Industry operators do their lifting and rigging work with shackles. These pieces of equipment are designed with safety precautions and efficiency in handling loads weight in tons. However, you shouldn’t mistake a shackle for the wrong load because they have different strengths.
Using the wrong one can lead to accidents. To avoid such a mistake, it’s necessary to know the different types of shackles, and this article has five common industrial shackles for lifting loads.
What Are Shackles?
Shackles are U-shaped metal links secure with a clevis or a bolt pin. In essence, it is a hinged metal loop with a locking pin. Some of the parts are highlighted below:
- The curved shaped attachment is a bow.
- The ears are the threaded parts with a hollow for pin insertion
- The pin is used to secure the shackles through the two ears, and it can be removed and adjusted.
- The shoulder is on the pin and holds the ears.
Aside from rigging and lifting loads, they also help with towing, hoisting, pulling, and tie-down operations. To choose a shackle, you must know the load’s weight and size, the shackle limit, and a few other factors.
Choose Your Shackles Carefully
It is glaring that the correct shackle type is necessary to avoid major accidents or damages. However, choosing the perfect one can be tricky. You need to know the weight of your lifting and rigging operations. Here are some factors to help determine the best shackle for an operation or weight.
- Check the working load limit of the shackle before choosing it.
- Check the attachment angle because you may need to change the working load limit to match it.
- Inspect the shackles and other rigging gears before using anyone.
- Avoid using shackles with kinking, corrosion, rust, warping, bending, or any deformity.
- Ensure you replace distorted or fractured screw pins.
- Call for a professional inspection at least once a year or as the manufacturer recommends.
- Avoid forcing or hammering pins into the ears of the shackles, even for permanent attachment. It is best to replace loosened pins than force them.
1. Anchor Shackle
Many people mistake the anchor shackle for the bow shackle. This is because they look alike and help with industrial lifting. The anchor type is made from galvanized steel and stamped with the weight load limit (WLL). A shackle is supposed to have a standard working load limit, but there are some non-standard ones with higher or lower working limits. Essentially, ensure you invest in shackles tested for reliability and lifting.
Anchor shackles are used in slacklining to hold anchors. The shackle is designed to be efficient for two or multiple directions of loads, like lifting a Highline anchor with many bolts. However, the loads are to weigh less than the shackle weight load limit. Anchor shackles are popular because of their standard dimensions.
2. Bow Shackles
Bow shackles and anchor shackles are similar in shape, but the former is bigger than the latter. The bow is made from stainless steel or titanium and can help with slacklining. The equipment has perfect geometry with a ½ (12mm) size, making it suitable for weighing anchors.
But the dimensions are also standard and consistent, making them common. However, remember they are made from stainless steel, so they are less reliable, unlike the anchor shackles.
3. Chain Shackles / D Shackles
Chain or Dee shackles is a straight-legged bi-direction shackle. The shackles can be used in two pull directions, especially when connecting gear pieces like a pulley. You can use them for more than two directions because of their geometry.
However, multiple uses will stress the bolt side leading to premature failure. Chain shackles may be called Dee shackles, but they are different because they have different geometry and materials.
4. Screw Pin Shackles
The screw pin shackle is quick and easy to tighten down with the threaded pin. They can also be easily disconnected, making them perfect for rigging involving pick and place or when slings and on operations that often require hardware change.
However, they are made for long-term or permanent installations. They are perfect for operations with side loads because of their multi-leg sling assemblies. However, it would be best if you reduced the WLL to prevent premature failure.
In addition, you can’t use a live line, such as a sling with a choker hitch, to prevent the screw pin from rotating, twisting, torquing, or unthreading the pin. Instead, you can use a mousse as a secondary securement pin to prevent the pin from unthreading during vibration or rotation. Use an iron wire to hold the collar of the pin and the adjacent leg of the shackle; twist the wire to secure them together. Ensure the screw pin thread is well tightened and the shoulder rests on the shackle body.
5. Bolt Type Shackle
The bolt-type shackle is the most secure version of all. The shackle has a bolt and nut alongside a cotter pin designed for a round pin and screw pin operations. The screw pin thread remains tight when rotating, vibrating, or torque. Therefore, they are the best for rigging operations and rotating tasks.
The constant tightening of the pin, like in other shackles, is unnecessary with bolt-type shackles because it is designed with a tightening nut and cotter pin. In addition, they are suitable for semi-permanent or long-term installation and in tasks that necessitate rotation.
Shackles make it easy to lift heavy loads. They are used to connect the loads to the machine so ensure you pick one that is suitable. Hopefully, this post has broadened your knowledge on shackles and, if put into practice, could avoid many mistakes.