East Portal, Moffat Tunnel through the Continental Divide, Colorado USA
This 10km tunnel was completed in 1928 and connected the Denver area to Utah and the Western United States by tunneling through the Continental Divide.
In the early 1980s the ventilation system was up-graded to three fans and associated duct work.
The pictured Gate House contains a large vertical-lift steel framed gate that seals the tunnel so that it can be pressurized. In this view it is closed. 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.
Exhaust fans pull air from the west and are used to clear the air after a train has past. The 10km tunnel can be cleared of exhaust in about 10 minutes.
When an eastbound loaded freight train is passing through the tunnel slowly its own exhaust is pushed and pulled with it, so cooling fans are used to push the air westward allowing the locomotive to travel in clean air. Otherwise the crew would be asphyxiated and the diesel engine choked.
East Portal, Moffat Tunnel through the Continental Divide, Colorado USA
This 10km tunnel was completed in 1928 and connected the Denver area to Utah and the Western United States by tunneling through the Continental Divide.
In the early 1980s the ventilation system was up-graded to three fans and associated duct work.
The pictured Gate House contains a large vertical-lift steel framed gate that seals the tunnel so that it can be pressurized. In this view it is closed. 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.
Exhaust fans pull air from the west and are used to clear the air after a train has past. The 10km tunnel can be cleared of exhaust in about 10 minutes.
When an eastbound loaded freight train is passing through the tunnel slowly its own exhaust is pushed and pulled with it, so cooling fans are used to push the air westward allowing the locomotive to travel in clean air. Otherwise the crew would be asphyxiated and the diesel engine choked.