IF there’s good communication, and one knows as a result that this type of load will be picked up, simply venting some or all of the air first before connecting to the main trainline would avoid this, right? Then again, with leakage being quite common in small amounts everywhere, combined with this kind of thing being possible anywhere really, wouldn’t this be best as a common practice?
A little clairifacation to the original question…
If your on the road, the conductor walks the train till he finds the leak…if its a gasket in the glad hands, he changes it out with one of the spares on his key ring, if its a hose that was not laced up, he laces it up, rear anglecock left open, he closes it, air hose damaged beyond repair you close the anglecock on the car ahead and set the car out, if there is no where or way to set the car out you button up the train ahead of the problem car and proceeded at restricted speed to the nearest location where the car can be set out.
Both GCOR and NORAC have specific rules regarding this.
If you in the yard picking up a track that has been worked already and is ready to depart, you call the car department, they will ride the train on thier scooter and find/fix the problem.
If its is a outlieing yard with no car department, you walk it and find/fix the problem.
As for finding the actual leak, with 90 psi of air blowing through a 1" opening in a glad hand/hose that was not laced up, well its pretty loud, you can hear it from 10, 15 or 20 cars away, it is a very distinct sound.
As for the handheld gauges we carry them with us so when we have to pick up cars that have no ground air supply we can do a initial terminal air test.
I have my engineer charge the line as I walk to the rear, laceing the cars as I go and doing a visual check of the cars, (if your lucky they are already laced up by the industry) then we use the hand gauge to check train line pressure and to compare the rear train line pressure against the locomotive gauge, minimun pressure is 85 pis and the rear has to be withing 5pis of the head end, we then do a leak down test, allowable for us is 1pis per minute, the locomotives’s compressor can easily over come that small leakage.
Once we confirm that, we perform a set and release to make sure the rear car’s brakes function properly, then I have my engineer set the brakes and
Interesting take on the I.T.A.B.T…
True enough. But now imagine a much smaller leak, and in a nosiy environment such as a windy day, next to a road engine running pretty fast - or worst of all, next to a busy highway with lots of truck traffic and tire noise and loud exhausts, etc. - hence my mention of the gage.
Interesting procedure otherwise - thanks.
- Paul North.
Air leaks sufficient to apply the brakes are sufficiently unique that they can be heard in almost all noisy environments.
Not that there’s any other way to do it out on the road, but doesn’t that mean you’re dragging a car with it’s brakes applied?
I’m sure they are - but the Original Poster’s question was different - it was about a leak where “the compressors are working but the pressure will not rise to 90 psi (or whatever it is) and the brakes therefore won’t release”.
Further, I’m now considering the ‘included’ problem of a much smaller leak that is just enough to exceed the allowable rate - from Ed’s post above: “. . . compare the rear train line pressure against the locomotive gauge, minimun pressure is 85 pis and the rear has to be withing 5pis of the head end, we then do a leak down test, allowable for us is 1pis per minute . . .” Only 1 psi in as long as a minute could be a fairly small leak, which would be hard to hear. (I’ll skip the fallacy of a long train having more places for air to leak from, because it also has more compressed air in its lines, and hence each car would have to lose its share of also about 1 psi - otherwise, the leak would be of air from multiple cars, hence more and louder and easier to hear, as you noted.)
- Paul North.
To me, in the original poster’s scenario the problem isn’t that the brakes won’t release, but that they either can’t get enough air on the rear end, and/or get the leakage to reduce enough to do or pass the air test. Some or maybe all of the car’s brakes may have actually released.
What Ed described, to me sounds like a Transfer Train air test. It’s less restrictive than a full blown Initial Terminal air test, but it is also limited to trains going at or under a set number of miles, etc. Ed’s version actually sounds more restrictive than Uncle Pete’s version, but to be honest I haven’t done one in years. I’d have to look up the requirements. I’m more used to the road brake test requirements.
An Initial Terminal test requires air pressure at the rear to be within 15 psi of the feed valve setting. If you’re running a 90 lbs train line, that means you need at least 75 lbs at the end of the train to do the test. There are two methods to determine brake pipe leakage. One is if the engine is equipped with an air flow meter, then to begin the test in addition to the 75 lbs on the end you need the flow to be 60 cubic feet/minute or less. If not equipped with the meter during the time the brakes are set, you cut out the automatic brake valve and watch the engine’s brake pipe gauge and how much in drops in one minute. Leakage can’t exceed 5 lbs per minute. If it does, you have to have any leaks corrected and start the test over.
Air leaks on the road while moving can happen due to an air hose or brake pipe going bad. It can also happen because of a drop in temperature. It isn’t unusual during very cold weather to see the flow and pressure at the rear change as the sun sets or rises.
I had an auto rack train last winter that went into emergency four times when ever the slack came in just a bit on the rear end. The air also came back
Paul,
You would simply bleed off the air from the remaining cars with the bleed rod…no air at all in the cars and they roll free.
You don’t carry runaround hoses?
Ed - I believe you’re replying to “TrainManTy’s” question as below, not mine (I had the same answer, which is how I recognized it). - Paul North.
Sorry about that, I should read first, then type!
But the answer, even though directed in error, is still the same.
Runaround hoses are normally in charge of the Car Dept and will be used where a car has at broken trainline that cannot be repaired in the field to permit the bad order to be picked up and brought to a regular car repair facility for actual repair.
If you can’t repair the airhose with the supplied wrench and replacement hose it may be possible to hang the runaround hose to allow you to continue moving… with airbrakes.
My carrier took our runaround hoses and re-railr frogs and chains off the motors about 10 years ago…their concern was we would get something on the ground, then re-rail it and not tell anyone about it…like I am going to let a re-railed LPG or chlorine car head out to interchange with out the car department going over it completly…
[:$]Had that happen to me this past weekend on our tourist RR. I cut the engine in and as I began walking to the rear of the train to begin my terminal brake test, I heard a hissing sound comming from the back of the train (as we have a long backup move crossing several roads, we have a horn & emergency brake valve on the caboose). The brake valve was cracked open just enough to make a lot of noise, but not enough to build up the air or “dump” the air. Once I closed the valve, everything was just fine.
I can understand the frogs (well, not really) but runaround hoses? I’ve never had to personally string one out, but I have had to handle trains where one was already being used due to a broken brake pipe. They must have confidence in us…?
It would be kind of fun if the LPG car and chlorine car were loaded and coupled together…[}:)]
- Erik
Well, the “railroad mentality”/ culture has changed quite a bit from ‘back in the day’, though not so much over just the last 10 years. Recall the likely apocryphal tale about 2 trains which had a head-on collision because one of the crews goofed up on their orders. No one was injured, but a fair amount of equipment was derailed and down in the ditch. Both conductors then walked forward from their respective cabooses to the point of impact. After looking over the mess, one turned to the other and said: “Don’t be in a hurry to call this in - I think we can cover it up !” [swg] [:-^]
- Paul North.
Speaking of run around hoses, is anyone familiar with any safety rules governing the safe and proper use of a run around hose? Would appreciate any help here. Thanks.