loop tunnel

loop tunnel

[′lüp ‚tən·əl]
(engineering)
A tunnel which is looped or folded back on itself to gain grade in a tunnel location.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
References in periodicals archive ?
Musk's company has also proposed a Loop tunnel that would run between Washington, D.C.