The Tunnel Boring Machine 600 from Akkerman has a sealed steering joint that allows for bidirectional, full articulation at the face of the bore and a high-capacity main bearing. Its two-speed drive motors operate in either low-speed/high-torque or high-speed/low-torque modes. This functionality allows operators to precisely tailor cutting speeds and torque in varying geology for optimal productivity. The operator controls steering, maintains line and grade, and monitors the soil removal process from an interior control station. As soil is excavated, dirt paddles propel it onto the belt or screw conveyor for transport to the haul unit. Carbide single bar, quad bar and sand shelves cutter heads come standard and can be changed underground as necessary. Mixed-ground disc cutter heads for high compressive strength geology, closed face cutter heads for unstable ground or custom cutter heads are also available. 800-533-0386; www.akkerman.com