The largest ever Crossover (XRE) TBM in China launched in late March 2021 in Guangzhou for contractors Sichuan Jinshi Heavy Equipment Leasing Co., Ltd and CREC Bureau 2. Onsite First Time Assembly (OFTA) was utilized to build the 9.16 m (30 ft) diameter Robbins TBM, taking just five months from the start of assembly to machine launch. The hybrid machine is boring the 2.5 km (1.6 mi) long Pazhou Line Lot PZH-1 of the Pearl River Delta Intercity Railway Project, which will offer better commutes for Guangzhou residents traveling to and from University City.
The machine will encounter various ground types during its bore, from moderately to strongly weathered argillaceous shales and sandstone to mixed face conditions. Much of the rock is fractured, while the quartz content is as high as 50 percent. “Not only are there poor ground conditions such as soft to hard uneven, fractured zones and full-face hard rock, but these sections appear to alternate frequently, which is the biggest challenge of the project. It will be a test of performance and tunneling efficiency for the machine,” said Yongsheng Qi, Project Manager for Robbins China. The tunnel is also expected to cross under rivers and other bodies of water with a cover of 20 to 31 m (65 to 100 ft). The ground strata connects to the river and is highly permeable, resulting in expected water pressures above 7 bar. The project’s success lies in stabilizing the water pressure at the face while ensuring acceptable advance rates and construction safety.
The Crossover TBM features both hard rock and EPB modes and is optimized for the rapidly changing ground found on the project. An adaptable cutterhead design and two-speed gear reducers known as the Robbins Torque-Shift system enable efficient tunneling in hard, mixed, and soft ground. An adaptable screw conveyor can be mounted in the center or bottom of the mixing chamber depending on the mode. To combat high water pressures the machine is fitted with high pressure seals and can statically hold up to 30 bar. The XRE TBM began its excavation in EPB mode and will shift to hard rock mode to continue excavation after 1.5 km (0.9 mi) has been bored.
The unique project is one of several mixed ground operations using Robbins Crossover TBMs in China. Two 6.91 m (22.6 ft) diameter XRE machines are currently boring sections of the Chongqing Metro Phase 2 in ground conditions ranging from weathered mixed granite to weathered pegmatite and adamellite. The project is under the same contractors as the Pearl River Delta bore. “At the Chongqing Metro project, we won the trust of the contractor with the performance of the Crossover machines; to date the highest monthly advance rate in Chongqing is 365 m (1,197 ft). This is one of the main reasons the contractor again selected a Robbins Crossover TBM for the Pearl River Delta project,” observed Qi.
With rates at Chongqing Metro as a precedent, the Pearl River Delta tunnel is scheduled to be completed by the end of 2021 and put into operation in 2023.
Global TBM Company, newly established by industry veteran Lok Home, is proud to announce the recent purchase of substantially all the assets of The Robbins Company. The company will operate as Robbins and with Mr. Home as the President and CEO. The acquisition will result in a seamless transition for a number of ongoing projects throughout the world, as Robbins renews its commitment to service, quality underground equipment, and top-notch support that its customers have come to expect. For a brief message from Lok Home, view the video here.
Home said the company has a bright future as a result of the transaction. We are starting off the new year with a respectable backlog of orders,” he noted. “In 2021 and beyond, our clients can depend on Robbins to deliver high quality machines, and technically superior machines for very difficult projects,” said Home. “That’s where Robbins really stands out.”
Home went on to say that Robbins is starting 2021 with no significant bank or institutional debt. “We have many projects to look forward to,” he continued. “Robbins is currently delivering Crossover machines and TBMs equipped for challenging geological conditions in many countries including the U.S., Norway, India, China and Canada.” The company’s conveyor and small boring machine divisions will also continue to deliver equipment worldwide.
Home emphasized that Robbins has always been focused on building the best and strongest machines. He pledged that they will continue to do that. “We still have our strong engineering team and we plan to continue our many industry involvements including the International Tunneling Association (ITA) and its associate member organizations. We’re glad to be a part of this community and this industry,” Home added.
The company expects to continue with exciting new developments as well, including a soon-to-be-unveiled non-circular rock boring machine. Robbins remains focused on creativity and innovation to solve the industry’s greatest challenges.
Robbins is one of the world’s foremost developers and manufacturers of advanced, underground construction machinery. Headquartered in Solon, Ohio, USA, Robbins is a total supply firm offering customized Tunnel Boring Machines, conveyors, cutters, and more, as well as knowledgeable field service personnel and technical support. The company has been an active industry participant and innovator for nearly 70 years.
From the first modern Tunnel Boring Machine built in 1952 to recent innovations such as the Crossover TBM for varied ground conditions, Robbins engineering and innovations have made a success of the world’s most difficult tunneling projects.
Come join us in Las Vegas, Nevada at MINExpo International, the largest mining show in the U.S., and found out more about our mechanized innovations for underground mining. Stop by our booth 24729 to speak with our knowledgeable sales staff and learn more with our ten-minute booth talks that will be happening throughout the show.
Robbins Ten-Minute Talks
Presented inside the Robbins booth
11:45 AM – Get to First Ore Quicker: Rethinking Underground Mine Development
3:30 PM – Shaft Boring Machines that work in the Most Challenging Conditions
10:00 AM – Light, Mobile Tunnel Boring Machines for Underground Mining
1:30 PM – Non-Circular Tunnel Boring: A Case Study at Fresnillo Mine
10:00 AM – The Future is Mechanized Mining: Using Customized TBMs to Honeycomb Mine the Ore body
1:00 PM – Continuous Conveyors paired with TBMs for Underground Mine Development and Operation
The Rapid Excavation and Tunneling Conference (RETC) is sponsored by the Society for Mining, Metallurgy & Exploration (SME). The show focuses on developments, technology, trends, and innovations that directly affect the tunneling and underground construction industry through a wide variety of technical presentations. Stop by the Robbins booth #506 to meet with our expert staff and found out the latest about our products and projects. Be sure to check out our technical presentation as well:
Monday June 14
8:30 AM Session – Difficult Ground
Rock Tunnels at High Water Pressure: Non-Continuous Pressurized TBMs vs. Slurry
Presented by Brad Grothen, Robbins Technical Director & Lok Home, Robbins President