"Bottling the Air"

[NW Mailing List]

Ken,
 
Good answer. You are exactly right about handling cars in the yard. 
 
In Roanoke, much the same as Bluefield, westbound trains used to be switched in the old "Pull-up" yard between 5th (Park)St. and 16th. Street. Cars, with the air bleed off, were cut off from the yard engine and would roll by gravity downhill. A brakeman (or car rider) would ride the car, controlling the speed so that it would not run into cars already in the track (or roll out the other end of the track). 
 
Cars stopped on the east end would have enough handbrakes applied to hold the anticipated number of cars being switched to that track. Once that number of brakes were set, the car riders would simply control the speed and "softly" couple to the cars in the train.
 
At the west end of the yard, where the grades are more level. we did what is called "flat switching". With the air bleed off the cars, the engine would pull the cars out of a track. When the appropriate track was lined up, the conductor would instruct (by hand signal or radio) the engineer to "kick" the cars. The engineer would get the cars rolling, then, at the appropriate speed and location, the conductor (or brakeman) would uncouple the car(s) and stop the engineer. The cars would then roll free into the intended track (hopefully, and usually), coupling to the cars already in the track. This would be repeated until the entire cut if cars was switched.
 
Regarding a comment by Richard Shell, that bottling the air could have unpredictable results; actually, the results are quite predictable. If there is any grade at all, the cars will eventually start rolling downgrade. This might take ten minutes, or six hours, but it generally will happen. Obviously, the results of that can be very unpredictable. They might (very fortunately) not hit anything, nor derail. On the other hand, they might run into the side of another train, or engine, or foul a main line, or derail, causing damage or injury.
 
That is why it is so very important for a crew to be familiar with the area in which they are working., Every part of the yard has its own idiosyncrasies.
 
Jeff

--- On Mon, 10/25/10, NW Mailing List <nw-mailing-list at nwhs.org> wrote:


From: NW Mailing List <nw-mailing-list at nwhs.org>
Subject: Re: "Bottling the Air"
To: "NW Mailing List" <nw-mailing-list at nwhs.org>
Date: Monday, October 25, 2010, 11:12 AM


Gene 


Technically I would seriously doubt that.


What was done on what you saw, and someone who actually was a brakeman/conductor like Jeff could confirm. In Bluefield yard, and other places, the cars were set out on tracks, and a certain number of cars had hand brakes tied down. That would depend on the size of the cut as to how many brakes were tied down. Once hand brakes were tied down, the switch engine would cut off, the air on the cut was dumped, causing an emergency application, but hand brakes had already been applied. Over time, the air system would leak off, depending on how long they had sat.


Once the yard shifter came in and coupled on to the cut, and applied its independent brake (for the locomotive) to hold it all in place. The brake systems on the cars had probably sat long enough that most if not all the air had bleed off the system, but the brakemen would walk along the cut to the triple valve on each car, and bleed off the remaining air, to release all air brakes. The brakemen did not couple the air line, therefore the hand brakes were all that would hold the cut. The hand brakes would still be on, once the air had been bleed, the brakemen would go along and release the hand brakes, the switch engine would pull back out, with the cut, into the clear, then shove the cut towards where they were to be put, if they were sorting cars, one man would pull the cut lever between the cars, and a brakeman would ride the cut, if needed for controlling the speed with the hand brake, while the cars rolled down into its track and couple with the
 other cars in that track, the brakeman would tie down the hand brakes, and the go back and do it again with another cut, etc.


Generally handing rolling cars, not coupled to a locomotive, was rarely done with air in the system. As Harry reported, air pumping can take some time to fill the entire train line. You used to see with the diesels, running at high RPMs while standing, the engineer, is running the diesel up to run the compressor faster, and pump air through the train quicker. A number of factors can determine how long it takes to pump a train, including, of course, train length, cold weather, how many leaks are in the system and how much initial terminal time that crew wants to report on their time sheet! I've heard of occasions where it would take several hours of pumping time to release all the brakes in a coal train.


In my younger days, when I was riding my bicycle down to the track, I'd sit and watch, and see eastbound coal trains get stopped by the signal at VN before going into South Yard, once the signal cleared, it might take them 30-45 minutes to pump air before they moved, and that was in good weather. They were great days, and I wish I had the interest and time to do that today, but alas, I have neither today.


Ken Miller



On Oct 25, 2010, at 9:12 AM, NW Mailing List wrote:


Ken;
 

Bluefield had a natural grade in both the East and West yard with the high point being in the area of the Round House. I remember as a young fellow in the East End of Bluefield, watching the "yard shifters" sorting the cars. There would be a number of cars released to freely roll to an appointed switch to make up trains. The Yard brakeman with his brake stick would control the speed until making couple with the other cars. I remember watching the men try to time the coupling just right and jump up in the air so as to miss the coming jolt of the sudden stop. I assume that free roll had to be done by "bottling the air", which was a common practice even in the late 50's. Also I remember watching "road shifters" push cars up to a speed and then stopping the locomotive allowing the cars to run freely though a switch, either coming to a stop on their own, or making couple with other cars.
 
Gene Arnold 
 
 
"Bottling the air" which I think, is now prohibited by most rule  
books, means to close the angle cock (air line) on both ends of the  
car or cut of cars before separating them from the train. That way,  
air stays in the system, and does not dump the air to emergency on  
that car or cut of cars. It is, among other things, made to speed up  
operations, as with air already in the train line of those cars, it  
means that the locomotive air compressor, does not have to run as long  
to pump air back into the system, which can be a considerable amount  
of time, meaning the crew can get underway sooner.

If the air is dumped from the car or cars, it sets those brake systems  
into emergency, and to release those brakes, the air system has to be  
pumped up again from the locomotive. By bottling the air, it means  
that only hand brakes, or chocks may be holding the cut of cars in  
place, which can lead to a drift off, or runaway, or difficulty  
coupling if the brakes are not holding well.

Ken Miller


________________________________________
NW-Mailing-List at nwhs.org
To change your subscription go to
http://list.nwhs.org/mailman/options/nw-mailing-list
Browse the NW-Mailing-List archives at
http://list.nwhs.org/pipermail/nw-mailing-list/

-----Inline Attachment Follows-----


________________________________________
NW-Mailing-List at nwhs.org
To change your subscription go to
http://list.nwhs.org/mailman/options/nw-mailing-list
Browse the NW-Mailing-List archives at
http://list.nwhs.org/pipermail/nw-mailing-list/
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://six.pairlist.net/pipermail/nw-mailing-list/attachments/20101025/3aab1c26/attachment.html>