Rigging mistakes are costly — both in terms of project delays and, more critically, in terms of injury and equipment damage. Whether you are managing a factory relocation, installing industrial equipment, or overseeing a heavy lift, understanding the most common rigging errors and how to prevent them is essential. Here, Reef Rigging identifies the mistakes we see most frequently in South African industrial environments — and exactly how to avoid them.
1. Underestimating Load Weight or Ignoring the Centre of Gravity
One of the most dangerous rigging mistakes is guessing a load’s weight or failing to determine its centre of gravity before lifting. A CNC machine, industrial press, or processing vessel that appears symmetrical may have a centre of gravity that is significantly offset from its geometric centre — due to internal components, motor housings, or structural reinforcements. An incorrectly positioned centre of gravity causes the load to tilt during lifting, creating unpredictable forces on rigging equipment and potentially resulting in a dropped load.
How to avoid it: Always verify the manufacturer’s stated weight and centre of gravity data before lifting. For machines where this information is unavailable, conduct a trial lift with the machine just off the ground to confirm the load hangs level before proceeding. Add the weight of all rigging hardware to your calculations.
2. Using the Wrong Rigging Configuration or Equipment
Rigging equipment is rated under specific conditions — and using it outside those conditions can cause failure. Common errors include using a wire rope sling at an angle steeper than its rated angle (which increases the effective load on the sling), using shackles that are undersized for the load, or rigging from a single pick point on a machine that requires two or more to remain level during the lift.
How to avoid it: Always calculate the sling tension based on the actual rigging angle, not the total load weight. Use a certified spreader beam where required to ensure lift points are directly above the rigging hardware. Never substitute equipment for a different type or size without verifying the new configuration’s capacity.
3. Failing to Inspect Rigging Equipment Before Use
Rigging equipment deteriorates over time, particularly under heavy use in industrial environments. Wire rope slings develop broken wires and kinks. Web slings suffer cuts and UV degradation. Shackles show wear at the pin and bow. Chain links develop stretch and surface cracks. Using damaged equipment — even for a load well within its rated capacity — significantly increases the risk of sudden failure.
How to avoid it: Inspect all rigging tackle before every use. Follow the discard criteria in the relevant SANS standards — broken wires, distortion, cuts, or corrosion beyond these limits means the equipment must be destroyed, not returned to the store. Never use equipment that does not carry a current load test certificate.
4. Poor Communication Between Team Members
Rigging operations involve multiple people working simultaneously — crane operators, riggers, spotters, and supervisors. When communication breaks down, even a routine lift can become dangerous. Ambiguous signals, radio interference, or simply not confirming instructions are understood are recurring causes of incidents on South African industrial sites.
How to avoid it: Designate a single banksman or lift supervisor who gives all crane signals. Use standardised hand signals confirmed by all team members before the lift starts. Conduct a pre-lift briefing covering the sequence, signals, and emergency procedures. Test radio equipment before operations begin.
5. Exceeding Crane Capacity — Especially at Extended Boom Lengths
A crane’s rated capacity changes significantly with boom length and radius. A crane rated to lift 100 tonnes at a short radius may only be rated for 30 tonnes at maximum boom extension. Pressure to complete a job with available equipment often leads to lifts that exceed safe capacity — especially when dynamic forces from movement or wind are not accounted for.
How to avoid it: Study the crane’s load chart carefully for the specific boom configuration being used. Add the weight of the lifting block and all rigging hardware to the load. Operate at no more than 85% of rated capacity for standard lifts to maintain a safety margin for dynamic loading. If approaching capacity limits, source a larger crane rather than proceeding at risk.
6. Inadequate Site Preparation and Ground Bearing Assessment
Mobile cranes exert enormous point loads through their outrigger pads. If the ground beneath the outriggers is not capable of supporting these loads, the crane can tip suddenly — one of the most serious accidents in the rigging industry. Many South African industrial sites have hidden services, old drainage lines, or soft fill beneath apparently solid ground that can give way under crane outrigger loads.
How to avoid it: Always obtain ground condition information from the site owner before setting up a crane. Use outrigger mats to distribute the load across a larger area. If ground conditions are uncertain, carry out a bearing capacity assessment before the lift.
7. Skipping the Pre-Lift Briefing and Lift Plan
Time pressure is one of the most common reasons rigging teams skip formal lift planning and pre-lift briefings. Yet the time invested in a thorough lift plan and team briefing is almost always recovered through smoother execution — and potentially saved through accidents avoided.
How to avoid it: Treat the lift plan and pre-lift briefing as non-negotiable requirements on every project. For critical lifts, these are also a legal requirement under South African health and safety law. A five-minute briefing that ensures everyone on site understands the sequence, signals, and hazards is one of the most cost-effective safety investments you can make.
Reef Rigging’s team follows formal lift planning procedures on every project. Contact us to discuss your rigging requirements, or read more about our health and safety approach.
Frequently Asked Questions: Common Rigging Mistakes
What is the most common cause of rigging accidents in South Africa?
Based on industry incident data, the most frequent causes of rigging accidents in South Africa are overloading of lifting equipment, use of damaged or uncertified rigging tackle, inadequate lift planning, and poor communication during operations. All of these are preventable through proper planning, equipment maintenance, and operator training.
How do you calculate rigging sling tension?
Sling tension increases as the angle between the sling and the vertical increases. At 0° (vertical), sling tension equals the load weight. At 30° from vertical, tension increases to approximately 115% of load weight. At 45°, it reaches approximately 141%. At 60°, tension is approximately 200% of the load weight. This means that slings rigged at wide angles must be significantly over-rated to handle the actual tension they experience during the lift.
When must rigging equipment be replaced in South Africa?
Rigging equipment must be removed from service when it shows damage that meets the discard criteria in the applicable SANS standards — including broken wires in wire rope slings, cuts or chemical damage to web slings, deformation or wear on shackles, or stretch or cracks in chain links. Equipment must also be removed from service if it cannot be positively identified as certified (i.e., if it lacks a valid load test certificate). There is no standard “age limit” for rigging equipment — condition and certification are the determining factors.