as the trend toward more highly detailed freight cars continues, i just wondered how many modelers are installing bleed rods on their equipment? i’ve just begun doing it and don’t really know why i bother other than because i think they look cool.
actually, they need to be a bit oversized just to be noticed and i am bending them on the end at 90 degrees for the older equipment and making the loop ends for the later quick release style.
grizlump
Perhaps you could educate the uninformed - what are “bleed rods”?
I have on contest models. I use a single strand of wire from a lamp cord. It is flexible, can be reshaped when accidently bumped and can be had in copper or silver color. It is so small that the copper color works out fine without any paint, you can’t tell if it is copper or rust colored.
It bleeds the air out of the cars brake system, including the reservoir so you can move them without any air in them. Necessary when pushing them over a hump, dragging them with a car puller, Polling or otherwise moving them without an engine connected to pump up the air and release the brake. IIRC In 1:1 scale it must be about 3/8" or so rod, and connects to a rocker valve on the valve body and runs to a small hole in the side of the car, conviently located for someone to grab it and bleed the air off the cars. I could be wrong in its operation, as I am only a model railroader and since I model 1:87 the brakes don’t work on my equipment. That last line was an attempt at humor, but when operations are serious one of the rules on my pike is you must take the time to bleed the brakes or set the hand brakes as approriate. It does take time if you have to walk the length of your train to accomplish the task.
Paul
Dayton and Mad River RR
Paul,You are correct…That’s exactly how you bleed the air.
Is there a mark/symbol on the car side or frame to help workers locate where the end of the rod is? (Our cars have a small white star next to or above the pull handle for dumping the air). Do the rods end with a handle or just a straight end?
Thanks
[:P]
some modern cars have a paint mark near the location of the bleed rod but that was not always the case.
the rod ends are always 90 degrees from the triple valve and extend all the way under the car so the air can be bled from either side. as i remember from years gone by, they did not extend out from under the car but were directly below the side sill.
on covered hoppers or open top hoppers, they were up on the “b” end of the car coming directly off the triple valve. most of the older cars had rods that ended with a 90 degree bend downward. these required you to pull and hold the rod until the air was completely exhausted. the later quick released types had the end bent into a loop. you just had to jerk these once and i think just the air pressure in the brake cylinder was expelled saving the air that was in the reservoir. this improvement made charging the train line a lot faster when you coupled up the hoses and put air back in a train
i haven’t been to an air brake class in decades so i am not aware of any modern day changes and actually don’t remember everything i once knew.
where i worked, the car inspectors would bleed the air brakes off while they were inspecting the arriving cut.
all this was necessary because once you reduce train line pressure below what it was charged to originally (about 70 lbs for freight trains back then) , air brakes apply on all the cars from the pressure in the reservoir acting on the back side of the brake cylinder. the brakes car only be released by equalizing the pressure in the system and bleeding all the air off accomplishes that. (except for the quick release types)
if a cut did not have to be switched then in cold weather the crew would “bottle” or save the air by making about a 15 lb service reduction and closing the anglecock before they cut the engine off.
if you google railroad air brakes or westinghouse air brakes you can find sit
t was a pretty good working description! [tup] It beats wading through a lot of jargon and theoretical description that wouldn’t include the useful stuff like the inspectors releasing the air.
Thanks [^]