Gantry Cranes Tandem Lifting Tips and Tricks for Long Precasting Beams
Precast Concrete Handling with Synchronized 2 Sets of Gantry Cranes

Before lifting, it's important to understand how the hoists share the load. Proper calibration and inspection prevent uneven lifting and potential damage.

• Each crane has hoists that lift its portion of the load.
• Hoists must be calibrated to share the weight evenly.
• Regular inspection of ropes or chains ensures reliability and safety.

Control systems are the brain of synchronized lifting. They manage crane movements and help operators maintain precise coordination.

• Can be wired, wireless, or PLC-based depending on the project needs.
• PLC systems allow automated synchronization and real-time adjustments.
• Load monitoring features help detect imbalance before it causes problems.

Safety interlocks act as a protective layer, preventing accidents during complex lifts. They ensure the operation stops immediately if anything goes wrong.

• Stop lifting if one crane moves faster than the other or if the load tilts.
• Protect both the concrete element and personnel on site.
• Reduce the risk of damage or accidents during lifts.

Using dual synchronized cranes offers clear benefits over single-crane or non-synchronized setups. Understanding these advantages helps engineers and buyers see why investing in a synchronized system is worthwhile.

• Stable lifts: Both ends move together, reducing sway and keeping the load level.
• Lower stress on concrete: Balanced lifting minimizes cracking, bending, or chipping.
• Precise placement: Elements can be positioned accurately, saving time and adjustments.

Calculating the load before lifting is critical. Knowing the weight, dimensions, and balance of precast elements helps prevent accidents and material damage.

Important calculations include:

• Weight and dimensions: Verify the exact size and mass of each panel or beam to ensure the cranes can handle it.
• Load distribution and center of gravity: Understanding where the weight is concentrated helps balance the lift and avoid tilting.
• Maximum crane capacity and safety margins: Never lift near the crane's limit; always add a safety margin of 10–20% to account for unexpected shifts.

Even with properly placed cranes and accurate calculations, the lift will only succeed if the synchronization system is set up correctly. Taking time to calibrate and test avoids costly mistakes.

Steps to follow:

• Calibration of hoists: Adjust hoists so both ends lift evenly and stay level during movement.
• Communication between crane sets: Ensure operators can communicate clearly, using radios or control systems, and confirm that cranes respond in sync.
• Testing load movement: Before lifting the actual precast element, perform a test run with a smaller load or simulate the movement to verify smooth operation.

Even with cranes calibrated and synchronized, the way you lift and move precast elements matters. Smooth, controlled operation reduces stress on the concrete and makes placement easier.

Practical tips:

• Simultaneous hoist operation: Both cranes should lift at the same time and speed to keep the load level.
• Adjust tension to prevent twisting or bending: Fine-tune hoist tension to match the weight distribution and avoid stressing corners or edges.
• Maintain smooth acceleration/deceleration: Avoid jerky starts or stops; sudden movements can damage the element or make it swing.

Accurate placement is critical, especially for panels, beams, or slabs that must fit into precise locations. Using proper tools and techniques makes the job faster and safer.

Key practices:

• Use guide frames or alignment tools: These help position elements without manual adjustment, reducing risk of damage.
• Avoid shock loading: Never drop or let the element settle quickly; gradual lowering protects both the concrete and the foundation.

• Both cranes should have accessible emergency stop buttons.
• Operators must know the procedure to stop lifts immediately if something goes wrong.
• Establish a clear chain of command for emergency situations.

• Use cranes equipped with overload protection to prevent lifting beyond capacity.
• Anti-sway devices help stabilize long panels and reduce risk of tipping or swinging.
• Regularly test these systems to ensure reliability.

• Plan for wind, uneven surfaces, or sudden obstructions.
• Adjust lift speed and hoist tension according to site conditions.
• Never attempt lifts in unsafe weather or unstable ground conditions.

• Check hoists, trolley wheels, and crane girders for cracks, deformation, or wear.
• Examine wire ropes and chains for fraying or corrosion.
• Verify rail alignment and crane end stops.

• Apply proper lubrication to hoist gears, rails, and moving parts.
• Clean and inspect wire ropes to avoid unexpected breakage.
• Maintain control panels and switches to prevent electrical faults.

• Document all inspections, maintenance, and repairs.
• Keep records of operator training and certifications.
• Ensure compliance with local safety regulations and standards.

• If cranes move out of sync, panels can bend, twist, or crack.
• Regularly inspect synchronization electronics and communication links.
• Train operators to monitor both ends visually and respond quickly to any imbalance.

• Minor misalignments during placement can create large installation problems.
• Use guide frames, alignment tools, or adjustable supports to ensure accurate positioning.
• Don't rush the placement; take the time to verify alignment from multiple angles.

• Uneven rails, obstructed pathways, or limited clearance increase lifting risks.
• Inspect and clear the site before each lift.
• Verify ground stability, crane spacing, and access for personnel and equipment.