How to Use a Single Leg Sling ?
A single-leg sling is a type of lifting or rigging equipment used in various industries to lift, secure, or move loads. It typically consists of a single length of material, such as chain, wire rope, or synthetic webbing, that is designed to connect a load to a lifting device like a crane or hoist.
Key Features of a Single-Leg Sling:
- Single Connection Point: The sling has one leg that attaches directly to the load and the lifting mechanism.
- Materials: It can be made from:
- Chain slings: Durable and suitable for heavy-duty applications.
- Wire rope slings: Strong and flexible for medium to heavy loads.
- Synthetic slings (e.g., nylon or polyester): Lightweight, softer, and ideal for delicate loads.
- End Fittings: Can include hooks, shackles, or eyes (looped ends) to connect securely to the load and lifting equipment.
Using a single leg sling effectively requires understanding its configurations and safety practices. Here’s a comprehensive guide on how to use a single leg sling for lifting and handling tasks.
Types of Single Leg Slings
Single leg slings can be made from various materials, including wire rope and synthetic fibers. They are typically used in three main configurations:- Vertical Lift: This is the most straightforward application, where the sling is used in a straight pull to lift a load vertically.
- Basket Hitch: The sling is looped under the load and the ends are connected at the top, which increases stability and load capacity.
- Choker Hitch: The sling wraps around the load and is threaded back through itself, providing a cinched grip on the load.
Steps for Using a Single Leg Sling
1. Inspect the Sling
- Before use, check for any signs of wear or damage, such as fraying or cuts.
- Ensure that the sling's rated capacity meets or exceeds the weight of the load.
2. Choose the Right Configuration
- Vertical Lift: Ideal for balanced loads.
- Basket Hitch: Use for wider or heavier loads to distribute weight evenly.
- Choker Hitch: Best for securing loads that may shift during lifting.
3. Attach the Sling
- For a vertical lift, connect one end of the sling to a lifting device (like a hoist) and attach the other end to the load.
- For a basket hitch, place the sling under the load, then bring both ends up and connect them to the lifting device.
- For a choker hitch, wrap the sling around the load, thread it back through itself, and attach it securely.
4. Use Taglines When Necessary
- If lifting beyond arm's reach or if there’s a risk of load rotation, use a tagline to maintain control over the load and prevent it from spinning
5. Lift with Care
- Begin lifting slowly to ensure that everything is secure.
- Monitor the load during lifting to adjust as necessary.
6. Lowering the Load
- When lowering, do so gently and ensure that no one is underneath or near the load path.
7. Post-Use Inspection
- After use, inspect the sling again for any damage incurred during lifting.
Safety Considerations
- Always follow guidelines for safe sling use
- Be aware of environmental factors that could affect lifting operations, such as wind or uneven surfaces.
- Ensure that all personnel involved in lifting operations are trained in using slings properly.
A single leg sling may be used to connect a lifting appliance to a load with a single lifting point such as the eyebolt on an electric motor. It may also be used in choke hitch either by back hooking or reeving one end of the sling through the other.
Two identical single leg slings may be used in combination to form, in effect, a two leg sling. Care is necessary to ensure that the hook of the lifting appliance is not overcrowded and it is recommended that the upper end of the sling legs to be connected by a shackle or link. Where this is done the legs must be symmetrically disposed and the angle of a leg should not exceed 45° to the vertical. The method of attaching the slings to the crane hook should ensure that the sling eyes or links are not damaged. Two single leg slings used as a two leg sling must be treated as a two leg sling for rating purposes. The combined SWL when the legs are at an angle between 0 and 45° to the vertical (0 to 90° included angle) is 1.4 times the SWL of the single leg.
We appreciate the following comments by Mr Knut Buschmann of Unirope.
A single leg WIRE ROPE slings shall NOT be used as a ‘single’ sling, alone. It will start to unwind the rope leading to an unsafe condition.
And YES, all single leg slings show a ‘single leg lift capacity tag’ but this is just for user information on the sling capacity and NOT an application suggestion.
Single leg WIRE ROPE slings shall only be used with other ‘single’ leg sling to form a ‘multiple’ leg arrangement so they are prevented to ‘rotate’ by themselves.
See:
That is why chain slings are chosen for ‘single leg’ applications because they do NOT rotate under load. The same is true for flat web slings.
But already ‘roundslings’ will start to rotate when loaded in a straight line, particularly when the slings are long. Also, single laid fibre rope slings (e.g. 3-4-12 strand) shall not be used by themselves in a single straight lift. They will start to rotate. Particularly, 12-strand fibre rope types will lose strength even when rotated once or twice already; the strands will become unbalanced.
(12 strand ropes are made from ½ of the strand in one, the other ½ in the opposite twisted direction. When you rotate the rope, ½ of the strands will now become longer (means they will carry much less load) and the other ½ will become shorter means, they will be overloaded. Like when you use a 19x7 rope allowing it to rotate under load).