05 November 2024
Raising The Bar Guidance - Mobile Crushing Plant Equipment Requirements
A Mobile Crushing Plant is a powerful piece of equipment used to process rocks, stones, concrete, and other materials into smaller, manageable pieces on-site. It’s often used in construction and highway projects to recycle materials and reduce the need for transportation, making it an environmentally friendly choice for managing waste. However, the crushing process involves high-risk elements, including rotating machinery, dust generation, and noise hazards. National Highways’ "Raising the Bar 1" guidelines outline stringent operational and safety requirements for using mobile crushing plants to ensure both safety and compliance.
General Minimum Requirements
The General Minimum Requirements (GMR) provide the foundational safety and operational standards for all equipment, including mobile crushing plants:
Daily Inspections: Mobile crushing plants must undergo daily pre-use inspections. Operators should complete a checklist to identify any issues, including potential wear on conveyor belts, hydraulic leaks, and malfunctioning controls.
Compliance with Legislation: Mobile crushers must meet UK regulatory standards, including UKCA certification and compliance with the European Commission Machinery Directive (2006/42/EC), with a declaration of conformity.
Safety Decals and High-Visibility Markings: Safety decals and high-visibility markings must be applied to access points, handrails, and controls to support safe use and handling.
Hearing Protection: Due to noise generated by the crusher’s operations, operators and nearby personnel must wear hearing protection whenever the equipment is in use.
Public Highway Compliance: When used near public highways, mobile crushers must display appropriate warning signage, lights, and flashing amber beacons, as specified in Chapter 8 of the Traffic Signs Manual.
Equipment-Specific Safety and Compliance Standards
Given the hazards of crushing operations, including material ejection, dust, and noise, specific standards are essential to ensure safe and compliant operation:
Amber Beacon and Seat Belt Indicator: An amber beacon must be installed to increase visibility. An external green light should also indicate when the operator’s seat belt is engaged; the green light may be turned off near public highways if required by lighting regulations.
360° Visibility Standards: Mobile crushers must meet 360° visibility requirements, achieved through mirrors, cameras, or other visual aids to help operators maintain situational awareness, especially in high-traffic or confined areas.
Reversing Alarm: A directional, white-noise reversing alarm should be installed to alert nearby personnel when the crusher is moving in reverse. The alarm must be clearly audible outside the cab.
Conveyor and Crusher Guarding: Guards should be in place over conveyor belts and moving parts to prevent personnel from accidentally coming into contact with the crusher’s components.
Dust Suppression System: Mobile crushing plants must be equipped with a dust suppression system to minimize airborne dust, which can pose respiratory hazards and affect visibility.
Hydraulic Pressure Relief: The hydraulic system powering the crusher should have a pressure relief valve to prevent over-pressurization, reducing the risk of leaks or burst lines.
Emergency Stop Button: Emergency stop buttons must be accessible to the operator and positioned at strategic points around the crusher to allow for quick shutdown in case of an emergency.
Crushing and Material Handling Standards
The crushing process involves handling large and potentially unstable materials, requiring specific safety and operational standards:
Load Management and Feed Control: Operators should ensure the crusher is not overloaded. Feed rates must be controlled to prevent jamming and avoid overloading, which can damage the crusher and increase operational risk.
Conveyor Safety and Stability: Conveyors should be securely positioned and regularly inspected for wear or damage. Operators should avoid overloading conveyors to maintain safe and efficient operation.
Dust Suppression During Crushing: Dust suppression systems should be activated during crushing to minimize airborne particles, particularly in dry conditions.
Avoiding Overhead Hazards: When positioning the crusher, operators should ensure it is clear of overhead obstructions, such as power lines or tree branches, to avoid potential hazards.
Material Ejection Control: Mobile crushers should have ejection shields or deflectors to manage material ejection and prevent fragments from being thrown out at high speeds.
Regular Inspections of Wear Parts: Wear parts such as jaws, hammers, and cones should be regularly inspected and replaced when necessary to maintain safe and efficient operation.
Operator Competency and Requirements
Operator skill and competency are critical for the safe and effective operation of mobile crushers, especially given the risks associated with material handling and crushing:
Licensing and Certification: Operators must hold the appropriate certification for mobile crusher operation and must be trained in the specific equipment they are using.
Crusher-Specific Training: Operators should undergo specific training on the crushing plant they will be using, including operation of conveyors, safety guards, and dust suppression systems.
Knowledge of Material Properties: Operators should understand the properties of the materials being processed, as certain materials may require specific handling techniques to prevent jamming or excessive wear.
Ground Condition Assessment: Operators must assess ground stability before positioning the crusher, particularly on uneven or sloped surfaces to prevent movement or tipping.
Emergency Procedures: Operators must be trained in emergency stop procedures and techniques for managing unexpected issues, such as material blockages or equipment malfunction.
Desirable Features
To further enhance safety and efficiency, additional features are recommended for mobile crushing plants:
Automatic Dust Suppression System: An automatic dust suppression system that activates as material is fed into the crusher helps maintain air quality and reduce the risk of respiratory hazards.
Stage V Emission Compliance: For projects with environmental goals, a Stage V-compliant engine is recommended to minimize emissions, particularly in sensitive or urban areas.
360º Camera System: A 360º camera system can enhance visibility, helping operators monitor the surrounding area and avoid potential collisions with people or obstacles.
Remote Control Operation: Remote control systems enable operators to control the crusher from a safe distance, providing added flexibility and safety, especially for managing blockages.
Anti-Vibration Seating: Anti-vibration seating reduces operator fatigue during long shifts, enhancing focus and reducing the risk of errors due to discomfort.
Automatic Load Monitoring System: A load monitoring system that alerts the operator to potential overloading or material flow inconsistencies can help maintain consistent operation and prevent equipment damage.
Hazard Identification and Mitigation
Operating a mobile crusher involves specific hazards, and proper hazard mitigation is essential to ensure safe operation:
Material Ejection and Fragmentation: The crushing process can result in flying debris and material ejection. Shields, deflectors, and maintaining a safe distance from the machine help reduce this risk.
Overloading and Blockages: Overloading can lead to blockages, equipment strain, and operational hazards. Load monitoring systems and feed control help operators manage material flow safely.
Dust Hazards: The crushing process generates significant dust, which poses respiratory risks. Dust suppression systems, combined with regular maintenance and PPE for operators, help minimize exposure.
Noise Exposure: Crushers generate considerable noise. Operators should use hearing protection, and noise reduction measures should be considered to limit prolonged exposure.
Crushing and Conveyor Guarding: Crushing and conveyor components pose an entrapment risk. Guards should be in place, and operators should avoid contact with moving parts.
Ground Stability Issues: Positioning on unstable ground can lead to movement or tipping, especially with heavy loads. Operators should assess ground conditions and use stabilizers where necessary.
Summary
The Mobile Crushing Plant is a crucial asset for on-site material processing on construction and highway projects, enabling efficient recycling and reducing the need for off-site transport. However, due to the risks associated with high-pressure crushing, moving components, and dust generation, strict adherence to National Highways' "Raising the Bar 1" guidelines is essential. By following protocols for daily inspections, dust suppression, visibility standards, and emergency stop functions, operators and site managers can ensure safe and effective use of mobile crushing plants. Additional safety features like load monitoring, remote control operation, and 360° cameras further enhance operational safety and environmental responsibility.
This article provides a comprehensive overview of the safety standards, operator requirements, and hazard management strategies for mobile crushing plants, ensuring compliance with National Highways’ standards for safe and efficient project execution.