Excavation of Large NATM Tunnel by Roadheader with Automatic Cutting Device

In case of NATM, mechanical cutting is desirable in view of the original purpose of not spoiling natural ground. As typical tunnelling machines, there are two (2) kinds available: one is "Full Face Excavator" known as TBM (tunnel boring machine), and the other is "Roadheader" known as Part Face Excavator. By the use of the former, accurate profile cut is made possible, but there is a limit in the shape of a cutting section. By the use of the latter, cutting of various sections is made possible, but in order to cut a section economically and accurately, operators are required to have a high level of skill. In this text, we introduce Automatic Controlled Profile Cutting System (hereafter "ACPC" System) developed as a roadheader.