Year: 2024

Swift Robbins TBM breaks through 11 Months Early

On May 8 in Nepal’s Sindhuli District a crowd of people attending the breakthrough of a speedy TBM had much to celebrate. The 6.4 m diameter Robbins Double Shield machine had overcome incredibly challenging geology to cross the finish line 11 months ahead of schedule.  Nepal’s Sunkoshi Marin Diversion Multipurpose Project (SMDMP), at 13.3 km in length, is one of the longest TBM-driven tunnels through the Himalayan mountain range and is only the second such tunnel to be completed in the country. View the breakthrough video here.

At a breakthrough ceremony attended by Nepal’s Prime Minister Pushpa Kamal Dahal, the crowd celebrated an epic TBM breakthrough 11 months ahead of schedule.

At a breakthrough ceremony attended by Nepal’s Prime Minister Pushpa Kamal Dahal, the crowd celebrated an epic TBM breakthrough 11 months ahead of schedule.

“The overall design of the Robbins TBM is proven, and the equipment’s performance and integrity are excellent. Additionally, its adaptability to the Himalayan geological conditions is very impressive,” said Mr. Liu Fengfan, SMDMP Project Manager for contractor B-2/COVEC (China Overseas Engineering Group Co. Ltd and China Railway No. 2 Engineering Group Co Ltd).

Ground conditions included two major fault zones with challenging and varied geology ranging from highly jointed mudstone, sandstone and conglomerate to quartzite, granite, and more.  The tunnel was bored through mostly igneous rock with maximum overburden of 1,320 m.

The TBM and its experienced crew were able to persevere through multiple instances of the shield becoming trapped with bypass tunnels required to free it, including one instance 4 km into tunneling that required 27 days’ worth of work to free the machine from collapsing and squeezing ground. Despite the challenges, the crew were able to more than make up the time with swift advance rates including an impressive 1,503.3 m in one month and 72.6 m in one day, both project records set in March 2024.

The success of the machine, despite adversity, is in part due to its proven design. The refurbished TBM was originally used at a smaller diameter on Nepal’s first TBM-driven tunnel, the Bheri Babai Diversion Multipurpose Project (BBDMP). The design incorporates many of the same components of that original machine, and the process involved final assembly on location at the jobsite. It’s something the contractor sees as a positive: “One of the highlights is that this machine integrates the overall structure of the 5.06 m diameter TBM from the Bheri Babai project. After upgrading to 6.4 m diameter, all new front shield components were not assembled in the factory. Instead, we adopted Onsite First Time Assembly (OFTA). This was very effective, and I find it particularly noteworthy,” said Mr. Jin Haikuan, Deputy Project Manager & TBM Production Manager for B-2/COVEC.

With tunneling complete, the work of providing both power and water can begin. The tunnel is connected to a new 28.6 MW surface powerhouse on the Marin River to alleviate the shortage of power supply in the area. It will also be used for farmland irrigation in the districts of Dhanusha, Mahottari, Sarlahi, Rauthat and Bara in the Terai Plain, diverting water from the Sunkoshi River to the Marin River for the project owner, the Department of Water Resources and Irrigation under Nepal’s Ministry of Energy, Water Resources & Irrigation.

The project’s successful completion is a triumph not only for the communities benefiting, but also for the future of tunneling in Nepal. “B-2/COVEC and Robbins have successfully introduced and spread TBM technology in Nepal and shown the advantages of it. This country needs more tunnels,” said Robbins President Lok Home at the breakthrough ceremony. “To have these good performances on these first two projects is really a good thing for the country and our industry.”

NAT 2024

Event Name: North American Tunneling Conference (NAT)
Dates: June 23-26, 2024
Location: Nashville, Tennessee, USA
Venue: Gaylord Opryland Resort & Convention Center
Booth: 901

Come join us in Nashville, TN June 23-26 at the North American Tunneling Conference, the premier tunneling event focusing on current projects, challenges, and successes in tunneling. Stop by our booth 901 to learn more about our ongoing and successful tunneling projects, and be sure to check out our insightful technical presentation.

Technical Presentation

Monday June 24
TBM Technology Session
Presidential Chamber A

11:25 – 11:45 AM

Long Haul TBM: Use of a Rebuilt Main Beam Machine at the DigIndy Tunnel System in Indianapolis, IN
Presented by Doug Harding, Vice President, Robbins & Christian Heinz, Tunneling Division Project Manager, J.F. Shea Construction

World Tunnel Congress 2024

Event Name: ITA-AITES World Tunnel Congress 
Dates: April 19-25, 2024
Location: Shenzhen, China
Venue: Shenzhen World Exhibition & Convention Center
Stand: F04

Come join us April 19-25 in Shenzhen, China for the ITA-AITES World Tunnel Congress, the premiere event for tunneling and underground construction. More than 2,000 professionals are set to take part in the world’s top-attended tunneling conference, where hundreds of technical papers will be presented on the latest topics of interest. Stop by our stand F04 to converse with our expert international team, and find out the latest about our products, projects, and talks at the conference.

Technical Presentation:

Monday April 22
Tech Session 7.1: Guidelines, Reviews & Prospects of Mechanized Tunneling
2:20 – 2:40 PM
CC207, Hall 18
Evaluating TBM Design and Performance, 30 Years Apart: The Lesotho Highlands Water Tunnel, Phase 1 and Phase 2
Presented by Brad Grothen VP Engineering