Rev. November 10, 2020
Hoisting and Rigging
This standard is intended as a guide for workers and supervisors in the fundamentals of safe hoisting and rigging. Knowledge of the equipment and materials with which we work is one of the most important factors in occupational health and safety. Each item has been designed and developed to serve a specific purpose. Recognizing its capabilities and limitations not only improves efficiency but minimizes hazards and helps prevent accidents.
This standard explains the safeguards necessary to control or eliminate these hazards and spells out other essential safety requirements.
Hoisting and Rigging Policy
Hoisting and Rigging Hazards
It is important that workers involved with hoisting and rigging activities are trained in both safety
and operating procedures. Hoisting equipment should be operated only by trained personnel only.
The cause of rigging accidents can often be traced to a lack of knowledge on the part of a rigger.
A safe rigging operation requires the rigger to know;
• The weight of the load and rigging hardware
• The capacity of the hoisting device
• The working load limit of the hoisting rope, slings, and hardware.
When the weights and capacities are known, the rigger must then determine how to lift the load
so that it is stable.
Training and experience enable riggers to recognize hazards that can have an impact on a hoisting operation. Riggers must be aware of elements that can affect hoisting safety, factors that reduce
capacity, and safe practices in rigging, lifting, and landing loads. Riggers must also be familiar with
the proper inspection and use of slings and other rigging hardware. Most hoisting and rigging accidents can be prevented by field personnel following basic safe hoisting and rigging practices. When an operator is working with a rigger or a rigging crew, it is vital that the operator is aware of the all aspects of the lift and that a means of communication has been agreed upon, including what signals will be used.
There are various regulations under the Act for construction in particular. The most extensive is the Construction Regulation (Ontario Regulation 213/91). Construction regulations are generally based on health and safety problems that have recurred over the years. In many cases, the regulations have been proposed jointly by management and labour groups as a means of controlling or eliminating problems that have historically resulted in fatalities, lost-time injuries, and occupational diseases.
The Construction Regulation has been periodically revised over the years.
Review Ontario’s Occupational Health and Safety Act, the Construction Regulation, and other
applicable health and safety regulations to make sure that you know what to expect from others
on the job and what others expect from you.
After the hoist rope, the sling is the most commonly used piece of rigging equipment. Observe the
following precautions with slings.
• Never use damaged slings. Inspect slings regularly to ensure their safety. Check wire rope slings
for kinking, wear, abrasion, broken wires, worn or cracked fittings, loose seizings and splices,
Rigging, Lifting, and Landing Loads
To ensure safety during hoisting operations, a field level risk assessment is required by all workers involved in the task. You must also ensure all affected persons are aware and clear of the hazard radius.
In addition, the following best practices should be carried out during the task.
• Rig loads to prevent any parts from shifting or dislodging during the lift
· Suspended loads should be securely slung and properly balanced before they are set in motion
• Keep the load under control
· Use taglines to control all loads
• Loads must be safely landed and properly blocked before being unhooked and unslung
• Never wrap the hoist rope around the load. Attach the load to only the hook
• The load line should be brought over the load’s centre of gravity before the lift is started
• Keep hands away from pinch points as slack is being taken up
• Wear gloves when handling wire rope
• Make sure that everyone stands clear when loads are being lifted, lowered, and freed of slings
• Before making a lift, check to see that the sling is properly attached to the load
• Never work under a suspended load
• Never make your own repairs to a sling
• Avoid impact loading caused by sudden jerking during lifting and lowering.
· Take up slack on the sling gradually
· Avoid lifting or swinging the load over workers below
• When using two or more slings on a load, ensure that they are all made from the same material
• Prepare adequate blocking before loads are lowered
Working Load Limit
The maximum force that you should load a component is the working load limit (W.L.L). The W.L.L
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. In example, a chain or gin wheel rated at 1000 pounds with a manufacturer’s DF of 3.
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.
Wire Rope Slings
The use of wire rope slings for lifting materials provides several advantages over other types of
sling. While not as strong as chain, it has good flexibility with minimum weight. Breaking outer wires
warn of failure and allow time to react. Properly fabricated wire rope slings are very safe for general
Chain slings are suited to applications requiring flexibility and resistance to abrasion, cutting and
high temperatures. Alloy steel chain grade 80 is marked with an 8, 80, or 800; grade 100 is marked with a 10, 100, or 1000. Alloy steel chain is the only type which can be used for overhead lifting.
As with all slings and associated hardware, chain slings must have a design factor of 5.
In North America, chain manufacturers usually give working load limits based on a design factor of 3.5 or
Always check with manufacturers to determine the design factor on which their working load limits are based. If the design factor is less than 5, calculate the working load limit of the chain by multiplying the
catalogue working load limit by the manufacturer’s design factor and dividing by 5.
Synthetic Web Slings
Web slings are available in two materials, nylon and polyester. Nylon is resistant to many alkalis whereas polyester is resistant to many acids. Consult the manufacturer before using web slings in a chemical environment. Nylon slings are more common but polyester slings are often recommended where headroom is limited since they stretch only half as much as nylon slings.
Synthetic web slings offer a number of advantages for rigging purposes. Their relative softness and width create much less tendency to mar or scratch finely machined, highly polished or painted surfaces and less tendency to crush fragile objects than fibre rope, wire rope or chain slings.
Rigging Hardware Inspection
Know what hardware to use, how to use it, and how its working load limits (WLL) compare with the
rope or chain used with it. All fittings must be of adequate strength for the application. Only forged alloy steel load-rated hardware should be used for overhead lifting. Inspect hardware regularly and before each lift. Telltale signs include;
· Severe corrosion
· Mismatched parts
· Obvious damage
• Should be equipped with safety catches
• Should be forged alloy steel with WLL stamped or marked on the saddle
• Should be loaded at the middle of the hook
• Should be inspected regularly and often
· Look for wear, cracks, corrosion, and twisting
· check throat for signs of opening up
• Available in various types
• For hoisting, should be manufactured of forged alloy steel
• Do not replace shackle pins with bolts
• Check for wear, distortion, and opening up
· Discard shackles noticeably worn at the crown.
• Do not use a shackle where it will be pulled or loaded at an angle
• Do not use screw pin shackles if the pin can roll under load and unscrew
Whenever the operator does not have a clear view of the load and its intended path of travel, a
signaller must direct operations. Signals may differ for each type of equipment since machine movements are different. Make sure that everyone involved knows the signals required for pendant cranes.
Towing and Lodged Equipment
An important weakness of chains is that they are not always the best choice for recovery. Chains also rust when you leave them out in the rain, and they can stretch when you use it to pull a load that was too heavy which leaves the chain weaker the next time you use it. Although a chain may have worked a thousand times before, it only takes one time for one link or a hook to fail and cause severe injuries or death.
· Never use chains for towing purposes.
Wire ropes (commonly called cables) work well for pulling out lodged vehicles and are commonly used by towing professionals. However, similar to chains, they are not designed for impact and should never be jerked on.
Recovery slings and ropes are commonly called jerk straps, yank ropes, and jerk ropes. They are
designed and fabricated for the ability to stretch. They are lighter than chains and cables. Recovery slings are typically made of nylon, which can be stretched, making them in the same manner as rubber bands or bungee cords. Recovery straps and ropes stretch but usually return to their original shapes. When a towing
vehicle pulls forward, the recovery strap continues to stretch until it builds up enough tension that it helps pull out a stuck vehicle.
Unlike cables and chains, you can get a running start and jerk on recovery slings. The design of the strap absorbs all the jerking motion. If you jerk on a recovery strap, you will actually pull the vehicle out very smoothly, whereas, if you jerked on a chain or cable, you would most likely snap the chain or risk a chance of whiplash from the sudden jolt.
Another advantage to using a recovery sling is that the towing vehicle should never have
to spin its wheels. If the towing vehicle is stopped in its tracks after repeated attempts with a tow
strap, you know the vehicle you are using to pull with is not large enough to get the job done.