BNSF's Cascade Tunnel Ventilation System, a Demonstration Of How It Works

[@espeescotty]

In the early 2000's I went to the East Portal of the 6.2-mile long Moffat Tunnel in Colorado. It is a similar setup there, with a huge ventilation building complex at the east portal and a door that blocks off the tunnel opening, but instead of blowing clean air into oncoming trains, the huge door closes after trains pass, and then the fans turn on and pull all of the heat and fumes through the tunnel where it is exhausted to the sides of the ventilation complex into the valley surrounding East Portal. So much exhaust is expelled from those fans that for about 100-feet, the whole area downwind of the fans was covered in soot and if the winds weren't blowing, the entire valley would fill with smoke. In addition, on my first couple of visits there, the fans were so loud, they could literally be heard a few miles away....I loved it all! By my last visit there in 2008, Union Pacific must have installed newer, much quieter fans, because the old howlers were gone. And up until the early 2010's, the Moffat Tunnel route hosted many eastbound loaded coal trains that ran mostly smoky GE AC4400's in 3+2+1 or 2+2+2 sets. And with an elevation of over 9,000 ft above sea level, those locomotives were really starving for air and even more smoky. It was quite a show.

[@KensTrains]

That would have been awesome to see and hear!

[@lewiemcneely9143]

I hauled concrete on a pumped storage project and the whole thing was in solid rock and had a fall of 900+ feet from the pond to where the generators were at lake level. There was a fan that ventilated the whole complex I could hear running from anywhere on the job. Screaming. I had a chance to go see it between pours and it was a circle about 8 feet in diameter. There was a Cat generator that would power the whole thing that was right below it and was covered in a building the size of a nice house. I shut the door and e a s e d away. Hopeyou're doing well from the proceedure, Palley!

[@espeescotty]

@@lewiemcneely9143 Hey Lewie, fancy meeting you here. An 8-foot diameter fan can move a large volume of air...and anything else that might be in that airstream. Probably self-preserving wisdom won that day, and you're here now to tell the tale. I just got home from my procedure. Still about 75% numb, but I can feel some aching coming on. I'm in a sling for a week, then rehab starts. So far, so good. Thanks, buddy! Catch you on the next one. 🤠👍

[@lewiemcneely9143]

@@espeescotty HEAL, Palley! I'll check on you! You know how I am and stay cool!

[@MobilTreff]

All of this could be saved if we didn't drive diesel junk across the country. Electric locomotives would make the whole thing so much easier. Or, as is common in Europe, we could use normal tunnel ventilation with fans on the ceiling and pipes to extract the pollutants.

[@kirkzevola5004]

Fun fact. I overheard BNSF’s Seattle East dispatch explain the history of how the Cascade Ventalation system works in terms of Amtrak Empire Builder trains #7 & #8 & different kinds of BNSF freight trains. According to BNSF Seattle East dispatch for Amtrak Empire Builder trains #7 & #8 it takes only one fan to clear the exhaust fumes from Amtrak since Amtrak is light & for different kinds of BNSF trains depending on the length and heaviness of the freight trains required either one or two fans. How cool is that.

[@Greatdome99]

I recall riding the Builder (in GN days) in the Great Dome Lounge car. As we emerged at Berne after 15 minutes of darkness, the entire car was full of smoke! Those full-lengh domes had had separate mechanical air conditioning and the crews were supposed to turn it off in the tunnel.

[@TheMW2informer]

@@Greatdome99what is GN days?

[@zyoninkiro]

@@TheMW2informer the Great Northern Railroad, the folks who built this tunnel and one of the railroads that were merged to form the Burlington Northern and later the BNSF. The GN was the northernmost of the transcontinental routes.

[@dieseldragon6756]

@@Greatdome99 Back in _Great Northern_ days? 😳 Are you sure that smoke didn't just come from fellow passengers cigarettes? 🙃🚬

[@dieseldragon6756]

What surprises me is that - For westbound trains (Going downhill) - They don't just let the locos go to idle and allow the train to coast under the dynamic brake. Not only would this save fuel, fumes and fares (As well as not having to turn the tunnel fans on) but it might actually achieve the impossible; _Make the Empire Builder run at an _*_acceptable_*_ speed!_ 😉 (Disclosure: I'm one of those folk for whom the entire westbound journey on the _Empire Builder_ proved absolutely slow and hellish for _not_ having been given a handy briefing on just how different American trains are to European ones. Needless to say; Next time, I'm taking a bicycle... 🚵💨🚂😇)

[@dennismundt7378]

Thank you for the video. It is interesting when you read the history of the tunnel on the Internet that the tunnel was initially operated electrically. Even back then, the performance of electric locomotives with purely electric operation on this route was evident. I can also understand that from a commercial point of view there was or is a time when operating with diesel-powered locomotives is more cost-effective. However, the development of power electronics has not stood still, and perhaps we could reconsider the option of whether operating with electric locomotives again might be the better choice in the future.

[@Love2Cruise]

I was thinking while watching this video: why didn't they just electrify this section?

[@kinezumi]

@@Love2Cruise most likely because special treatment on this section for standard locomotives (this ventilation system) is cheaper than specialized locomotives and delays caused by switching out diesels for electric ones would be. Same goes for running hybrid power sources (diesels with pantographs that could shut down the prime movers for the tunnel).

[@ivanoffw]

@@kinezumi Electric helper locomotives could wait at either end of the tunnel, attach to the front of the train, Then they could shut down, or at least idle the diesel locomotives for the passage through the tunnel. Then at the other end the electric locomotives decouple and run down a siding so they are ready for the next train.

[@Julia_and_the_City]

​​@@Love2Cruise I'm going to make a guess: there probably used to be overhead wiring in this tunnel (hence why the tunnel is so tall) but the added height was used to be able to run double-stack container trains instead. I don't know whether that's true but it fits a pattern of US railroads elsewhere.

[@Love2Cruise]

@@Julia_and_the_City That makes most sense, especially since it was originally electrified.

[@jerroldkazynski5480]

My Dad and Grand Dad were Trainmen. Dad took the family on vacations and visited a variety of RR sites. I remember Moffat Tunnel, probably late 1950s or early 60s. Thanks for the video.

[@majobis]

Makes me wonder what type of air pressure builds as the fans spins. The forced air being blown for 7 miles has to be pretty high I imagine.

[@thejoe9065]

Very low pressure. Only cause it is a high volume of air does not mean the pressure is high. Its probably like 0,1 bar or less.

[@majobis]

@@thejoe9065 I did not think of low pressure as the air being forced through the tunnel. I learn something new every time I see stuff like this.

[@mojaveclimber]

It's a high volume of air.

[@dickfitzwelliner2807]

Low pressure, high volume.

[@gregebert5544]

I rode thru here on a westbound Amtrak in the 1980's; longest tunnel I've ever been in. The exhaust fumes were minimal despite dual-loco pulling us uphill. Pitch black except for an occasional light about every 1/4 mile, so nothing interesting to see except a glimpse of exhaust. I'm pretty sure I saw at least 1 signal, though I cant imagine stopping a train in the tunnel except for a serious emergency. I think we were going 25-30 MPH, so it was about a 15 minute event. It didn't take long for the tunnel to get dark behind us, mostly because we kept going farther in; impossible to see the door closing and at that time I had no idea it even had a door.

[@tux_the_astronaut]

If there is a single in the tunnel it’s probably a distinct signal to just tell the train what the next signal down the track will be showing

[@DakarNick]

​@@tux_the_astronautDistant? There are two, an intermediate and an absolute at the east end for EB traffic.

[@thekittenofwar4421]

There is one "signal" in the tunnel I know of, but I think it just indicates whether the door at east portal is open/working or not. There could be others, I just never had them pointed out to me.

[@DakarNick]

@@thekittenofwar4421 Two. An intermediate and an absolute. At West Winter Park we get an Advance Approach. At East Winter Park we get an Approach. We then do track speed, 40 mph, prepared to stop, which is also the max speed of an Approch.. The intermediate is always a Restricting and the absolute is always a Red. At about 1.2 miles from the intermediate, once the gate opens, the signals will upgrade to Clears.

[@seantaft9281]

I bet a derailment in that tunnel would be difficult to deal with

[@bryanp.1327]

I'm sure that's why they travel so slow, I'd hate to be the engineers that have to go fix a broken buckle in there though if that were to happen.

[@drewlucas6266]

Wouldnt mind a close up of those fans. They sound like they are giant and spin at a relatively high RPM.

[@expatbe]

There are no videos or pictures close up. Kind of a off limits area. If you look up BNSF Cascade tunnel ventilation wiki has a shot that if you zoom in you can see the pipes leading. If you look up tunnel ventilation you will see examples of the fans. They are about the size of a Airbus A320 engine.

[@UTtrainsignalmodeler]

​@@expatbeNot discounting that the slow ramp up on the fans is likely controlled by a large Variable Frequency Drive, industrial motors that would be powering these fans are likely still rated for standard RPMs for three phase motors operating at 60Hz. In most cases, standard nominal phase locked rotational speed on a four pole motor is around 1800 rpm, not counting for slip. While possible, I doubt the motors are two pole units. While the speed would increase up to around 3600RPM, the voltage would also increase significantly. With that said, there may be some construction criteria or features implemented by the fan manufacturer that gives it that high pitched sound.

[@expatbe]

@@UTtrainsignalmodeler that's over my head! But nice to know.

[@bryanp.1327]

I love big industrial motors like those, the huge current draw and the sound, you can almost feel the lights dimming in the area. Puts a smile on my face.

[@NewDestinationEng]

I'm not really a train guy but I'd like to deep into the whole exhaust system operation. As a mechanical engineer I love big equipment

[@jacksonsdrones]

For the crew, they don't see a light at the end of the tunnel! 😂 Great Video! Really cool system they got going!

[@DakarNick]

Great video and explanation. I'm an Amtrak engineer and go through the Moffat Tunnel regularly.

[@bobbymacd1978]

If you listen closely, you'll notice that the second round of fan noise (after the train exits) is louder than the first (when the train is in the tunnel.) They have twin fans and only run both when (a) the tunnel is empty and (b) when there is a westbound train in the tunnel, since in that case the wind is at the train's back. Driving on Route 2 by the complex, I have learned to notice the difference. Also, the tunnel is straight uphill going west to east, so the times required to flush the tunnel can be less for trains going west (downhill) since their engines are not working as hard.

[@therooster6104]

Very educational thank you never knew about this tunnel before 🤝 for the younger folks I’m 63 never stop learning 👊

[@KensTrains]

Glad you enjoyed it! It’s never too late to learn something new.

[@szymonczuwara3670]

Very interestning solution Greetings from Europe Thank you

[@StormySkyRailProductions]

Wow what an awesome and interesting video. We enjoyed watching Ken and have a wonderful rest of your day. Steve

[@KensTrains]

Glad you enjoyed it!

[@KellyClowers]

Very cool, I grew up near the second longest train tunnel in the US, it also has huge fans, though I don't know if it closes a door like this one.

[@rc4lifebnsf]

Thank you, finally someone made a vid on exactly how it works

[@shift8769]

Thanks for the video. I've seen several videos of trains passing through this tunnel and always wondered why the door was there. Now I know :)

[@KensTrains]

Glad you enjoyed it!

[@frankschultz4170]

Expensive tunnel to operate. It sounds like it has really big blowers.

[@jasonbabila6006]

I worked in that tunnel numerous times, the dispatcher would run just one fan at 50% for air flow and blow out the smoke from our trucks and machines.

[@KensTrains]

Thanks for those details!

[@danielhildebrand6892]

Has to be surreal working in the tunnel.

[@Markus_Teltschik]

Hallo I have a quick question. I am a traindriver in Germany. If we had such a tunnel with a door on each end, that door would be connected to a signal that a train canˋt hit the door (if everything is working as intendet). Now to my question, are the doors on Cascade Tunnel guarded by a signal or something else which brings the train to stop before it can crash into a closed door?

[@danielhildebrand6892]

@ yes there is a interlock light mid tunnel. And only one side has a door on the east portal. And literally takes under a min if that to open.

[@dieseldragon6756]

@@danielhildebrand6892 Looking at the design of the door, I think it's also been designed in such a way that if a train were to come into contact with it the door would break easily, be pushed to the side, and do little risk or damage to the train - Allowing a „break thru“ event to be relatively safe, if not operationally inconvenient. 👍

[@southwestxnorthwest]

The fans are actually two 800 horsepower turbines that sit just to the left and out of view from the tunnel doors. I've been there and watched them in action.

[@cadence4527]

Thank you. I wanted Hyce to do a video explaining this, but you beat him to it.

[@FreezerBurn.]

Just another quiet day in the forest😂

[@Lukelins1]

What I could not hear you

[@elwinprice667]

Very impressive! I like to know how things work! Thanks 😎

[@KensTrains]

I'm glad you enjoyed it! Thanks.

[@franzkoviakalak6981]

Super interesting, thanks for sharing. Those fans sound serious.

[@KensTrains]

Glad you enjoyed it!

[@Sacto1654]

I believe the Moffat Tunnel west of Denver has a similar ventilation system.

[@STi_Studios]

Can confirm 👍🏻

[@brianrigsby7900]

Wow! Sounds like a huge jet engine!!

[@crunchycrispybacon]

I would love to be walking in that area with a coffee. Looks nice.

[@KensTrains]

It’s a beautiful location!

[@tvm73827]

Incredibly interesting video! Thank you for sharing with your viewers/fans and educating us. Not a day goes by that I’m not impressed by this country.

[@txmmoore]

You should have shown the control room for this. Emerson's x-stream gas analyzers hard at work.

[@ctwalston1565]

Wow!! The double stacked container BARELY clear!!😳

[@KensTrains]

Yup. In fact, the portal on the other end of the tunnel has notches cut into it to give extra clearance for them.

[@vernonsaayman9741]

Thanks, never knew this, one would think theres always air in the tunnel,

[@dieseldragon6756]

If my experience as a passenger is anything to go by; All of the air is in Amtraks boardroom... 🐌💨🚂😉

[@joshlikescola]

American railways do anything but electrify challenge completed 🎉 It is cool though

[@jimihendrix991]

The new Cascade Tunnel was opened on January 12, 1929. The new line had 72.9 route mi (117.3 km) or 93.2 route miles (150.0 km) electrified, between Skykomish and Wenatchee. Electrification was removed in 1956, after a ventilation system was installed to eliminate diesel fumes.

[@dieseldragon6756]

@@jimihendrix991 They _removed_ the electrification?!?! 😳 They weren't employing a certain Dr. Beeching as their infrastructure manager, by any chance? 🤔

[@EntertainmentWorldz]

great video 👌👌😍😍

[@fatwalletboy2]

Well blow me....this is fascinating....never seen anything like before on the railways.....brilliant

[@GilmerJohn]

That door looks like an accident waiting to happen. It might make sense to have the fans of several outlets to the tunnel with the air flow directed away from the portal that now has the door. This would actually suck air from that portal. It wouldn't be as efficient but would eliminate the possibility of an accident.

[@3nuklr]

IIRC, There actually was a collision between a train and an older door. Going off of really poor memory, I think the old door was black and white checkerboard pattern and was different physically. This new door being red (or orange, I'm colorblind) and white and moves from side to side. Maybe one of the railfan guys here can elaborate ?

[@SocialistDistancing]

I'd like to get a look at those fans.

[@briancampbell1210]

When they were digging the tunnel originally they bored a vertical shaft down through the mountain, so that they could dig from both ends and also both directions from inside the mountain, thus cutting the construction time quite a bit. I've often wondered if that vertical shaft still exists. You'd think that if it did it might be pretty useful for ventilation, but I've never heard any mention of it. It's hard to imagine they filled it in after the tunnel was dug though, I mean what would be the point of that?

[@robertfowler217]

Does the same action occur if the train is going in the opposite direction

[@rockadoodoo]

Yeah, how does it work going the other direction?

[@louisletourneau3429]

The front locomotives gets fresh air but what happens with DPU middle and rear units ?

[@leadslinger49]

Thanks, that was interesting. I wonder if they had to modify the tunnel to accommodate the double stacks?

[@KensTrains]

The west portal has small notches visible where it appears to have been modified for that purpose.

[@DavidWsTrainVideos]

How cool is that. Very interesting

[@RobertP-zk8vh]

very cool never knew about this tunnel

[@WBS001]

Non-train guy here. If they're only hosting one train at a time, wouldn't it make more sense to have fans at both ends pumping air through a service duct to the center of the tunnel and let the air pressure push the stale air (etc) out both ends. In NY/NJ, it's done that way (for more than a century) on the Lincoln and Holland tunnels. Admittedly, it's cars, busses and trucks as opposed to trains, but I'd think (don't know) the theory would be similiar. Yes/no?

[@KensTrains]

Possibly could work? Keep in mind that the tunnel is almost 8 miles long and that would require a significant additional amount of infrastructure to be built for type of system.

[@bobbymacd1978]

There is no service duct as the mid-point of the tunnel is 800 feet below ground.

[@spinosaurusrex11]

Very nice presentation of information. Thanks for posting +1 sub.

[@KensTrains]

Thanks for watching and subscribing!

[@kirkzevola5004]

Stupid question does the Ventalation system clear out exhaust fumes from westbound trains. I know your video showcased an eastbound I was wondering if they do the same process for westbounds.

[@KensTrains]

It seems that I read somewhere that they close it up and run the fans for a short time, like 10 minutes, after a westbound goes through it. But I’m not 100% sure.

[@Greatdome99]

It's all downhill for westbounds, so the diesels are at idle. They do, however wait until smoke clears from eastbound trains. All crews have emergency breathing devices on board.

[@pjtemplin]

An old fog chart says 5m for westbound after westbound, 30m for eastbound after eastbound, or 15m for the other two combinations.

[@sanddabz5635]

@@Greatdome99 That's fascinating!.... I would have never in my life ever even remotely thought about emergency breathing devices for train crews, but now..... it's like duh!?.... After considering the output of the fumes from these locomotives I can't believe I wouldn't have thought this out logically myself.🥴🤣

[@expatbe]

@@Greatdome99 I remember when I was transporting new hires (crew shuttle) they are each fitted with their own mask in order to keep a tight seal on the face. But I never knew if they had O2 tanks or if that was on the locomotive or if it's just a big filter kit.

[@davewestner]

Sounds like a diving Stuka! Hope there's no residences close by. Also, imagine freight hopping thru that tunnel? That'd be nasty if you were in an open car.

[@courtneykensington8190]

The sound of the fans reminds me of the sound of a feller buncher saw

[@sanddabz5635]

This was fantastic! I never even knew something like this existed, but now I do, and I understand how it works now. It may have been in the video and I missed it but how long does it take the train to traverse the length of the tunnel?😁

[@KensTrains]

Thank you! Glad you enjoyed it. The length of time would depend off course how slow it goes because of how heavy it is. But a minimum of 20 minutes for a freight based on the speed limit.

[@sanddabz5635]

@@KensTrains Thanks!

[@jamsohnson8579]

I expected smoke to come billowing out like a Cheech and Chong event.

[@KensTrains]

The smoke/fumes go out the other end.

[@luisbaker2787]

Why do they close the door while venting? Wouldn't it work better with the door open? Question

[@hondaman08]

If left open, the air would go right out this end. It needs a “blockage” to push against forcing the air through the whole length.

[@luisbaker2787]

@@hondaman08 Thank you!

[@GEVOlutionCPKC]

Another breaking it friend awesome capture New subscribe 🚂💯✔️🔝👍🏼

[@223shakey]

Where does the air go out? Are there exhaust fans at the West Portal, or does the air just exit through the portal opening? Does it matter which direction a train is going.

[@KensTrains]

The air goes out the west portal. The west portal looks just like a “normal” tunnel portal. A train going the other direction doesn’t require ventilation because it is coasting downhill. I believe a short flush sequence is done after Westbound though.

[@Ninjan33r]

How does it work for the westbound trains?

[@STV-H4H]

As a young boy, I had a couple opportunities to experience this tunnel. My dad was an engineer for the BN, still in the 70s my dad was able to be allowed to bring me to work. Since my grandparents were in the eastern central part of Washington, I could be taken to see them a few times that way. Later in the 80s, I was older and not so interested, and the BNRR and other such things had to be vigorously clamped down on. But watching this video is a nice reminder of those times The ventilation system might’ve been something he explained to me at the time, but today watching this, I’m blown away by how it works. (Pun intended)

[@timmyers1006]

My stepdad also worked as an engineer his whole life, And in the early 70's did work out of Skykomish for awhile. We lived in Auburn so we would go up and see him. I also got an opportunity to ride along, wasnt it fun back then. He normally ran the pusher engines so would be in back. Anyone that was on the back was required to wear respirators, but the night I got to go, he was in the leading locomotives no respirators required. We left Skykomish around 3 am so it was all dark during the ride up, and within a few minutes into the tunnel I was asleep. woke up soon after. Ended up having to take the train to Cashmere. There I took another nap, then we returned. I Remember them telling me to look out for mountain goats but I never seen any. Of course, soon after entering the tunnel west bound, I fell asleep. It was still a fun day for an 11-12 year old. A few years later I got to play Nightwatch man on a steam train he helped rebuild and run on the track between Concrete, and Mt Vernon. He was a great man. RIP Fred 'Blackie' Moser. I now live in Sultan Washington, and travel the pass multiple times a year and always look at that area when driving by. (Still havent seen mountain goats up there) '

[@STV-H4H]

@ interesting. I called my dad while I was still not beyond halfway through this video to ask him about the tunnel. He had some really interesting stories (well one was particularly interesting) I’m sure, but the one that he brought up was while he was on a helper engine somewhere in the middle of a mile long (I think he said it was that long, he’s not as sharp these days when recollecting his days that long ago. But it was mid or early 70s. The train had a brake line fail, while it was inside the mountain. So they had to shut down all the engines to stop making exhaust, while the brakemen searched for the broken hose line. It was a 4-5hour event by the time it was able to either start rolling again or to get out of the tunnel. Such a long train takes a long time to start moving, especially when it’s going the uphill direction. I’m assuming that meant they were eastbound, I don’t recall. Typically it was an hour or so journey from end to end, traveling as slow as they did. They always had to monitor the speed as well as the engines actual power levels, or they would overheat since airflow was essentially only the wind created by the ventilation fan systems. In truth I really don’t think I can remember much of my journey, except that I know I did it for sure one time. I have other memories of a (I think it was another line, but still up in the north cascades, the towns you mentioned. I can mostly recall Concrete, Skykomish and a couple others, but that is mostly from years later when I have traveled through hi-way2 when my girlfriend (now recently ex wife, mother of our two kids whom we camped and other stuff around Mt Baker and East of the mountains in Wenatchee in I will guess 96 or seven. I grew up mostly in federal way, 72 till I finished high school in 83, During this period. Before FW I had my earliest years in Des Moines, 67-72. Later in the 80s I lived for a couple years in auburn. 84-85 ish. Now I’m in Madison Wi. Dad retired in early 2000s, can’t remember the year. Your dad’s name didn’t immediately pop into my memory. Though it might later. I knew a bunch of RR people who dad worked with, one, the guy I bought my first car from, he lived on the western hillside of Kent I think, maybe Des Moines, 288th is coming to mind. Can’t recall his. Rod I think. Wow, suddenly a bunch of names are coming out of the cobwebs. Cool stuff though. Thx. 😎

[@MidnightWarrior1976]

Ken: A complex question that I have been wondering about for years. Every investment (the tunnel) has a return. Even 2X is not bad in general. The question is what the return on investment there has been for this tunnel. (My guess is it could be 100X) Could this be in the top 10 of investment return in American history?

[@KensTrains]

I have no idea, but it’s interesting to think about.

[@eisenbahnertv]

Imagine a foolish kid going inside there and suddenly the doors close and loud ass fans start blowing 💀

[@nickdawson9270]

Purging the tunnel afterwards looks as challenging as the first phase of ventilation. Is this tunnel only used for freight? In which case giving the train crews oxygen masks might be more cost effective or is that actually the up for when the fans fail?

[@dieseldragon6756]

The tunnel also carries the _Empire Builder_ passenger trains that use this route, though - Provided they don't have my fat backside on board - They require less blowing for the trains being much lighter thus producing less fumes. 👍 Don't forget that the trains themselves also need air to make their combustion process work; And those diesels need a *lot* of it. If you sent a train into that tunnel unventilated, there's a strong chance it'd asphyxiate and stall. 🛑

[@nickdawson9270]

@@dieseldragon6756 Thanks for your response and explanation. I live in the UK and was unaware of the tunnel's existance until the 'magic' of the KZbin algorithm offered up the video. What a wonderous thing the internet is, and what a piece of engineering the tunnel is! The height of the tunnel seems to just allow for double-height containers. Extraordinary foresight way back in 1929, but I guess the real design reason was an attempt to deal with exhaust smoke from steam-powered trains. I wonder why the civil engineers had to end up with a gradient through the tunnel. A level track would have saved a lot of energy. Flat and straight is always the best recipe for a railroad or railway. Brunel achieved that, as far as he could, on the GWR in the 1840s. I take all your points on board. I wondered why the RR did not stay with a variant of the earlier electric traction but seeing the potential power of the combined diesel locomotives I guess that there would be problems providing the equivalent energy by overhead high voltage along the tunnel length without significant voltage drop. Electric locos are inherently lighter too so poor adhesion to cope with as well. If it works, don't try to fix it is a good rule in life.

[@dieseldragon6756]

@@nickdawson9270 No worries! 😊 Funnily enough I live in the UK too, but learned about the tunnels existence when a train I was travelling on passed through it. The need for the train to hold outside of the tunnel for the air to be purged (A BNSF freight train had just passed us heading east, so lots of thick diesel smoke needed to be extracted first) struck me as highly unusual, so I read-up and learned a bit more about it after my trip! 😇 We don't see this here because we employ different approaches to design. The Channel Tunnel employs the service/evacuation tunnel (Which runs between the two main bores) as the main air inlet from the ventilation equipment installed at Shakespeare Cliff and Sangatte for breathable and circulated airflow, but the CT also has an absolute ban on non-electric trains. Even the service vehicles are electric, and the TML „ThunderBird“ diesel locomotives (The last resort option for recovering stricken trains in the case of absolute electrical failure) have full-scale fume capture and scrubbing equipment built in to them. 🚭 Similar UK tunnels - The London bores of HS1 (Electrics only) and the Severn Tunnel (All trains) - Employ similar approaches. The latter sometimes operates like the Cascade tunnel if necessary (There are air quality sensors and fans can be set to renew tunnel air if needed) but this is less common for the STs shorter length and the fact most UK passenger trains have automatic ventilation shut-off to prevent fumes or stale air being drawn into passenger saloons. 👍 The gradient in the Cascades might be for two reasons; The terrain might not favour a level tunnel (In this case a level tunnel means starting off 190m lower down, meaning the tunnel would need to start from around Glacier Park East, be close to 160km in length, and much of the geology in that area is dense stone and granite) but the intent might also have been that a non-level tunnel would permit natural ventilation of smoke, on the assumption smoke would always drift up and toward the eastern portal of its own accord. Sadly, that latter theory doesn't work out in practice. 🚬 The removal of the electric traction - And tunnel electrification in general - Was most likely to do with industrial pressure on government, particularly that of the oil and automotive industries to make America absolutely dependent on their fossil fuels. The fact the electric arrangement would have meant changing locomotives and re-forming trains at both ends of the tunnel (Costing time and money) also would have encouraged BNSF to move over to diesel-only operation once it became practical and affordable. 💸 Had the old arrangement been in use when I passed through the Cascades, my journey time would have been extended by at least another two hours...Bad enough in itself, but my train was already running 26 hours late when it reached the east portal. I wouldn't have minded, except it turns out that Delay/Repay *isn't* a thing on the North American railway system...Heck, my train (Arriving Seattle 27,5h behind schedule) was regarded _„slightly delayed“_ by the official metrics that were in use at the time! 🌳💨🚂😳 What did I learn from my trip? I learned that the next time I need to travel from Chicago to Seattle, I'll use a bicycle. It's only a short distance by my measure, I'll have more freedom over route options, and it so happens all that time I spent riding around French cities had had the unexpected impact of making me the only British person to have a natural gravitation to driving on the _right!_ 🏔🚵💨🤘😁

[@petermiller9712]

great video thanks

[@Rembrant65]

The world contains Infinite detail. Outside of the rail industry who would have known this was a necessity? Besides the (currently) 11K viewers of this video?

[@AnontheGOAT]

It’s widely know amongst rail fans too. 😊

[@cameronbracken3228]

Sounds like a place that would be massively benefited by electrification. No smoke, no soot, no health risk, no pollution.

[@KensTrains]

Maybe. But the electricity would have to be produced somewhere else. So the pollution would be produced, just at a different location.

[@dasbooterror]

@@KensTrains Sure but economies of scale and efficiency come into effect really quick on that front. The previous electrification of the tunnel was done via hydroelectric, and Washington state itself gets ~66% of its power from hydroelectric over all meaning much of that pollution would be very low, if the tunnel was re-electrified. Additionally trains would be able to run through the tunnel even faster without the 30min tunnel smoke clearing needed between trains now. Additionally, as more "green" power is connected to the grid (Solar, Wind, Hydro) or if more nuclear (or the pipedream, fusion), electric locos win out even faster in this case. Thats before we even discuss grid regen returns from the electrical locomotives. Even if you assumed it was all done at a larger fossil fuel power plant, the higher efficiency of such a plant vs the diesel electric plant on the locomotives is astounding. Typical US coal plant has ~33% efficiency. Typical modern diesels do 20-25% with the newest units off the line just finally approaching 28%. The power plant will also have better pollution control hardware due to its size and stationary nature, as compared to anything board the loco.

[@AN-kn1qt]

@@KensTrainsbut the energy expenditure of running the ventilation system would be absent, and power stations are inherently less polluting to some extent on account of always running at maximum efficiency. No unproductive idling, no rolling coal just to get up a hill. Electric trains also have the advantage of using electricity that is in part generated by renewable sources and non-renewable low-polluting sources like nuclear power, whereas diesel-electric locos must derive every watt they need from the fossil fuel they use. It’s also astounding how unhindered catenary systems can be-climbing the uninhabitable mountains of Norway on the Bergen Line in the dead of winter? No problem 🦾😅🔌

[@w00derice]

It was until the 50’s. About 73 miles of that route, because of Cascade tunnel. Between Wenatchee and Skykomish.

[@johanssonb]

@@AN-kn1qt not to mention that electric traction motors are vastly more efficient at converting energy into movement than diesel engines

[@KaijuForceNeo]

Be Honest with us: You first heard of this Tunnel from the show “Extreme Trains!”

[@edconway9072]

Is this eastbound trackage only? If not how does the westbound trains' cycle work?

[@sptraxide]

Great video! Thanks!

[@intermodal2091]

Nice video bro!

[@KensTrains]

Thank you for watching!

[@kennydings3879]

Nice video. How are you able to find out what train this is and where it’s going?

[@KensTrains]

Pretty much requires knowing people who are connected with the railroad that can get the info for you.

[@jerroldkazynski5480]

In the "old days" the RR published Time Tables for their lines. These were updated regularly stating Train Number departure times for each direction of movement on those lines, listing all the stations, especially passenger trains. Such as Departing Denver Westbound at 8 AM (and days) Arriving at Salt Lake City (or others) at 1 PM. Smaller stops between major depots would be listed as well - this is just an example.

[@GACamp0]

I assume, at an earlier in point in time, steam locomotives ran through this tunnel. Do you know when this ventilation system was introduced? Or did they use the wet cloth over the face method?

[@KensTrains]

I believe it was electrified during the steam era. Locomotives had to be switched out to go through it.

[@brianporter4352]

It was electrified until 1956. The electrification was between Wenatchee and Skykomish. The Great Northern decided to end the electrification in 1956 due to the expense of maintaining the catenary.

[@GACamp0]

@@brianporter4352 Very interesting. So, the electric power units lived in either Wenatchee or Skykomish depending on which side of the tunnel they were needed on a given day, I assume. Quite a rigamarole to have to stop a huge freight drag to change out power, but necessary.

[@brianporter4352]

@@GACamp0 The current tunnel was opened in 1929. This replaced a smaller tunnel at a higher elevation. The electrification was originally a 3 phase system, but with the current tunnel opening, the electrification was changed to a single phase 11kv system-similar to the Pennsylvania RR electrification on the NE Corridor. The electrification was pretty efficient, but with the adoption of the diesel locomotive it was decided to abandon the electrification. Some would argue if the ending of the electrification was a good idea, since the tunnel is a little bit of a bottleneck with the exhaust fans.

[@dieseldragon6756]

For the more Metric among us; This is *12,35km* long, and the difference in elevation is *190m.* 📏🇪🇺👍 I've been through this once, on a trip to Seattle about ten years back. Learning that the train takes a good 30 minutes to pass through it in the eastern direction (An average speed of just 15,5mph/24,8km/h), I'm glad I was travelling west! 🐌💨🚂😋 That said, I've never seen a tunnel ventilation system work like this in Europe; On the Channel Tunnel (30mi/50km) we have two intake shafts and use the central evacuation tunnel as the main ventilation duct. Taking the Cascade approach there would _blow_ Eurostar and Le Shuttles operations wide apart! 🌬🚄😋

[@schrap72]

That is fascinating!!!!!

[@P61guy61]

Thank you for sharing.

[@stephenwalls9277]

I wonder if there is an approach signal to stop a train entering if the fans don't start for some reason.

[@KensTrains]

There is a signal at the other end of the tunnel to indicate to the crew that it’s running. They would see it before they enter it.

[@LasseGreiner]

How does it work for the trains going in the opposite direction?

[@robertreynolds1044]

Is this Stampede pass out of Auburn?My name is Bicycle Bob and I approved this message and I have caught out of Auburn twice, with a bicycle!

[@AnontheGOAT]

No. Cascade tunnel at Stevens Pass.

[@robertreynolds1044]

@@AnontheGOAT thanx

[@Crewsy]

So how does it work for a west bound train or is this an east bound only tunnel?

[@TheNorthwestWind]

thanks for this

[@raysrails2164]

Wow just amazing

[@Law_Abiding_Citizen_ok]

What happens if train goes opposite way ?

[@RaulSavala-em1vb]

Well that's amazing, 👍

[@SOU6900]

Imagine all the extra control logic and circuits needed to work this system, both today and back in the old days.

[@MrTrashmasterfx]

I don’t think it’s that complex, rather simpel when you think about it.

[@SOU6900]

@MrTrashmasterfx I mean, yeah, maybe if it's just a timing circuit like what was used on Saluda.

[@MrTrashmasterfx]

@@SOU6900 I was think the same thing.

[@stevengiles346]

Is there a similar setup on the other end for trains running in the opposite direction?

[@Law_Abiding_Citizen_ok]

Said that the equipment was at this end only!, so what if train goes other way?

[@stevengiles346]

@ Exactly!

[@aaron34nismo]

Did anyone else notice that at the start of the video the cars were all going backwards on the road behind the tunnel ?

[@Loco4Locomotives]

What's the process for a westbound train? Or since they're on a descent, are they always staying ahead of the fumes without the fans?

[@KensTrains]

I believe it's just a short flush after the train has passed through it.

[@ragmt09]

Why is the door necessary? Why not run fans with the entrance open?

[@KensTrains]

Because without the door, the air would come out this end. It needs to be forced through the tunnel and out the other end.

[@michiganrailfan2141]

Quick question, I'm planning a trip up to the Cascade tunnel, and I see on a map that there is an access road coming off of US-2 how far can you go before it's "No Trespassing? I assume were you're sitting in the video is accessible without going onto private property?

[@KensTrains]

Unfortunately you can’t get in there very far before you come to a No Trespassing sign. But I was able to get closer because I use a drone for my filming.

[@xjAlbert]

Grading this video "A" for enthusiasm, but many questions are left untouched. How does the air flow through the tunnel system? Where are the fans located? How big are they? What do they look like? How long does it take the a train to pass through the tunnel? How many trains per day use the tunnel? Where is the tunnel operator located? A graphic might answer many questions.

[@CoffeyPot1989]

That's cool. How come the shut it and turn fans on and turn off when train exits. What's the science behind that

[@hondaman08]

With the door closed, all air gets pushed along the length of the tunnel, across the front of the locomotive and out the other end. As the train approaches the closed end, the door opens to allow for the train to pass through.

[@sleddy01]

which way do the fans blow and why is the door closed if you want to ventilate?

[@stargazer7644]

Because if you left the door open the air from the fans would just come flying out the close end instead of blowing 7 miles to the other end.

[@IainHendry]

I find this absolutely terrifying

[@rickchapman9232]

Where does the smoke come out from the tunnel?

[@KensTrains]

The other end of the tunnel.

[@robertfowler217]

How do they keep people and animals out of the tunnel

[@YourLocalRailfan]

Do I spy an H1 Dash9?

[@davidhull1481]

Presumably it works the same way for trains going the other way? Also, I do appreciate your efforts but I was expecting something more than a picture of a gate closing and the sound of fans.

[@KensTrains]

Well, unfortunately there isn’t more than that to show. That’s why there is text in the video, to narrate what is happening. For trains going the other way, they don’t need the ventilation because they are going downhill and are not generating near the fumes that a training pulling up the hill are. As far as I know they just run through it like any other tunnel with nothing extra happening, but I do think a short flush is done after they exit.

[@davidhull1481]

@@KensTrains Thanks. I wasn’t really complaining, I guess I just expected something different.

[@4sl648]

How does it function when the train is going the other direction?

[@KensTrains]

I believe it just does a short flush cycle after the Westbound train is completely through it.

[@a.bergantini4129]

I don’t understand why they close the tunnel when the fans are on… wouldn’t it make air circulation worse?

[@KensTrains]

The tunnel only closes on this end, and the air blows through the tunnel and out the other end, which is open.

[@macjim]

I would have thought those double stacked containers would have negated the blown air and push the exhaust fumes back up the tunnel… 🏴󠁧󠁢󠁳󠁣󠁴󠁿

[@RABSTRAINS]

Not new technology. This has been around forever. It may be new for Sycamore but systems like this have been installed in many local areas over the years.

[@spacecat7247]

Can we actually see this ,internally, in action?

[@KensTrains]

Unfortunately, no. The only thing that can be seen that I don’t show in the video would be louvers on the back side of the portal here where I’m assuming the air is pulled in through by the fans.

[@Trust291]

Question: How many fans are in the tunnel and how big they are?

[@KensTrains]

According to Wikipedia there are 2 fans and they are both powered by 800 horsepower electric motors. I do not know the dimensions of the fans though.

[@Trust291]

@@KensTrains I wonder are they on both sides east and the west.

[@KensTrains]

They are only on the east end.

[@Trust291]

@KensTrains Wow, they are some powerful fans.

[@garysheehan5907]

I think there may be some confusion here. I'm pretty sure the doors are closed after a train to clear the tunnel of smoke. It doesn't make sense to close them and force air onto an oncoming train.

[@KensTrains]

The door is closed with fans running both during the time the train is inside the tunnel, as well as after it clears. That’s literally the purpose of the system, to force fresh air over the head end of the oncoming train, and then to force the fumes out of the tunnel after the train is gone.

[@garysheehan5907]

@@KensTrains I understand.

[@garysheehan5907]

@KensTrains the tunnel is charged with fresh air after a train clears the tunnel. Hitting that much surface area (the train) with the pressure of the fans is an incredible waste of resources. (Fuel/electric) It has always been my understanding that the train moving forward in the tunnel was always enough fresh air for the crew. ???

[@KensTrains]

Well apparently it’s not enough in this situation. It may seem like an incredible waste of resources to blow against the train, so obviously they wouldn’t do it if they didn’t have to.

[@Greatdome99]

Yes it does. Diesels climing up a 1.6% grade with a heavy train will overheat in those tight confines--and mid-train DPUs & pushers will conk out due to lack of oxygen. That's why SP used SD40-T2 "tunnel motors" over Donner.

[@Markus_Teltschik]

hallo all together I have a quick question. I am a traindriver in Germany. If we had such a tunnel with a door on each end, that door would be connected to a signal that a train canˋt hit the door (if everything is working as intendet). Now to my question, are the doors on Cascade Tunnel guarded by a signal or something else which brings the train to stop before it can crash into a closed door?

[@KensTrains]

Yes, there is a signal system integrated into the door/ventilation system. Also there is no door on the other end, only on this end.

[@Markus_Teltschik]

@KensTrains ok what's the purpose of the door? I russia there are doors on tunnelportals to prevent people getting in the tunnels, but when there is only one door on that tunnel instead of two that would make not much sence.

[@KensTrains]

⁠@@Markus_TeltschikThe fans are at this end of the tunnel. The door closes here to make so the air has to go through the tunnel and out the other end. If there was no door here, the air would simply come out this end and the system would be ineffective.