Liebherr crawler cranes used for US Route 191 realignment

The Utah Department of Transportation (UDOT) is working to improve safety along a hazardous stretch of US Route 191 near Vernal, Utah, USA. The US-191 Realignment Project aims to replace 4.2 kilometers (2.6 miles) of steep switchbacks with a safer, more gradual roadway to accommodate motorists and commercial vehicles.

Densification’s compaction of the realignment site was the first phase of the project and laid the groundwork for the improved highway. Photo: Liebherr

A key part of this project involves stabilizing the soil to create a solid foundation for the new road. Densification, Inc., a contractor specializing in soil compaction, was brought in to perform dynamic compaction—a process that densifies soil by repeatedly dropping heavy weights. The company used two Liebherr HS 8100 HD duty cycle crawler cranes for the job.

Each crane dropped 18-metric-ton (40,000-pound) weights from 21 meters (70 feet) to compact the ground, followed by 11-metric-ton (24,000-pound) weights from 6 meters (20 feet) for final surface stabilization. The cranes’ automated winch system ensured precise drops while preventing rope damage. Their operator cabs, equipped with armored glass, provided additional safety.

The project site posed a challenge due to its 152-meter (500-foot) elevation change. To address this, Liebherr worked with Densification, Inc. to develop a custom load chart, ensuring the cranes operated safely on sloped terrain.

Robert Shaffer, Vice President of Densification, Inc., noted that the Liebherr cranes’ reliability and performance played a key role in keeping the project on schedule.

With soil stabilization complete, work on the realignment continues. Once finished, the new section of US-191 will provide a safer and more efficient route through this previously difficult stretch of highway.