In the world of heavy lifting, an assumption is a dangerous thing. When dealing with complex fabrications like skids, pressure vessels, or unevenly loaded modules, the “estimated weight” on a drawing is rarely enough to guarantee a safe lift.

At Prem Holdings, we believe in verifying the data before the rigging is ever applied. One of our most reliable methods for determining the exact Center of Gravity (CoG) is Manual Compression Weighing.

Why “Close Enough” Isn’t Good Enough

Fabrication drawings provide a theoretical CoG. However, welding additions, paint thickness, and internal piping modifications can significantly shift that point. If the crane hook isn’t centered exactly over the actual CoG, the load will tilt or swing the moment it leaves the ground.

To prevent this, we perform physical weighing operations on-site.

The Method: 4-Point Compression with Rotation

As seen in our recent operation at the Port Klang Free Zone (PKFZ), we utilize high-capacity compression load cells to gather precise data. But we don’t just place them and read the numbers. We follow a rigorous rotational verification protocol:

1. Placement: The skid is jacked up, and four calibrated load cells are placed at the primary structural corners.
2. Compression: The load is lowered onto the cells, ensuring the weight is fully distributed.
3. The “Rotation” Technique: To eliminate any potential calibration bias between individual sensors, we utilize a rotation method. The load cells are rotated through the 4 positions (e.g., Cell A moves to Position B, B to C, etc.) and readings are taken 4 times.
4. Calculation: These multiple data points are averaged to calculate the CoG with pinpoint accuracy (often within millimeters).

This manual method effectively “cancels out” device error and provides a true weight distribution profile of the cargo.

Watch the Process in Action

We recently documented this process on a heavy industrial skid. Notice how the team carefully positions the cells to ensure a stable, level reading.

The Results—By using this method, we provide our clients with:

Endorsed Safety: Data that can be confidently used in the final Lifting Operation Plan.

Total Verified Weight: Often different from the shipping manifest.

Exact CoG Coordinates: Allowing the Lifting Engineer to adjust sling lengths before the lift starts.

Need Accurate Weight Verification?

Whether it’s a 50-tonne skid or a 600-tonne module, accurate CoG calculation is the foundation of a safe lift. Contact Prem Holdings today to schedule a weighing operation for your next project.

📞 Call us at +6014 942 2186
📧 Or email us at sales@liftingandrigging.com.my to request a free consultation or learn more about our tailored solutions.

Let us help you lift smarter, safer, and more efficiently—every time.