The Automatic Safe Load Indicator (SLI) for Hydra Cranes is an intelligent overload protection and safety monitoring system designed for mobile and pick-and-carry crane operations. The system continuously monitors load, lifting movement, and crane operating limits to prevent overload, tipping risk, and unsafe lifting.

This system enhances operator safety, protects equipment, and ensures compliance with lifting safety regulations.

Key System Components

1. Tensiometer (Load Sensor)
The tensiometer measures the actual load on the lifting rope in real time.

Functions:
• Continuous load monitoring
• Accurate load data for safe lifting calculation
• Overload detection and warning

2. Cable Rolling Drum (Boom Angle & Length Sensor)
Installed on the boom, this unit contains dual inbuilt sensors that measure boom angle and boom length in real time.

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

3. Limit Switch
The limit switchprevents 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 the load sensor, cable drum sensor, and limit switch, then calculates safe lifting conditions using built-in crane safety logic. If the crane approaches unsafe limits, the system provides immediate warnings and can automatically stop crane movement via the hydraulic cut-off.

When unsafe conditions occur, the system provides:
• Visual alarms
• Audible warnings
• Automatic hydraulic cut-off protection

Key Features
• Real-time load monitoring and overload protection
• Anti-Two Block protection
• Automatic hydraulic cut-off for unsafe lifting
• Designed for mobile and pick-and-carry cranes
• Operator-friendly display interface
• Robust and reliable system for harsh site conditions
• Improves lifting safety and operational control

Benefits
• Prevents crane tipping and overload accidents
• Protects crane components and hydraulic systems
• Improves operator awareness and decision-making
• Reduces downtime and maintenance costs
• Promotes a strong safety culture in lifting operations