Link-Belt crawler crane logs more than 5,000 hours and 425,000 tons on tunnel project
Watch the Link-Belt 298 Series 2 handle a tunnel boring machine
A Link-Belt lattice crawler crane that spent eight months supporting a tunnel boring project racked up more than 5,000 hours of operation and lifted more than 425,000 tons in total - while doing a job that usually needs two machines.
Jay Dee Contractors, part of a public-private partnership that led the construction of a modernization project along I-75 in Michigan, was responsible for a four-mile combined sewer outflow tunnel located 100 feet below the existing highway, with multiple stormwater shafts located along the right-of-way down to the new tunnel.
To support that work, Jay Dee purchased a new Link-Belt 250-ton 298 Series 2 lattice crawler crane midway through the project, to help speed up operations. It handled a number of big lifts - and many, many smaller ones.
"The scope of this job really requires two cranes: a duty cycle machine to lift out the muck boxes from the tunnel being dug and a heavy lifting crane to lift out the sections of the tunnel boring machine (TBM) at the beginning and end of the project. Instead, we just used the 298 (Series 2)," said Brian Hagan, Vice President of Engineering and Operations of Jay Dee Contractors.
During the tunnelling project, earth (or "muck") moves to the rear of the 400-foot TBM through a conveyor system. It was then dumped into five train cars - muck boxes - that were lifted back to the surface by the 298 Series 2. Each lift weighed between 50,000 and 60,000 pounds. That operation was repeated for every five feet of tunnel dug out on the 21,000-foot project.
Over the course of the project, the crane completed more than 4,200 muck box lifts, totalling more than 425,000 tons of soil removed.
At the end of the project, Jay Dee had one more series of lifts for the 298 Series 2 - the TBM itself.
The boring machine, consisting of a cutter head and shield at the front, followed by ten gantries that house equipment supporting the boring operation, was disassembled underground. The cutter head and shield are about 35 feet long and are the heaviest part of the 400-foot-long assembly. The middle shield, weighing 208,000 pounds rigged and measuring 17 feet in diameter by 20 feet long, was one of the key lifts the 298 Series 2 performed.
