I just computed the size of my N scale hump yard. The total size is 186 feet of track. That equates to 5.65 scale miles of track. The arrival yard has a capacity of 95 cars, The classification yard can hold 209 cars, the departure track will hold 80 cars and the local yard will hold 18 cars. These are the major yards. There are all of the other tracks associated with a hump yard and the engine and car shops… The size is 19 feet long and 19 5/8 inches wide.
That’s huge, I got to see the Hump yard in Pasco, Wa. it seemed to stretch on forever.
For the sake of newcomers who may not realize that you are using the term “hump yard” in a different way from the prototype, here is the reference to the earlier thread where the differences were discussed.
http://cs.trains.com/mrr/f/88/t/228384.aspx
Real life hump yards handle individual cars rolling freely, which is why retarders are needed. Handling coupled strings of cars over the “hump” is not the same thing. On a real hump yard (prototype or model), retarders are needed to keep the later cars rolling into a body track from slamming into the cars already stopped there.
As I stated then, you may call it whatever you like, of course, but for everyone else, the differences between what you are doing and a real hump yard are worth noting.
A hump yard uses gravity to allow the cars to move down to the classification tracks, whether retarders are used or not. My hump is 1 3/8 inches to the rail tops from ground level and to not need retarders, as the cars roll far enought into the classification tracks that the next car down just bumps it and couples up without any deraulments.
We’ve been through this before in the other thread, so this is my last post here. You might read that thread again, the issues are still the same.
In that thread, you said that you weren’t humping single cars (which is of course what makes a hump yard a hump yard in real life or the model)
Pushing a “string of cars” over the hump together is not the same thing as humping a single car. That’s why it does not seem to me that you are actually modeling a “hump yard” in the way everyone else uses the term.
But if and when you have a video of your yard operating without retarders while humping single cars, I encourage you to post that here and prove physics (and me) incorrect. Show what happens after there are four to six or more cars in one of the bowl tracks. What happens with the next single car down that track?
To recap: once you have several cars in one track, the next single car freely rolling down bound for that track must arrive with significant force, since without retarders it will be rolling just as fast as the first car down the track – fast enough to reach the far end of the track – but there are already cars parked there. So they will slam into the cars that already went down that track. It’s physics.
There is a reason that only a handful of model railroad layouts in any scale have had successful tr
Just goes to show…it isn’t the size of the hump yard that matters…but how you use it… David B
Whether I hump one car or three cars, the effect is the same, they roll cleanly down the hump and roll a sufficent distance that the next car or cars just couple up to them,
Lets get back to my original point, which is that you can build a complete operating hump yard in reasonable size area in N scale.
IIRC, an early Trains article on hump yards was titled, Three, and a flock of singles.
Prototype hump yards can handle coupled cuts and/or single cars. One of my pickies with Ed Ravenscroft’s hump was that his could only handle singles - even when successive cars went into the same track in the bowl.
As for description of your complex, it sounds just like (fill in half a dozen major prototype yard names here.) The hump and classification tracks don’t stand in lonely isolation. Cacole notwithstanding, a prototype hump yard will have engine facilities, arrival and departure tracks, thoroughfares - and maybe even a track and a service road under the crest of the hump.
Chuck (Modeling Central Japan in September, 1964 - flat-swiched)
Yes, if I remember correctly???, I think it might be Baily yard that has the road under the hump. I saw a picture of it years ago adn canno rembmeber if that wa sthe one.
Except that as Cuyama pointed out, as the track becomes filled up, that “sufficient distance” becomes shorter and shorter until eventually a car hits the rest of the pack with enough speed to derail. Your idea only works if you limit each track to holding a few cars, not exactly what yard tracks were meant for.
Steve S
The ten classification tracks run from 62 to 101 inches to the fouling point in length broken into two groups of five. One set of five for eastbound trains and th eother for westbound trains… More than enough to run a decent number fo cars into them, before the cars are pulled to make up a train.