powered Swivel
This is a motorized swivel that acts as free spinning swivel but if and when needed it can also twist the steel wire rope. These types of swivels are typically used in tower cranes. It makes sure that both the falls between the wire rope end connection and the sheaves are free of twist.
End Words
It’s important that you have an idea about the different types of swivels used for steel wire ropes, so that you are able to make the right choice in this regard. Otherwise, you might end up making the wrong choice and choosing a swivel that makes a mess of your steel wire rope.