Has anyone built a hump yard?

[Anonymous]

Just curious...

I am adding a modern humpyard to my layout, and would like to know if anyone has EVER built one of these on their layout. I really want to know how they control the cars descent down into the classification tracks, or if anyone has any ideas how to control it. With a scale grade/hump for the cars to descend down, the car could derail or smash into another car without scale track retarders. Anyone have any ideas?? Thanks again.

-Wolv33

[BR60103]

I remember an article by Ed Ravenscroft (?) in the 60s or 70s about the hump yard he built.
He used compressed air bowing against the cars for retarders. He said that using a standard time for the blow seemed to be enough to compensate for the different rolling characteristics.
I don't really remember the mechanical details but it probably incorporated a lot of relays.

David

[Anonymous]

Thanks David,

Unfortunately, that is probably out of my range of experience or expertise. LOL!

Besides, I would worry that too much air would derail the cars in their descent.

The only thing I have come up with so far is making a grade so that it does not descend too quickly, but heck, that would be an awfully long grade. Thanks. Hopefully someone has a more practical idea.

-Wolv33

[Anonymous]

David:

In the early to mid 1980's MR made a number of videos that were the precursor of Allen Keller's current videos. They were called MR Video Layout Tours. In one of those Ed's hump yard was featured, including a discussion of how it was built, how it operated and how it was maintained.

Jim

[Anonymous]

In the mid 1980s, MR had an article on a hump yard plan whereby the grade was realistically small, and cars moved at scale speeds by having one of the rails on each track, move back and forth while the other rail remained stationary. When movement of the rail was just the right speed (slow forward/fast backward), the result was that the freight cars moved slowly along. The rails were driven by a lever mounted on a cam, and turned by a motor. I believe the Model RR Club of New Jersey was planning this, but I don't know if it ever came to fruition. No doubt a complex concept, but fascinating. Anyone know if this was ever implemented?

[Anonymous]

Well guys,

I am still working on the concept. I am testing my grade theories by using different sizes of trestle and 9-inch straights as a testbed. Maybe if I stuck a wavy S-curve in there, that would slow the cars down. I shall have to try that. In the design, I have made my classification tracks long enough to accomodate 25 cars, but once the tracks got near to full, I would still have the possiblity of a car crashing into another, possibly bending or breaking my couplers.

I will keep plugging at it though. Thanks for all the replies.

-Wolv33

[BRAKIE]

At one of the clubs I go to we have a working hump.We use compress air.The air is delivered to the "retarders" by plastic model airplane fuel line.The hump operator adjusts the air by control knob. This is how it works.You uncouple a car at the being of the hump adjust the air and the car(s) roll into the bowl at a scale speed.No! The air does not derail the cars!BTW the cars weight is that of you normal athearn/MDC car kit.We do not add any extra weight. This hump has been in use for 10 years and gives very little problems outside of normal maintenance.

[Anonymous]

Cool!

Hey, would it be possible for a schematic of the devices used, or do you guys have a website or somewhere I can look at it? Thanks...

-Wolv33