(under subclass 57) Processes comprising the making of a horizontal bore either from the surface or from an accessible hole.
SEE OR SEARCH THIS CLASS, SUBCLASS:
61, for processes which may direct a bore in a horizontal direction or form a horizontal bore from an inaccessible bore or hole.
SEE OR SEARCH CLASS
299, Mining or In Situ Disintegration of Hard Material,
10+, for a process of recovering valuable material from the earth or disintegrating hard material in situ and including forming horizontal tunnels.
405, Hydraulic and Earth Engineering, 138+, for a method or apparatus for forming a lined tunnel; and subclasses 154+ for a method of laying a pipe or cable into a submerged or subterranean location.
