I just read several very interesting articles on the operation of Hump yards. My question is has anyone modeled a working HO hump yard and if so maybe you could share some of your ideas. It sounds like something I would like to tackle.
Terry
This has come up a few times in recent years - the usual problems are with modelling the slope (must be steep enough to move the cars but not so steep as to cause them to take off at mach 3…) and the “retarders” (the devices used to slow the cars down, not sure if the same term is used over there) - I’m wondering if you could use an electromagnet and steel ballast weights to achieve this, after viewing the effects of Kadee magnets on Athearn BB metal axles (most amusing - the worst-effected did an interesting shimmy back and forth over the magnet!). You’d need to be able to activate it at exactly the right moment, but with a little practice it should be feasible - worth a try to my mind.
RailroadingBrit. Thanks for the reply. Yes all of my reading used the term “retarders” so it must be a universal term. The slowing of the car was the most imposing problem that I saw as well. Your idea of the magnet might be the ticket. Maybe glue a larger piece of metal sheet to the bottom of the car and have one of the Kadee electro magnets and juice it just at the right time to slow it down. Hmmmm, sounds like an interesting and fun project even if it doesn’t ultimately work.
Terry
Glad I could help! - must stress that I’ve not tried it, but the electromagnets would seem to be the most sensible method - I’ve heard of compressed air being used but it had a tendency to blow cars off the tracks!
One of the Kalmbach video layout tours from many years ago featured an operating hump yard in HO scale. The cars were slowed with blasts of air coming from jets under the track. There wasn’t much explaination other than that if I recall correctly.
It would be a major project, both in size and in the complexity of controlling the trains. Such yards are now being phased out by the prototype.
Bob Boudreau
John Armstrong talks a little about modeling a hump yard in “Operations” but it is limited in how much grade to put in etc. Still worth a look if you have it. If not it’s worth having anyway.
Way back in the 60’s I was at a club layout that had a (sort of) working hump yard. Mucho problems. Problems are (in no particular order) cars do not all weigh the same even if you weight them to a formula, the balance is different - some heavy at the ends, some in the middle and different height above the rail. Not all the trucks roll the same - some tighten up on curves etc.
The air blast affects different cars differently according to the shape and other factors. At the top of the hump not all the couplers would release equally - some would pop right off and some would have to be nudged with the switcher. This would affect the speed of the car.
At the bottom, you could only allow about 3 cars- after that they would hit too hard because in effect now the track is shorter.
In the end, they used a matched set of identical cars over the hump during shows to minimize the problems. Use was always “at your own risk” for the owners of the cars. Took at least 3 operators - engineer, retarder operator and somebody at the bottom to catch runaways, derails etc.
The club that I am member of has a working hump yard.The hump yard uses air as retarders…The air is passes through plastic tubes and by adjusting the air you adjust the car’s speed down the hump and into the bowl…This hump works flawlessly and we hump around 200 cars a hour.
Our freight car standards is simple:
1.All couplers must be at the correct height per the KD coupler height gauge.
2.All trucks must be free rolling with metal wheels and in proper gauge.
3.Weight is what ever weight the cars come in except impact and front runners.The weight of these cars must match that of Athearn BB kits or RTR cars…We do not follow RP20.1.
Yes,our freight car standards work very well and has for years.[:D]
I’ll second brakie’s post! I have a working hump yard: 12 tracks shortest track 12 ft. I run 50 car frt trains and hump them in two cuts. If there’s an experienced opr working the lower end, I can hump a train in 15 minutes which works out to Brakie’s 200 cars an hour. The lead up to the hump is along a north wall and is about 15 ft lonf w/ a 2% grade. It’s straight for about 8 ft then curves to the left and crosses my 5 track ar/dptr yard. Since the crest of the hump had to clear the tracks below, I started with an elev of 4" which turned out to work fine. To figure the grade on the classification tracks, I cut the sub-base out of 1/2" plywood in the shape of the yard and tacked on some track and switches. I found that I needed a fairly steep grade to get through the switches but that I could moderate it once the cars got through. Rather than use a steady grade down to the bottom I used a moderate grade until the test cars started to slow, then steepened it for a bit to give them a boost, moderating it again until it hit .0 elev. Here is where I made my big mistake! I should have gone to -1/2" or so to give cars a short up-grade into the switches. As it is, if a car gets through the retarders w/o being slowed enough it’s into the lower end switches we go.
The retarders are an adaptation of a design by the late Ed Ravenscroft from the 50s. He made a two track yard, stub ended at the bottom so you had to pull cars back up the hump, but he did hit on the idea of using a shot of compressed air to effect the slowing. I use brass tubes set in holes in the middle of the track at about a 15 degree angle. They’re activated by 12 volt solenoid valves that were from after market smog control devices. Finding a source of affordable solenoid valves will be your big problem. I lucked out on mine. Control is through a rotory switch to control which track’s retarder is to be activated and the a push button to shoot the air. The degree of retardation is controled by how long the air blas
Ed Ravenscroft in the 70s made a working hump yard the focus of his retirement-years Glencoe Skokie Valley. MR had several articles on his layout in the early 1970s.
Jim Rice’s experience sounds similar to the hump yard our club has, except we don’t have any kind of retarder. The top of the grade is steep, about 6% if I recall, then levels down to 3% after about 2 feet, then eases to level after another 4 feet. At the top we have three Kadee permanent magnet uncouplers in a row, and these seem to work reliably. The yard itself is double ended and is about 20 feet long, running along one wall. Free rolling, good tracking trucks are a must, along with reliable operating couplers.
Jim and Tom,I wuz wonderin’ if’n your club uses a puller crew for your hump bowl? We have been told our hump operation is unique because we use a puller crew.[:p]
Tom,I like the idea of using KD uncoupling magnets for retarders… [:D]
BTW…Our hump incline is 2.5%…This works quite well for us… Also the 200 car a hour number is based on the four 50 car trains that arrives in the Riverview yard…Like all trains that is “yarded” they need to be classified into other trains.
Unit trains goes into staging.Pig/stack trains goes to one of the two intermodal yards to be classified into outbound trains.
I believe the prototype retarders were to keep the cars within the 5 mph coupling speeds. and they roll better too…
I tend to believe now you dont need retarders for the model if you stick to your shiggins with good rolling trucks, and design the yard right.
The hump needs a short “kick” grade for the uncouplers and then maintain a good
grade to keep rolling for a long distance with a reverse grade near the end to keep cars from rolling on.
I might have a hump yard on my new layout, not sure yet if I will, but its a possibility I would.
I am modeling a hump yard. the hump is set at a half an inch above the bowl and the rise at the end of the bowl is a quarter of an inch. I have also changed the wheelsets of my HO cars to KD and Proto2000 wheelsets.
Any steeper and my cars will roll out the bottom of the bowl.
I will use clear toothbrush bristles as my retarders if necessary.
So far the hump yard at the club has only been operated during shows. One guy will randomly run cars down the hill and set the tracks for sorting. Then when the string is all sorted, he just runs down the hump and picks up another string for resorting. Amazing how many daisy pickers we accumulate at this area during a show.
I have visited the NY Society of Model Engineers club open houses for over 25 years, and they have an excellent humb yard that uses air to retard the cars. It works great now, but the first time I saw it (Ithink it was their 1st year with it) an old balsa(?) wood box car didn’t have anywhere enough weight - it not only sailed back up the hump, but became airborn!!! Matbe one of their members could enlighten us more on how it works![:)]
What are prototype RRs using to sort high volumes of cars if they are phasing out hum yards? I remember the old flat yards requiring a switcher to place everthing, and also remember as many roads updated their yards with humps. Has it come full circle and flat yards are coming back?
Well at one time a heads up crew could flat switch a lot of cars during their 8 hour shift…We would “kick” cars instead of shoving them into place…With today’s size yard crews I don’t think we will see the demise of the hump with todays traffic.
I saw Ed Ravenscroft’s later hump yard in action about 30 years ago. As I recall, it was a four track yard, turnouts just below the single-track hump, air retarders that were timed so slow-rolling cars received little or no air blast. He had standardized his cars to the then-current NMRA specs (he was a past president of the NMRA), and had also standardized his wheels and sideframes with the most free-rolling types then available. Incredibly, he used horn-hook couplers - and they worked.
Hump yards were needed for “loose car” traffic. Unit trains don’t need much switching.