Single Link-Belt crawler used instead of two smaller cranes3 November 2023
Contractor uses large Link-Belt lattice boom crawler to speed up tunnel building operations.
Jay Dee Contractors of Livonia, Michigan, USA, is part of OCP, a Public-Private Partnership with John Laing, AECOM, Dan’s Excavating, and AJAX Paving for construction of I-75 Modernization Project Segment 3 in Oakland County, Michigan. The company was awarded the contract for the tunnel portion of the build, a four-mile combined sewer overflow located 100 ft. (30.4 m) below the existing highway with multiple stormwater shafts located along the right-of-way of the new highway draining down to the new tunnel.
Jay Dee Contractors purchased a new Link-Belt 250-ton (227-mt) 298 Series 2 lattice crawler crane midway through the project to help speed up operations. In eight months on the tunnel boring project Jay Dee Contractors logged over 5,000 hours on the 298 Series 2. Earth or “muck” as it’s called is brought to the rear of the 400 ft. (121.9 m) tunnel boring machine (TBM) via a conveyor system that runs from the front cutter head section back to the rear of the tunnel boring machine. The recently drilled ground is dumped into five train cars or “muck boxes” that are then transported back to the surface above by the 298 Series 2.
“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.
For every five feet of tunnel dug, five muck boxes are brought to the surface with each one weighing between 50,000 and 60,000 lbs (22 679 and 27 215 kg) when filled (for reference the tunnel is 21,000 ft long). Over the course of the project the 298 Series 2 completed over 4,200 muck box lifts that total over 425,000 tons of Earthen soil removed for the new tunnel shaft.
“There were several benefits to using a bigger crane like the 298 (Series 2) for this project. If you do need to pick stuff up on the surface it has the reach to make things easier for storing everything coming out of the tunnel. It just made for a quicker operation,” said Hagan.
Jay Dee Contractors completed the tunnel portion of the project in summer 2023 and began the process of disassembly of the TBM to bring it back to the surface piece by piece.
The full tunnel boring machine consists of a cutterhead and shield in the front, and then 10 gantries that follow behind that house equipment that support the tunnelling operation underground. The cutterhead and shield are ~35 ft long, and including the gantries, the whole system is 400 ft. (121.9 m) long. The heaviest portion of the TBM is the cutter head and the shield, which consists of a front shield, middle shield, and a tail shield,” said Hagan.
The middle shield is the heaviest lift of those sections, weighing 208,000 lbs. (94 347 kg) rigged and measuring 17 ft. (5.1 m) in diameter, by 20 ft. (6.0 m) long. Jay Dee then began the process of moving each section back to their main yard in Livonia for maintenance following the project.
A video of the job can be seen here: https://www.youtube.com/watch?v=siuND0ixNdo