You must lift a rectangular skid weighing using a standard 2-leg sling hitch. The slings are 10 feet long , and the vertical distance from the load hooks to the crane hook is 8 feet . Step 1: Calculate the Tension Factor Divide the length of the sling by the vertical height. Step 2: Determine Load per Leg Divide the total weight by the number of lifting legs. Step 3: Calculate Total Sling Tension Multiply the load per leg by your tension factor.
LAF=Sling LengthSling HeightLAF equals the fraction with numerator Sling Length and denominator Sling Height end-fraction D/d Ratio Calculation
: You are lifting a 10,000 lbs load with two slings at a 45-degree angle. Safe Working Load (SWL) and Design Factor rigging engineering calculations pdf free download
Avoid horizontal sling angles below 45 degrees. Angles below 30 degrees are exceptionally hazardous. 2. Center of Gravity (CG) Determination For asymmetrical loads, calculate the distance ( ) from a reference point to distribute weight safely.
Calculating this ensures you can adjust to keep the load level during the initial pick. 4. Wire Rope and D/d Ratios You must lift a rectangular skid weighing using
For complex, repetitive calculations, these free tools are invaluable.
F = 10,000 kg x 9.81 m/s^2 x 1.5 m F = 147,150 N Step 2: Determine Load per Leg Divide the
The angle at which a sling is rigged significantly changes the amount of tension applied to that sling. As the horizontal angle between the sling and the load decreases, the tension inside the sling increases exponentially. The Sling Angle Factor (SAF)
Mastering rigging engineering calculations is fundamental to ensuring safety, compliance, and efficiency. With the resources shared in this guide, including the Bechtel Rigging Handbook and the Handbook of Rigging, you can build a digital library that will support your work for years. By understanding key formulas, adhering to standards, and applying best practices, you are taking the most important steps toward becoming a safer, more effective rigging professional.
Before a crane even hooks onto a load, the rigging engineer must ensure the ground can support the crane's weight plus the load. GBP = (Crane Weight + Load Weight) / (Outrigger Pad Area)