I love good practical jokes.
A little humor!!!
Several years ago I was in Colo. Springs on busines and as I did when I had time late in the day I called an old friend who was a partner in a major garage door business. This firm installed more that garage doors; ranch and farm gates were a specialty.
As my friend and myself sometimes exchanged practical jokes I decided on the spur of the moment to try another. Disguising my voice I called and got the receptionist, (who knew me). I gave a fictious name as an engineering official with the D & RGW and advised that I was waiting on another call but would like to know if their firm had the ability to install doors on the Moffet Tunnel that could be operated by train crews with an electronic opener that each lead engine would have. I knew this was my friends specialty but proceeded by telling the receptionist, who did not recognize my voice, I was in C. Springs and would come to their plant and offices later in the day if they were interested. Of course they were interested and the lady told me to come by as they would stay open to see me.
I entered the office about five minutes before their usual closing time and announced my D & RGW name to the receptionist who broke into laughter and after controlling her emotions called my friend to announce that the man from the Rio Grande was here. My friend and his partner came into the reception room and proceeded to provide me with a few names that shall not be presented here. Then they broke out the cocktail glasses and advised that I had one coming for this prank; and of course they got back at me later.
....Thanks Dale....That's pretty wild. The engines shutting down.
Quentin
That is right Quentin. This also caused pressure to build up in front of the train, and the engineer's ears would pop in some tunnels when the door went up.
Jack Wheelilhan wrote an interesting article in the 2-00 CTC Board magazine. He was helping with the delivery of GN's first GP30s in 1963. When the Cascade Tunnel doors went up, all four GP30s shut down because of the Paxton-Mitchell Crankcase Pressure Detection Device.
....Haven't had too much comment of what the tunnel entrance doors purpose are....
As I wrote earlier in this thread, I thought tunnel doors purpose {at least in some cases}, is to keep the tunnel air "in place" while a train works it's way thru so the radiators of the engines can have "new" air as it moves forward and not the heated air surrounding the engine if it would be allowed to be "pushed ahead" as the train moves forward.
Any thoughts....
Steam Is King wrote: 1. No need. First, the pitson effect works in short tunnels of singletrack with tight tolerances betwen tunnel walls and train cars on high speed trains2. If this is the extent of your knowledge you better stay away from matches. .Chico
1. No need. First, the pitson effect works in short tunnels of singletrack with tight tolerances betwen tunnel walls and train cars on high speed trains
2. If this is the extent of your knowledge you better stay away from matches.
.
Chico
1). So then you actually agree that Piston effect is one method employed for tunnel ventilation? we agree then
2). Hey , it was you trying to insist that Chimneys function only because the air moving horizontally across the stack, I was just lampooning the fact that chimneys are more versatile than you were admitting to.
Hot air rises, but then you obviously are aware of that.
Poppa_Zit wrote: Modelcar wrote: ....P Z: Doesn't the "Tunnel Motors" have to do with modifications to the unit's cooling systems.....?Could be. But the only major difference I was aware of -- again, I'm not a locomotive expert -- was that the air intakes were located lower on tunnel motors, down near the walkway to have a chance of sucking in air instead of exhaust.
Modelcar wrote: ....P Z: Doesn't the "Tunnel Motors" have to do with modifications to the unit's cooling systems.....?
....P Z: Doesn't the "Tunnel Motors" have to do with modifications to the unit's cooling systems.....?
Could be. But the only major difference I was aware of -- again, I'm not a locomotive expert -- was that the air intakes were located lower on tunnel motors, down near the walkway to have a chance of sucking in air instead of exhaust.
Those are radiator air intakes, the engine air intake is the grille near the top of the long hood right behind the cab, and it is in the same location on the tunnel motor as it is on a regular version.
.....Laurel Hill, Ray's Hill and Sideling Hill tunnels were bypassed some years ago.
Originally there were 7 tunnels on the original 160 miles of Turnpike that opened in Oct. 1940.
The remaining 4 still in use, have had a parallel tunnel bored next to them to provide 4-complete lanes...2 each way. {So these are on original sites}.
Yes, some of the turnpike has been rerouted....Example: Near Breezewood and east....About 13 miles....Believe this change eliminated the Rays Hill and Sideling Hill tunnels. Another area is east of Allegheny tunnel....{not effecting the tunnel}, and on down towards New Baltimore.
Laurel Hill {west of Somerset}, was bypassed by a mammoth cut but still maintained the max grade @ 3%....Same with all the by passed tunnels. No grade steeper now {since relocations}, then on original area of Turnpike than 3%.
Recent changes also includes massive work adding another lane on up grades for slow moving vehicles, etc......
Edit: P Z....In rereading your question about some tunnels not on original locations....Got to thinking, maybe you mean...compared to original RR tunnels. If that's true, the Allegheny tunnel used for the turnpike was moved about 85' south of original RR bore as that bore had some unstable rock inside and the engineers decided to move as stated above to a better rock strata, etc.....
Another item: Laurel Hill tunnel {east}, entrance {for the RR was to be about 1000' farther east than where the Turnpike locaters started with their east entrance, but did go in on original bore.
....Can add just a bit to P Z's mention of cutting ROW up and over when building tunnels.
Building the original 160 miles of Pennsylvania Turnpike required to create {and or finish}, a total of 7 tunnels.
I remember they did cut a ROW {clear cut}, up and over to open a path along the exact route of the tunnel below.
But in building the tunnels for that project I am reasonably sure there are no vertical shafts for ventilation. Of course these would be highway tunnels....{not originally intended to be though}. Back in the late 1880's they were intended to be RR tunnels.
Each tunnel has a vast ventilating {powered large fans}, system in place to remove unwanted exhaust as necessary. Believe there was one that required just a powered vent system at one end as it was the shortest of the seven tunnels. There is space above the ceiling of the tunnels to carry the venting flows, etc....with vents at appropriate locations along it's length.
Modelcar wrote: ....Bucyrus: Yes, hadn't thought of the fact you mention of less oxygen available for the engines in the long tunnel.....and with the fuel delivery set....Guess the result would be excessive smoke.And yes, I agree, the last engine was one with very bad smoking condition....Again, I wonder how it continues to run. The prime mover certainly needs oxygen to make combustion.
....Bucyrus: Yes, hadn't thought of the fact you mention of less oxygen available for the engines in the long tunnel.....and with the fuel delivery set....Guess the result would be excessive smoke.
And yes, I agree, the last engine was one with very bad smoking condition....Again, I wonder how it continues to run. The prime mover certainly needs oxygen to make combustion.
Isn't that why they built "tunnel motors"? I'm not an expert, but to me it appears none of the four units in the video is a tunnel motor.
Murphy Siding wrote: Didn't most tunnels have ventilation shafts, that were put in during, or prior to construction?
As far as I can tell in my research, most tunnels over a quarter-mile long were built with vertical ventilation shafts. When building a long tunnel the first thing that was done by the surveyors and engineers was to remove all of the trees and foliage up the side of the mountain/hill on a line exactly over the intended line of the tunnel and down the other side. This gave those guys a clear look "over the top" with their instruments (trig?) so they could start digging from both ends simultaneously and have everything line up. Sometimes they ran a telegraph wire over the top so they could communicate with the crew on the other side. At the same time they were able to use trig to drop vent shafts from the top that would meet up with the tunnel when the diggers got to that pre-determined distance. So most tunnels had three or more crews working simultaneously. In the "old days" they also worked around the clock.
Modelcar wrote: ....Interesting video.....Alarming, if there would be crew in the following engines...{I'm assuming there was not}.Under this specific situation, I'm even wondering how the following engines have enough oxygen to continue to run....?? And these weren't even steam engines...! {Smoke...}. One would think smoke would be minimal. But realizing if it is upgrade, they probably are in notch 8 and by the appearance, some seem to be "over rich in fuel", or whatever causes all that black smoke.
....Interesting video.....Alarming, if there would be crew in the following engines...{I'm assuming there was not}.
Under this specific situation, I'm even wondering how the following engines have enough oxygen to continue to run....?? And these weren't even steam engines...! {Smoke...}. One would think smoke would be minimal. But realizing if it is upgrade, they probably are in notch 8 and by the appearance, some seem to be "over rich in fuel", or whatever causes all that black smoke.
It is a lack of oxygen in the tunnel that causes the smoke. The oxygen is reduced while the fuel delivery remains the same, so the condtion is "over rich in fuel" as you say. The last engine seems to be smoking more than the others, but I think they are all clearing up as they get further away from the tunnel.
Is this a more or less routine occurrance with such trains coming through this tunnel? If it is, it sure would seem to be an attractive photo shoot location, and I would expect to see more videos of the performance.
Thanks to Chris / CopCarSS for my avatar.
Convicted One wrote: selector wrote: but I would have thought the very trains, themselves, would do a passable job of running cleansing air through the tunnels when the locomotive had passed in the lead. Each car front acts like a mini-impeller blade as it enters the lead portal and encourages a bowshock of air to move ahead of it as it makes its passage along the tube. Or, so it would seem natural to hope. So, why doesn't it? "piston effect" is what they call it, and you are absolutely correct.They also had tricks such as making one portal of the tunnel higher than the other, to make the entire structure 'breath" like a giant chimney.
selector wrote: but I would have thought the very trains, themselves, would do a passable job of running cleansing air through the tunnels when the locomotive had passed in the lead. Each car front acts like a mini-impeller blade as it enters the lead portal and encourages a bowshock of air to move ahead of it as it makes its passage along the tube. Or, so it would seem natural to hope. So, why doesn't it?
but I would have thought the very trains, themselves, would do a passable job of running cleansing air through the tunnels when the locomotive had passed in the lead. Each car front acts like a mini-impeller blade as it enters the lead portal and encourages a bowshock of air to move ahead of it as it makes its passage along the tube. Or, so it would seem natural to hope. So, why doesn't it?
"piston effect" is what they call it, and you are absolutely correct.
They also had tricks such as making one portal of the tunnel higher than the other, to make the entire structure 'breath" like a giant chimney.
Here is a little pistion effect being demonstrated by a coal train coming out of Mullan Tunnel as beaulieu mentioned. I posted this once before in another thread on smoke, but it fits here and is fun to watch (unless you are Al Gore).
http://www.youtube.com/watch?v=H-ztLI8op04&mode=related&search=
Turn up the sound.
Beaulieu is right. The accident in the Rickentunnel on the Bodensee-Toggenburg-Railway did not concern a passenger-train. I found the following text in wikipedia. It was a freight train, hauled by a Swiss-Federal-Railways mogul. The accident happend on 4-10-1926. The tunnel (5+ miles) lacked ventilation and had a bad reputation among crews. It was in a 1,5 % grade. The engine was fired with a kind of coal that generated high quantities of CO and less steam than the coal previously used. The train stalled in the tunnel, and the crew died, while trying to start the train. A first rescue-attempt ended dramatically with three rescuers dying, too. Only a second rescue-attempt was successful. In 1927, Swiss Federal Railways electrified the tunnel and banned steam-engines from it.
By the way, the Arlberg-tunnel on the namesake mountain-railroad in Austria was known for the center-section being often very sticky. It was one of the first mainline-electrifications in Austria.
The reason that all long tunnels are sloped is for drainage, not air movement. Sand Patch Tunnel on CSX has a ventilating shaft in the middle, in steam days there was a chimney on top to enhance the movement of air up and out of the tunnel. Piston effect works well for faster moving passenger trains, but poorly for slow moving freights. I have ridden the Empire Builder through both Flathead and Cascade Tunnels, the air quality is much better in Flathead than in Cascade, although train speed is higher in Flathead Tunnel. A picture of a westbound freight coming out of Mullen Tunnel on the MRL is something to behold, the tunnel doesn't have mechanical ventilation and train speeds are low with 4 or 5 locomotives on the head end, the smoke boiling out of the tunnel just ahead of the train and then swirling around the locomotives and cars. Respirators are required to be on board, in case the train stalled or had to stop, strong winds out of the west also cause extra problems. On tunnels with doors, the door is always located on the uphill end, and air is forced in from the end with the door. Mt. MacDonald Tunnel, on the CP, has two doors and two sets of fans.
I have a history book on Swiss railways and there is no mention of a diaster of a passenger train in a tunnel. The book is published by the SBB Historical Foundation.
I've run them, and theres not much draft pulled on moving smokestacks on steam locomotives, not at all. The pressure on a steamer smokestack is from the inside of the smokebox out - the exhausted low-pressure steam is directed forcefully upwards through the smokebox and out the stack which really causes a suction causing a negative pull back in the firebox. It sucks in more air through the flue pipes from the firebox pulling air into the firebox and making the fire hotter and the fireman shovel harder. The faster the loco goes the more exhausted steam and the stronger the draft and the better the fire burns.Locos stored outdoors woth banked fires overnight on very windy nights often had the hostkler put a stack cover on so the coals would slowly smoulder all night instead of burning away.
#1 DO a google for "piston effect tunnel ventilation" and you'll see for yourself
1. No need. First, the pitson effect works in short tunnels of singletrack with tight tolerances betwen tunnel walls and train cars on high speed trains.But theoriginal question was about pre-electric days when the steam trains moved at slower speeds through long tunnels which didn't move as much air.There was no piston effect if the train had to make an emergency stop in a tunnel.And if the tunnel was double track like at Altoona there was no pitson effect at all. You should read the finest book of the era Practical Railroad Engineering by Clifford F. Bonnet (start on page 173).
#2 Really? so then if there is no outside wind, one better not light a fire in the fireplace?
If this is the extent of your knowledge you better stay away from matches.
The effect you cite may apply to moving smokestacks, but when contemplating CHIMNEYS (which is what I said, not "smokestack") heat naturally rises, forming a draft as warmer air passes
2. A proper vertical chimney without a fire will pull a slight draft (lookup ambient chimney draft), and moreso if there is a wind blowing across its top. You answer your own question - a chimneuy with wind moving air across the top is no different than a smokestack on a moving traion pulling some degree of draft. Same as putting a lighted cigarette into a bottle and blowing across the opening will create the same type of lift present in proper aiprplane wing designs. Wind moving at speed hotizontally across the top of a wing or across the opening of a chimney will cause a low pressure condition which results in lift. While heat from a fire will also move air up a flue, wind will also pull it. That's one of the reasons fireplaces have dampers.
Steam Is King wrote: [#1]No way.The idea forthe vertical ventilation was to keep train crews and passengers from being asphyxiated while the train was in the tunnel, not to clear the tunnel behibnd the train, which is what your piston effect would do in a very short tunnel not in one over an eighth mile long. In long tunnels it would cause a mild compression and turbulencethat wouldactually drive the smoke and gasses into the cars. [#2] Chimneys breathe because the air moving horizontally across the stack creates negative (low) pressure which pulls air up the flue. Chico
[#1]No way.The idea forthe vertical ventilation was to keep train crews and passengers from being asphyxiated while the train was in the tunnel, not to clear the tunnel behibnd the train, which is what your piston effect would do in a very short tunnel not in one over an eighth mile long. In long tunnels it would cause a mild compression and turbulencethat wouldactually drive the smoke and gasses into the cars.
[#2] Chimneys breathe because the air moving horizontally across the stack creates negative (low) pressure which pulls air up the flue.
#2 Really? so then if there is no outside wind, one better not light a fire in the fireplace? The effect you cite may apply to moving smokestacks, but when contemplating CHIMNEYS (which is what I said, not "smokestack") heat naturally rises, forming a draft as warmer air passes
Dan
No way.The idea forthe vertical ventilation was to keep train crews and passengers from being asphyxiated while the train was in the tunnel, not to clear the tunnel behibnd the train, which is what your piston effect would do in a very short tunnel not in one over an eighth mile long. In long tunnels it would cause a mild compression at the locomotive and a mild lowpressure turbulence just behind it that wouldactually drive the smoke and gasses into the cars. Chimneys breathe because the air moving horizontally across the stack creates negative (low) pressure which pulls air up the flue. Same principle of lift on an airplane wing.So your one portal higher than the other idea would not work -- can you find examples?; I doubt it.And don't try to say the tunnel was built on a grade to get one portal higher than the other, the last thing they needed was to work a steam engine harder in an enclosed space.
...But aren't those entrance "doors" on some tunnels there to keep the air from moving as a train makes it's way thru the tunnel....so the engine has "new" air to cool the coolant in the engine cooling system.
In other words if the train was "pushing" the tunnel air ahead of it all the way thru....the radiator would be trying to remove heat from the cooling system with already warmed air since it is stagnant, and riding along with the train.....
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