Gantry cranes enable the lifting and moving of heavy loads across a fixed area. While these machines enhance productivity and efficiency, they also present significant hazards if not operated correctly. Understanding common gantry crane accidents and implementing preventive measures is crucial for maintaining a safe working environment, and it should be part of your gantry crane training.
Overloading Incidents
When a crane attempts to lift a load beyond its rated capacity, structural failure may occur, potentially causing catastrophic consequences. The crane might tip over, components could break, or the load might drop unexpectedly.
To prevent overloading incidents, operators must always verify the weight of loads before lifting and ensure this weight falls within the crane’s safe working load (SWL) limit. This includes accounting for the weight of lifting gear, such as slings and shackles, which must be subtracted from the crane’s overall capacity. Implementing and using load-indicating devices provides an additional safety measure by warning operators when approaching maximum capacity limits. Always refer to the manufacturer’s load charts to understand how the crane’s capacity may vary based on the position of the load and trolley.
Collisions with Structures or Personnel
Collisions occur when a gantry crane, or its load, strikes people, other equipment, or structures in the working area. These accidents can result in serious injuries, damage to property, and disruption to operations.
The prevention of collisions requires implementing exclusion zones beneath and around the crane’s operating path. Clear signage and physical barriers can help maintain these zones. Additionally, installing proximity warning systems or anti-collision devices on the crane can alert operators to potential obstructions. Regular training for operators on spatial awareness and proper movement techniques is essential. In situations where multiple cranes operate in the same area, procedures must be established to prevent the cranes from occupying the same airspace simultaneously. For crane speeds less than 40 m/min, buffers are acceptable, but for speeds greater than 40 m/min, proximity switches or devices are necessary.
Falling Loads
Loads may fall from cranes due to inadequate rigging, equipment failure, or improper operation. Falling loads present an extreme danger to personnel working below and can cause significant damage to property.
Preventing falling loads begins with proper load assessment and appropriate rigging techniques. Operators and riggers must select the correct slings and hardware for each specific load, considering factors such as weight, shape, and centre of gravity. Regular inspection of all lifting gear for wear, damage, or defects is crucial. Tag lines should be used to control loads during movement, particularly for bulky or long items. Ensuring loads are properly balanced before lifting will prevent unexpected shifting that could lead to falls. A trial lift, raising the load just a few centimetres off the ground and checking its stability, should become standard practice before completing any full lift.
Electrical Hazards
Gantry cranes operating near power lines face significant electrical hazards. Contact with overhead electrical lines can result in electrocution, fire, and equipment damage.
Maintaining a minimum clearance of 4 metres from overhead power lines is essential when operating mobile gantry cranes. For fixed gantry cranes installed near electrical infrastructure, proper insulation and guarding should be in place. All electrical components of the crane should be regularly inspected and maintained by qualified electricians. Operators must receive training on recognising electrical hazards and understanding emergency procedures in case of electrical contact. If a crane does make contact with electric lines, the operator should stay in the cab if safe to do so, warn others to keep clear, and request emergency assistance.
Mobile gantry cranes – those on wheels that can free roam – present a greater risk in this incidence.
Instability
We mentioned mobile gantry cranes which can be wheels or driven around. These can be destabilised by potholes and surface undulations, and by one of the wheels becoming blocked by an obstacle. In the worst case scenario, the crane tips over or suffers other serious damage.
Crushing Incidents
Crushing accidents occur when personnel are caught between the crane and a fixed structure, between moving parts of the crane, or between the load and another object. These incidents often result in severe injuries or fatalities.
To prevent crushing incidents, clear communication protocols must be established between crane operators and ground personnel. Implementing a spotter system for operations with limited visibility can significantly reduce risks. All personnel should receive training on identifying potential crush points and safe positioning during crane operations. Emergency stop buttons should be accessible and functional, allowing for immediate shutdown in dangerous situations. According to the Crane Association of New Zealand, maintaining adequate clearances of at least 600mm between cranes and fixed objects is essential for preventing crushing incidents.
Mechanical Failures
Mechanical failures, such as brake malfunctions, cable breaks, or structural defects, can lead to serious accidents. These failures often result from inadequate maintenance or inspection practices.
A comprehensive preventive maintenance programme is the primary defence against mechanical failures. This should include daily pre-operational checks, regular inspections by qualified personnel, and scheduled maintenance according to the manufacturer’s recommendations. Any identified issues should be addressed immediately, with the crane taken out of service if necessary. Documentation of all maintenance activities provides a valuable record for tracking recurring issues and planning preventive measures. Wire ropes should be regularly checked for broken wires, strand distortion, kinks, excessive wear, and corrosion.
Weather-Related Accidents
Outdoor gantry cranes are vulnerable to weather conditions that can compromise safety. High winds may cause loads to swing unpredictably or put strain on the crane structure. Rain can create slippery surfaces, and lightning poses an electrical hazard.
Operators should always check weather forecasts before beginning crane operations. Clear guidelines should be established regarding maximum wind speeds for safe operation, typically specified by the crane manufacturer – note that the same considerations are relevant for other plant that operates outdoors, such as EWPs. Operations should be suspended during thunderstorms due to lightning risks. For cranes left unattended during adverse weather, proper securing procedures must be followed to prevent movement or damage. Outdoor gantry cranes should be equipped with anemometers to monitor wind speed in real-time.
Documentation and Compliance
Maintaining proper documentation is crucial for ensuring compliance with regulations and tracking safety performance. Records should include inspection certificates, maintenance logs, operator qualifications, and incident reports.
Gantry cranes must undergo regular inspections by competent persons, with results documented and retained. The Approved Code of Practice for Cranes specifies that gantry cranes should be inspected annually by an equipment inspector. Pre-operational checks should be performed daily and recorded in a logbook. Any crane that is considered unsafe should be immediately withdrawn from service, locked out, tagged out, and made safe to the satisfaction of an equipment inspector before further use.
Emergency Response Procedures
Despite preventive measures, emergencies can still occur. Having well-established emergency procedures can make the difference between a minor incident and a catastrophic event.
Every workplace using gantry cranes should develop a comprehensive emergency response plan that includes procedures for power failures, overload situations, load swings, structural failures, control system malfunctions, and personal injuries. This plan should clearly define roles and responsibilities, establish communication protocols, identify evacuation routes and assembly points, and include regular drills to practice procedures. Emergency contact numbers should be easily accessible, and rescue equipment should be available for prompt response to injured workers, including crane operators.
Prevention Through Training and Procedures
Beyond specific preventive measures for each type of accident, comprehensive training programmes form the foundation of gantry crane safety. All operators should receive formal training and certification as required by the Health and Safety at Work Act 2015 and the Approved Code of Practice for Cranes.
Clear operating procedures should be documented and communicated to all relevant personnel. These procedures should cover routine operations, emergency responses, and maintenance protocols. Regular safety meetings and toolbox talks help reinforce safe practices and provide opportunities to address emerging concerns.
Check out our overhead gantry crane course to see if it suits your requirements for training.
Darren has written over 3000 articles about driving and vehicles, plus almost 500 vehicle reviews and numerous driving courses. Connect with him on LinkedIn by clicking the name above
