The Moffat Tunnel East Portal and Ventilation Exhaust System

The Moffat Tunnel was completed in 1928 and connected the Denver area to Utah and the Western United States by tunneling under the Continental Divide. The tunnel is still in use today and the ventilation system has been modified extensively over the years as may be seen in this video. Shown here are many different views that normally aren't available to the regular visitor to the East Portal. Interestingly, the portal is nowhere near the tunnel's entrance into the mountain. There were no trains running the day of the video because of track maintenance. Rail traffic was re-routed through Cheyenne, WY for several weeks.

1. Building in the center foreground is the original fan house. It housed two fans (rectangular buildings in the center of the frame) which pushed air from east to west – against normal barometric flow. The fans had only one speed and one direction. They are no longer in service.
2. From 1982 to 1984 the ventilation system was up graded – without taking the tracks or the ventilation system out of service for more than a few hours at a time. The “new” system starts at the tall square building – the Gate House - and includes the square shaped concrete and three fans and associated duct work.
3. The Gate House contains a large vertical lift steel framed gate that seals the tunnel so that it can be pressurized. The door is counter-weighted and fail safes up in an emergency. The center of the door has a frangible panel that allows a train to break though it in the event that the gate does not rise.
4. The fans and square ducts that run on either side of the Gate House are exhaust fans that pull air from the west and are used to clear the air after a train has past. These fans are 9’ diameter radial axial fans driven by 1,500HP electric motors and variable speed drives. 6.2 miles of tunnel could be cleared of exhaust in about 10 minutes and ready for another train.
5. The fan with the round duct (upper right) is the Cooling Fan that pushes air against an east bound train. Fully loaded coal trains move slowly and the exhaust is pushed along with the locomotives (piston effect). The cooling fan creates enough pressure to move the exhaust past the train and aids the locomotives and the crew. The Cooling fan was 1,250HP
6. The area under the low roof next to the canal houses all of the controls and two emergency generators. A smaller generator powers pumps, controls, and other ancillary equipment needed to start and maintain the larger generator that is capable of running all of the fans and the gate house. Weather is tough at the East Portal it needs to be self-sufficient. The larger generator is powered by a 16 cylinder EMD locomotive engine.

©2017 Feight Studios
Artwork and prints: http://www.feightstudios.com
Railroad Art and prints: http://www.feightstudios.com/railroad.html

Music: "Autoran" ©2017 Frasier Feight
Hear more at: https://soundcloud.com/platinumx999

DJI Mavic: http://click.dji.com/ALU0LU3KEgxY28E00eci?pm=cs

Видео The Moffat Tunnel East Portal and Ventilation Exhaust System канала Don Feight