(sketches; elevation; cross-section; site) (4-26)
Tunnel reconnaissance obtains essential
information about underground galleries,
railroads that have manmade covers, such a snow-sheds.
Underground or covered portions of roads or railroads are the subject of _______________________________
The profile sketch indicates the water level, and an elevation o the stream bottom and approaches.
The water level. stream bottom and approaches are sketched in the _________________________________ .