Summary - Reader Response Draft #1

Leonard's (2022) article “Innovation at the end of the tunnel” informs the public about the traditional Tunnel Boring Machine (TBM) and the challenges that advanced technology face in completely changing how tunnels are constructed. Population growth and urbanization are driving the growing demand for subterranean infrastructure (Ramsey, 2017) as more clients look for underground space to meet the demands for transportation, infrastructure, utilities, wastewater, power, and other services. For a long time, human strength has been the primary determining factor in construction techniques. Furthermore, new techniques such as the TBM also didn't appear until the industrial revolution, the building of railroads, and the mining of tunnels (Leonard, 2022). According to Leonard (2022), tunnel drilling has been attracting newcomers, such as the start-up Petra, Hypertunnel and Elon Musk, boss of Tesla with his Boring Company, to the game, ready to challenge the established order with their advanced technology namely Artificial Intelligence (AI), robotics and drones which will be able to streamline the process of tunnel drilling and ultimately revolutionize how people use the underground region.

The TBM remains superior to advanced machinery and technologies because of its efficiency. It also has the ability in minimizing environmental impact which saves time and money. It also offers a broad range of diameters to bore through a variety of soil and rock strata, albeit one of the main drawbacks is that TBMs are expensive to build and maintain.

The start-up, Petra, is developing the first contactless technology for tunneling into hard rock. Initially creating a plasma torch to cut through rock at temperatures beyond 10,000 degrees Fahrenheit without grinding it, Petra eventually abandoned the concept as the high temperature turned the rock into lava, impeding operations (Nast, 2021). Petra’s new semi-autonomous robotic device, ‘Swifty’, demonstrated that it was able to bore holes with diameters ranging between 46 to 152 cm through any geology and utilizes a mixture of gas and heat exceeding 1,800 degrees Fahrenheit to break rocks into small pieces (Blain, 2022). However, despite Petra's claims that this technology will make tunnelling more efficient and less expensive (Blain 2022), it does not demonstrate that 'Swifty' is competent in completing larger-scale projects of more than two meters in length, a feat that TBMs are capable of.

Despite their reputation for being enormous and slow, TBMs are often used because they are far more efficient to bore modern tunnels which are expanding due to population growth and urbanization. TBMs reduces environmental disruptions as they are capable of supporting soft ground by balancing the earth's weight and the pressure applied to it (Railsystem, 2015) thus reducing construction risks and requiring lesser ventilation which enhances worker health and safety by limiting exposure to harmful gases associated with machinery operation (Pompeu-Santos, 2019). This considerably reduces the time and expense of building the tunnel, making them suitable for use in areas that are becoming increasingly urbanized.

However, Elon Musk believes that the construction of tunnels can be accelerated with the help of new technologies. The Prufrock TBM, developed by Musk's Boring Company, is designed with increased power and improved cooling systems in several iterations of the conventional TBM and Prufrock could even construct the precast portions of the tunnel while mining as doing so avoids the necessity of stopping the TBM every five feet, as is typical for TBMs used in soft soil (Company, 2022). In contrary, the Prufrock is still four times slower than a snail (Leonard, 2022), despite what The Boring Company anticipated, as opposed to a typical TBM which can travel 15 km per year, two times faster than Prufrock (Goel, 2011). A growing number of experts in civil engineering and tunneling dispute Musk's assertion that he can dig tunnels far more swiftly and cheaply. Musk's Boring Company was regarded as a simple "vanity project" and Musk was labeled "full of hot air" by the CEO of one of the largest tunnel boring machine manufacturers in the world (Farivar, 2021, Para 7). This exemplifies that critics’ reservations about Prufrock's revolutionary tunnel-building invention.

Despite the many benefits of TBMs, it has its drawbacks-one of which relates to its expensive maintenance cost and development. Expenses include TBM transportation costs, tunnel ventilation system, equipment to convey excavated material, and a high voltage electrical supply to the TBMs (Service, 2015). The features of the ground to be drilled also influences both the type of TBM that should be constructed and its cost. TBMs can bore through hard and soft rock strata to create tunnels with diameters ranging from a meter to more than 16 meters (Railsystem, 2015). According to (Xiaoyang Zou, 2018), the rate of cutter wear increases as the rock type changes from soft to hard indicates that the cutter is more vulnerable to wear and the prematurity of cutter failure is one of the primary problems in TBM tunneling since the disc cutter accounts for at least one-fifth of the project cost and takes up around one-third of the overall project time.

In conclusion, there is sufficient proof to demonstrate that TBMs outperform many recent technical advances. As demand grows for tunnels in challenging locations, engineers must stay abreast of evolving technology and how to utilize new methods and tools to enhance projects while reducing environmental disturbance. Tunnel drilling could eventually become faster and more environmentally friendly as technology advances.

References

Assets Publishing Service. (2015). High Speed Two A Guide to Tunnelling Costs. https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/434516/HS2_Guide_to_Tunnelling_Costs.pdf

Blain, L. (2022, January 7). Petra's remarkable thermal bore cuts through undrillable rock. New Atlas. https://newatlas.com/technology/petra-thermal-drill-robot/

The Boring Company. (2022). Prufrock — The boring company. https://www.boringcompany.com/prufrock

Clark, G., & Ramsey, M. (2017, October 18). Advanced Technologies Help to Overcome Tunneling Challenges, Save Time and Money. Tunnel Business Magazine.

Farivar, C. (2021, June 8). Fort Lauderdale officials say Elon Musk’s new tunnel to the beach can’t come fast enough. NBC News. https://www.nbcnews.com/tech/tech-news/urban-tunnels-musk-s-boring-co-draw-industry-skepticism-n1269677

Kajastie, N. (2022, May 4). Future of geotechnics: Disrupting tunnelling. Ground Engineering (GE). https://www.geplus.co.uk/features/future-of-geotechnics-disrupting-tunnelling-05-04-2022/

Leonard. (2022, January 26). Innovation at the end of the tunnel. Leonard, foresight and Innovation by VINCI. https://leonard.vinci.com/en/innovation-at-the-end-of-the-tunnel/

Nast, C. (2021, December 9). This new tech cuts through rock without grinding into it. WIRED. https://www.wired.com/story/new-tech-cuts-rock-without-grinding-it/

Railsystem.net. (2015). Tunnel boring machine (TBM) |. | everything about rail system…. https://railsystem.net/tunnel-boring-machine-tbm/

Sakellariou, M. (2020). Tunnel engineering: Selected topics. BoD – Books on Demand.

Singh, B., & Goel, R. K. (2011, June 24). Chapter 14 - Rock Mass Quality for Open Tunnel Boring Machines. Science Direct. https://www.sciencedirect.com/science/article/pii/B9780123858788000148

Zou, X., Zheng, H., & Mi, Y. (2018). Performance evaluation of hard rock TBMs considering operational and rock conditions. Shock and Vibration, 2018, 1-17. https://doi.org/10.1155/2018/8798232