Summary + Thesis + Supports #2

Designed to optimize performance while maintaining safety standards during underground excavation, the Herrenknecht Tunnel Boring Machine (TBM) is a state-of-the-art piece of engineering (Herrenknecht, n.d., Our Tunnelling Technology section). At the forefront is the cutter head, a rotating mechanism equipped with disc cutters or other cutting tools designed to fragment rock and soil as it advances (Wikipedia, 2024). According to Wikipedia 2024, the excavated material, often referred to as "muck," is then collected and transported away from the tunnel face via a conveyor system, which may include belt conveyors or screw conveyors, ensuring continuous removal of debris.To ensure precise alignment during tunnelling, TBMs are equipped with advanced guidance systems. These systems often utilize laser-based technology, where a laser theodolite and a laser target form the precise navigation system for steering the machine exactly (Herrenknecht, n.d.). Modern Tunnel Boring Machines employ hydraulic thrust cylinders, which exert force against the tunnel lining or gripper systems to propel the machine forward, as seen in Single Shield TBMs where these cylinders are positioned around the circumference to push the shield forward from the previously built tunnel ring (Herrenknecht, n.d.).

TBMs significantly enhance the accuracy and efficiency of tunnel construction compared to traditional methods; however, their large size and logistical challenges may make traditional techniques more suitable in certain niche situations.

Support #1 (Efficiency): First of all, TBMs greatly enhance the efficiency of tunneling projects, enabling faster completion compared to traditional methods.

Support #2 (Accuracy): Also, unlike traditional tunneling methods, modern TBMs leverage cutting-edge technology to navigate underground with unmatched precision, ensuring that tunnels are excavated accurately with minimal deviation.

Counter argument: While TBMs have significant advantages in terms of accuracy and efficiency, their large size and complex logistics can make traditional methods, such as drill and blast, a more reasonable choice for confined tunneling projects.