By Madeline Norgaard

Financial assumptions of yesterday may not be adequate for today’s new turbine technology. Typically, bigger turbines demand the use of larger, heavier cranes for installation. In fact, 1,000-ton cranes are becoming common on construction sites throughout the United States. Moving these larger cranes between turbine sites presents new risks to project cost, schedule and safety; which many owners are not considering in their initial planning.

Unfortunately, in recent years the wind industry has experienced serious safety incidents involving the use of larger cranes. Mortenson’s construction team and our AWEA industry partners have taken a serious look at how to safely transport larger cranes across project sites. While larger cranes inherently present more risk, the greatest risks are found in what we can’t see: the soil. An important risk factor is understanding the composition of the ground and its ability to support the movement of heavier machinery and equipment. We’ve learned a lot through the process and strive to lead the industry forward by helping our customers anticipate and overcome the challenges associated with installing bigger turbines.

There are several strategies for safely moving cranes, and we’ve outlined general schedule impacts in the table below. Often identified through a geotechnical analysis, if the soil between turbine sites cannot support the crane’s bearing pressure, partial or full breakdowns may be required, which can significantly lengthen the turbine erection schedule. Additional crane and crews may be required to maintain desired production levels.