Summary - Reader Response Draft #4

Edited: 28 Feb 2023

             For a long time, human strength has been the primary determining factor in construction processes (Leonard, 2022). The article "Innovation at the end of the tunnel" (Leonard, 2022) informs the public about the traditional Tunnel Boring Machine (TBM) and the challenges that advanced technology faces in completely changing how tunnels are constructed. Population growth and urbanization are driving the growing demand for subterranean infrastructure as more clients look for underground space to meet the demands for transportation, infrastructure, utilities, wastewater, power, and other services (Ramsey, 2017). According to Leonard (2022), tunnel drilling has been attracting newcomers, such as the start-up Petra and Elon Musk, boss of Tesla, with his Boring Company, to the game, ready to challenge the established order with their cutting-edge robotic technologies, which will be able to streamline the process of tunnel drilling and ultimately revolutionize how people use the underground region.

Due to its capability in minimizing environmental effects, the TBM remains superior to cutting edge robotic technologies from Petra and Elon Musk in terms of operation safety, time-savings and cost-efficiency. TBMs offer faster tunnelling speeds and can complete larger-scale tunnel projects with a broad range of diameters to bore through a variety of soil and rock strata, albeit one of the main drawbacks is the upfront production cost of a TBM.

One of the advantages of the TBM is its ability to minimize environmental impact while enhancing operational safety during tunnel construction, which have been expanding due to population growth and urbanization. TBMs ability to balance the earth's weight and pressure helps to prevent environmental disruptions, which could have serious implications for human safety and the ecosystem (Railsystem, 2015). Additionally, TBMs reduce the need for ventilation, which improves worker health and safety by limiting their exposure to harmful gases associated with machinery operation (Sakellariou, 2019). Hence, TBMs offer a safe and environmentally friendly solution for tunnel construction in densely populated areas, while minimizing the risks associated with traditional tunnelling methods such as blasting which leads to time and cost savings. 

Faster tunnelling is also made possible by TBMs, and this boosts construction efficiency. They have extreme rates of tunnelling of 15 kilometres per year and 15 meters per year, and sometimes even less (Singh & Goel, 2011, p.1). 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 (The Boring Company, 2022). According to Leonard (2022), the Prufrock is still four times slower than a snail. Despite what The Boring Company anticipated, a typical TBM is still two times faster than the Prufrock (Singh & Goel, 2011). This exemplifies how TBMs outperform sophisticated technology with their speed.

Another benefit of the TBM is its efficiency in constructing larger-scale tunnels. The start-up, Petra, has a new semi-autonomous robotic device, 'Swifty', which 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). Petra claims that this technology will make tunnelling more efficient and less expensive (Blain 2022). According to Railsystem (2015), TBMs, often known as "moles," are able to excavate circular cross-section tunnels through hard and soft rock strata to create larger tunnels with diameters ranging from a meter to more than 16 meters. This demonstrates that TBMs are superior to cutting-edge technology in their ability to finish larger-scale projects.

One drawback of using TBMs is the high upfront production costs. According to a study by Singh and Goel (2011, as mentioned in Okubu et al., 2003), TBM setup and disassembly procedures are significant. Expenses include TBM transportation, tunnel ventilation, excavated material conveyance equipment, and a high-voltage electrical supply to the TBMs (Railsystem, 2015). This implies that using a TBM to construct a tunnel would be more expensive because of the lengthy procurement and assembly process; hence, using a TBM to construct a tunnel is not economically feasible for short tunnels.

In conclusion, tunnel-building companies should favour adopting the use of TBM due to its advantages over other advanced technologies. As demand grows for tunnels in challenging locations, engineers must stay abreast of evolving technology allowing for more efficient and cost-effective operations of these TBM machines.

 

References

UK Government. (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/

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

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

Okubo, S., Fukui, K. & Chen, W. (2003) Expert System for Applicability of Tunnel Boring Machines in Japan. Rock Mechanics &; Rock Engineering,; 36, 305–322. https://doi.org/10.1007/s00603-002-0049-6

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

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