Neophyte Brake Questions

[Anonymous]

For many months now, I have been operating trains on Microsoft Train Simulator not knowing what all of the indications on the brakes meant. But, as long as I knew that the ";:" key was for releasing brakes and the one next to it was for applying, I got along farely well. But then, I got the new Mountain issue of TRAINS today, and it had illustrations of brakes, as well as terms, and I just can't take not knowing any more! And so, here are my questions:

1.) How does one turn up retarders (or are they retainers--I can't remember), and what change in the break system does this effect?

2.) What are retarders (retainers) to begin with?

3.) What do the terms "all applied" "self lap," "lap," "continuous service," "suppression" and "hold," mean, and how is the "emergency" positon of the brake lever any different from a very large application of the brakes?

4.) On the brake gauges, which colors denote which measurement (i.e. red indicates main reservoir pressure, etc.).

Other than that, I have a rudementary understanding of how the air brake works, but any help you could give me would be more than appreciated.

Sincerley,
Daniel

[Anonymous]

Dan, look at the old thread I pulled out; that ought to explain the 24RL and 26L pretty well. As for retainers, they do just that...they retain air in the brake cylinders when the brakes are released. This was a critical job when brake systems had no pressure maintaining feature [p.m. compensates for the train line leakage. without it, whatever your leakage is, say, 3lbs per minute, is how fast your brakes leak on. take a 6 lb reduction...one minute later, it's 9 lbs; after two, it's 12 lbs. at this point, if you released the brake, off you'd go on the hill and the brake wouldn't be recharged. that's where the retainers come in...] . This allowed you to recharge the brakes while holding them back on some grade. The feature isn't much used today except in very steep grades, and they were set or released by a flesh-and-blood brakesman walking the train to do just that.

[wabash1]

and to further the exsplanation of emergency against big applacation is in a full service applacation your only going to get a 35lbs reduction to the cars no matter how much you take off the equalizer . so if needed to stop quick you have emergency and this dumps another 20lbs to the wheel ( lbs might be wrong but its more pressure to the wheel to stop) and this is exausted at the car. remeber each car has a resivior and emergency resivour . sorry this is so short of answer the steaks are done and so am I.

[Anonymous]

Dear skeets and wabash1,
Thank you for your help. I have a new question now: how do retainers keep air in the brake cylinders?

Most appreciatively yours,
Daniel

[wabash1]

retainers do just that retain. they wont let the air exhaust to the atmosphere. this holds the cylinder out. there are 3 positions on them i cant remeber all of them but i will try the first one is direct meaning it exhauste directly to the atmosphere when you release the brakes the second one is hold meaning it will hold 20lbs after you release the brakes the third is slow direct which slowly releases the air over a period of time. ( someone correct me if i am wrong.)

[Jackflash]

With a 90 pound brake pipe, a service application of brakes will put
a maximum of 64 pounds of air into the brake cylinders of the cars,
with a emergency application 77 pounds of air goes to the cylinders,
with a service application the signal travels the length of the train a
little over 500 feet per second, with a emergency application the
apply signal travels the length of the train at over 900 feet per second,,,
jackflash

[Rodney Beck]

Retainers do have 3 positions they are exuaust, high pressure & low pressuere. The retainers are more often set when operating in heavy grade on a set number of cars for the tonnage of the train as per time table instructions or are used when tieing the train down on the main track along with hand breakes to hold the train when the power is cut off. Rodney conductor BNSF

[Anonymous]

Dear wabsh1, Jackflash, and Rodney Beck,
Thank you very much for your help. It is most appreciated.

Sincerely,
Daniel

[Anonymous]

Actually, there are four positions on a retainer: direct release, low pressure, high pressure, and slow direct release. The slow direct release allows a full release, but only after a period of time has elapsed; this is intended to eliminate a stop to turn the retainers down after reaching the bottom of the grade. This was covered in the Air Brake story in April TRAINS . . .