Various grave accidents and disasters involving tower cranes have been written down in history. Most of these unfortunate incidences happen when the weather conditions aren’t at their best. This is mainly because tower cranes are supported by a small structural mass which is found below it and as such, they tend to be susceptible to the elements. Under strong winds, they will sway in any direction and can cause accidents and damages to its surrounding area.
If there is a tower crane being used or present in your construction site, there are different steps and ways you can observe and follow to ensure that your crane survives extreme weather conditions and mitigate possible accidents and structural damages. These include the following:
1. Make sure that the operator follows the correct protocols after using the crane. There are certain procedures crane operators have to do before leaving the equipment. If they are using a luffing jib, the crane should be left with the jib luffed up in parking position. In case they are operating a hammerhead or flat top crane, before leaving it, the hook block must be brought back to the jib and left slightly away from the cabin. By doing so, the operators will ensure that the hook block will not blow in the wind freely and hit the cabin or swing around and injure anyone below the equipment.
2. In addition, the operator should release the crane parking brake and left in free slew when high winds are expected. Operators must ensure that there is nothing that can make contact with the jib within a 360 degree radius around the crane. Following these safety practices enable the slew ring to move freely with the wind and not fight against it. In case the parking brake is left on and the slew ring is parked in a fixed position, there is a huge risk that the wind will blow against the jib and impose loads on the crane that it’s not engineered to sustain.
3. Make sure there are no tools, bolts, nuts or any debris that can blow off the top of a crane during severe weather. This means removing anything on top of the tower crane that can be blown off and fall down. Failure to do so can result in a major incident or fatality for not only the workers on the job site, but also innocent pedestrians which are passing by the construction area.
4. Finally, once the weather condition has normalized, have the tower crane undergo a thorough examination before using it again. This is to ensure that everything is in working order. Have the operator perform a max load test to make sure that there hasn’t been significant damage to the crane during the storm. Have the site structural engineer inspect the tie-in points of the tower crane to the building to ensure that the structural stability of the crane has not been compromised because of the additional wind loadings on the crane and building.