Western Railroad Discussion > Flathead Tunnel

Thought this was in a post a while back but cannot find it. What year was the Flathead Tunnel built, what are the basic dimensions (clear height above rail, width, length) and what wss the cost? Finally, was this paid for entirely by the Army Corps of Engineers? Thanks for any answers or direction.

Bruce

and what are the wait times for the trains to have the exhaust fans clear the tunnel?

66

The Flathead Tunnel is a 7.01-mile railroad tunnel in the Rocky Mountains approximately 28 miles to the west of Whitefish, Montana. It is the second-longest tunnel in the United States. Speed through the tunnel is approximately 50 mph.

History

The construction of Libby Dam required the relocation of 60 miles of the Burlington Northern Railroad tracks, relocating the town of Rexford, MT and the building of a new tunnel which opened in 1970. The east portal has a door that can be closed and fans to ventilate the tunnel.

Chris



Edited 1 time(s). Last edit at 11/11/17 17:49 by Mudrock.

I got out my "Railway Line Clearances" 1987/1988 annual issue, and it shows clearances for a segment from Sandpoint to Cutbank, including the Flathead Tunnel.  It doesn't say if the Flathead Tunnel has the most restrictive clearance on this segment, which also includes many other tunnels.  A 53' shipping container is 8' 6" wide.  The "RLC" shows at 20' above top of rail, there is 4' 2'' width.  At 18' 9", there is 8"3" width, at 18' 6", there is 8' 8" width, and at 18' 3", there is 9' 3" width.  In 1987, a container could not stick up higher than 18' 6" with minimal sway.  The tunnel is completely straight, so curves don't further restrict the clearance.  If this is too restrictive for double-stacked domestic containers, then the tunnel has been notched since 1987.

mapboy

Still wanted to know the costs, so I kept searching. Finally found this information from the University of North Texas:

https://digital.library.unt.edu/ark:/67531/metadc170843/m1/13/

Page 5 gives a total cost of the tunnel and approaches (I have not yet dug deep enough to find out how far the approaches are considered) of $45,395,329 in 1969.

The RSMeans historical cost index, using January 1, 2016 at 100, puts July of 1969 stood at 13.0. So, not counting on all of the environmental studies and mitigation that would be required for a similar project of $45.4 million in 1969 would be $349.2 million today, or approximately $50 million/mile, or $9,448/LF. I can only offer a WAG that the environmental side of it would add another 25% or more to the cost these days.

This is for a tunnel project NOT in an urban area, and NOT through solid granite or very, very poor soil. Also, not sure what the ventilation system renovation cost a few years ago.

Bruce

The report says that Walsh-Groves was the low bidder and was awarded the contract to build the tunnel. It doesn't say who built the remainder of the line relocation. Maybe BN did being reimbursed by the Government?



Edited 1 time(s). Last edit at 11/12/17 16:52 by CA_Sou_MA_Agent.

goneon66 Wrote:
-------------------------------------------------------
> and what are the wait times for the trains to have
> the exhaust fans clear the tunnel?
>
> 66

Upgrade for eastbound trains, so a flush can be anywhere from 20-30 minutes (it varies). Flushes after a westbound are obviously much shorter, like 10 minutes.

As for clearances, there are two tunnels around Bonners Ferry that are more restrictive. Those very large/articulated BNSF auto racks have a 10mph slow order for those tunnels, no such slow order for the Flathead.