The Automatic Safe Load Indicator (SLI) for Telescopic Cranes is an advanced overload protection and lifting safety system designed for truck-mounted and mobile telescopic cranes. The system continuously monitors load, boom angle, boom length, wind speed, and lifting limits to ensure safe crane operation and prevent overload or tipping.

This intelligent solution enhances operator awareness, protects crane components, and supports compliance with lifting safety standards.

Key System Components

1. Tensiometer (Load Sensor)

Installed on the hoist rope, the tensiometer measures the actual lifting load in real time.

Functions:

• Continuous load monitoring
• Overload detection and warning
• Provides accurate load data for safe lifting calculations

2. Cable Rolling Drum (Boom Angle & Length Sensor)

Installed on the boom, the cable rolling drum contains dual inbuilt sensors to measure boom angle and boom length.

Functions:

• Provides real-time boom geometry data
• Enables accurate working radius calculation
• Supports SLI safe load computation

3. Anemometer (Wind Speed Sensor)

The anemometermeasures wind speed at crane height.
Functions:

• Real-time wind monitoring
• High wind alarm and warning
• Prevents lifting during unsafe weather conditions

3. Limit Switch

The limit switch prevents over-hoisting and unsafe hook travel.
Functions:

• Prevents hook block collision with boom tip
• Protects crane structure and lifting equipment
• Improves operational safety

4. Hydraulic Cut-Off Valve

The hydraulic cut-off automatically stops crane movement when overload occurs.
Functions:

• Automatically stops unsafe crane operations
• Prevents tipping and structural damage
• Provides active overload protection

5. Monitoring Display Unit

Installed inside the operator cabin, the monitoring display provides real-time lifting information and warnings.

Displays:

• Actual load
• Safe Working Load (SWL)
• Angle / Radius (m)
• Boom Length (m)
• Alarm and warning messages
• System status and alerts

How the System Works

The SLI system collects data from multiple sensors and processes it using built-in crane load charts. The system continuously calculates the safe lifting capacity based on crane configuration and operating conditions.

When unsafe conditions occur, the system provides:

• Visual warnings
• Audible alarms
• Automatic hydraulic cut-off protection

Key Features

• Real-time load monitoring and overload protection
• Accurate boom angle and length measurement
• Wind speed monitoring for safe lifting
• Anti-Two Block protection
• Automatic hydraulic cut-off system
• Designed for truck-mounted and mobile cranes
• Rugged and reliable for harsh site conditions

Benefits

• Prevents crane overload and tipping accidents
• Protects crane components and lifting equipment
• Improves operator awareness and decision making
• Reduces downtime and maintenance costs
• Promotes safe and efficient lifting operations