Large Scale Central

Question about the Cascade Tunnel

Steve Featherkile said:

I suppose that makes sense, but there is always the third rail technology…

True, but where are you going to power swap? Seattle to Wenatchee? Or Sky to Leavenworth like in the old days? Swapping power takes time (and thus money). So the solution is to run stacks through Cascade, and empty coal/grain, and light manifest over Stampede. Any heavy trains get run through the Gorge.

Not to put too fine a point on it, it was Sky to Wenatchee, in the old days. The Chumstick Cutoff bypassed Leavenworth and the Tumwater.

Why not Seattle to Wenatchee?

How long would it take to do a power swap, compared to increased utility of the Cascade Tunnel?

Just thinkin’…

Steve Featherkile said:

Not to put too fine a point on it, it was Sky to Wenatchee, in the old days. The Chumstick Cutoff bypassed Leavenworth and the Tumwater.

Why not Seattle to Wenatchee?

How long would it take to do a power swap, compared to increased utility of the Cascade Tunnel?

Just thinkin’…

Originally the helper district was from Sky to Leavenworth (old Cascade Tunnel), than after the new tunnel was built the district went to Wenatchee… So when I said Sky to Leavenworth I was talking about the original tunnel, not the new tunnel.

A power swap wouldn’t take much more than 30-40mins. But you’d have the cost of re electrifying the whole subdivision, acquiring new locomotives, etc. Overall you might save “time” but the “cost” would be much higher… And how are you going to get electricity to run the motors? Buy from BPA?

The much more practical thing in my mind would be to undercut the Stampede Tunnel for double stacks. Any train originating or terminating out of the Port of Tacoma could go through Stampede instead of Scenic. But then enlarging the Stampede Tunnel opens up a whole new can of worms that goes back to the MILW folding, and UP trackage rights… As Stampede has room to double track from Lester to Easton… All the bridges are double track width (not sure if they could hold the new modern weights of heavier trains with two on the bridge at once).

The tunnel is interesting. When a non-responsive BN engineer ran through the doors several years ago…well, they found the “spare” set, Morrison’s company did the electrical work for backups and a new second door.
Original (still in use) goes up and down. New door, outside of old one, goes side to side. They alternate.
Never be on the bridge with fans on “full” and have the door open…you may get wet as it blows you into the creek.

There is (or used to be) and “air lock” to the left of the tunnel door as looking from outside.

On excursions, we used to enter the tunnel, fans on full, doors closed…amazing…in the old days.

Can you imagine going thru that back in the days of steam power?

Toc,

I think BN only uses the new door now. The old door is in ‘backup’ mode. The airlock that your talking about still exists, as an emergency exit. Along with instructions in the rulebook about how to open both doors manually.

Here’s a nice picture of the cloud of smoke that comes out the E. Portal…

I found a link with a nice diagram that explains with pictures what I was discussing.

http://dslweb.nwnexus.com/tawhite/CASCADE%20TUNNEL.html

Craig Townsend said:

Toc,

I think BN only uses the new door now. The old door is in ‘backup’ mode. The airlock that your talking about still exists, as an emergency exit. Along with instructions in the rulebook about how to open both doors manually.

Last time I was up there, I observed sequential operation of the doors. Explained to me it keeps them moving…bearings, guides, motors.
Leave it to BunSniff to kill that functionality…and next time a Santa Fe engineer runs through the door, it will take 3 weeks to get the backup doors functional again, eh?

Curmudgeon mcneely said:

Leave it to BunSniff to kill that functionality…and next time a Santa Fe engineer runs through the door, it will take 3 weeks to get the backup doors functional again, eh?

There’s a reason being the “F” in Santa Fe… Almost as good as flatlander RFE’s that come up on the hill and think they know everything.

Maybe this is a dumb question, but why don’t they drill some holes down into the tunnel to provide ventilation?

How GN solved the problem in the early 1900’s.

John Bouck said:

Can you imagine going thru that back in the days of steam power?

They didn’t. That’s why they electrified the tunnel. They had problems with crews getting near asphyxiated in the old tunnel at the top of the hill.

@ Craig, I didn’t realize that you had jumped that far back in history. Since the old Leavenworth yard is now occupied by the town of Leavenworth and US 2, it didn’t occur to me that you would consider that to be a viable option. :slight_smile:

Ray Dunakin said:

Maybe this is a dumb question, but why don’t they drill some holes down into the tunnel to provide ventilation?

Its a long drill, Ray. They’d probably hit oil, first. :slight_smile:

John Bouck said:

How GN solved the problem in the early 1900’s.

I’d forgotten about those, JB. Any idea on how well they worked? It looks like the exhaust would back draft right into the cab.

From a strictly engineer’s (not choo choo, calculator guy) point of view. It is very expensive to enlarge a tunnel. It is possible and has been done, but it has to outweigh the alternative. At this time it must be too dang expensive.

To answer Ray’s question. A simple and probably cheaper solution would be to drive a second smaller ventilation tunnel parallel to the Cascade. Then install connecting drifts between the Cascade and new vent tunnel. Install ventilation fans in these new drifts to pull the air away from the train and into the ventilation tunnel and then push the bad air out. With this solution you would be able to have almost continuous movement of traffic because you would not have to mess with pressuring the tunnel and pushing air.

Steve Featherkile said:

Ray Dunakin said:

Maybe this is a dumb question, but why don’t they drill some holes down into the tunnel to provide ventilation?

Its a long drill, Ray. They’d probably hit oil, first. :slight_smile:

Actually the old vertical shaft is still in place, but it has been capped off in both the tunnel, and at the surface. I’ve been told that the reason it was capped off was because of ventilation. I’m not exactly sure how but if it was open it would change the physics of the air moving through the tunnel. The other access tunnel that still exists (and is in the same shape) is the Pioneer Tunnel that runs just to the S. of the main tunnel. Same problems with air dynamics. The pioneer tunnel only has a portal on the W. end as well.

Here’s some good reference photos for those who don’t know the area.

West Portal.

Pioneer Tunnel Portal about 60’ south of the W. Portal.

I have somewhere a picture that shows the Mill Creek Shaft (the vertical shaft, Cascade Tunnel and Pioneer Tunnel. Here’s the best I could find online of the drawing that I was thinking about.

Slightly better, and official from GN promotional on the tunnel construction.

Another interesting tidbit about the Cascade Tunnel is that the fans are driven off a EMD powerplant. I’m not sure if it was the 12 or the 16 cylinder model that powered the fans…

Jake Smith said:

From a strictly engineer’s (not choo choo, calculator guy) point of view. It is very expensive to enlarge a tunnel. It is possible and has been done, but it has to outweigh the alternative. At this time it must be too dang expensive.

I’m guessing the biggest expense, by far, would be the cost of routing all trains somewhere else, since they can’t simultaneously enlarge the tunnel while running trains through it.

I find this subject fascinating so I did a little digging. This engineer came up with a pretty good solution. Minus the Underground science stuff. I think he has a pretty good idea.

http://www.int.washington.edu/s2/AppendixM.pdf