05 November 2024
The Mobile Crane is a versatile lifting machine designed to move heavy loads, often over large distances, using a telescopic or lattice boom mounted on a wheeled or tracked undercarriage. Mobile cranes are widely used on construction sites and highways due to their flexibility, mobility, and capacity to handle complex lifting tasks. However, due to their significant lifting power, height, and potential for instability, strict safety standards are necessary to mitigate risks. National Highways' "Raising the Bar 1" guidelines provide essential safety and operational requirements to ensure safe and compliant mobile crane usage on all projects.
General Minimum Requirements
The General Minimum Requirements (GMR) establish baseline safety and operational standards for all types of equipment, including mobile cranes:
Daily Inspections: Mobile cranes must undergo thorough pre-use inspections daily. Operators should complete a checklist, checking for any mechanical issues, such as wear on the boom, hydraulic system leaks, or braking issues.
Compliance with Legislation: Mobile cranes must meet UK regulatory standards, including UKCA certification and compliance with the European Commission Machinery Directive (2006/42/EC), along with a declaration of conformity.
Safety Decals and High-Visibility Markings: Safety decals should be clear, visible, and legible. Handrails, access points, and operational controls should be marked in high-visibility colours to support safe use.
Seat Belts: Seat belts are mandatory and must be worn by the operator at all times to enhance safety during movement and lifting operations.
Public Highway Compliance: When used on public roads, mobile cranes must have registration plates, operational lights, and flashing amber beacons as specified in Chapter 8 of the Traffic Signs Manual.
Equipment-Specific Safety and Compliance Standards
Mobile cranes present unique operational and safety challenges due to their lifting power, height, and boom extension capabilities. The following additional standards apply:
Amber Beacon and Seat Belt Indicator: An amber beacon is required for visibility, along with an external green light that indicates when the operator’s seat belt is fastened. The green light may be deactivated on public roads where lighting regulations restrict its use.
360° Visibility Standards: Mobile cranes must meet 360° visibility requirements, achievable through mirrors, cameras, or other visual aids to ensure operators can see around the machine, especially when manoeuvring or setting up.
Reversing Alarm: A directional, white-noise reversing alarm should be installed to alert nearby personnel when the crane is reversing. The alarm must be clearly audible outside the cab.
Stability and Outrigger Controls: Mobile cranes should be equipped with outriggers or stabilizers, which must be deployed and securely set on firm ground before any lifting operation. Operators must verify that all stabilizers are fully extended according to manufacturer guidelines.
Load Moment Indicator (LMI): All mobile cranes must have an LMI system that warns the operator if the crane’s load moment (weight x distance) approaches the tipping point, helping prevent overloads.
Boom Angle and Extension Limiters: Boom angle and extension limiters are necessary to control the crane’s height and reach, particularly when operating near obstacles or power lines.
Automatic Stability Control: Automatic stability control systems are recommended to ensure the crane remains within safe operational limits, adjusting the crane’s configuration as necessary.
Emergency Stop Button: A clearly marked emergency stop button should be accessible to the operator, allowing for immediate shutdown of all crane functions in case of an emergency.
Lifting Operations Standards
Lifting operations are the primary function of mobile cranes, requiring compliance with Lifting Operations and Lifting Equipment Regulations (LOLER) to ensure safety and effective load handling.
LOLER Certification: Mobile cranes must have a valid LOLER inspection certificate, renewed every 12 months, and all lifting accessories should undergo a six-monthly inspection.
Certified Load Limits: The Safe Working Load (SWL) must be clearly marked on the crane, and operators should ensure they do not exceed these limits to maintain stability.
Lift Plan and Risk Assessment: Each lift must be supported by a detailed lift plan and risk assessment, including details about load weight, height, and swing radius. Operators must follow these guidelines closely.
Overload Warning Systems: Mobile cranes should have overload warning systems that alert operators if a load exceeds safe limits. These systems are essential for preventing accidents and equipment damage.
Hoist Rope and Safety Catches: All lifting hooks must have a safety catch to prevent loads from detaching. Hoist ropes should be checked regularly for wear or damage and should be appropriately rated for the crane’s maximum load.
Wind Speed Monitor: Mobile cranes must be equipped with a wind speed monitor, and operators should halt lifting operations if wind speeds exceed the manufacturer’s recommended limits.
Clear Exclusion Zones: Exclusion zones should be marked around the crane to ensure personnel stay clear of the swing radius and any load paths, minimizing the risk of accidental contact.
Operator Competency and Requirements
Operator skill and competency are crucial for safe and effective crane operation. The following standards apply:
Licensing and Certification: Operators must hold the appropriate license category, such as a Construction Plant Competence Scheme (CPCS) qualification or equivalent, for mobile crane operation.
Mobile Crane-Specific Training: Operators must complete training specific to the crane model they are using, covering lifting protocols, boom extension, stability management, and emergency procedures.
Understanding of Load Dynamics: Operators should understand how load positioning, boom angle, and extension affect the crane’s center of gravity and stability, especially during complex or high lifts.
Safe System of Work: Operators must be familiar with the site’s Safe System of Work (SSoW) and sign onto the Plant, Vehicle, and People Management Plan (PVPMP) before beginning operations.
Emergency Procedures: Operators must be trained in emergency procedures, including stopping the crane, safely lowering loads, and deploying the emergency stop in case of malfunction.
Desirable Features
To further enhance safety, efficiency, and environmental compliance, certain additional features are recommended for mobile cranes:
360º Camera System: A 360º camera system provides improved visibility around the crane, helping operators maintain situational awareness and avoid obstacles or personnel.
Remote Control System: Remote control systems enable operators to manage crane functions from a safe distance, allowing for more precise handling, especially in confined or high-risk areas.
Stage V Emission Compliance: For projects with environmental goals, Stage V-compliant engines are recommended to reduce emissions, particularly in urban or environmentally sensitive areas.
Anti-Collision Sensors: Anti-collision sensors alert operators when the boom or other crane parts approach obstacles, reducing the risk of accidental contact with structures or other equipment.
Automatic Load Monitoring System (LMS): An LMS continuously monitors load weight and balance, automatically adjusting the crane’s configuration to enhance stability and prevent overloading.
Boom Height and Slew Limiters: Height and slew limiters prevent the crane from extending or rotating beyond designated limits, particularly useful for working near obstacles or power lines.
Hazard Identification and Mitigation
Operating a mobile crane involves specific hazards, and proper mitigation is essential for safe operation:
Tipping Risks: Mobile cranes are at risk of tipping if operated on uneven ground or when lifting loads beyond capacity. Outrigger deployment, load monitoring systems, and stability control are essential to mitigate these risks.
Swing Radius and Load Path Hazards: The crane’s boom and load swing radius can pose risks to nearby personnel. Establishing clear exclusion zones and marking swing radii reduce the chance of accidental contact.
Overloading Hazards: Exceeding the crane’s load limits can cause structural damage and instability. Load moment indicators, certified load limits, and overload warning systems help prevent this hazard.
Overhead Obstructions: Mobile cranes often work at height, increasing the risk of accidental contact with overhead structures or power lines. Height limiters and clear exclusion zones are essential to prevent this risk.
Wind Hazards: High winds can destabilize loads, particularly on long booms. Wind speed monitors should be used, and operations should be paused if wind speeds exceed safe limits.
Noise and Vibration Exposure: Mobile cranes can generate significant noise and vibrations. Operators should use hearing protection, and steps should be taken to reduce exposure to prolonged vibration.
Summary
The Mobile Crane is an invaluable tool for lifting heavy loads on construction and highway projects, offering mobility and versatility. However, its lifting capacity, boom height, and operational complexity require strict adherence to National Highways' "Raising the Bar 1" guidelines. By following protocols for daily inspections, stability controls, load monitoring, and visibility, operators and site managers can ensure safe and efficient crane operation. Additional safety features, such as anti-collision sensors, automatic load monitoring, and Stage V emissions compliance, can further enhance safety and environmental responsibility.
This article provides a comprehensive overview of the critical safety standards, operator requirements, and hazard management strategies for mobile cranes, ensuring they are used in line with National Highways’ standards for safe and efficient project execution.