Help from a real railroader - What is "Bottling the Air"?

Jdevleerjr posted:

While riding the train at Starsburg I overheard to people say that they "Bottle the Air" when running the locomotive around the train.  This saves them time.  One of them said it is illegal and they are very surprised that they do this.  He said if something were to happen while the locomotive wasn't attached that the train can roll into the NS mainline.

So can someone explain what bottling the air means?  Is it illegal?  If so would Strasburg actually do this?

The process of "bottling the air" is when the Engineer makes a substantial automatic brake valve reduction on the train line. Then, a crew member closes BOTH train line angle cocks at the rear of the locomotive, then cuts the locomotive off from the train. Thus, the train is left with a substantial, i.e. NOT an emergency brake set, while the locomotive proceeds to "run around the train" or do some other switching, leaving the train sitting there with the brakes applied, but NOT in emergency.

Yes, it is a "time saving" procedure, but potentially VERY dangerous, especially in freight service. That said, obviously the Strasburg Rail Road operating crew have this procedure down pat, plus the sitting train set is never really left "unattended", while the steam locomotive runs around the sitting passenger train set. Any member of the train crew remaining on board could easily put the train set into emergency. As far as "the train can roll into the NS mainline", that is not true, as the passenger train would only "roll" towards the freight cars spotted in the pick-up/set-out track adjacent to the main line track.

Not familiar with that particular term but I'd bet what they're doing is closing the brake pipe angle-cock before the train-line breaks when uncoupling. Doing that causes brake pipe pressure to be maintained instead of being released thus setting the train brakes in emergency. Once Power has run around the train and re-coupled brakes can be quickly released by raising train-line pressure. If train-line pressure had been released a full recharge (filling of each car's main reservoir) would take a lot more time. 

On Edit: Heh. Not a real railroader but HOTWATER is 

On every railroad I have ever worked for, bottling the air was against the rules. It may be a violation of a federal rule, too, but I’m not sure of that and I’m not where I could look it up.

The danger in bottling the air is that even though the train brakes were applied before the engine cuts away from the train, it is possible for those brakes to release. If only one car has an internal leak in the service valve, that can allow air to leak back into the brake pipe. With modern air brakes, just a 1.5 to 2 pound increase in the brake pipe pressure will release the brakes!

On the short trains that Strasburg runs, bottling the air would not save any appreciable time on the run around move. Strasburg is a well run outfit, and I doubt that they are doing this, especially with people on board those standing cars.

The Strasberg Railroad passenger cars are equipped with Type L triple valves.  Type L triple valves do not have the accelerated release function, so “bottling the air” has no effect on them. 

Thanks everyone!    

David Johnston posted:

The Strasberg Railroad passenger cars are equipped with Type L triple valves.  Type L triple valves do not have the accelerated release function, so “bottling the air” has no effect on them. 

I guess they only "think" they're saving time.

gunrunnerjohn posted:

David Johnston posted:

The Strasberg Railroad passenger cars are equipped with Type L triple valves.  Type L triple valves do not have the accelerated release function, so “bottling the air” has no effect on them. 

I guess they only "think" they're saving time.

Well, in fact they, the Strasburg Rail Road crews, are indeed "saving time", since they do NOT have to pump up the train air after an emergency application. Have you visited/ridden the Strasburg and witnessed how quickly they can run the locomotive around the train? They even have spring switches at both ends of their rail road, to speed-up operations.

They do switch quickly, I'll say that.  I guess you're saying David is wrong about the valves and their use?

gunrunnerjohn posted:

They do switch quickly, I'll say that.  I guess you're saying David is wrong about the valves and their use?

No, David is correct, and THAT is why they, the Strasburg crews, are able to do what they do. If their equipment had the current/modern ABDW "quick acting" equipment, then it would be a completely different story. Also, all the current "modern" freight cars they receive and ship, are equipped with the latest ABDW "quick acting" brake valves, thus they do NOT "bottle the air" on those.

Another interesting term is "peddling off the air". Maybe the experienced rails here could explain that potentially dangerous procedure here as well?

Ah ha, thanks for the explanation.   The details of how they performed the direction switches eluded me.  I know they don't take much time to shuttle the locomotive, but I didn't know exactly why that was unusual.

Tinplate Art posted:

Another interesting term is "peddling off the air". Maybe the experienced rails here could explain that potentially dangerous procedure here as well?

Never heard of THAT term. Maybe you mean "****ing away the air"?

Well, their protective software will not allow me to use the proper railroad term. It relates to "urinating" away the air.

Tinplate Art posted:

Another interesting term is "peddling off the air". Maybe the experienced rails here could explain that potentially dangerous procedure here as well?

On every car the air used to pressurize the brake cylinder, which applies the brakes, comes from the auxiliary reservoir. On a freight train there is only one pipe that runs the length of the train.  The pressure in that pipe is reduced to set the brakes and increased to release the brakes. The auxiliary reservoir is recharged when the brake pipe is at the release pressure. The recharging of the auxiliary reservoir is done through a very small choke so the air used for recharging does not effect the operation of the brakes. On a long train there could be 100 or more auxiliary reservoirs recharging at the same time, so each reservoir gets only a tiny amount of air. 

When going down a long grade the engineer cannot repeated apply and release the brakes as that would slowly reduce the auxiliary reservoir pressure on every car as they are not having enough time to recharge to the full pressure. This reduces the amount of braking available and can result in the train running away due to a lack of braking.  This may be referred to as the term you referred to.  

The engineer has really three choices if dynamic brakes are not available.  One is to make long significant brake applications on steep parts of a hill and long recharging times on less steep areas.  Second choice is to stop the train and hold it with engine brakes and hand brakes while recharging the auxiliary reservoirs.  The third option is to set retainers, which restrict or plug the exhaust from the brake cylinders keeping the brakes applied, while the brake pipe is in release and the auxiliary reservoirs are being recharged. The retaining valves have to be manually set on each car at the top of the hill and manually released at the bottom of the hill.  All three of these options could make for a very slow trip.   

I watched them one day and it looked to me that a crew member on the Strasburg end opened up the anglecock on that end after the engine cut away from the other end. 
I don't care what you say, bottling the air is not good practice!

The NS had a bad run away in Virginia a few years back when a crew did this.

 Apparently one crew would cut away leaving the air bottled on the mainline ,then the next crew would come up to the other end and couple turning the air back in when they coupled.

 Problem was the train rolled away going down hill before being coupled up to it and and derailed near an elementary school.

David Johnston posted:

The Strasberg Railroad passenger cars are equipped with Type L triple valves.  Type L triple valves do not have the accelerated release function, so “bottling the air” has no effect on them. 

And what makes you think that?

Big Jim posted:

David Johnston posted:

The Strasberg Railroad passenger cars are equipped with Type L triple valves.  Type L triple valves do not have the accelerated release function, so “bottling the air” has no effect on them. 

And what makes you think that?

If you read and understood what Hotwater explained above, you would understand the old Type L valves don't work the way the modern freight car valves do.  Not only have been doing this for decades, and not only is crew in attendance, no doubt the local FRA person - likely many of them over the years - have observed the operation and not had an issue.  Also it is my understanding, this isn't illegal... in other words, forbidden by the FRA and like, but is generally a rule with modern freight roads.  

Hotwater didn't explain anything. If you understand car braking equipment at all you know that that an increase in brake pipe pressure will cause brakes to release. The fact that these brakes don't operate like the newer brakes doesn't mean that they will stay set if the air is bottled. If a leak occurs and the brakepipe pressure increases enough, then the brakes are coming off. Also, if you understood the braking system on newer brake systems you would know that bottling the air will not always cause a brake release. 
With the short length of these trains combined with the short time involved in running around the train and if the brake equipment in good working order, if the proper procedure is followed, the brakes should not release on their own if the air was bottled. That does not make it a safe practice!
All of this aside, with the short length of the trains, very little time would be saved by bottling the air.

Big Jim posted:

If a leak occurs and the brakepipe pressure increases enough, then the brakes are coming off.

Wait...how will the brake pipe pressure increase if a leak occurs?

Also, I thought a reduction in trainline pressure causes the brakes to apply?

smd4 posted:

Big Jim posted:

If a leak occurs and the brakepipe pressure increases enough, then the brakes are coming off.

Wait...how will the brake pipe pressure increase if a leak occurs?

If a leak occurs from the emergency reservoir through the a car's brake valve, allowing increased pressure INTO the train line brake pipe, the the brakes could/will release since the train line air pressure increased. 

Also, I thought a reduction in trainline pressure causes the brakes to apply?

Correct. But now what with all these modern ABDW "fast acting" brake valve, just a 1 1/2 pound increase in train line air pressure, the ABDW valves release. They are VERY sensitive.

It is possible under the right circumstances, for an internal leak within the car's brake system valves to allow air to internally leak back into the train line. If the train line (brake pipe) pressure increases by only a couple of pounds, the brakes will release. It has happened many times.

I personally watched it happen to us once on the Ohio Central when we bottled the air on a cut of cars to "save time." In less that two minutes the brakes released. We were on a slight grade and the cars started slowly rolling away. Fortunately we were in position with the engine to catch them quickly before any damage was done. But there was no time saved, that's for sure!

If the Strasburg does this on a regular basis and has done it for years without incident, that's fine. The siding at Leaman Place may be level, so even if the brakes did release, the cars won't go anywhere. As I said in my original post about this, I don't know if this is a Federal rule or a local rule. If it's not prohibited on the Federal level, then they aren't breaking any rules. However, I'm with Big Jim when he stated above, "That does not make it a safe practice!"

Hot Water posted:

smd4 posted:

Big Jim posted:

If a leak occurs and the brakepipe pressure increases enough, then the brakes are coming off.

Wait...how will the brake pipe pressure increase if a leak occurs?

If a leak occurs from the emergency reservoir through the a car's brake valve, allowing increased pressure INTO the train line brake pipe, the the brakes could/will release since the train line air pressure increased. 

 

 

FYI, the SRC cars with P valves don't have emergency reservoirs to feed a self release.  A difference between modern and old.   Thus, Strasburg ends up sitting in the position of maintaining the HUMAN knowledge of operating equipment unfamiliar to many current professional railroaders, a real plus for rail preservation and some of the easiest information to lose that once lost might be very difficult to recover.   I find it interesting they also end up having to educate their FRA inspectors in the operation of their legacy equipment.  Some also might ask why, on occasion, SRC doesn't run excursions on Amtrak, as they did years in the past.  One can imagine not only having to educate the locate Amtrak inspector, but everyone else up the chain of command on everything from plain bearings to brake systems.  Let alone steam locomotives.

Cheers,

Bob

This thread has been very informative.  I find it hard that SRC would do anything dangerous.  It seems to be such a well ran business.  I plan to visit many more times in the future and next time I am there I will ask someone on the staff if they "Bottle the Air"

A key thing here is that the train is not left to it's own designs while the engine runs around it. The train is manned so in the case of leak-back in a brake valve re-pressurizing the train line any crew member on-board could/would simply pull an emergency valve. No safety issue involved. 

What I find silly is that they would think that they are saving time to begin with by bottling the air. The train is too short to "save" any appreciable amount of time. And, if there is a lack of reservoirs, then all the less time saved pumping air!
This is not a "race". No one is pressed for time. Do they also not apply hand brakes before cutting away from the train in order to "save time"?

Big Jim posted:

This is not a "race". No one is pressed for time. Do they also not apply hand brakes before cutting away from the train in order to "save time"?

Exactly.

I don't know what their operation looks like, but it sounds like ours on the New Hope Valley, where we have a long passing siding. We park the train up near one of the switches (all hand brakes are applied, no bottling) uncouple the locomotive, go past the switch, manually throw it then move the engine onto the siding, and lining the switch back for the main line.

Then we roll down the siding past the train, where the folks can get a good look at the engine. At the far end, we throw the switch, enter back onto the main line, line the switch for the main line and move back to couple up with the train at the opposite end. After recoupling, we pump up the line.

It was always my impression that this gave the folks on the train a good show of real railroading: Using and releasing the hand brakes; throwing and closing switches manually; pumping up the line.

Honestly, you’re all making too big a deal out of this.  Yes, they bottle the air on the runaround moves.  At no time is the train unattended; there are several trainmen aboard at all times.  They do air tests when they couple up on every run.  Moreover, they’ve probably been doing it this way for 60 years and haven’t had a runaway yet.  We’re not talking about a cut of freight cars left unattended on a grade...