Tunnels
Subtitle: machine excavation, rate of progress, machine data.
Contributors: Engineering and Research Center (U.S.). Division of Design.
Series: REC-ERC (Series) -- 72-9.
Publisher: U.S. Dept. of the Interior, Bureau of Reclamation, Engineering and Research Center, Office of Design and Construction
Published: 1972
Place of publication: Denver
Language: eng
Subjects: Boring machinery.; Excavating machinery.; Tunneling -- Equipment and supplies.; Tunnels -- United States.; Water tunnels -- United States.
Other titles: Machine excavation, rate of progress, machine data.
Notes: Cover title.

"February 1972."