List of All Safety Formula
21. Cost of Incidents
- Cost Of Incidents = Direct Costs + Indirect Costs
- Indirect Costs: Lost Productivity, Training Replacements.
22. Total Man Hours Worked (TMHW) Formula
- TMHW = Total number of Employees x Number of Hours Worked Per Day x Number of Workdays
23. Load Moment Calculation
- Load Moment = Load x Load Radius
- M = W x R
- M = Load moment ( tons – meters or KN – m )
- w= Load Weight ( tons or KN )
- R= Load radius ( meters ) ( measured from the center of rotation to the load’s center of gravity )
24. Crane Capacity Calculation
- Crane Capacity = Load Moment / Load Radius
Note: This must be within the crane’s rated capacity from the manufacturer’s load chart.
25. Stability check formula ( Overturning Moment )
- Stability factor = Resisting Moment / Overturning Moment
- Sf = MR / MO
- MR = Resisting Moment ( due to counter weights, outriggers, etc.)
- MO = Overturning Moment ( due to load and boom position)
Safe Lifting Condition: Stability Factor should be ≥ 1.4 for mobile cranes and ≥ 1.5 for tower cranes.
26. Sling Angle Load Calculation
- F = W/ 2 x Cos (θ)
- F = Force in each sling leg (kN or Tons)
- W = Load Weight (kN or Tons)
- θ = Sling angle (degrees from vertical)
Safety Note: A lower sling angle increases tension and can cause failure. Recommended angles: 30° to 60°.
27. Wind Load Calculation ( for Outdoor Lifting )
- Fw = 0.613 x V2 X A x CD
- Fw = Wind Force (kN)
- V2 = Wind Speed (m/s)
- A = Projected area of the Load (m2)
- CD= Drag Coefficient ( Varies with shape, typically 1.2 to 2.0)
- Safe Wind Speed Limits:
- ≤ 10 m/s (36 km/h): Normal operation
- 10-14 m/s (50 km/h): Use caution
- ≥ 14 m/s (50 km/h): Stop lifting
