Rigging Hardware and Slings
Identification of the different types of rigging hardware, slings, and hitch types
Rigging Hardware
Only hardware that has been specifically designed for overhead lifting can be used. This hardware is commonly manufactured by companies whose specific business is the manufacturing of rigging hardware. Other rigging hardware will be designed and engineer certified for specific limited use applications (for example spreaders).
Eye Bolts
Eye bolts are mainly used for vertical lifts. Eye bolts are threaded bolts with a vertical ring at their head. When they are used in a bridle sling application, the sling angle to the horizontal to the load should never be less than 45 degrees. Use plain or shoulderless eye bolts for vertical loading only. Angle loading will bend bolts.
Each sling leg should be attached to a shackle then to an eye bolt.
Swivel Hoist Rings
They are designed to rotate, pivot and are suitable for use in vertical and angle lifting. The swivel hoist ring has the same capacity when used in a vertical lift or in a lift at any sling angle from the horizontal of the load. A swivel hoist ring can be used by itself or in pairs.
HR-125C
(for chain slings)
HR-125W
(for web slings)
Shackles
Shackles are normally used with lifting equipment that have lifting lugs (bolted on, forged, cast, or fabricated lugs). There are two main types of shackles used in the hoisting of loads. They are the screw-pin and the bolt-type (anchor). The screw-pin is secured by threading the pin through the shackle until the threads are fully seated and hand tight. Do Not Substitute the shackle Manufacturer’s screw-pin! The bolt-type is secured with a nut and cotter pin. Replacements can be supplied by the shackle manufacturer or other commercial suppliers.
Screw Pin Anchor Shackle
Bolt Type Anchor Shackle
Proper Word Usage Definition:
Shackles – certified pieces of rigging hardware that are utilized for rigging various kinds of loads. These loads are lifted and transported by different types of lifting equipment.
Clevises are specifically designed for securing loads for transport and bundling materials for shipping. They are not designed for lifting loads.
Hooks
Hoisting hooks are made of forged alloy steel, carbon, or bronze. They must indicate their rated safe working loads and require hook latches that will ensure that unloaded slings remain on the hook. Hooks are safely loaded only in the widest portion of the saddle. They must support the load in a direct-pull configuration. Sorting hooks do not require a hook latch, as they are reinforced in the bow to prevent stretch. Sorting hooks are normally used to engage the open ends of the pipe.
Hooks with Hook Latches
Sorting Hook
Gathering Ring or Master Link
Most rings and links have the safe working load stamped on the forging. If they are not stamped, consult the applicable manufacturer’s chart to find the SWL before using them.
Master Link
Pear Shaped Link
Welded Master
Link Assembly
Spreader, Lifting and Equalizing Beams
Spreader beams are used to suspend long loads. They reduce the risk of load tipping, sliding or bending. They are used to maintain acceptable load sling angles and to help remove sling load crushing.
Equalizing beams are used to equalize, or support loading on dual hoists during tandem lifts.
Lifting beams are normally used where there is no room for rigging, such as an overhead crane application. They are designed to carry large awkward loads.
Spreader Beam
Equalizing Beam
Lifting Beam
Load Indicating Device (LID)
LID’s are a device that measures and displays load or force
LID’s shall only be used in accordance with the recommendations of the LID manufacturer or a qualified person
See ASME B30.26-2015 Chapter 26-6 for further details
Slings
Slings are generally made of chain, wire rope, nylon web, or some form of synthetic material. They are defined as “…an assembly to be used for lifting, when connected to a lifting mechanism at the sling’s upper end and when supporting a load at the sling’s lower end” (ASME B30.9).
The following components must have a rated load at least equal to that of the sling with which they are used:
Hooks
Rings
Pear-Shaped links
Any other sling attachment
Chain Slings
Chain slings must be made from Grade 8 alloy steel and designed for hoisting loads. They are flexible, resistant to abrasions, cuts and high temperatures. There must be a manufacturer’s mark to indicate that they are made from an alloy steel. The alloy steel grade rating for a chain sling used for hoisting purposes must be grade 8 or better.
Grade 80 alloy steel chain slings must be manufactured and tested in accordance with applicable standards.
Grade 80 refers to 1/10 the tensile strength, being 800 newtons / mm².
The following components must have a rated load at least equal to that of the
alloy chain with which they are used:
Oblong links
Welds
Mechanical coupling links
Each sling must have a permanently affixed identification mark that provides the following information:
Name, symbol or trademark of manufacturer
Chain grade and size
Number of legs
Rated load and angle on which it is based
Reach (length)
There must be no welding on chain sling components.
Wire Rope Slings
Wire rope slings are flexible. They must have a tag that identifies the manufacturer
and the SWL for vertical, choke, and basket capacities. This identification should be
maintained for the life of the sling.
The basic element in the construction of a wire rope is a single metallic “wire”.
Several of these wires are laid helically around a centre to form a strand.
Finally, a number of strands are laid helically around a core to form a wire rope.
The primary function of the core is to serve as a foundation of the rope to keep it
round and to keep the strands correctly spaced and supported.
Synthetic Slings
Synthetic web slings are fabricated by sewing woven synthetic webbing for the purpose of hoisting, lifting, and general material handling. They are soft and flexible so they will not mark, scratch, or crush the load. They are made from nylon or polyester. Nylon is resistant to alkalis and polyester is resistant to acid. This needs to be taken into consideration when working in an area exposed to chemicals.
Each sling must be marked identifying these items:
Name or trademark of manufacturer
Manufacturer’s code or stock number
Rated loads for each hitch type
Type of synthetic material
Synthetic web slings are normally used for lifting painted or polished objects, finely finished machinery and other items with fine finish or fragile components. Their elasticity allows them to hug the load and prevent slippage or damage.
Structural and Mechanical Lifting Devices
Manual chain hoists and lever hoists are the most commonly used and effective for lifting or pulling loads into balance.
The rated load marking of a structural or mechanical lifting device must be visible on the main structure. Each lifting device must also be marked with their individual load ratings. Identification in the form of a nameplate or other permanent marking must be affixed to the equipment showing the following:
Manufacturer’s name and address
Serial number
Lifter weight, if over 100 pounds (45 kilograms)
Rated load capacity
Manual Chain Hoist
Manual Lever Hoist
Hitch Types
Single Vertical Hitch
Refers to attaching a load to a single sling. This type of hitch is not recommended as the load tends to rotate during travel, twisting in one direction and then the other.
100% of rated capacity
Single Choke Hitch
Refers to passing one end of the sling through the eye of the other end gripping the load around its middle. It is not recommended because it does not provide load balance and tends to cause the load to rotate, tip and possibly slip during travel.
80% of rated capacity for web and chain slings
75% of rated capacity for wire rope slings
Angle Adjusting on Choke Hitch – Never adjust the natural angle (approximately 120 degrees) of the choke hitch to the load. Do not force the choked eye down close to the load, this will drastically reduce the capacity of the sling.
Single Basket Hitch
Refers to cradling a load in a U-shape sling that is supported in two places so that each leg only supports half the load weight. This type of hitch helps to prevent the load from twisting, but the load can shift.
200% of rated capacity
Reverse / Inverted Basket Hitch
Is not an industry recommended
practice, as it is possible for the load to slip.
Turning Hitch
Refers to passing the centre of the sling through the two eyes and then being placed onto the hook. Use a double choker to turn loads. Place both sling eyes on top of the load pointing in the direction opposite to the direction of the turn. It distributes the weight of the load between the two legs and provides good control over load turning travel. Never use a basket hitch to turn a load.
Bridle Hitch
Refers to attaching more than one sling to a load. This type of hitch requires the load to have lifting lugs or a lifting device to which the sling legs can be secured, usually done with the use of a shackle.
Worse Case Scenario: In the event of a severe accident this hardware will help ensure the load stays on the hoist hook.
Bridle Choke Hitch
Refers to passing one end of the sling through the eye of the other end to secure the load (web or wire rope slings). Hooks must be placed outward from the centre of gravity. The bridle choke hitch does not provide 360° contact with the load and should not be used with loose bundles. Care must be taken when using this hitch to secure a load of loose materials by adding an additional wrap to secure the load (e.g. tubing, pipe, rebar, etc.). Opposite travel attachment is recommended on solid loads to ensure balance and secure load during travel.
Double Wrap Choke Hitch
Refers to wrapping the sling completely around the load prior to passing it through the eye at the other end of the sling. This tightens as the load is lifted due to the noose formed at the point of choke.
Bridle Basket Hitch
Refers to cradling a load with two U-shaped slings. They should be positioned under the load to provide balance. They should be far enough apart to provide a stable foundation and at an angle no less than 60 degrees. Load shifting may occur with this type of hitch.
Double Wrap Basket Hitch
Refers to looping a sling completely around a load. This hitch provides 360° contact to the load and is suited to handling loose loads such as pipes, rods or smooth cylinders. This hitch not only increases support but also grips and tightens to the load.
Double wrap hitches can be used in pairs to grip the load on all
sides, reducing the possibility of load slippage.
Worse Case Scenario: In the event of a severe accident, double wrapping the choke and basket bridle sling applications will grip and tighten to the load and help ensure that the load remains secure.
NOTE: A double wrap bridle basket hitch is best suited to handle loose bundles.
Basic Rigging Knots
Square Knot
Clove Hitch Knot
Bowline Knot
Half Hitch Knot
End Of Lesson: