I see references to switching cars or cuts of cars with "no air."
If there's no air in the brake pipe, that would usually mean the brakes are applied. So "no air" must mean no air in the reservoirs or cylinders also, right?
Does a crew member bleed off the reservoirs and cylinders one at a time by walking along the cut? And how exactly is this done?
Still in training.
Lithonia OperatorI see references to switching cars or cuts of cars with "no air." If there's no air in the brake pipe, that would usually mean the brakes are applied. So "no air" must mean no air in the reservoirs or cylinders also, right? Does a crew member bleed off the reservoirs and cylinders one at a time by walking along the cut? And how exactly is this done?
Upon arrival in a terminal, the Car Inspectors will perform a walking inspection of the cars in the inbound train after the power has cut away. A part of their inspection is to actuate the 'bleed rod' that will bleed all the air off the car and its resevoirs. After the Car Inspector report the completion of thier inspection and remove their Blue Flags from the track - the cars in the track can be switched, the cars will not have air on them.
There are yards and terminals where all switching is done with the trainline charged and cars are 'moved' to their desination track - they are not cut off on the fly to free roll to a stop.
Never too old to have a happy childhood!
Thanks, Balt.
Then there was time that an old head (yes, older than I!) cut the air back in for a hump shove. The pinpuller and hump conductor got quite a surprise when the first pin was pulled.
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)
BaltACDUpon arrival in a terminal, the Car Inspectors will perform a walking inspection of the cars in the inbound train after the power has cut away.
I've heard legends of that.
We've always had to bleed our own air.
It's been fun. But it isn't much fun anymore. Signing off for now.
The opinions expressed here represent my own and not those of my employer, any other railroad, company, or person.t fun any
zugmann BaltACD Upon arrival in a terminal, the Car Inspectors will perform a walking inspection of the cars in the inbound train after the power has cut away. I've heard legends of that. We've always had to bleed our own air.
BaltACD Upon arrival in a terminal, the Car Inspectors will perform a walking inspection of the cars in the inbound train after the power has cut away.
Yep - in low volume locations in the hinterlands, where there are no car department employees.
BaltACDYep - in low volume locations in the hinterlands, where there are no car department employees.
I've worked some bigger yards where yard crews normally bled inbounds.
Now with PSR, car insepctors are rarer than unicorns.
It used to be that you had to bleed all the air from the brake cylinder and air reservoir to release the brakes. This required holding the bleed rod for maybe one to two minutes. Now the air can be released from just the brake cylinder by giving a quick pull on the bleed rod. This allows the brakes on a cut of cars to be released more quickly and also leaves air in the reservoirs which shortens the recharge time since the air pressure does not have to be built up from zero.
When the changeover to the new system was being made some cars were equipped with two bleed rods; one for the quick release and another for the full bleed.
Mark Vinski
mvlandsw It used to be that you had to bleed all the air from the brake cylinder and air reservoir to release the brakes. This required holding the bleed rod for maybe one to two minutes. Now the air can be released from just the brake cylinder by giving a quick pull on the bleed rod. This allows the brakes on a cut of cars to be released more quickly and also leaves air in the reservoirs which shortens the recharge time since the air pressure does not have to be built up from zero. When the changeover to the new system was being made some cars were equipped with two bleed rods; one for the quick release and another for the full bleed. Mark Vinski
Johnny
Deggesty mvlandsw It used to be that you had to bleed all the air from the brake cylinder and air reservoir to release the brakes. This required holding the bleed rod for maybe one to two minutes. Now the air can be released from just the brake cylinder by giving a quick pull on the bleed rod. This allows the brakes on a cut of cars to be released more quickly and also leaves air in the reservoirs which shortens the recharge time since the air pressure does not have to be built up from zero. When the changeover to the new system was being made some cars were equipped with two bleed rods; one for the quick release and another for the full bleed. Mark Vinski I watched a trainman trying to release a sticking brake in this manner on a car in a train as the train was moving slowly about 45 years ago.
I watched a trainman trying to release a sticking brake in this manner on a car in a train as the train was moving slowly about 45 years ago.
Been there, done that. It's a real pain, especially if you are trying to roll cars by (gravity drop) and they stall, which always happens after they get foul of the switch.
To properly disable the air brake on a defective car one must first close the cutout cock, which is usually underneath the car. Then bleed it off.
Sometimes the newer bleed rods will fail to catch and stick open properly. Then you have to stand there and hold it until it finishes blowing. The bleed rods sometimes break or become disconnected from the valve, in which case you have to reach under the car and grab the valve to bleed it off.
Greetings from Alberta
-an Articulate Malcontent
I thought that with no pressure in the brake pipe, the triple valve would be directing air from the reservoir to the cylinder. So as the cylinder is bled, the reservoir would keep replacing that air, up until the point where both the cylinder AND the reservoir would have no pressure.
Please explain how you can bleed the cylinders, but have the reservoirs retain their pressure.
Thanks.
They designed a bleed valve that can do that. When it first started they added a second valve and bleed rod to existing brake valves. Newer brake valves were built with this feature included in a single bleed valve.
Thanks, Mark.
I've been reading up on brakes, but I never saw any mention of that, at least that I can remember.
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