I hear that the Moffet tunnel is 8 miles long,correct? If one where to stand right in front of the bore. Could one see light at the other end? Allan.
I’m not sure if this holds true for the Moffat, but I’ve heard that alot of long tunnels are bored with alittle slope to them for seepage run-off (makes sense), and since they’re usually designed to circumvent a high-altitude divide, the slope at both portals would best be going down from a peak somewhere in the middle, hence there’s no way you could look straight through from one end to the other.
The Cascade Tunnel on BNSF in Washington is the longest in the United States at 7.79 miles. Moffat Tunnel is around 6 miles long, I’m not sure of the exact length.
I’m pretty sure it’s only about six miles long. But what Brian says still holds true. Also remember that the door at one end is often closed to aid with purging the locomotive exhaust from the bore.
The best gradient is uniform drainage gradient of about .2%. Cascade Tunnel is on about 1.6% ascending eastbound. Yes you can see the west end once you get past the east portal. Can not see eastbound because of door on east end.
A peaked tunnel is a smoke trap. Stampede Tunnel on the ex NP is that way and it was always bad in steam days.
Mac
moffat tunnel does a have an apex with ascending grades from each end to the middle tunnel is 6.2 miles long the apex is at 9,239 feet above sea level, and yes the tunnel still fills with smoke and is very hard to keep the smoke from getting bad in there
The Hoosac tunnel is 4.75 miles long - the longest in it’s day. One day I drove up to the west portal and saw what looked like a 100W light bulb hanging from the tunnel only a few hundred yards in. I also felt a cold breeze coming from the tunnel. About 10 minutes later, I saw this:
There was a longer railroad tunnel in the USA, also under the Divide. During 1976 Amax opened a 42" mining railroad which had a 9.6 mile double track tunnel. The western mouth of the tunnel is west of Moffat Tunnel, but there is no eastern mouth. The tunnel ends at an underground Molybdenum mine near Georgetown. Phelps Dodge replaced the railroad with the world’s longest conveyor of its kind; a fifteen-mile elevated belt that passes underneath the Continental Divide through the old train tunnel and then above ground to the Mill. The Henderson Mine RR was featured in the September 1981 Trains magazine.
Very interesting. Thanks. One more Question. How would one know when a Train is going to exit a Tunnel?
Like they said Moffat is about six miles long, but it has enough of a hump inside that no light passes through. Cascade is short enough that light can get through, but if the tunnel gets much longer than that (say, 10-12 miles) then you have to consider the curve of the earth. As I recall a 12-mile tunnel on a constant grade won’t pass any light, for that reason.
If you want to see what a tunnel looks from end to end go to Portland OR then North Columbia St where there is a UPRR tunnel that takes the trains under Portland [:D]
I don’t know about Moffat, but I know you can see through the big hole on Donner.
A rush of dirty air, muffled noise, hotly persued by a bright headlight.[:D]
-or you are rules qualified, radio qualifies and the DS tells you!
Mudhicken (Well trained California Tunnelrat)
…Believe 12 miles will produce about 8’ of earth curvature.
I didn’t know there was a door on one end of the Moffat Tunnel. Which end? Is it closed when there is no train in the tunnel? Whenever the California Zephyr is about to enter the tunnel, a crew member makes an announcement that everyone is to stay in the car they are currently in until the train exits the tunnel. This is to keep the doors between cars closed to prevent fumes from entering the cars.
Is it true there are two bores? one for trains and one for water for Denver?
Thank you. W6.
The west end of Moffat is right at the Winter Park ski area. In fact you go under the railroad to get to the bus unloading area. I had a major fall coming down the headwall unprepared for the Denver Zephyr in D&RGW colors exiting the tunnel. I’m lucky I didn’t get seriously hurt because my attention to what I was doing was severely compromised.
According to a website that quoted some stats from the ski train brochure the Moffat tunnel is 6.2 miles long. I’m not 100% certain but I think there are doors at both ends. for both ventilation and intruder control. I’ve been though it twice and the car attendant on the Cal. Zephyr called it “6+ miles of scenic colorado darkness”
Door and fan motors at East Portal of Moffat Tunnel…tunnel fans can direct air in either direction (generally toward end with lower barometric pressure)…there is a huge investment in making sure that the tunnel air “vents” & cools and can handle another train in 45-48 minutes.
Isn’t the Moffat road (and tunnel) abandoned in place? I thought UP abandoned a chunk of that line (maybe I am thinking of Tenesse pass) when they bought the DRGW.