I was reading a thread on trainorders and this popped into my head.

Suppose your running down the line and you loose your air pressure, that means no brakes, no power reverse, etc..How do you stop the train?
and then what do you do?

thanks
Alan

adofmsu@aol.com

Straight air in the train line, Alan? Wouldn't losing trainline air pressure activate an application in the automatic air brake which has been standard in this country for over 100 years?

Power reverse had a steam emergency supply to be cut in when air was unavailable.

Dave

irondave@bellsouth.net

OHHH, yeah...dam I cant believe I asked that.
Now I feel really stupid.

The heat down here is like hell, must be cooking my brain.

Thats it, I blame the heat, HAHAHa



adofmsu@aol.com

> Suppose your running down the line and you
> loose your air pressure, that means no
> brakes, no power reverse, etc..How do you
> stop the train?
> and then what do you do?

All of the times I've experienced MR pressure loss, which over the years are more numerous than I care to remember, the train brakes come on by themselves.

When the main reservoir pressure drops below that of the brake pipe, the automatic brakes will gradually apply at a rate dependent on brake pipe leakage without your applying them. You can't release them; all you can do is stop. Don't be afraid to big hole the train either (won't big hole below 50 psi in the brake pipe). There is a rather unique, non-steam locomotive set of circumstances where this doesn't happen.

It's also dependent on the rate of main reservoir pressure loss. If instantaneous, you would hear the reservoir explode. If gradual, as would be the case of a reservoir drain cock breaking off or a pipe connected to the main reservoir fracturing, you would still be able to stop the train using the automatic.

You would also hear the air compressor running constantly, unless it failed, in which case you would have the aforementioned gradual pressure loss.

If it's a light engine equipped with 6-ET and newer brakes, then you would have problems because there would be no air in the MR for the distributing valve to use for pressurizing the brake cylinders. With A-1, SWA, or any other system which uses a triple valve with an auxiliary reservoir and NO relay valve, you would have the automatic available to use (once).

If you didn't notice the pressure loss - - do you keep your ear tuned to the sounds of the locomotive? check your gauges once and a while? - - how did you get qualified as an engineer in the first place?

As for operating the power reverse, you can horse the linkage over with a bar and secure it with a chain, although you wouldn't be able to adjust valve cut-off afterwards.

If you were running an electric railway vehicle (old fashioned kind) with straight air and you lost your air you could come to stop using the hand brake. Usually these were set up to operate on all axles unlike a parking brake on a locomotive. Be kinda slow but you would be able to get back to the carbarn.


lamontdc@adelphia.net

Most hand brakes pull the brake rigging and apply the brakes as if you had used the air. You can also "jack" the traction motors to get the car stopped.

And of course in the olden days on a steam train, the brakemen could "walk the tops" and tie down the hand brakes.

Electric City Trolley Museum Association

I think what he may be getting at is cycle braking until the air normally stored in the reservoirs is depleted, thus the loss of braking ability. Certainly dynamic braking is an option to a point, but after that fails to slow the train on a heavy grade, might as well hope for the best. This is why you never try to recover the brake on a train that has gone into emergency on a steep grade, retainers have to be set on a sufficient number of cars to keep the air in the reservoirs until such time as it is safe to release.

Just throw out the anchor, that usually works.


johnathon_kruger@hotmail.com

> When the main reservoir pressure drops below
> that of the brake pipe, the automatic brakes
> will gradually apply at a rate dependent on
> brake pipe leakage without your applying
> them. You can't release them; all you can do
> is stop. Don't be afraid to big hole the
> train either (won't big hole below 50 psi in
> the brake pipe).

As a licensed engineer how has routinely handled freight trains in excess of 2 miles in length and/or weighing 15,000 tons, let me add an opinion here...

Unless it was a life or injury threatening emergency, I'd be much more inclined to let the brakes apply at a service rate and gradually stop the train. A full service application (assuming you're working from a 90-psi trainline) will take you down to 64 pounds in the trainline, and will stop nearly any train relativey quickly while still buying time to use the emergency portion if needed. Throwing the thing "in the hole" only increases your chances of derailment (due to excessive compression forces) or ripping the train into smaller parts (excessive tensile forces).

Granted, tourist or museum operations rarely use consists where physical forces of that scale come into play, but an unexpected emergency brake application can throw unsuspecting passengers around the train, and cause otherwise preventable injuries.

Training engineers to remain calm and level-headed under unusual circumstances, and bringing the train to the safest available stop (as opposed to automatically throwing the thing in emergency when something goes wrong), should be priority number 1. Facing a slew of lawsuits because the engineer panicked and sent people somersaulting down the aisles can be just as bad, or worse, as an engineer who doesn't know what to do.

The only time one should really think emergency aplication first (outside of obvious situations where someone's well being is subject to an immediate threat), is if the train lost its main res air while the cars' brakes were released and not sufficiently charged to allow a stop using a service application.

Sometimes, the safest course of action is knowing not to use an emergency application when it isn't needed.

Fiv4HghStk@aol.com

> As a licensed engineer how has routinely
> handled freight trains in excess of 2 miles
> in length and/or weighing 15,000 tons, let
> me add an opinion here...

I was speaking as a licensed engineer who used to run 9,000-13,000 ton, 2 mile long freight trains but now runs passenger trains at 79 mph for hundreds of miles a day. I didn't really qualify my statements, the original post was rather vague about the situation.

> Unless it was a life or injury threatening
> emergency, I'd be much more inclined to let
> the brakes apply at a service rate and
> gradually stop the train. A full service
> application (assuming you're working from a
> 90-psi trainline) will take you down to 64
> pounds in the trainline, and will stop
> nearly any train relativey quickly while
> still buying time to use the emergency
> portion if needed. Throwing the thing
> "in the hole" only increases your
> chances of derailment (due to excessive
> compression forces) or ripping the train
> into smaller parts (excessive tensile
> forces).

Yes, definitely so, but a full service reduction all at once on a long train is virtually guaranteed to produce similar results.

> Granted, tourist or museum operations rarely
> use consists where physical forces of that
> scale come into play, but an unexpected
> emergency brake application can throw
> unsuspecting passengers around the train,
> and cause otherwise preventable injuries.

Most main line passenger trains are unable to generate such draft and buff forces either, until you haul 20-30 boxcars on the rear. Plugging a passenger train at anything above about 20 mph, even one of 11 cars with 4-5 boxcars on the rear, rarely causes any problems, except perhaps to someone's ego. Much below 15, yes you do start to throw passengers around, particulary ones who are (or rather, just were) standing up.

> Training engineers to remain calm and
> level-headed under unusual circumstances,
> and bringing the train to the safest
> available stop (as opposed to automatically
> throwing the thing in emergency when
> something goes wrong), should be priority
> number 1.

Here's the scenario that came to mind: a relatively new engineer running a passenger train at 79 mph. He hasn't had the benefit of firing for old timers for prolonged periods of time (i.e. years); never expierenced the joys of clinging to the seatbox sucking up vinyl in a switch engine sailing down a grade with several loads of propane, not being able to stop nor slow down even though all the brakes are fully applied. Not only is this (non-)experience level the norm for the newer passenger engineers of today, it's also the norm for piglets on the class 1 railroads, with the exception of those who work grades like the Tehachepies, Donner Summit, and the like. Back to the story: here you are Mr. Newguy, flying along at 79, bearing down on a 35 mph curve (roll-over speed is 70), and you move the [automatic] handle of your shiny new 30-CDW brake valve to suppression (a 12-15 psi reduction), and *nothing happens*, no air blow, no brakes apply. You've never had the brake valve fail to blow air before, and that curve is going to be here in less than 30 seconds. What are YOU gong to do? Have we reached the point of equalization? Is the equalizing reservoir depleted? Has quick service failed? Have the MU-2A and A-1 Reduction relay valves failed to interact properly? Has the brake valve itself failed? The 30-CW module?? What about the P-2A valve or the VX vent valve, did they do their thing? Did the NS-1 reducing valve fail to reduce pressure properly? Why is it that I just looked at all my air brake gauges but can't recall what they said? Plug it and we'll analyze the situation later.

>Facing a slew of lawsuits because
> the engineer panicked and sent people
> somersaulting down the aisles can be just as
> bad, or worse, as an engineer who doesn't
> know what to do.

> The only time one should really think
> emergency aplication first (outside of
> obvious situations where someone's well
> being is subject to an immediate threat), is
> if the train lost its main res air while the
> cars' brakes were released and not
> sufficiently charged to allow a stop using a
> service application.

Any passenger train which uses the 26-C system with a Main Reservoir pipe through the train can lose its MR pressure when an MR hose parts somewhere in the train. This is actually a rather common occurrence, and the closer the parted hose is to the front of the train, the faster the MR pressure loss. And no, one F59 (or an F40 or a GE running at elevated RPM producing HEP) can't run the compressor fast enough to compensate. Two usually can, but one can't.

> Sometimes, the safest course of action is
> knowing not to use an emergency application
> when it isn't needed.

Don't forget: relatively new engineer, 79 mph bearing down on a 35 mph curve, never had the problem before . . . . .

BTW, if the train line (brake pipe) falls below 50 psi, quick action *cannot be relied upon* to propagate through the train. This is true for both freight and passenger.

> I was speaking as a licensed engineer who
> used to run 9,000-13,000 ton, 2 mile long
> freight trains but now runs passenger trains
> at 79 mph for hundreds of miles a day. I
> didn't really qualify my statements, the
> original post was rather vague about the
> situation.

I wasn't questioning your credibility, merely adding another point of view. :-)

> Yes, definitely so, but a full service
> reduction all at once on a long train is
> virtually guaranteed to produce similar
> results.

Depends on the situation and equipment, but it is a possibility, though likely less severe than in an emergency application.

> Most main line passenger trains are unable
> to generate such draft and buff forces
> either, until you haul 20-30 boxcars on the
> rear. Plugging a passenger train at anything
> above about 20 mph, even one of 11 cars with
> 4-5 boxcars on the rear, rarely causes any
> problems, except perhaps to someone's ego.
> Much below 15, yes you do start to throw
> passengers around, particulary ones who are
> (or rather, just were) standing up.

True again, but I really should have elaborated further on the intent of my message. My comments were aimed more at those who are on the operations side as a hobby or part-time, as most tourist and museum RR engineers tend to be. Some have more extensive experience, while many do not. In one RR I used to be involved with, there were more than a few "weekend wonders" who thought emergency brake applications were good compensation for approaching a station platform "too hot." I've also had to do my own version of "Swan Lake" (not a pretty sight, by the way) when one such engineer used the independent brake to stop a five car passenger train in the yard. Your point about not being afraid to use the big hole is valid. I was simply adding that it's not always the answer, and prospective engineers should be taught what situations are worthy of plugging the train, and what aren't.

> Here's the scenario that came to mind: a
> relatively new engineer running a passenger
> train at 79 mph. He hasn't had the benefit
> of firing for old timers for prolonged
> periods of time (i.e. years); never
> expierenced the joys of clinging to the
> seatbox sucking up vinyl in a switch engine
> sailing down a grade with several loads of
> propane, not being able to stop nor slow
> down even though all the brakes are fully
> applied. Not only is this (non-)experience
> level the norm for the newer passenger
> engineers of today, it's also the norm for
> piglets on the class 1 railroads, with the
> exception of those who work grades like the
> Tehachepies, Donner Summit, and the like.

Ahhhhh, the joys of getting one's self in a jam, then thanking God over and over again after you got yourself out of it... gotta love 'em... NOT. Does dropping down a 1.78% grade at 50MPH into a slow speed crossover, with a huge PIOI (Pittsburgh to Oak Island, lots of nasty petrochemical-type stuff in the train), winding out the dynamos, making a 10 pound reduction in anticipation of slowing for the interlocking, and seeing the hind end do nothing because someone has closed an angle cock 1/3 of the way back in the train, count? I could tell you the first word I said when I realized what was happening, but Erik might not like those type of words showing up here. :-)

Funny you should mention the more mountainous regions of the country. Every once and a while, when I get a new-hire conductor, I wait until we're in the middle of descending our longest grade, which is in the vicinity of 1% (there are a couple of 1.7-2.0%'ers, but they're short). When we're screaming down the hill in full dynamic, and a little air squeezed out of 'em, I casually mention how you really have to hold them back on this particular hill. When the conductor agrees, I then tell them that the grade near Altoona is twice as steep, and that some other ones around the country are 3 and 4 times as steep. The look on the conductor's face is often priceless. :-)

> Back to the story: here you are Mr. Newguy,
> flying along at 79, bearing down on a 35 mph
> curve (roll-over speed is 70), and you move
> the [automatic] handle of your shiny new
> 30-CDW brake valve to suppression (a 12-15
> psi reduction), and *nothing happens*, no
> air blow, no brakes apply. You've never had
> the brake valve fail to blow air before, and
> that curve is going to be here in less than
> 30 seconds. What are YOU gong to do? Have we
> reached the point of equalization? Is the
> equalizing reservoir depleted? Has quick
> service failed? Have the MU-2A and A-1
> Reduction relay valves failed to interact
> properly? Has the brake valve itself failed?
> The 30-CW module?? What about the P-2A valve
> or the VX vent valve, did they do their
> thing? Did the NS-1 reducing valve fail to
> reduce pressure properly? Why is it that I
> just looked at all my air brake gauges but
> can't recall what they said? Plug it and
> we'll analyze the situation later.

In this particular scenario, I absolutely agree... you're talking about a situation where there is an imminent danger. If you were just leisurely cruising along on relatively straight and level territory, with time to safely stop the train by other means, then it might be different. Depends on the situation and the physical characteristics. Again, emergency is always an option, but in some situations it's not always the best one. The key thing is being able to make that distinction.

> Don't forget: relatively new engineer, 79
> mph bearing down on a 35 mph curve, never
> had the problem before . . . . .

Even for an engineer with lots of experience, I think you'd be talking some serious pucker factor.

> BTW, if the train line (brake pipe) falls
> below 50 psi, quick action *cannot be relied
> upon* to propagate through the train. This
> is true for both freight and passenger.

CR used to teach engineer trainess that 40PSI was the magic number, but I wouldn't want to get myself into a situation where I had to debate the validity of those extra 10 pounds. :-)


Fiv4HghStk@aol.com

It's worth mentioning that my original reply to your comments, Pete, were only in regard to the scenario where you're losing pressure and the system is applying braking force, at a service rate, on its own.

To generalize, if I'm losing pressure and the brakes are coming on by themselves, then I'd be inclined to not pop the air unless I absolutely had to. If I'm trying to put the air on, and it's not responding (as in your last message), then I'm sure as hell going to brace myself, then dump 'em. I'll try and figure out what happened while I'm waiting for the RFE or Trainmaster to come out and pull my tapes. :-)

I wasn't being critical of your response, just trying to point out (for those here who don't have the benefit of practical experience) a situation where an engineer wouldn't necessarily use an emergency brake application in respose to an air brake problem.

My apologies if you took it as being critical of your skills and/or response.

Fiv4HghStk@aol.com

--snip--

> In one RR I used to be involved with,
> there were more than a few "weekend
> wonders" who thought emergency brake
> applications were good compensation for
> approaching a station platform "too
> hot." I've also had to do my own
> version of "Swan Lake" (not a
> pretty sight, by the way) when one such
> engineer used the independent brake to stop
> a five car passenger train in the yard. Your
> point about not being afraid to use the big
> hole is valid. I was simply adding that it's
> not always the answer, and prospective
> engineers should be taught what situations
> are worthy of plugging the train, and what
> aren't.

I agree it's not necessarily the answer. Although it can be done sucessfully with light touch, it's not for the novice. The more responsible of our weekend warriors were aware that you shouldn't do this. Once they gained experience and developed good habits, I showed them how. They were also arguing that a [passenger] train should not be moved a short distance dragging the train brakes. It's essential to do it this way if you want absolute control of slack and be able to stop on a dime, as in spotting for loading a wheelchair -- I showed them how to do that too.

> Ahhhhh, the joys of getting one's self in a
> jam, then thanking God over and over again
> after you got yourself out of it... gotta
> love 'em... NOT. Does dropping down a 1.78%
> grade at 50MPH into a slow speed crossover,
> with a huge PIOI (Pittsburgh to Oak Island,
> lots of nasty petrochemical-type stuff in
> the train), winding out the dynamos, making
> a 10 pound reduction in anticipation of
> slowing for the interlocking, and seeing the
> hind end do nothing because someone has
> closed an angle cock 1/3 of the way back in
> the train, count? I could tell you the first
> word I said when I realized what was
> happening, but Erik might not like those
> type of words showing up here. :-)

How about a 75 car train with two FREDS, one of which is 10 cars back, connected to the brake pipe and communicating with the front EOT? I wasn't involved with this, but know where it happenend. My own personal favorite out of control incident was flying down a 4 or 5% grade at 25 mph with loads of lube oil and spent nasty chemicals around a 10 mph curve on the side of a hill directly above some 15 connected propane cars in the gas rack tracks. Applied *all* the brakes a 7 mph too . . . wheee.

> Funny you should mention the more
> mountainous regions of the country. Every
> once and a while, when I get a new-hire
> conductor, I wait until we're in the middle
> of descending our longest grade, which is in
> the vicinity of 1% (there are a couple of
> 1.7-2.0%'ers, but they're short). When we're
> screaming down the hill in full dynamic, and
> a little air squeezed out of 'em, I casually
> mention how you really have to hold them
> back on this particular hill. When the
> conductor agrees, I then tell them that the
> grade near Altoona is twice as steep, and
> that some other ones around the country are
> 3 and 4 times as steep. The look on the
> conductor's face is often priceless. :-)

The old timers told me that the mark of a good engineer is to "go like hell until the last second and gas 'em". I've had a lot of fun scaring head end brakemen doing this. Now I agitate RFEs by having the speedometer needle come to rest at precisely the right speed when the front drawbar goes by the increase speed board for the opposite direction. I had one almost pull the air. Once he figured out what I was doing, all he wanted to talk about was the last baseball game.

> In this particular scenario, I absolutely
> agree... you're talking about a situation
> where there is an imminent danger. If you
> were just leisurely cruising along on
> relatively straight and level territory,
> with time to safely stop the train by other
> means, then it might be different. Depends
> on the situation and the physical
> characteristics. Again, emergency is always
> an option, but in some situations it's not
> always the best one. The key thing is being
> able to make that distinction.

--snip--

The point I try to make to the new guys is not to be ashamed of plugging it if something's going seriously wrong and they haven't experienced such a situation before. I then go on to tell them that if they're still plugging it after a few experiences with Mr. Toad's Wild Ride, I'm going to jump in their s**t. There are also those who never really get the feel.

> CR used to teach engineer trainess that
> 40PSI was the magic number, but I wouldn't
> want to get myself into a situation where I
> had to debate the validity of those extra 10
> pounds. :-)

As I recall, the 50 psi figure came from WABCo and SP publications. Interesting . . . medium speed on the PRR and its successors is 30 mph, while out west it's been 40 for decades. Same with restricted speed, back there 15 mph max, out here 20.