Air barking while classifying cars?

Question

When the air hose on a train is disconnected, the brakes automatically lock up, how to railraods hump cars with this in mind?

Answer 1

Beaten to the punch again, by one who knows...

By operating the release rod, air is exhausted from the brake cylinder, and the car becomes free-wheeling.  Often times a brakeman or conductor may ride the car while in motion, controlling its speed or stopping it with the hand brake.

In hump yards, the cars are allowed to roll freely after passing the "crest" of the hump.  Some are quite high in elevation, depending on far the cars must be able to roll on their own steam.

In one hump yard I have worked in, there were a total of 49 "classification tracks" in the hump "bowl."  Cars are routed into the proper rails by operation of the switches by the hump Yardmaster.  His tower is usually at the crest of the hump.

Further down are the Car Retarder Operators (CROs).  These guys control the speed of the cars by operating what are essentially huge clamps (car retarders), that are pneumatically controlled, from their individual towers.  They clomp on to the wheels to slow the car to an acceptable speed (no coupling faster than 4 MPH should ever take place, to avoid potential damage to lading or creating shifted loads).

The are EXTREMELY loud, as well.  People living within earshot of an operating hump yard can tell you all about it.

Of course, cars carrying Hazardous Material must not be humped or cut off in motion, EVER.  Other cars may carry temporary placards that may read, "Do Not Hump."  This is usually because of a delicate load.

Many new hump yards, as well as some that have been rebuilt, are much more automated today.  More often than not, a switchman wearing a box that allows him to operate the engine by remote control while standing on the crest, in a position to uncouple the cars as they come over the crest.

Cars rolling on their own are nothing unusual in rail yards, hump yards, or while performing industry switiching.  They make very little noise and can sneak up on ya without ya ever knowin' their there.  That is what makes these types of places the types of places that should be avoided.

Probably more info than your wanted, but once I get goin' I dunno when to shut up...

Answer 2

Someone has to walk the train and "bleed" the brakes before a train can be humped.

What they are doing is manually relaesing the air brakes on each car prior to the cut of cars being shoved up the hump lead so they can roll free.

Contrary to what some people think, the hump does indeed allow each car to roll freely on it's own without being attatched to an engine.

The same thing has to be done before a train or cut of cars can be flat switched, the air brakes have to be released,

usually by carmen but quite often it is by the switch crews.

good question

Added later to Hogheads about the no hump cars, we called the spur at the top of hump for them the "go to h**l spur"

Answer 3

Once again, Hoghead and Rango got here before me. I think I must work more than those two do. I'm an Engineer now, but I got my start as a Switch Foreman in a large classifying/ switching yard. After a train pulled in to the yard, the engines would uncouple and go to the "barn".  This is where you are correct when you said the brakes would automatically lock up. Now, one or more employees would walk the train and pull each air-bleed-rod. This allows air to escape from the brake cylinder and the brakes release. Now the cars are free to roll for classifying. Once a train is made up on a track, someone goes out and walks the length of the train re coupling the air hoses, so it's ready for the engines to couple up and put the air to the braking system.  But, if a hose is overlooked and not joined, the Engineer knows it right away before ever moving.  And there's maybe a mile of train back there. This is called "Dumping air all over the ground".  Because the pressurized air is blowing through the system and out the unconnected hose. Someone needs to re-walk the train to find the fault.

Answer 4

Each must be coupled to another car with an engine, or engine, to provide air to release the brakes.  The hump in the yard is not used to coast cars into position.