Rigging – Methods of Slinging Hitches

Over view

There are many rigging methods for different kinds of loads being handled. It should be noted that a rigging method which is suitable for handling one load might not be suitable for handling another load. In fact, each rigging method has its limitations. The methods shown in this section are intended to be typical examples and should not be regarded as exhaustive.

It should be noted that though wire rope slings are used for illustration, the methods shown in this section are also applicable to the use of suitable chain sling.

The owner of any double or multiple sling shall ensure that it is not used in raising or lowering or as a means of suspension if –

  • the upper ends of the sling legs are not connected by means of a shackle, ring or link of adequate strength; or
  • the safe working load of any sling leg is exceeded as a result of the angle between the sling legs.

Slings carry their loads in one of three primary sling hitches. Most slings can be used in all three sling hitches, but some slings are designed for use in only one hitch. Slings have the largest work Load Limit when used in a basket hitch.The vertical hitch Work Load Limit is 50% of the basket hitch. The synthetic choker hitch work Load Limit is a maximum of 80% of the vertical hitch work Load Limit.

Slings must be securely attached to the load and rigged in a manner to provide for load control to prevent slipping, sliding and/or loss of the load. A trained, qualified and knowledgeable user must determine the most appropriate method of rigging to help ensure load control and a safe lift.


Sling passes through one end around the load, while the other end is placed on the hook. Load control is limited with only one sling rigged in a choker hitch. A choker hitch will never provide full 360 degree contact. For full contact use a Double Wrap Choke Hitch. See Choker Hitches. The Choke Point should always be on the sling body, not on the sling eye, fitting, base of the eye or fitting, splice or tag.


One end is on the hook, while the other end is attached directly to the load. Use a tagline to prevent load rotation.


The sling cradles the load while both eyes are attached overhead. As with the choker hitch, more than one sling may be necessary to help ensure load control.

Sling-To-Load Angle:

The Sling-to-Load Angle is the angle formed between a horizontal line and the sling leg or body. The Sling-to-Load Angle has a dramatic effect on sling Work Load Limits. Slings with adequate capacity to handle the “scale” weight of the load have catastrophically failed because the Sling-to-Load Angle and increased tension were not taken into account.

This principle applies in a number of conditions, including when one sling is used to lift at an angle and when a basket hitch or multi-leg bridle sling is used. When selecting a sling, always consider the Sling-to-Load Angle and the tension that will be applied to the sling. As the Sling-To-Load Angle decreases, the tension on the sling leg(s) increases.

Single-leg sling:

Vertical or straight lift (Fig-1) :

A vertical or straight lift is only suitable for lifting a load that will be stable when suspended from a single lifting point.

Basket hitch (Fig-2 ):

A basket hitch should only be used when the sling is passed through part of the load and the load is balanced on the sling. The lifting should not commence until a shackle is connected to the sling legs. The included angle of the sling should not exceed 90 degrees.

Simple Choker Hitch (Fig-3) and Double and Choked (Fig-4) :

These two slinging methods do not grip the loads completely and should be used only when the loads are easily stabilized or cannot slip out of the sling.

Choker hitch double wrapped (Fig-5) :

The general limitations for this sling method is similar with simple choker hitch, except that with the double wrapped choker hitch the load is gripped more fully, and hence is secured more effectively.

The simple choker hitch or choker hitch double wrapped method should not be used for handling composite loads such as loose bundles of tubes, or bars or wooden battens unless the friction grips between the parts is sufficient to prevent them slipping from the sling. As far as possible, such composite loads should first be tied up securely at their ends by steel wires or similar means of adequate strength.

Fig – 1 Vertical or straight lift


Fig – 2: Basket hitch


Fig-3: Simple Choker Hitch


Fig 4- Doubled and choked


Fig- 5:Choker hitch double wrapped


Fig 6:Two single-leg slings used with direct attachment


Multi-leg sling:

A multi-leg sling may have two, three or four legs (Fig-6 to 12 ). It provides a more stable lifting arrangement than a single-leg sling.

Generally, multi-leg sling methods are :

  • two-leg slings used with direct attachment (Fig. 6);
  • two-leg slings used in choker hitch (Fig. 7);
  • two-leg slings used in basket hitch (Fig. 8);
  • two-leg slings used in double wrap choker hitch (Fig. 9)
  • two-leg slings used in double wrap basket hitch (Fig. 10);
  • three-leg slings used in direct attachment (Fig. 11); and
  • four-leg slings used with direct attachment (Fig. 12).

When using multi-leg slings, care should be taken to ensure that:

1) the slings are of the same length;

2) where the slings have different safe working load ratings then the load that can be lifted is related to the least safe working load; and

3) the attachment points of a two-leg sling to the load are far enough apart to give stability without exceeding 90 degrees (Fig. 6, 7 & 9). In the case of two-leg sling used in basket hitch or a four-leg sling, the angle between any two diagonally opposite legs should not exceed 90 degrees (Fig. 8, 10 & 12) unless the sling is so marked. In no circumstances should the included angle exceed 120 degrees. For a three-leg sling, any one leg should make an angle of not greater than 45 degrees with the vertical.

The two-leg slings used in choker hitch, basket hitch, double wrap choker hitch and double wrap basket hitch should not be used for handling composite loads such as loose bundles or tubes, bars or wooden battens unless the friction grips between the parts is sufficient to prevent them slipping from sling. As far as possible, such composite loads should first be tied up securely at their ends by steel wires or similar means of adequate strength.













BASKET HITCHES -Right / Wrong:

Inverted basket hitches are referred to as equalizing hitches because the sling is free to slip through the hook based upon the load weight distribution. Be sure to employ the “four ends down”, North to South, load engagement system.

Slings “skipping” through hardware components can become damaged. Balancing the load is critical and necessary to prevent sling damage and failure . Extra care should be taken when using slings in a basket hitch to balance the load to prevent slippage. As with the choker hitch, more than one sling may be necessary to control the load.

As with the choker hitch, more than one sling may be necessary to control the load.If practical, take a full wrap around the load to grip it firmly; be sure when using multiple slings that they do not cross over each other. Wrapping the load is a legitimate method of minimizing excessive sling length. Other methods, such as, twisting and knotting radically reduce sling Work Load Limits. When the load is “wrapped” the sling Work Load Limit is not increased, but load control is.


CHOKER HITCHES – Right / Wrong:

The choke hitch should always be pulled tight before the lift is made, not pulled down during the lift. A sling rigged in a choker hitch (not double wrapped) does not make full contact with the load. Use multiple slings to balance the load, and wrap the load to ensure full contact. Ensure multiple slings do not cross. Choke on opposite sides of the load, if this action will not damage the load and maintain load control.

Always use a choker hitch when turning a load. If the sling is not rigged properly, the turning action will loosen the hitch, resulting in load slippage. Place sling eyes on top of the load, pointing the opposite direction of the turn. The body is then passed under the load and through both eyes. Blocking should be used to protect the sling and facilitate removal. Basket hitches should not be used to turn a load. Always downgrade the choker Work Load Limit when the angle of choke is less than 120°.

For a tighter choke hitch, which provides full, 360° contact with the load, take a full wrap around the load before choking the sling. Ensure that multiple slings do not cross. When the load is “wrapped” the sling Work Load Limit does not increase, but load control does.


Double Choker Hitch:

The Double Choker Hitch if applied properly will facilitate equalization of the loading on the sling legs over the lifting hardware. If applied improperly, one of the legs will share a greater portion of the load and equalization will not occur. The Double Choker Hitch Work Load Limit is twice the regular Choker Hitch Work Load Limit.

Sling tension – Different horizontal planes :

Sling Tension – Leg Length/Headroom:

Calculating the tension imposed on slings or individual legs of a multi-part sling system will enable the sling user to select slings with adequate work Load Limits.

Use the following steps to calculate the tension imposed upon the individual sling legs, when you know the leg Length (L) and Headroom (H).

1)Determine the Load Factor (LAF):

Divide the leg length (L) by the headroom (H)

L ÷ H = LF
Example: 20 ÷ 15 = 1.33 Load Factor (LAF)


2)Determine the Share of the Load (SOL) for the individual sling legs:

Divide the load weight by the number of sling legs.

Load weight ÷ number of legs = Share of the Load (SOL)

Example: 12,000 lbs ÷ 3 legs = 4,000 lbs. (SOL)


3) Multiply Load Factor by the Share of the Load to determine Sling Tension

Load Factor x Share of the Load = Tension

LAF x SOL = Tension

Example: 1.33 x 4,000 = 5,320 lbs.

Please Note: Tension calculations are based upon:

  1. Sling attachment points being equidistant from the center of gravity
  2. Sling attachment points being equidistant to each other.
  3. Sling attachment points being on the same horizontal plane
  4. Equal sling leg lengths

Planning all Lifts:

Lifting operations must be planned to ensure that lifts are carried out safely and efficiently. The following points must always be considered:

  • Where loads are to be picked up
  • Where loads are to be placed
  • What areas are to be passed over
  • Proximity of the public
  • Any obstructions in the way
  • How the load is to be slung
  • How slings are to be removed and access to them
  • How the crane driver will be directed
  • The weight of the load
  • The radius of the lift
  • Any loads from a crane or outriggers and the capacity of the ground or slab to support them
  • Weather conditions and light.

The Project Health and Safety Plan will record the overall project specific arrangements for the control of lifting operations. The Project Lifting Plan will detail the specific arrangements for lifting.

The Schedule of Common Lifts will define and describe the ‘common lifts’ on the project. Depending on the nature and complexity of the lift these could be categorized as:

  • Basic
  • Standard
  • Complex.

Basic lifts involve:

Loads of established weight where there are no hazards or obstructions within the area of operation. Typical examples are pallets of bricks or blocks, bundles of re bar, scaffold tubes.

Standard lifts involve:

The lifting of general, frequently handled items of established weight,with no special lifting accessories being required. This booklet describes the slinging of this type of load and the methods shown are to be used, unless stated otherwise by the appointed person.

Complex lifts may include:

Large pre-cast units, plant such as air handling units, generators etc.

Therefore, complex lift operations will require:

  • Consultation with the manufacturer, supplier or designer regarding the correct way of slinging complex loads
  • Careful planning
  • The production of a specific method statement.


  • Ensure that only authorized slingers / signalers attach or detach loads or signal the crane operator.
  • Discuss operations with the crane operator.
  • Ensure capacity of crane is sufficient to land load before lifting.
  • Include the weight of the slings etc in the load on the lifting hook.
  • Seek expert advice when using eyebolts, plate clamps, bull dog grips, chain blocks etc.
  • Obtain confirmation that pre-fabricated rebar assemblies such as pad foundations and beams have been fabricated to allow safe lifting.
  • Ensure that scaffold towers you are asked to move are designed to be lifted safely.

Don t’s:

  • Wrap hand/tag lines around hand or body.
  • Use tie wires or banding to lift loads.
  • Leave a suspended load unattended.
  • Pass loads over the public.
  • Use lifting accessories for towing or pulling.
  • Ride or climb on machines or suspended loads.
  • Lift near power lines.
  • Stand or walk beneath a load.
  • Connect two or more independently slung loads at different levels on the same lift (sometimes known as chandelier lifts).

Click the below links to downloads rigging slings hitches documents




Rigging – Fiber Ropes, Knots & Hitches

Fiber rope is a commonly used tool which has many applications in daily hoisting and rigging operations.

Readily available in a wide variety of synthetic and natural fiber materials, these ropes may be used as

  • slings for hoisting materials.
  • hand lines for lifting light loads.
  • taglines for helping to guide and control loads.

There are countless situations where the rigger will be required to tie a safe and reliable knot or hitch in a fiber rope as part of the rigging operation. Fastening a hook, making eyes for slings, and tying on a tagline are a few of these situations.

This section addresses the correct selection, inspection, and use of fiber rope for hoisting and rigging operations. It also explains how to tie several knots and hitches.


The fibers in these ropes are either natural or synthetic. Natural fiber ropes should be used cautiously for rigging since their strength is more variable than that of synthetic fiber ropes and they are much more subject to deterioration from rot, mildew, and chemicals.


Is the most common fiber rope used in rigging. It floats but does not absorb water. It stretches less than other synthetic fibers such as nylon. It is affected, however, by the ultraviolet rays in sunlight and should not be left outside for long periods. It also softens with heat and is not recommended for work involving exposure to high heat.


This fiber is remarkable for its strength. A nylon rope is considerably stronger than the same size and construction of polypropylene rope. But nylon stretches and hence is not used much for rigging. It is also more expensive, loses strength when wet, and has low resistance to acids.


This ropes are stronger than polypropylene but not so strong as nylon.They have good resistance to acids, alkalies, and abrasion; do not stretch as much as nylon; resist degradation from ultraviolet rays; and don’t soften in heat.

All fiber ropes conduct electricity when wet. When dry, however, polypropylene and polyester have much better insulating properties than nylon.


Inspect fiber rope regularly and before each use. Any estimate of its capacity should be based on the portion of rope showing the most deterioration.

Check first for external wear and cuts, variations in the size and shape of strands, discoloration, and the elasticity or “life” remaining in the rope.

Untwist the strands without kinking or distorting them. The inside of the rope should be as bright and clean as when it was new. Check for broken yarns, excessively loose strands and yarns, or an accumulation of powdery dust, which indicates excessive internal wear between strands as the rope is flexed back and forth in use.

If the inside of the rope is dirty, if strands have started to unlay, or if the rope has lost life & elasticity, do not use it for hoisting.

Check for distortion in hardware. If thimbles are loose in the eyes, size the eye to tighten the thimble (Figure 2.1). Ensure that all splices are in good condition and all tucks are done up (Figure 2.2).
                                          (Figure 1.1)                                                                                                     (Figure 1.2)

Working Load Limit:

The maximum force that you should load a component is the working load limit (WLL). The WLL incorporates a safety factor (SF). The SF provides additional protection above the manufacturer’s design factor (DF). The design factor is the safety factor to which the manufacturer builds. The SF and DF do not provide added capacity. You must never exceed the WLL.

  • Let’s calculate the WLL of a chain or gin wheel rated at 1000 pounds with a manufacturer’s DF of 3.

Note: Section 172 (1) (d) of the Construction Regulation requires a SF of 5.

This requirement is greater than our DF, so the capacity must be reduced accordingly.

WLL = 1000 pounds (rated capacity) x 3 (DF) / 5 (SF)

WLL = 600 pounds

In this example, the chain or gin wheel has a stamped capacity of 1000 pounds, but, in compliance with the Construction Regulation, it can safely lift a maximum capacity of 600 pounds.

Fiber Rope Selection:

Select the size and type of rope to use based on manufacturer’s information; conditions of use; and the degree of risk to life, limb, and property. The WLL of fiber rope is determined by multiplying the working load (WL) by the SF. The minimum breaking strength (MBS) is the force at which a new rope will break.

The manufacturer’s DF provides a layer of safety that has been determined by the manufacturer.
The SF, if greater than the DF, adds an additional layer of safety to meet the requirements of users and regulators. Together, these added layers of safety provide protection above the MBS to account for reduced capacity due to

  • wear, broken fibers, broken yarns, age
  • variations in construction size and quality
  • shock loads
  • minor inaccuracies in load weight calculations
  • variances in strength caused by wetness, mildew, and degradation
  • yarns weakened by ground-in or other abrasive contaminants.

If you notice rope that is defective or damaged, cut it up to prevent it from being used for hoisting.
Let’s calculate the WLL of a rope to lift a WL of 250 pounds.

Note: Section 172 (1) (d) of the Construction Regulation requires a minimum SF of 5.

For more critical lifts that could risk life, limb, or property, a SF of 10 to 15 may be necessary.

WLL = 250 pounds (WL) x 5 (SF)

WLL = 1,250 pounds

In this example, to meet the WLL you must use a rope with an MBS of 1,250 to hoist or lower a WL of 250 pounds. See manufacturers’ specifications to select the appropriate type of rope.


  • To unwind a new coil of fiber rope, lay it flat with the inside end closest to the floor. Pull the inside end up through the coil and unwind counterclockwise.
  • After use, recoil the rope clockwise. Keep looping the rope over your left arm until only about 15

feet remain. Start about a foot from the top of the coil and wrap the rope about six times around the loops. Then use your left hand to pull the bight back through the loops and tie with a couple of half hitches to keep the loops from uncoiling ( Figure 2.5).

( Figure 1.3)

  • Remove kinks carefully. Never try to pull them straight. This will severely damage the rope andreduce its strength.
  • When a fibre rope is cut, the ends must be bound or whipped to keep the strands from untwisting. Figure 2.4 shows the right way to do this.

Figure 1.4


  • Store fiber ropes in a dry cool room with good air circulation – temperature 10-21°C (50-70°F) humidity 40-60%.
  • Hang fiber ropes in loose coils on large diameter wooden pegs well above the floor (Figure 2.5).

(Figure 1.5)

  • Protect fiber ropes from weather, dampness, and sunlight. Keep them away from exhaust gases, chemical fumes, boilers, radiators, steam pipes, and other heat sources.
  • Let fiber ropes dry before storing them. Moisture hastens rot and causes rope to kink easily. Let a frozen rope thaw completely before you handle it. Otherwise fibers can break. Let wet or frozen rope dry naturally.
  • Wash dirty ropes in clean cool water and hang to dry.


• Never overload a rope. Apply the design factor of 5 (10 for ropes used to support or hoist personnel). Then make further allowances for the rope’s age and condition.

• Never drag a rope along the ground. Abrasive action will wear, cut, and fill the outside surfaces with grit.

• Never drag a rope over rough or sharp edges or across itself. Use softeners to protect rope at the sharp comers and edges of a load.

• Avoid all but straight line pulls with fiber rope. Bends interfere with stress distribution in fibers.

• Always use thimbles in rope eyes. Thimbles cut down on wear and stress.

• Keep sling angles at more than 45°. Lower angles can dramatically increase the load on each leg (Figure 1.6). The same is true with wire rope slings.

• Never use fiber rope near welding or flame cutting. Sparks and molten metal can cut through therope or set it on fire.

• Keep fiber rope away from high heat. Don’t leave it unnecessarily exposed to strong sunlight, which weakens and degrades the rope.

• Never couple left-lay rope to right-lay.

• When coupling wire and fiber ropes, always use metal thimbles in both eyes to keep the wire rope from cutting the fiber rope.

• Make sure that fiber rope used with tackle is the right size for the sheaves. Sheaves should have diameters at least six – preferably ten – times greater than the rope diameter.

(Figure 1.6)


Wherever practical, avoid tying knots in rope. Knots, bends, and hitches reduce rope strength considerably. Just how much depends on the knot and how it is applied. Use a spliced end with a hook or other standard rigging hardware such as slings and shackles to attach ropes to loads.

In some cases, however, knots are more practical and efficient than other rigging methods, as for lifting and lowering tools or light material.

For knot tying, a rope is considered to have three parts (Figure 1.7).

(Figure 1.7)

The end is where you tie the knot. The standing part is inactive. The bight is in between.

Following the right sequence is essential in tying knots. Equally important is the direction the end is to take and whether it goes over, under, or around other parts of the rope.

There are overhand loops, underhand loops, and turns (Figure 1.8).

Overhand Loop             Underhand                        Loop Turn

WARNING – When tying knots, always follow the directions over and under precisely. If one part of the rope must go under another, do it that way. Otherwise an entirely different knot – or no knot at all – will result.

Once knots are tied, they should be drawn up slowly and carefully to make sure that sections tighten evenly and stay in proper position.


Never jams or slips when properly tied. A universal knot if properly tied and untied. Two interlocking bowlines can be used to join two ropes together. Single bowlines can be used for hoisting or hitching directly around a ring.

Bowline on the Bight

Used to tie a bowline in the middle of a line or to make a set of double-leg spreaders for lifting pipe.

Pipe Hitch:

Reef or Square Knot:

Can be used for tying two ropes of the same diameter together. It is unsuitable for wet or slippery ropes and should be used with caution since it unties easily when either free end is jerked. Both live and dead ends of the rope must come out of the loops at the same side.

Two Half Hitches:

Two half hitches, which can be quickly tied, are reliable and can be put to almost any general use.

Running Bowline:

The running bowline is mainly used for hanging objects with ropes of different diameters. The weight of the object determines the tension necessary for the knot to grip.

Make an overhand loop with the end of the rope held toward you

(1). Hold the loop with your thumb and fingers and bring the standing part of the rope back so that it lies behind the loop

(2). Take the end of the rope in behind the standing part, bring it up, and feed it through the loop

(3). Pass it behind the standing part at the top of the loop and bring it back down through the loop.

Figure-Eight Knot:

This knot is generally tied at the end of a rope to temporarily prevent the strands from unlaying.

The figure-eight knot can be tied simply and quickly and will not jam as easily as the overhand knot.
It is also larger, stronger, and does not injure the rope fibers. The figure-eight knot is useful in preventing the end of a rope from slipping through a block or an eye.

To tie the figure-eight knot, make an underhand loop

(1). Bring the end around and over the standing part

(2). Pass the end under and then through the loop

(3). Draw up tight.

Figure Eight Knot