Anyone a fan of trains? How about a fan of train tunnels? Well,
here are some big tunnel fans. The cache is located at the east
portal of the Cascade Tunnel. The building next to the portal (near
the cache) houses giant axial fans used to ventilate the nearly
8-mile long tunnel.
If you've spent a lot of time around diesel engines you know
that it doesn't take very long for them to fill the air up with
smoke and fumes. Now take four or five hard working locomotives and
put them in an almost 8 mile long tube and it gets pretty
unpleasant in a hurry! In the early days of the Cascade tunnel this
wasn't a problem, the electric locomotives didn't generate any
fumes and the little stoves in the cars put out relatively little
smoke. When electric operation was discontinued the Great Northern
installed large fans at the east end of the Cascade tunnel to blow
the fumes out of the bore. When a train clears the east portal the
doors there close behind it and the fans are activated, blowing
cool air into the tunnel to feed the diesel engines. When the train
exits, the fans clear the fumes for thirty minutes before any
additional train gets clearance to enter. This "tunnel flushing"
makes a tremendous racket sounding like an industrial-size vacuum
cleaner. See a picture of the
West Portal during the Purge
When I stopped here to place the cache the fans were operating.
In your log, describe whether or not a train was passing through,
and whether or not the fans were running. Depending on when you
arrive, the place may be quiet, but if you’re lucky you may
experience the sounds of the ventialtion system, and even luckier
if you see a train exiting or entering the portal. Please do not
venture past the guard rail onto the portal grounds as it is posted
as private property.