Shield Machines and Tunnel Boring Machines (TBMs)
Komatsu has consistently led the industry in technology as a maker of TBMs since its development of Japan's first model in 1963. By capitalizing on their high Quality and Reliability, Komatsu has continued to meet customers' needs and expectations in the best possible manners, expanding their market overseas, such as in China, today.
Slurry Shield Machines
These shield machines offer safe and economical performance in the confined acquifer sediment layer below groundwater in urban and suburban areas. They pour an additive in earth and sand excavated by cutter bits, transforming them into impermeable and pseudoplastic flow mud. They excavate forward by counteracting the mud pressure generated by the thrusting shield jack against the mud pressure of the face and groundwater pressure, while keeping a good balance between the volume of excavating and discharging earth.
Water-pressure Shield Machines
These shield machines offer safe construction especially in a high water-pressure environment, such as under rivers and oceans, as well as deep underground. As they require a small amount of power for excavation and feature less wear of the cutter, they are also suitable to construct long-distance and large-diameter tunnels. They pressure mud water, treated according to soil types, and supply water in the cutterhead chamber by the slurry pump and stabilizes the face by counteracting face water and mud pressure. Excavated earth is transported to the ground in the fluid form through waste sludge exhaust pipes, and then it is treated in the muddy water treatment plant and separated into earth and water.
Other shield technologies
Based on the slurry shield and water pressure shield machines, Komatsu supplies a variety of forms of application-specific TBMs by incorporating special technologies. These TBMs include models for use in long-distance construction, sharp-curve construction, simultaneous construction, which performs boring and segment assembly at the same time, rectangular shield, underground-junction shield, and master-slave shield.
TBMs (for bedrock)
These TBMs are designed to excavate bedrock for construction of tunnels in the mountains. They don't create mud or water pressure in front of the cutterhead, as they break bedrock by their disc cutters. Their models include open-type, double-shield type and inclined shaft TBMs.
Hybrid Shield Machines
They combine the shield technology to excavate underground water and the TBM (for bedrock) technology, allowing for a wide range of applications. In addition to mud, sand and bedrock, they can also excavate boulder bed. Komatsu offers two types, the water-pressure and mud-pressure type hybrid models.