As a year-round general contractor, we do not always get to work in ideal weather conditions. As most construction sites are outdoors, weather conditions and temperature can further complicate the rigging and lifting process. Weather delays and hazards can drastically slow the pace of any project, so it is essential to know how to handle harsh conditions and temperatures that can affect crane operation.
Depending on the type of crane and load, it is best practice for the lift director, crane operator, rigger, and site superintendent to conduct a risk assessment and action plan for operating during the following four conditions, which are some of the most common and challenging hazards for all types of projects. The action plan can include stopping a project until conditions improve.
1. Reduced Visibility
Fog, rain, snow, and sleet are more common in winter. These weather conditions can significantly reduce visibility, making lifts more difficult for even the most experienced and skilled operators. While visibility conditions can be somewhat predicted through the weather forecast, some weather conditions may occur without warning. If visibility is severely impaired, lifts may need to be postponed until conditions improve.
2. High Winds
Every crane has a different capacity or rating for wind resistance. For example, some mobile cranes are rated to resist winds up to 25 MPH, while others can withstand winds up to 35 MPH. It is important to monitor the weather forecast to stay informed of potential periods with high wind speeds. Also, keep in mind the material being handled by the crane during wind gusts. If it has a solid surface, it can act much like a kite and increase the load force on the line. This load force might be reduced for a mesh-like load that allows the wind to pass through without much resistance.
3. Ice Buildup
Operating a mobile crane in icy weather can be extremely hazardous. Loads may freeze to the ground and become more difficult to lift. Additionally, ice may form on loads and crane booms, further impairing lifting ability. Be sure to perform all safety checks on load materials and major crane components to ensure that they are free of ice.
4. Freezing Temperatures
Extreme cold can increase strain on operators and equipment alike, negatively impacting the precision, accuracy, and strength of mobile cranes and all the people involved in lifting operations. One should also pay close attention to the steel, hydraulics, rigging devices, and hoists, which can also be compromised in severe cold. Freezing temperatures reduce the rated capacity of mobile cranes and increases the risk of damage. The crane industry recommends a 1% reduction in capacity for every degree below zero.
To help combat these and similar issues, ensure that all equipment is properly insulated and run it for a few minutes to warm it up before operating. It is also a good idea to let equipment run for a few minutes before operation to help dislodge any potential ice and help prevent build-up.