In Nepal, the greeting ‘Namaste’, while pressing both palms together in front of the chest, signifies both ‘hello’ and ‘goodbye’. It implies a circular concept of time that I rather like—I certainly think I will be coming back to this country of high mountains, valley forests, and yes, tunnels.
The Adventure Begins
When I first learned that I would be visiting Nepal to see a swift-moving tunnel project making an impact in a local community, I was pretty jazzed. I also took it upon myself to overpack. The Bheri Babai Diversion Multipurpose Project (or BBDMP for short) is a 12 km long tunnel that travels below protected forest considered part of the Bardia National Wildlife Reserve. This is an area home to tigers, rhinos, Asian elephants, leopards, and more. And, most worryingly for me, mosquitoes.
Mosquitoes love me. I’m not entirely sure why they love me so much, but let’s just say that if there’s a mosquito within a 2 km radius it will find me. Thus, I decided to be prudent and go all out when packing. I purchased a whole new set of safari clothes, the most potent bug spray I could find in copious amounts, and much, much more. I stuffed everything into two suitcases and set off on my journey.
A full 24 hours of traveling later (the journey from Seattle, USA to Kathmandu is no joke, folks), and I arrived in the Kathmandu airport…with no checked luggage. Through a gross miscalculation (what a way to learn a lesson!) I also had not packed hardly anything in my carry-on bag. I had no clothing with me, and more importantly, no bug spray. What was I to do?
Rolling with It
After discovering that my bags were several days away, I decided to forego any hope of reuniting with them during my trip. Instead, I rolled with it. After a one-hour local flight from Kathmandu to Nepalgunj, we arrived at our destination. Nepalgunj is a frenetic, dusty town located around 8 km from the Indian border and one hour from the BBDMP site. The culture is heavily influenced by India, and we had many meals of delicious spicy curry and fried bread. The streets were lined with small shops and marketplace stalls, but to my dismay, no department stores.
After a quick Google search my coworkers and our guests with us for the site visit headed to the nearest approximation, known as Rani Mart (Rani means ‘queen’ in Hindi). To my surprise, I purchased a whole new wardrobe and everything I needed for 1/10th of the price I would have paid for it in the U.S. (though the sizing on the tags was quite a bit larger!) I was feeling very pleased with myself.
A Little Perspective
The next day we were ready to visit the jobsite. I couldn’t help but notice the rolling blackouts that plagued the city and the vast stretches of farmland requiring huge water resources. The people in the surrounding area make do with limited resources in ingenious ways—I was intrigued to see, for example, that every outlet requires you to flip an on-switch before the current becomes available. Perhaps we Americans could save significant energy if we made a setup like this a national standard. Local hotels, including one we stayed at, use solar panels for their power and air conditioning, and harvest rain water in order to reduce their usage.
All of this made me realize how much the BBDMP will impact the surrounding areas. This was confirmed in a meeting we had with Nepal’s Department of Irrigation (DOI), the project’s contractor China Overseas Engineering Group Co. Ltd. (COVEC), and consultant Geodata. The tunnel is sourcing water from the Bheri River to the Babai River, traveling through mountainous Himalayan geology known as the Siwalik Range. The water, as the project’s name suggests, is for multiple purposes. The estimated annual benefit in Nepalese Rupees is $2.9 billion for irrigation, and $4.3 billion for hydropower, making a total of $7.2 billion in benefits once the project becomes active.
The completed tunnel will irrigate 51,000 Ha of land and provide 48 MW annual generating capacity. That’s not to mention the environmental benefits: The Babai River currently swells each monsoon season and then runs extremely low in drier seasons. It is connected directly to the groundwater table, which is being aggressively depleted. With a regulated flow during all seasons, the groundwater table will see less depletion year-round.
The impact, in other words, is huge. Learning all of this made my obsession with my missing luggage seem inconsequential in comparison. I had my bug spray and some clothes. That was all I needed.
The First Nepalese TBM
With such a landmark project for the region, its proponents were willing to look to the latest technology during the planning phase. Our local representatives, MOSH Tunnelling, had been working since the 1990’s to bring a TBM to Nepal, a country known for its Drill & Blast tunneling. While TBMs had been considered multiple times, each time conventional tunneling had been chosen.
When the BBDMP was fast-tracked as one of the country’s “National Pride Projects” feasibility studies showed that Drill & Blast excavation could take as long as 12 years. The DOI needed a faster option, and they found it in TBMs. They began working with MOSH Tunnelling and Robbins to bring what would be the first Nepalese TBM ever into the country—a 5.06 m diameter Robbins Double Shield. The process for the DOI to acquire funding for the project and select a contractor through international competitive bidding took seven years, spanning from 2007 to 2015, when project commencement officially began.
Fast forward to our site visit in November 2018 and the project is far exceeding expectations. Tunneling has topped out at 1,202 m in one month with an average of around 740 m per month. The knowledgeable COVEC team have traversed a major fault zone, the Bheri Thrust, with no problems, and overcome a stuck TBM shield with a bypass tunnel constructed in just five days. Overall, the TBM is far ahead of schedule and the results are of national importance.
The local community, national media, and government are all watching how the TBM excavation plays out at BBDMP. Given the strong performance, they are now considering TBMs for a host of future multipurpose water projects. It’s the kind of result that opens up a whole new marketplace.
Into the Forest
After a great site visit, we chose to relax for one day at a spectacular local lodge that offered jeep safaris into the Bardia Wildlife Reserve. Currently home to nearly 90 tigers (a number that is rapidly increasing through conservation efforts) we were hopeful of perhaps seeing one of the striped cats in the forest. Our guide was knowledgeable, our jeep sturdy and our driver adept as we traversed bumpy roads and forded a few streams on our safari drive. We saw mischievous macaques, tree-dwelling langurs, a host of brightly colored birds, and various deer. We saw several enticing tiger prints…but the tiger itself remained elusive. Obviously, this means that I must go back!
A Lesson Learned
After traversing a tunnel, traipsing through the forest, and some swift sight-seeing in Kathmandu on our last day, I felt I had come full circle. I was ready to head home, but with an eye towards future opportunities to return to Nepal, whether for business or vacation. I will be back. But next time, you can rest assured, I will only bring what I can fit in my carry-on.
On October 4, 2018, onlookers watched as a 3.8 m (12.5 ft) diameter Robbins Main Beam TBM completed its epic journey. The TBM, christened “Driller Mike”, after local rapper and activist “Killer Mike”, overcame extremely hard rock conditions along a curving 8.0 km (5.0 mi) tunnel to bolster the city of Atlanta, Georgia, USA’s water supply.
The new tunnel brings the Atlanta Water Supply Program one step closer to increasing the city’s water capacity to between 30 and 90 days depending on daily usage. “Our schedule for the project was very aggressive but the project team stayed together to overcome issues related to the mining of the tunnel,” said Bob Huie, Project Director for the PC Russell JV, the Construction Manager at Risk (CMAR) for the project.
The unique structure of the project team is credited with the overall project success despite challenges. “I’m proud of our team. They had obstacles and challenges and challenging ground, but they stuck together and didn’t give up, and they were successful. There was great leadership and supervision all around,” said Larry Weslowski, Tunnel Superintendent for the PC Russell JV.
The project is only the third such large construction project in the U.S. to use the CMAR structure. The PC Construction/HJ Russell JV was selected as the CMAR for the project, who then purchased the Robbins Main Beam TBM for the tunnel. The designer for the construction works including tunnel and shafts, JP2—consisting of Stantec, PRAD Group, Inc., and River 2 Tap—specified the hard rock TBM. Operation and assembly of the TBM was then sub-contracted to the Atkinson/Technique JV.
The robust TBM was assembled using Onsite First Time Assembly (OFTA) at the massive Bellwood Quarry site with help from Robbins personnel. “The guys built everything per the specs to help with scheduling. It was a challenge but there was no negativity during the process,” said Weslowski. Despite summer temperatures hitting 43 degrees Celsius (110 degrees Fahrenheit) and 100 percent humidity, the TBM was ready to launch by October 2016.
Hard granitic rock challenged the 19-inch disc cutters from the outset. “There was ground so hard that it would take eight hours to go 1.5 m (5 ft). It was between 117 and 310 MPa (17,000 and 45,000 psi) UCS. The beginning of the job was tough,” said Weslowski, but he added that once the learning curve had been overcome “they started breaking project records left and right towards the end. We got a best day of 38.4 m (126 ft). Rates just kept increasing.”Other challenges included groundwater encountered during tunneling. “We did encounter groundwater contamination that required remediation. This remediation work was completed successfully,” said Huie.
With tunneling complete, the USD $300 million project for the City of Atlanta’s Department of Watershed Management is on track to meet its scheduled overall completion date of September 2019. The project will turn the inactive Bellwood quarry into a 9.1 billion liter (2.4 billion gallon) raw water storage facility connecting with the Chattahoochee River and various water treatment facilities.
On September 18, 2018, a Robbins mega-sized slurry machine, measuring 13.7 m (44.8 ft) in diameter, made its first cut into hard rock. The epic launch at an urban jobsite was made possible by Onsite First Time Assembly (OFTA) of the TBM in Japan for the Hiroshima Expressway Line 5 project. The contractor, a joint venture of Obayashi-Taisei-Kosei, had a strict timeline of eight months to adhere to when it came to machine assembly. “This deadline was very important. After assembling the TBM, I think OFTA was appropriate for this project,” said Mr. Ryota Akai, Deputy Project Manager for the Obayashi JV.
Due to the project location there were also restrictions on delivering the TBM—in order to meet controlled transportation limits within the city, the TBM had to be divided into small transportable weights and sizes, then assembled in a small jobsite measuring just 30 m (100 ft) wide x 60 m (200 ft) long. The 2,400 metric ton (2,650 US ton) machine will bore 1.4 km (0.9 mi) of the 1.8 km (1.1 mi) long tunnel that, once completed, will significantly improve traffic conditions in Hiroshima.
The massive machine is the country’s first foreign-made large diameter Slurry TBM to excavate hard rock in Japan. “There is a lot of hard rock in Hiroshima,” said Mr. Akai, “and Robbins has a lot of experience boring hard rock.” The machine is expected to encounter granite with rock strengths up to 130 MPa (19,000 psi) UCS. Those involved in the project are excited to see what effect this will have on how Slurry TBMs are used in the future. “The development of this TBM is a milestone,” said Mr. Kiyomi Sasaki, General Manager of Robbins Japan, “it will lead to new tunnel applications worldwide.”
The design of the Slurry machine is robust in anticipation of potentially abrasive rock conditions and water pressures up to 13 bars. “The Robbins machine is very tough, for example the weight is very heavy. The cutterhead, both its material and structure, are very tough. It will not break in hard rock,” said Mr. Akai.
In preparation for the conditions, the machine was designed for 20-bar water pressure. The robust cutterhead was fitted with 20-inch and 17-inch diameter pressure compensating cutters, which utilize a patented design to effectively operate under high pressure. The joint venture intends to change the disc cutters an estimated 10 times during the bore as part of the machine’s maintenance.
Throughout the assembly and launch process the joint venture crew worked with Robbins Supervisors who assisted and provided guidance. “Robbins crews have a lot of experience; they help us every day despite the language barriers. I appreciate it,” said Mr. Akai.
The new Expressway Line 5 tunnel will directly connect Hiroshima’s urban area with a major national highway network and is expected to improve access to Hiroshima Airport. Tunnel completion is planned for 2020.
In this short clip, Robbins Field Service personnel discuss how they handled boring through hard rock, fault zones, and water inflows at the Thuong Kon Tum Hydro Project in Kon Tum Province, Vietnam.
If you’re tunneling in mixed face conditions, where any combination of rock and soil may be present in the tunnel cross section, you expect the project to be a challenge. When variability is a constant, things like surface settlement, abrasive wear on your TBM, and the proper ground conditioning are a concern. Despite these variables, your project can still be a success. With the right technology, crew, and operating methods, consistent TBM advance rates are achievable in even the most variable conditions.
In this complimentary 60-minute webinar, Robbins Vice President Doug Harding and Engineer Greg Michaelson will explore mixed face conditions, delving into recent case studies of EPB and Crossover TBMs in the field. Harding and Michaelson will make recommendations based on proven designs and methods, drawing from the experience of our knowledgeable field service personnel. Whether you’re a contractor operating the TBM, a consultant specifying the equipment, or an owner with an upcoming project, consistent excavation is possible in variable geology.
Traveling in the tunneling industry is basically a regular commute for some. A lot of us don’t think twice about the destination, we just do it with a mission in mind. My mission as Robbins Marketing Manager was this: a small conference in Ho Chi Minh City. Okay, easy! As the date approached, about a month before, I kept hearing about how well our Main Beam TBM was doing in Vietnam, at the Thuong Kon Tum Hydroelectric project, despite a gauntlet of challenges. I talked to some project engineers and field service personnel who told me it was in a remote location in Kon Tum Province. And then I heard more about traveling to that site: a 6-hour drive from Da Nang, through nauseating windy, narrow roads, climbing elevations with no speed limits to speak of. But that’s cool, I thought, glad I don’t have to go on that ride.
“Wait, why not just go to the jobsite for a video and photo shoot? We can have it ready for the breakthrough in October,” says Desiree Willis, Robbins PR manager a couple weeks later. What!? A few days after that, it was all planned. Ron, our videographer, Ken, our photographer, and Keri Lin, our marketing manager from Robbins China, set off with me on a last-minute adventure. The 17.4 km long Thuong Kon Tum HEPP tunnel will be the country’s longest once complete. A 4.5 m diameter Robbins Main Beam TBM and continuous conveyor system were supplied to bore a section of the tunnel.
Maybe because I was bracing myself for the worst as far as the drive goes, I didn’t feel like it was that bad. The scenery was jaw dropping with lush jungle, rice paddies and scenic villages, and so many distractions on the sides of the road that I just completely avoided looking ahead. Problem solved! The coolest distractions were the scooters driving on these mountain roads: what they were carrying, how many people were on them, their driving technique. My favorite site was seeing a whole family of people—a 5-year old kid in the front, the dad driving, the mom in the back and a toddler sandwiched in between the parents—on a run-down 125 cc scooter. Then there’s the animals: a litter of stray dogs, adorable black piglets making road crossings that almost made me swear off bacon, herds of cows, goats, etc.
But how the heck did they get the machine, assembled by Onsite First Time Assembly (OFTA), to the site? Apparently, the previous contractor built portions of the roadway to the jobsite while components were staged at the port site. Several bridges, previously built only for light traffic with scooters and carts, were rebuilt or reinforced in order to carry the heavy TBM components. In a road conditions survey report by logistics firm SDV Vietnam Company Ltd., the original bridges were described as “having no shoulder”, and as having “blind corners and sharp curves”. The OFTA process allows a TBM to be assembled on location, saving time and money in terms of shipping costs and project schedule. The machine had successfully made it to the site, as it had launched in 2012.
Upon arriving at the jobsite, I was immediately impressed with the site and the surroundings, especially after hearing about all of the challenges the project had back when the TBM was launched, under a different contractor. The TBM launched into complex rocky conditions that turned out to be quite different than in the original geological study. The machine sat abandoned 2.6 km into the tunnel with equipment sitting idle for months, waiting for a change in circumstances. In 2015, Robbins signed a contract with the project’s new contractor CC47 to supply full refurbishment and to operate the equipment with a full Field Service team. Since then, Robbins Field Service has generally been kicking butt.
The machine was running as expected, so filming interviews and the machine went smoothly. I learned a lot from the interviews, mainly from the Robbins guys we interviewed—PN Madhan, Robbins Engineering Geologist, and Greg Adams, Robbins Field Service Manager. “It’s a workhorse of a machine and still in great condition, considering all of the difficult ground it’s been through,” Greg mentioned. Massive granitic rock wasn’t the only challenge they faced—the team also endured a handful of major fault zones requiring rock bolting and the use of the McNally Roof Support System, as well as some huge water inflows.
Greg did warn our photographer and videographer that they were going to face heat with extremely high humidity. When John McNally, Robbins Field Service Manager-Asia, took over the project site, he managed refurbishment of much of the equipment inside the tunnel along with the camp’s living quarters. This included adding a ventilation tube, keeping the tunnel at a cool 34°C. That’s the temperature AFTER installing the ventilation. Read more about the challenges here.
The crew at the camp quarters, and the jobsite in general, were very welcoming. Greg and Taylor Hwang, Robbins project manager, arranged for a special dinner just for us on the first night—steak and French fries, an American staple! The crew on site mainly consists of English-speaking expats, Chinese, Thai, Vietnamese, Indian and Philippine guys, so the cuisine varied every day. We hung around that night for a while, listening to stories from some of the field service crew. This is while we were fawning over the pet falcon that one of the field service guys owned. I think the falcon liked living there, because his string wasn’t even tied to the perch at one point. Taylor told us that there were some families and children of the crew living there, who had to find ways to pass the time in this little remote village. He even told us they had pet monkeys at one point. I peeked into a living quarter and saw a drum set made with those Danish butter cookie tins that you get at Christmas. That’s one way to pass the time! Before we were about to leave, some of the Thai people at the site had brought in a bucket with a cover over it. I was curious and went to take a peek, because they started adding salt to the buckets. It was about 30 river snakes (possibly river eels, but they called them snakes) writhing violently because of the sodium touching their skin. Then they started preparing them one-by-one, sticking a nail into their heads and gutting them. It was quite mesmerizing, really.
We only had two full days of shooting video and photos. Before the 6-hour drive back to Danang, all of us got caffeine-drunk on two strong Vietnamese coffees served with condensed milk each. I suspect it’s the perfect combination of the tenaciously strong espresso dripped into a puddle of pure sugar syrup (condensed milk) that singlehandedly causes adult ADHD from the first sip. During the drive down (which was much worse, I didn’t realize how much elevation we climbed going up), we were already reminiscing about the stories and experiences shared at the jobsite. When talking to the field service crew, they were all excited for the coming breakthrough later this year, but it seemed they were just a bit melancholy too. They were at this site for years, in a tiny remote village in the mountains of Vietnam, building friendships and routines. With only a handful of meters left to go on the tunnel, they’ll soon be off to the different parts of the world where they came from. I’m fortunate to have experienced everything I did on this trip and can’t wait to come back to this beautiful country.
On August 29, 2018, a 9.26 m (30.4 ft) diameter Robbins Crossover (XRE) TBM crossed the finish line at the Akron Ohio Canal Interceptor Tunnel (OCIT). A press day followed on September 5, where companies and members of the media were invited to view the giant machine. The machine—dubbed “Rosie” in honor of Rosie the Riveter, an icon representing American women who worked in factories and shipyards during World War II—overcame tough ground conditions during the bore.
“One of the most challenging aspects of this job was that we launched right into the most difficult part. We had 60 m (200 ft) of soft ground, a very short reach, and then from there we went right into a mixed face for 180 m (600 ft),” said David Chastka, Project Manager for Kenny Construction, a joint venture contractor on the project with Obayashi. “It took everybody we had in the industry, everybody from Robbins, to fight through that first 240 m (800 ft).”
The TBM was designed for the project’s geology, which transitioned from soil to partial face shale to full face shale rock. The Crossover XRE included features of both EPB and Hard Rock Single Shield TBM types, with a versatile cutterhead that could be configured for hard rock or soft ground conditions. While in soft ground and mixed face conditions the machine operated in closed mode, but once it hit solid rock crews switched excavation to open mode.“The machine had the power to get to the other side and made advance rates we never thought we were going to get. It was very successful in hard rock,” said Chastka. Advance rates once in full-face shale rock reached a high of 34 m (111 ft) in one day (two 10-hour shifts). Muck removal was achieved using a Robbins continuous conveyor, and conveyor availability remained high throughout the project.
“I am most proud of the team that I have had the pleasure of being a part of,” said Don Smida, Robbins Field Service Technician. “The overall scope of a project of this scale is immense, and the amount of daily cooperation & hard work that has been asked of The Robbins Company, the local unions, city staff, and Kenny-Obayashi is extremely important in reaching our common goals. I think we should all be proud of our teamwork going forward from a successful completion of the tunnel and into a successful disassembly of Rosie.”
Now that tunneling is complete, the machine will be disassembled and removed from its retrieval shaft this autumn. “The Ohio Canal Interceptor Tunnel is the largest public improvement project in our City’s history and a significant investment in our environment and infrastructure that will benefit Akron residents and businesses for generations to come,” said the City of Akron’s Mayor Daniel Horrigan. “Projects of this kind are inherently dangerous, and I am incredibly proud that the tunneling portion was completed without any major injuries, thanks to a dedicated team of professionals. And although Robbins is an international company with worldwide impact, we were pleased to be able to work with a local Northeast Ohio firm on this significant project.”
The OCIT Project for the City of Akron, Ohio, USA consists of the construction of a conveyance and storage tunnel system to control Combined Sewer Overflows (CSOs) for several regulators in the downtown Akron area. The EPA-mandated project includes the 1.89 km (1.17 mi) conveyance and storage tunnel, as well as drop shafts, diversion structures, consolidation sewers, and related structures.
Robbins and joint venture contractor Kenny/Obayashi worked together to achieve a short startup schedule at the Akron Ohio Canal Interceptor Tunnel. Field Service personnel assisted in TBM assembly and trained crews to achieve a smooth startup. Watch this short for a quick word from Kenny Construction’s Project Manager David Chastka on working with Robbins Field Service.
In this short video, David Chastka, Kenny Construction Project Manager, discusses how Robbins Field Service and his team surmounted the challenge of launching immediately into difficult ground at the Akron Ohio Canal Interceptor Tunnel.
Event Name: TAC/NASTT-NW Tunnelling & Trenchless Conference
Dates: November 8-9
Location: Edmonton, AB, Canada
Venue: Fantasyland Hotel at the West Edmonton Mall
Robbins Utility Tunneling Manager, Tom Fuerst, will be presenting “Lessons Learned at Montreal’s Rue Jarry Project: Overcoming Flooding and Rebuilding a TBM to Finish on Schedule,” at this year’s TAC/NASTT-NW Tunneling & Trenchless Conference. The show will be held on November 8 and 9 in Edmonton, Alberta.