Tunnel ventilation question

[Semper Vaporo]

I vaguely remember a story of a tunnel in Switzerland where some number of passengers died due to smoke left by the previous train.  I don't remember the details, except that a law was passed that required a person to be stationed at each end of the tunnel and no train would be allowed to enter until they could look through the tunnel and see each other.

Have you ever seen the photo of the SP's "breather apparatus" for engine crews... right out of a 1930's "space" movie.

 

[samfp1943]

Here is a link that covers the history and operations a Cascade Tunnel[Stevens Pass]. Hopefully, it will answer some questions:

http://en.wikipedia.org/wiki/Cascade_Tunnel

 

[selector]

This assumption from a man who keeps learning how little he knows, 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?

I can see that a hard-pulling Class Y, or two of them, struggling to yank 8000 tons at just over 10 mph might not get that result as the cars aren't generating much of a front, but after 30 mph they ought to do much better....or...what?

[cacole]

A video I have about the Norfolk Southern says the tunnel ventilator fans were controlled by the dispatchers.  Some tunnels had doors at each end that could also be remotely opened and closed by a dispatch center.

[rrnut282]

I could be wrong, but I don't remember reading about any "tunnel tender" jobs on the railroads.  I thought most tunnels of that era used Mother Nature to clear the air.  That's why crews hated them on busy lines (more than 4 trains a day).  I believe mechanical ventilation of RR tunnels didn't become popular/desirable until after the means to acheive it cheaply were available.

[Poppa_Zit]

In the pre-electric days, how did they operate the huge fans at the top of the vertical shafts that exhausted smoke and gasses from long tunnels? I'd assume steam power for lack of anything else, yes?

So then did they have 24-hour, 7-day crews up there on duty? How did they move fuel and water up the mountain to operate the steam engines? Or did they use a system of belts and pulleys from steam engines at track level? Did the fans operate only when a train came through?

The shafts on the tunnels at Gallitzin, Pa., and Gray Summit, Mo, have been sealed since the steam era. Do any old vent shafts still exist, in operation?