Safety Principles for Lifting Equipment in Industry

In industries such as construction, manufacturing, and logistics, lifting equipment plays a crucial role in moving and handling heavy loads. However, the process of lifting heavy objects always carries significant risks of occupational accidents, especially when the equipment operates with heavy loads, high lifting heights, and in complex working environments.

Therefore, compliance with lifting equipment safety principles is a mandatory requirement to protect people, ensure stable equipment operation, and maintain production efficiency. These principles are built upon technical regulations, practical operating experience, and root cause analysis of accidents in the lifting industry.

The following article will summarise and analyse the core safety principles when using lifting equipment, ranging from technical requirements and operating environments to inspection procedures and personnel training.

Legal framework for lifting equipment safety management in Vietnam

In Vietnam, lifting equipment is classified into a group of machinery and equipment with strict occupational safety requirements. Due to the specific nature of operating with heavy loads, high lifting heights, and complex work environments, the management of this equipment is built on a relatively strict system of technical standards and regulations. This legal framework controls the entire lifecycle of the equipment, from design, manufacturing, and import to installation, operation, and technical inspection.

National technical regulations on lifting equipment safety

The most important foundation in the legal system is QCVN 7:2012/BLDTBXH – National technical regulation on occupational safety for lifting equipment. Promulgated by the Ministry of Labour, Invalids and Social Affairs, this regulation outlines mandatory requirements to ensure safety during the use of lifting equipment at construction sites and factories.

QCVN 7:2012/BLDTBXH establishes safety management principles for various stages, including:

• requirements for the design and manufacture of lifting equipment
• regulations on installation and operation
• safety technical inspection procedures
• requirements for the management and supervision of equipment during use

Consequently, enterprises using lifting equipment must adhere to a unified standard system, minimising the risk of accidents during operation.

Related technical standards

Besides national regulations, the Vietnamese technical standard system also plays a vital role in ensuring the safety of lifting equipment. Some typical standards include:

TCVN 4244:2005 – Lifting appliances: Design, manufacture, and technical inspection

• This standard specifies requirements for the structure, load calculation, quality control, and technical testing of lifting equipment. It is considered the core standard for ensuring the durability and load-bearing capacity of lifting equipment during use.

TCVN 5863:1995 – Lifting appliances - Safety requirements for installation and use

• This standard focuses on regulations related to the installation, dismantling, and operation of equipment. It emphasises factors such as construction safety, electrical safety, fire prevention, and working conditions for employees.

Additionally, many other specialised standards are applied to control critical components of lifting equipment, such as standards for inspecting wire ropes, electrical systems, or operating signals.

Scope of application for types of lifting equipment

Under current regulations, the legal framework for lifting equipment safety applies to many common types of industrial equipment, including:

• various types of cranes (tower cranes, mobile cranes, crawler cranes, etc.)
• overhead cranes and gantry cranes in factories or cargo yards
• electric hoists, electric winches, and hand winches
• lifting equipment utilising wire ropes or chains

The detailed classification of equipment helps regulatory agencies and inspection bodies apply the correct technical standards to each type of equipment, thereby improving the efficiency of safety control.

The system of technical regulations and standards is not only legal in nature but also acts as a technical risk management framework for the entire lifting industry. Through regulations on design, inspection, and operation, this system ensures that lifting equipment is used in safe conditions, minimising the risk of occupational accidents and protecting the lives of workers.

=> Read more: Lifting equipment standards in Vietnam

Accident dynamics of lifting equipment

Accidents involving lifting equipment rarely occur due to a single isolated cause. In most cases, incidents are the result of a simultaneous chain reaction between technical factors, the working environment, and human operational behaviour. When these factors combine with heavy loads and the dynamic energy of the lifting system, even a minor deviation can lead to instability or the structural destruction of the equipment.

Analysing accident dynamics helps to clearly understand the physical mechanisms behind incidents, thereby building more effective safe operation principles.

Instability and equipment overturning

One of the most serious accidents when operating lifting equipment is equipment overturning, which frequently occurs with forklifts or mobile cranes. Mechanically, all lifting equipment must maintain a state of equilibrium based on the principle of load distribution and the centre of gravity of the entire system.

The equipment's centre of gravity consists of three main components:

• the dead weight of the equipment itself
• the counterweight
• the load being lifted

For the equipment to operate stably, the projection of the centre of gravity must always fall inside the base polygon (the area created by the contact points of the wheels or outriggers with the ground). When the load exceeds limits or is unevenly distributed, the centre of gravity can shift outside the stability zone, resulting in lateral or longitudinal tipping of the equipment.

This phenomenon usually occurs in situations such as:

• lifting loads exceeding the design capacity
• Incorrect determination of the load centre
• lifting loads too far from the equipment's centre
• moving while lifting loads at high altitudes

Impact of inertial forces during movement

When lifting equipment moves, especially forklifts or self-propelled cranes, the generated inertial forces can alter the equilibrium state of the system.

For example, when a forklift turns at high speed, centrifugal force acts on the centre of mass of the equipment and the load, causing the center of gravity to shift toward the outside of the turn. If this force exceeds the equipment's stability limit, the forklift can tip over sideways.

Similarly, during sudden braking or rapid acceleration, longitudinal inertial forces create an overturning moment around the front or rear wheel axle. This can cause the equipment to lift off the ground and lead to a serious accident.

Environmental factors also increase the risk of instability, such as:

• slippery or wet floors
• sloping or uneven terrain
• soft or sinking ground

Under these conditions, the coefficient of friction between the wheels and the ground drops sharply, making the equipment difficult to control when carrying a load.

Risk of dropped loads due to mechanical failure

Besides equipment overturning, dropped loads are one of the most common and dangerous types of accidents in lifting operations. This incident is usually related to mechanical failures in the lifting system, such as:

• lifting brake failure
• pressure drop in the hydraulic system
• broken wire ropes
• deformation of the crane hook or lifting accessories

When a heavy load falls freely from a certain height, its potential energy quickly converts into massive kinetic energy. The impact force generated when the load hits the ground can destroy the equipment, surrounding structures, and pose a direct danger to workers in the area.

Accidents due to limited visibility and blind spots

Another crucial factor in the accident dynamics of lifting equipment is blind spots during operation. Due to the large size of the crane structure or the load being lifted, the operator often cannot observe the entire working area.

Obscured spatial zones can lead to many dangerous situations, such as:

• colliding with workers in the operational area
• colliding with other structures or equipment
• damaging goods and materials

To mitigate this risk, it is often necessary to use a signalperson (signalman) or supportive signal systems to help the operator precisely control the movement of the lifting equipment.

Safety principles in the installation environment and workspace

In addition to the technical elements of the equipment, the installation environment and workspace directly affect the level of safety when operating lifting equipment. Many severe accidents in practice do not stem from mechanical faults of the equipment but from unsuitable environmental conditions, such as weak foundations, high winds, or violating safe clearances with power grids. Therefore, controlling the installation area and organising the workspace is a vital principle in the lifting safety system.

Ensuring stable foundations and installation structures

Before putting lifting equipment into use, the installation area must be thoroughly surveyed and prepared to ensure the load-bearing capacity of the foundation and support structures. For stationary lifting equipment like overhead cranes, gantry cranes, or tower cranes, the foundation system and installation structure must be able to withstand the maximum working load as well as forces generated during operation.

Particularly, for rail-mounted moving equipment such as overhead or gantry cranes, the rails must meet technical requirements such as:

• ensuring the straightness and parallelism of the two rails
• maintaining coplanarity within allowable tolerances
• controlling the gaps at the rail joints

If the tracks are misaligned or subsided, the equipment can suffer from wheel jamming, derailment, or generate torsional stress on the main girder structure, increasing the risk of equipment damage and occupational accidents.

Controlling the impact of weather conditions

For lifting equipment operating outdoors, such as tower cranes, container gantry cranes, or construction cranes, weather conditions can strongly impact the stability of the equipment. Wind is the most dangerous factor because it creates immense pressure on the crane structure and the suspended load, increasing the equipment's overturning moment.

According to safety regulations, outdoor equipment installation, dismantling, or operation activities must be suspended when hazardous weather conditions occur, such as:

• heavy rain or thunderstorms
• strong winds of level 5 or above
• restricted visibility

Continuing to operate equipment in adverse weather conditions can destabilise the load and lead to the risk of crane overturning or dropped loads.

Establishing danger zones and controlling the workspace

During the installation or operation of lifting equipment, the area surrounding the equipment must be clearly designated as a danger zone. This is the area where there is a potential for dropped loads or collisions while the equipment is active.

Common control measures include:

• setting up safety barricades around the working area
• placing hazard warning signs
• restricting unauthorised personnel from entering the operating area

In particular, the area directly beneath the load's travel path must be strictly controlled to prevent the risk of accidents caused by falling loads or collisions with the lifting equipment.

Ensuring safe clearance from electrical systems

One of the most serious risks when operating lifting equipment is the danger of electrical discharge from high-voltage power lines. Because cranes and lifting equipment often have tall, far-reaching metal structures, they can come close to the power grid system if the working location is not well-controlled.

Even if the equipment does not directly contact the conductor, high voltage can still cause an arc flash phenomenon, where the electric current jumps across the air gap and transmits into the metal structure of the equipment. This incident can cause the equipment to catch fire or electrocute the operator.

Therefore, during the construction and operation of lifting equipment, it is imperative to maintain minimum safe clearances from power lines according to each voltage level. Adhering to these clearances helps minimise the risk of electrical discharge and protects the safety of the entire working area.

System Voltage Level	Minimum Safe Clearance	Scope of Application
Up to 1 kV	1.5 m	When lifting equipment moves or works near power lines
1 – 20 kV	2.0 m	Applied to construction and lifting equipment in areas with medium-voltage lines
35 – 110 kV	4.0 m	Minimum distance when cranes or lifting equipment work near high-voltage lines
150 – 220 kV	5.0 m	Applied to areas near power transmission lines
500 kV	6.0 m (recommended ≥ 6 m)	Safe clearance when working near ultra-high-voltage grids

Notes:

• Clearances are calculated from the nearest point of the lifting equipment (crane boom, cable, load hook) to the electrical conductor.
• Even if the equipment does not directly touch the power line, high voltage can still cause an arc flash through the air.
• When working near power lines, safety supervisors and warning signs should be deployed to ensure safe clearances are consistently maintained.

Ensuring safety when working at heights

During the installation or maintenance of lifting equipment, many tasks must be performed at great heights. Therefore, workers participating in high-altitude work must meet health requirements and be fully equipped with personal protective equipment (PPE).

Basic safety requirements include:

• using safety harnesses when working at heights
• checking that the anchor points for the safety harness are secure
• complying with working-at-height procedures according to regulations

Fully implementing personal protective measures helps minimise the risk of falling accidents during the installation and maintenance of lifting equipment.

Safe operation principles for lifting equipment

During the use of lifting equipment, the operational phase is the time with the most potential risks. Once a load is lifted off the ground and moves through space, the system is subjected to various forces such as inertia, bending moments, and load swing. Therefore, compliance with safe operating principles is the decisive factor in controlling risks and ensuring stable equipment operation.

Lifting loads vertically

A fundamental principle in lifting engineering is that the load must be lifted vertically. The centre of the crane hook needs to lie on the same vertical axis as the gravity passing through the centre of mass of the lifted object.

Actions such as dragging loads on the ground, jerking loads, or lifting diagonally are strictly prohibited. When a load is lifted off-centre, lateral pulling forces emerge and create adverse bending moments on the equipment's structure. These forces can cause rapid wear on pulleys and winding drums, causing the wire rope to slip out of the grooves or even break during operation.

Do not exceed the allowable load capacity

Every lifting appliance is designed with a safe working load limit. Exceeding this load capacity can alter the equipment's equilibrium, cause structural deformation, or destroy load-bearing components.

Therefore, before lifting a load, it is essential to:

• accurately determine the weight of the goods
• Check the equipment's load chart
• ensure the load is evenly distributed on the lifting accessories

Overloading not only endangers the equipment but also increases the risk of the machine overturning or dropping the load during operation.

Do not leave suspended loads unattended

During operation, the load must not be left suspended in the air when the operator leaves the control position or when the equipment is stopped. When a load is suspended in the air for an extended period, the entire load force is concentrated on the braking system and load-holding mechanism.

This continuous loading can reduce the effectiveness of the braking system, leading to brake slippage or unexpected load dropping. Therefore, when work needs to be paused, the operator must lower the load to a safe position before leaving the equipment.

Do not stand or work under suspended loads

One of the most critical safety rules when operating lifting equipment is to absolutely never stand or work beneath a suspended load. Even if the load appears stable, incidents such as broken cables, damaged hooks, or loss of hydraulic pressure can still occur unexpectedly.

If manipulation with the load hook is required, the rigger is only allowed to approach when the load has been lowered close to the ground, usually not exceeding one meter from the worker's standing position. This helps minimise the risk of accidents if a load-drop incident occurs.

Use standard control signals

In industrial environments, loud noise and long working distances make verbal communication between the operator and ground staff difficult. Therefore, a standard hand signal system is utilised to control lifting equipment.

These signals are standardised according to technical regulations to ensure everyone involved in the lifting process clearly understands the meaning of each gesture. The operator must only execute a manoeuvre upon receiving a clear signal from the signalperson, helping avoid deviations during coordinated work.

Control load speed and movement

During the lifting and moving of a load, all manoeuvres must be performed slowly and steadily. Sudden acceleration or stopping can create violent load swings, altering the centre of gravity and destabilising the equipment.

The operator needs to ensure:

• lifting the load gradually at the start
• avoiding sudden braking or abrupt crane rotation
• keeping the load stable throughout the movement process

Well-controlled load speed and movement help limit swinging and ensure safety for both the equipment and the work area.

Safe operating principles for lifting equipment are built upon fundamental mechanical laws and practical experience in the lifting industry. When strictly adhered to, these principles significantly reduce the risk of occupational accidents, protect equipment, and ensure that production activities run stably and efficiently.

=> Read more: Safe and proper operating procedures for lifting equipment

Safety control of wire ropes and crane hooks

In a lifting system, wire ropes and crane hooks are the two components directly bearing the force when lifting loads. The entire load from the equipment is transmitted through the rope and hook system before acting on the goods. Therefore, the technical condition of these parts has a decisive impact on the level of safety during operation. If the ropes or hooks suffer reduced load-bearing capacity, the risk of rope breakage or hook slipping can lead to severe dropped load accidents.

Degradation mechanism of wire ropes

Wire ropes in lifting equipment must endure multiple repetitive loads, such as tension, bending, and friction with pulleys or winding drums. During long-term operation, these impacts will alter the metal structure of the rope, leading to material fatigue and mechanical wear.

Common types of wire rope damage include:

• breakage of outer steel wires
• reduction in rope diameter due to wear and tear
• surface corrosion due to humid environments or chemicals
• deformation or twisting of the rope

These signs indicate that the load-bearing capacity of the wire rope has deteriorated and requires thorough inspection before continued use.

Standards for inspection and discarding of wire ropes

The inspection and assessment of wire rope conditions must adhere to technical standards, typically TCVN 10837:2015, which stipulates the methods for inspecting, maintaining, and discarding wire ropes used in lifting equipment.

According to this standard, the evaluation of wire ropes is based on numerous criteria, such as:

• The number of broken steel wires over a specific length of rope
• the degree of surface corrosion and wear
• the reduction in the rope's diameter compared to its original size
• abnormal deformations of the rope

When these indicators exceed allowable limits, the wire rope must be discarded and replaced immediately to prevent the risk of snapping while lifting loads.

In addition to periodic inspections by technicians, operators also need to perform daily visual inspections to detect early signs of rope damage before the equipment is put into operation.

Controlling crane hooks and lifting accessories

The crane hook is the intermediary component connecting the cable system to the load. During operation, the hook must withstand immense tensile forces along with concentrated stresses at the contact points with chains, wire ropes, or lifting accessories.

According to technical standards for lifting equipment, crane hooks must be inspected regularly to detect signs of mechanical degradation, such as:

• cracks on the hook body
• excessive wear at the contact points
• widening of the hook opening compared to its original dimensions
• deformation or twisting of the hook body

If the above signs appear, the lifting equipment must be taken out of service immediately to inspect and replace the crane hook to guarantee safety.

Controlling the installation and replacement of wire ropes

The process of replacing or installing new wire ropes must also be carried out according to strict technical procedures. When unwinding rope from a reel, ensure the rope is spooled off from a rotating reel, avoiding pulling the rope directly over the flange, as this can cause twisting or structural deformation of the rope.

Additionally, when cutting the wire rope, measures must be taken to seize (bind) both ends to prevent the inner steel strands from unravelling. Proper installation ensures the wire rope operates stably and maintains the lifting equipment's design lifespan.

Inspection and load testing system for lifting equipment

In the industrial lifting sector, the safety of equipment is not a static state but a continuous control process throughout the equipment's lifecycle. According to Vietnamese law, lifting equipment falling under the list of items with strict occupational safety requirements must undergo periodic technical inspections and load testing before being put into operation. This inspection system helps early detection of structural damage risks, reduced load-bearing capacity, or faults in the equipment's operating mechanisms.

Types of lifting equipment inspection

Under current regulations, lifting equipment must undergo three main types of inspections throughout its service life:

Initial inspection

• Performed after the equipment is fully installed or imported, right before being put into use. The goal of the initial inspection is to confirm that the equipment fully meets technical and safety requirements according to prescribed standards.

Periodic inspection

• Conducted on a specific cycle while the equipment is in use. Periodic inspection helps evaluate the wear and tear of load-bearing parts and the operational status of the mechanical, electrical, and hydraulic systems.

Extraordinary inspection

• Carried out when the equipment experiences an incident, after major repairs, replacement of critical components, or when the equipment is relocated and reinstalled in a new position. This inspection aims to ensure the equipment still meets safety standards after changes in structure or operating conditions.

Inspection contents during the inspection process

The lifting equipment inspection process involves multiple technical testing steps to comprehensively assess the equipment's condition. Some key inspection contents include:

• inspecting load-bearing metal structures such as girders, frames, and towers
• inspecting the wire rope system, chains, and lifting accessories
• inspecting the braking system and lifting mechanisms
• inspecting the electrical system and safety protection devices
• inspecting load limiters and warning devices

Through these inspection steps, inspection experts can detect hidden defects within the equipment before they develop into severe incidents.

Static and dynamic load testing

One of the most critical steps in the lifting equipment inspection process is technical load testing. This is the method for directly evaluating the load-bearing capacity of the equipment under actual conditions.

The load testing process usually includes two types of tests:

Static load testing

• The equipment lifts a load heavier than the rated working load and is held in a static state for a specified duration. The purpose of the static load test is to check the load-bearing capacity of the equipment's structure and assess the deformation of load-bearing parts.

Dynamic load testing

• After completing the static load test, the equipment proceeds to the dynamic load test, typically with a test load reaching about 125% of the rated working load. During this process, the equipment must execute manoeuvres such as lifting, lowering, moving, and rotating the load to check the operation of the braking system, transmission mechanisms, and structural stability.

If the equipment passes these tests without displaying abnormalities like load slipping, structural deformation, or mechanism failure, it will be issued an inspection certificate and allowed to continue operating.

Managing equipment records and logbooks

Upon completion of the inspection, the lifting equipment must be affixed with a safety inspection stamp and issued an inspection certificate valid for a specific period. The enterprise utilising the equipment is responsible for storing inspection records and monitoring the equipment's condition through an operational logbook.

The equipment logbook typically records information such as:

• equipment operating hours
• maintenance and repair sessions
• periodic inspection results
• incidents occurring during operation

Managing records and equipment logbooks helps enterprises better control the technical condition of their lifting equipment while providing a basis for planning subsequent maintenance and inspections.

Personnel training and safety culture

Besides the equipment and work environment factors, humans are the most critical link in the lifting equipment safety system. Although equipment is designed with various protective mechanisms like safety brakes, load limiters, or automated warning systems, these technologies can be rendered ineffective if the operator lacks knowledge or fails to follow safety procedures. Therefore, personnel training and building a safety culture within the enterprise are the keys to minimising occupational accidents.

Training requirements for lifting equipment operators

According to Vietnamese law, jobs related to operating lifting equipment are classified into the group of occupations with strict occupational safety requirements. Personnel directly involved in operating, maintaining, or slinging loads must undergo occupational safety training in a specialised program.

The group of personnel required to undergo training includes:

• operators of cranes, overhead cranes, and forklifts
• load slingers (riggers)
• personnel issuing lifting equipment control signals (signalmen)
• Maintenance and repair technicians for lifting equipment

The training program not only instructs on equipment operation manoeuvres but also equips workers with knowledge about the machine's operating principles, how to identify safety hazards, and methods for handling emergencies.

=> Read more: Regulations on lifting equipment operators under current laws

Safety training contents for lifting equipment

A lifting equipment safety training program generally includes the following core subjects:

• legal knowledge on occupational safety
• operating principles of lifting equipment
• How to read the equipment's load charts
• Methods for inspecting equipment before operation
• slinging techniques and load balancing
• procedures for handling incidents and emergencies

Comprehensive training helps operators clearly understand the technical limits of the equipment, thereby avoiding dangerous practices like overloading, off-centre lifting, or operating under unsafe conditions.

Training cycles and knowledge updates

To ensure workers always grasp the latest safety regulations, occupational safety training certificates for this job group usually have a specific validity period and must be renewed periodically.

Retraining helps workers:

• update themselves on new technical standards
• catch up with changes in equipment technology
• learn from safety incidents that have occurred within the industry

Consequently, the skills and safety awareness of employees are consistently maintained at a high level.

Building a safety culture in the enterprise

Beyond individual training, enterprises must cultivate an occupational safety culture throughout the entire organisation. A safety culture is a working environment where every employee is acutely aware of the importance of safety and proactively participates in risk prevention.

Key elements to building a safety culture include:

• encouraging the reporting of safety hazards
• conducting periodic safety inspections in the workplace
• empowering workers to stop work when risks are detected
• maintaining strict discipline in equipment operation

When a safety culture is established, behaviours that violate procedures are minimised, and workers tend to proactively adhere to safety rules on the job.

Conclusion

Safety when using lifting equipment is a comprehensive system comprising multiple interconnected elements, from the technical design of the equipment and working environmental conditions to operational procedures and the competency of workers. Accidents in the lifting sector rarely happen by chance; they are the result of a combination of equipment failure, operational errors, and a lack of risk control in the workplace. Therefore, complying with safety principles is a mandatory requirement to ensure that production activities take place stably and sustainably.

Through systems of technical regulations, inspection procedures, and control over wire ropes and crane hooks, coupled with safe operating principles and workspace organisation, businesses can drastically minimise the risk of accidents related to lifting equipment. However, the ultimate deciding factor still lies with the people. A well-trained workforce with a strong sense of discipline and a clear understanding of the equipment's technical limits will play a crucial role in maintaining safety during operation.

In a context where the industry is increasingly dependent on modern lifting systems, building a comprehensive safety management system not only helps businesses comply with legal regulations but also contributes to protecting assets, improving production efficiency, and, most importantly, ensuring the safety of workers.