Was hoping someone with more technical knowledge than I have could enlighten me on this.
CSX's line from Atlanta to South Carolina runs behind my workplace. Two nights ago, a long train of loaded auto racks was making its way into Howell Yard, going maybe 15-20mph. All of a sudden, there was a loud, almost explosive release of air that seemed to come from everywhere. The train gradually slowed to a stop, but no slack ran in. After a couple of minutes, the engineer notched up and began rolling again.
Would excess air pressure in the trainline cause this "blow-off"? If so, does it happen automatically, or is it controlled from the cab?
could have been a kicker.. if the engineer was strech breaking the train and set the air and it kicks.. it would do exactly that... an air hose close to the engin could have come undone and dumped the train..or the engineer dumped it for some reason from the head or rear end..
csx engineer
carknocker1 wrote:That blow off you heard was the train going into emergency .Most likely 2 auto racks air hoses came apart and that caused the train to go into emergency . Auto Racks do this quite a bit due to the way end air hoses are set up under the car to allow the couplers to swing back and forth .
Wouldn't it have taken a bit longer than a couple of minutes to remake the line after the dynamiter and then pump the train back up? I'm a bit confused by the time frame.
It would all depend on where the break in the train was as to how long it would take to reconnect the hose , and generally it dosen't take long to air the train back up and get moving again
Slack might have run in if the break were near the head end. But if the application were initiated anywhere behind you in the train, you wouldn't have seen any run-in.
Oh, by the way, just getting the pressure back and moving out is a rule violation (at least on our railroad). Cause of the application has to be determined and the train has to be visually inspected to see if there had been any undesired effects.
Carl
Railroader Emeritus (practiced railroading for 46 years--and in 2010 I finally got it right!)
CAACSCOCOM--I don't want to behave improperly, so I just won't behave at all. (SM)
ok - let me throw this into the mix. We are watching a loaded coal train set out BO cars.
It is sitting still and that same explosive sound happens. I have heard it on two different occasions. Train hasn't moved for several minutes and doesn't move for several more.
It isn't auto racks. So now what?
Mook
She who has no signature! cinscocom-tmw
Mookie wrote: ok - let me throw this into the mix. We are watching a loaded coal train set out BO cars. It is sitting still and that same explosive sound happens. I have heard it on two different occasions. Train hasn't moved for several minutes and doesn't move for several more. It isn't auto racks. So now what?Mook
If they are done setting out and putting the train back together, my guess is the trainman just coupled up the air hoses and opened the anglecock too fast, dynamiting the brake pipe. Sometimes those anglecocks can be either real easy or real hard to turn and if turned too fast, the control valve (also called the triple valve) on some car senses the drop in air pressure as the air starts to flow and "thinks" an emergency application is being made and goes to the emergency position.
Jeff
Ah - thanx Jeff. Sometimes they take so long and are so quiet about it, they catch me checking my eyelids for holes. Kinda scary when it happens...
To add to what Jeff wrote - I've dumped a train when putting air to it. Like he said, open the anglec**k too fast and "pow!"
We've also had cases where someone closed the wrong anglec**k when breaking a car away. Instead of dumping the air on the car being left, the whole train goes.
It really doesn't take that long to recharge the train, though.
Larry Resident Microferroequinologist (at least at my house) Everyone goes home; Safety begins with you My Opinion. Standard Disclaimers Apply. No Expiration Date Come ride the rails with me! There's one thing about humility - the moment you think you've got it, you've lost it...
tree68 wrote: It really doesn't take that long to recharge the train, though.
It is the type of cars how long the train is and the outside tempeture is what determines how long it takes to get enough air to move the train. steel cars take the longest then auto racks . if you take 15 degree morning and 8000 feet of auto racks ive been setting 30 min to air them up. a 8000 ft steel train is around 45 min to a hour and if you have air leaks it can be longer yet. on a 95 degree day the air comes up quick and after a short set and release your moving.
as far as slack run in if there is a emergency applacation i have never had one the slack stays pretty much like it is and there is no such thang as brake pipe overload we set the air pressure and it never goes over that there is no such thing as brake pipe overload. what you heard was a train going into emergency.
wabash1 wrote: tree68 wrote: It really doesn't take that long to recharge the train, though. there is no such thang as brake pipe overload we set the air pressure and it never goes over that there is no such thing as brake pipe overload.
there is no such thang as brake pipe overload we set the air pressure and it never goes over that there is no such thing as brake pipe overload.
csxengineer98 wrote: wabash1 wrote: tree68 wrote: It really doesn't take that long to recharge the train, though. there is no such thang as brake pipe overload we set the air pressure and it never goes over that there is no such thing as brake pipe overload. that isnt 100% true... there is a such thing as overcharged brake pipe.. and yes we set the feed valve to set the EQ res to a set PSI..but there have been cases where the automatic brake valve has failed for what ever reason and pumped up the trainline to the point where it blew out air hoses or actule pipeing... it is rare..but it can happen...i remember hearing a story a few years ago round the yard office story about some ice or something clogging up the brake valve..and ended up pumping the train up to a rear brake pipe PSI of around 120... he was able to get the problem fixed befor it blew up the brake pipe air hose or triple valve at some point in the train..csx engineer
The feed valve is what controlls the amount of air going into the brakeing system, this is the controll we set the brake valve only is a adjustment tool( best way i can describe it) that reduces and then recharges the brake pipe to the set value. the brake pipe and hoses can be adjusted for and run at air pressures of 110psi . and the hoses can tolerte higher as well as the brake pipe. the engine and all the air piping there handles up to 140-160psi . the main thing is that the trains dont have pressure overload braking system if it goes into emergency its because of air hose seperation a air hose worn thru or a emergency application. and less frequent brakage of brake pipe. this is why i say there is no overload system , also a air dryer spitting or exhausting is not a air overload type device , its designed to do spitting of air mix with water( its supposed to be just water) this is what most people here from the engines.
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