1. THE EFFECTS OF WIND ON CRANES AND THEIR LOADS
Houston Business Roundtable – Feb. 12, 2013
THE EFFECTS OF WIND ON CRANES AND THEIR LOADS
Matt Gardiner, P.E.

2. PRESENTATION OVERVIEW
Houston Business Roundtable
PRESENTATION OVERVIEW
Wind Effects
Standards & Regulations
Wind Related Accidents
Lift Planning Considerations
Questions

3. 1
Wind Effects

4. About wind… Wind speeds are measured at 33 feet above ground1
WIND EFFECTS
About wind…
Wind speeds are measured at 33 feet above ground
Wind speed increases with height
Gusts can be a bigger problem than sustained winds
Look for obstructions to wind
Look for potential areas that funnel or redirect wind

5. How does wind affect a lift?1
WIND EFFECTS
How does wind affect a lift?
Wind applies forces directly to the load (sail effect)
Wind applies forces directly to the crane
Drift can cause tip-overs or side-loading
Drift can eliminate clearances with boom or other obstructions
Drift (inward) can cause backward instability
Wind on load can cause load control issues

6. 2
Standards & Regulations

7. 2 Crane manufacturers, OSHA and ASME provide wind requirements
STANDARDS & REGULATIONS
OSHA Regulations
Crane manufacturers, OSHA and ASME provide wind requirements
§1926 Subpart CC
§ (h)(12) and § (b)(4)(iii): Wind effects must be considered during A/D ops for mobile and tower cranes
§ (c)(1): Power line drift from wind when working inside Table A distances
§ (h): Equipment securement requirements from storm warnings
§ (n): Capacity adjustment requirements due to wind
§ (k)(8)(i): Personnel hoisting requirements – 20 mph at the platform?
§ (e)(6)(v) and § (e)(3): Wind indicators required on tower cranes and cranes on barges
§ (m)(1)(ii): Load charts must consider 40 mph winds for cranes on barges
§ (n)(1)(i): Rated capacity reduction requirements (as applicable) due to wind for cranes on barges

8. 2 ASME B30.5 - 2011 STANDARDS & REGULATIONS
ASME Standards
ASME B
(h)(2): Site Supervisor responsible to ensure potential effect of wind is addressed
(b)(5): The effect of wind on the load and crane has to be noted and considered
(g): For operations within a FULLY ERECTED/EXTENDED BOOM LENGTH of Table (same as OSHA Table A), horizontal and vertical power line drift due to wind shall be added to the minimum clearance distance in the Table
Also requires consultation with utility owner to get specific clearances

9. 4
LIFT PLANNING CONSIDERATIONS

10. What does the manufacturer say?4
LIFT PLANNING CONSIDERATIONS
What does the manufacturer say?
Most manufacturers recommend capacity reductions above 20 mph
Most manufacturers set maximum allowable wind speeds for operations
Always consult the operations manual for instructions

11. What is the wind forecast?4
LIFT PLANNING CONSIDERATIONS
What is the wind forecast?
Check with reliable sources (NWS, NOAA, official stations)
Look for peak projected sustained and gust speeds AND wind direction(s)
Speeds tell you how much force can be applied
Direction tells you how the crane and load will be loaded by wind
Remember that wind forecasts are at a height of 33 feet and your cranes and loads may be much higher

12. 4
LIFT PLANNING CONSIDERATIONS
Food for thought
Will the wind generate enough force to significantly move the load?
Will the wind generate enough force on the crane’s boom to jeopardize stability?
Can the wind cause load control problems?
Are there nearby buildings that can funnel or redirect wind flow?
Has the Operations Manual been consulted for limitations?
Is there anything nearby that can be affected by wind that could interfere with the lift?
Are there any on-site weather stations or anemometers?

13. References 4 OSHA Regulations ASME Standards
LIFT PLANNING CONSIDERATIONS
References
OSHA Regulations
ASME Standards
Crane Manufacturer (Operations Manual)
Cranes and Derricks, by Howard Shapiro

14. 5
QUESTIONS?