This tunnel is aliased from Auran Tunnel Dark kuid 1:1029 by Chris Sprague (nawlins). It is compatible with Trainz version 2.8 and above.
The Auran track has been replaced with MP Track Wood V2 kuid2:69871:2004:2 and has been spaced at 3.5m gauge for UK running.. The track was created by Phil Skene as a replacement for Joseph Pav's excellent MP Track Wood which Auran has rendered obsolete in TS2010 and above.