With so many hump locomotives sold, why are hump yards so rare. In many years of searching, the only photo I can find on the internet is of a hump yard under construction:
http://www.railroadmuseum.net/images/Hump%20Yard%2040221a.jpg
My thought is that it’s because of the difficulty of controling car speed off the hump. I wouldn’t want to add one to my line because I’d be afraid of any damage my freight could take while crashing into eachother as they classified. If someone could make a model speed-retarder this issue would probably become moot, but until then, my rolling stock is just a bit too delicate to throw down a grade into eachother.
~METRO
They take a lot of space, model cars don’t coast nearly as well as real cars so operation isn’t as reliable as one would like, and car retarders are very difficult to model. There are a few reasons to start off with.
Regards
Ed
Problems modeling a ‘hump yard’ are not the track (easy) - it’s the 'rolling.
Once a car start’s rolling how do you stop it?
Not all cars roll equally. Some stop halfway down.
Some bang and break couplers.
Real railroad’s use retarders that gage the speed and computers figure out just how far and fast it needs to go.
A lack of humping is a good thing, David, at the animal shelter. Oh!!!, you mean railroad hump yards! Yea, they eat up a lot of space. As for car retarders, I vaguely recall one solution was a piece of clear nylon “wisker” sticking up between the track to scrape the bottom of the car to slow it down.
Maybe there’s a use for old tooth brushes.
Oh…I thought…never mind!
Our old club layout had a hump yard. Small tubes came out betwen the rails and they were hooked up to an air compressor, regulated of course. As the cars went down the nearly 40% grade the operator would open the valve as needed to slow the cars. Like real life there waasa a main and then secondary ones as the car made its descent. It was cool but huge.
Jesse
Wow I’m glad I caught that spelling mistake. i would have been booted off the forum. Whew…
I remember reading in some older planning books about various schemes to give cars a “boost” at the top of the hump to get them rolling. I’m not aware of anyone actually doing any of those, though.
Unfortunately, hump yards don’t compress real well for modeling and, as others have stated, car performance (free rolling wheels) is far from consistent.
FJ and G
I ask that question awhile back and as you can see there are a lot of reasons why it would be difficult.
But it would be a lot of fun to operate and to watch.
I thought about under track moving magnets and satelite tracking GPS systems but none of my ideas seemed very likely. If anyone figures it out they will be heros.
Jon - Las Vegas
Just a thought, but could you use the old problem with metal wheelsets (axles attracted to uncoupling magnets) to some advantage here - energise an electromagnet under the track to different levels depending on how much you need to slow the car down. Only snag I can see is that they usually “kick” the car onwards as it passes, but I’m guessing with a little experimentation this could be solved. Most cars have a steel ballast weight inside that would probably work for this purpose. Just a crazy idea!
I’ve got one! It’s 12 tracks wide with the shortest track being 14 ft.
Two of the objections noted above are valid. Probably the more dificult is retarders. I tried a bunch of posibilities and most turned out to be more derailers than retarders. Credit for the solution goes to the late Ed Ravenscroft who, in the early fifties, came up with the idea of a shot of compressed air to slow down the cars. The yard he used it on was only two tracks wide and you had to pull the cars out by dragging them back up the hump but the retarder problem was elegantly solved. Of course you have to find a way to control the retarders. I lucked out and located some 12 VDC solenoid valves (from after-market smog control devices) which, after some tweaking would hold 35PSI of air pressure (well, pretty much hold it) that only cost about $1.65 each. Unfortunately,
as the ones I’ve got bite the dust I’ve had to canabalize one of the three banks of retarders to replace ones that go bad. One of my short term projects is to devise some kind of cheap, workable valve to replace them.
The other problem is space. A double ended yard takes a prodigious amount. In my case I have the luxury of a 25X26 building (since expanded by a 12X24 extension) dedicated to the RR. I run frt trains of 40-50 cars. The hump yard and it’s adjacent arrival/departure yard take up the west wall. The crest of the hump is over the arr/dptr yard which gives me an elevation of +4" at the crest of rhe hump. The hump itself is on about a 2% grade and takes up 12 ft. The tail track from the arr/dptr yard is another 15 ft. (I break inbound trains in halves to hump). Add 4 ft. at the top and bottom of the yard to go from 12 tracks to one and another 15 ft for the lower end tail track (when putting a train together I double over half of the tracks for one half of the trains and then go back and do the other half). As you can see, when all the parts are tied together, I use up about a scale mile or more of wall.
You know this could be solved(the car slowing) by the DCC companies I’m sure they could make a system of wheel retarders like the real ones and electrically run them with DCC comands. Down side to this is it would be expensive but I’m guessing doable. Rob
The club that I am a member of has a working hump complete with a 18 track bowl*.This hump is 18’ long…The retarders uses air to slow the cars down by small plastic tubes.These retarders will only turn to a preset air pressure so there is no danger of blowing a car off the tracks or ending up with a runaway car by using to much air.Its easy to use and lots of fun.We use one magnet at the end of the hump on the slope that faces the bowl…
- A “puller crew” to make up the trains…All operation at the club is DC.
MR had an article on building a hump yard, you used air jets to slow the cars.
Building one takes some expertise and its a unique operation,
I built one, not completed, but I may be building a different one eventually.
Too many different cars with different rolling capabilities make a hump yard not always practical, you need good rolling trucks.
Its not for everybody, but if you got the gusto for it, go for it.
I am thinking about building a hand propelled one. Pretty crazy, huh?
The club I am a member of is adding a hump yard to their new extentsion, it uses the old air method. When i was there last night they had a guy testing the air system with various freight cars. Looks like it needs a little tweaking.
I know this would get a little expensive, but wouldn’t it be possible to build a hump yard with multiple independently controlled blown air retarders and some sort of speed detector that could measure the speed of the car at various places. Then a simple program would be run that would fire an appropriate number of retarders based upon the speed of the car. The multiple retarders are simply multiple air lines controlled with multiple solenoids. The speed detector could be two infared occupancy detectors at a given spacing. Velocity is simply the time it takes to get from one sensor to the next divided by the distance between the detectors.
A local model club has a hump yard that they run on their open houses. The car speed is controlled by air. It is very condensed and seems more for show than practicality. It is a neat feature, but I can see why it is not convenient for most model railroads.
car speed is determined by timing, air is on till a described time and is shut off, so a slow car isnt retarded. (no joking)
.
In addition to the space required for the yard, you need a pretty big layout to feed the yard and then use all the trains you put together. Even with a lot of staging, we’re talking a pretty big operation here. Even with compression you have to make it pretty big to avoid a caricature. For those of us with a home layout, do we really want to dedicate most or all of our space to one feature? Personally, I do not.
Enjoy
Paul