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Post by mrsocal on Mar 29, 2014 5:14:47 GMT -8
I am very interested in finding out if anyone has ever modeled a semi working hump yard. With hump and modeled retarders, the whole nine yards.
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Post by mlehman on Mar 29, 2014 7:08:58 GMT -8
Scotty, It's been done. The one I vaguely remember is from roughly the 60s/70s and used puffs of compressed air to act as the retarders . Probably too early for any sort of computer control like would be possible today. I suspect it's the one by Ed Ravenscroft mentioned din this thread: cs.trains.com/mrr/f/88/p/228384/2549392.aspx#2549392Apparently, someone at the Springfield show has displayed some modules of a hump yard, so maybe someone who attends those can tell us more? |
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Post by mrsocal on Mar 29, 2014 7:43:29 GMT -8
Thanks buddy, and Wow! Leave it to the Germans to git it done. That was cool. I have always been fascinated by the mechanics and workings of a hump yard, it is just mezmerizing. As for the Springfield show, I would be interested to see anything from that too.
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Post by jamesbrodie67281 on Mar 29, 2014 8:34:40 GMT -8
In my early firing days 1950 our first shifts were on the hump pilots large (to us) 4-8-0T engines or an ailing 0-8-0 that might be waiting for a space to go to the shops for a general overhaul. there were three humps an up yard--down yard and No2 up yard. The up and down main humps had two engines working round and about and if an extra heavy load was left on the receptions for humping then the two pilots pushed over together. The maximum number of wagons over the hump at once was five and there were 'chasers' who ran alongside the wagons braking with the side lever hand brakes slowing to the required speed then lift the brakes off and leave the wagon/s run into the sorting sidings the chaser then returned back to the hump top for the next raft of wagons to brake into the sidings. Now and again one of the pilots would go over the hump top to push roads down when wagons hadn't run in far enough. The target for an eight hour shift was 1,000 wagons a shift. I based my hump on the No2 yard where there was only two receptions and a run round road which also served as a feeder road with traffic from the up yard to the down receptions. The pilots on this turn were normally an 0-6-0ST loco or again an ailing train engine waiting works. seventy wagons was the normal loading and in those days all the wagons were non auto braked infact the engines were steam brake only. Two receptions and run round road cum other direction departure road--six sorting sidings cum train departure sidings and one road ''a van kip'' a siding specially for brake vans (cabooses). Sometimes I used to have the sidings to sort into wagon types and other times the roads were for destinations. Like the real yard I had a 0-6-0T pilot engine for train preparing. My main traffic was 1 empty mineral wagons, 2 single and double and bogie bolster wagons loaded,3 box wagons, 4 tank cars,5 brake vans, 6 wagons for re humping. I got round poor running wagons by classing them as 'not to be hump shunted' and they/it were/was lowered into the yard still coupled to the pilot engine. As space was at a premium the receptions and yard were built on a curve. The new 0 gauge hump yard has the receptions laid adjacent to the sorting sidings, photo to follow later. Jim Brodie.   |
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Post by onequiknova on Mar 29, 2014 18:53:08 GMT -8
Go to youtube and search HO scale hump yard. They all have one thing in common. Cars rocketing around at 80MPH down the hill. HO scale cars don't have the mass for it to be done realistically, at least from what I've seen.
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Post by Brakie on Mar 30, 2014 3:09:33 GMT -8
Go to youtube and search HO scale hump yard. They all have one thing in common. Cars rocketing around at 80MPH down the hill. HO scale cars don't have the mass for it to be done realistically, at least from what I've seen. John,The Shelby(Oh) HO club has/had(club went private years ago) a working hump yard and some very skilled operators that knew how to use the air valves and the cars rolled at a realistic speed. It was a very impressive operation. |
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Post by Spikre on Apr 1, 2014 11:25:19 GMT -8
 have seen 2 at the same Club,the NYSME layouts in Carlstadt NJ. they had both O and HO that used the Air Jet system. the O worked fine,but the HO would blow the cars off the track if the operator wasn't careful. this was back in the 70s, but havnt been back since. Spikre 
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Post by riogrande on Apr 1, 2014 11:56:53 GMT -8
Now that I think about it, there was a article in MR magazine back in the 1990's about a guy in California with a large attic who modeled the SP. I think his model RR had a hump yard as one of the major features.
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Post by ambluco on Apr 2, 2014 8:54:49 GMT -8
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Post by stevef45 on Apr 4, 2014 2:25:54 GMT -8
NYSME still has the operating HO scale hump yard with the air to slow the cars. They were supposedly working on something to be a lil more prototypical.
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jhuteman
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Whut cho doin there Bo?
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Post by jhuteman on Apr 25, 2016 2:51:55 GMT -8
Seen it tried a few times but they always need 'help' these don't mass out quite the same as the 'real' ones do so it's not easy but it CAN be done! Your grades will not be 'proto' but you can make it happen.
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Post by valenciajim on Apr 25, 2016 17:24:15 GMT -8
On one of the original videos done by Allen Keller for MR in the 1980's there was a video with Allen McClelland's layout and that of his close frond, whose name I think was Al Santel (SP?) Mr. Santel's layout featured a working hump yard with compressed air to slow down the cars. As I recall, the video even showed how it was made. So if you can get your hands on that old video, you might get some helpful info.
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bcrn
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Post by bcrn on Apr 26, 2016 22:16:01 GMT -8
the central iowa railroad club in des moines ia i belonged to in the late 70's early eightys, had a hump yard when the layout was behind beggars banquet, in the drake area. we didnt have issues with rocketing cars, it was mostly cars stalling out. i also remember someone had done a project on a 9 inch? vibrating straight track, to help cars make it to the right track. i dont recall what magazine the article for this was in. the track section was set up to rapidly move forwards, and backwards, and when a freight car would roll onto it, it would give the car a kick in the direction of the track you desired it to be in.
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Deleted
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Post by Deleted on Apr 30, 2016 10:00:06 GMT -8
Seen it tried a few times but they always need 'help' these don't mass out quite the same as the 'real' ones do so it's not easy but it CAN be done! Your grades will not be 'proto' but you can make it happen. An 100 ton HO gauge car would weigh in at about 2300 pounds if scaled down! Then it would roll prototypicaly, but require stronger bench work than most layout's have. |
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Post by edwardsutorik on Apr 30, 2016 11:40:17 GMT -8
An 100 ton HO gauge car would weigh in at about 2300 pounds if scaled down! I come up with a different number: A typical loaded freight car these days weighs about 263,000 pounds (131.5 tons). I divide that by 87.1 THREE times and get .398 pound (6.37 oz). A typical HO model of a modern freight car is about 8" long. NMRA standards suggest a weight of 5 oz. Ed |
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Post by Deleted on Apr 30, 2016 11:52:18 GMT -8
An 100 ton HO gauge car would weigh in at about 2300 pounds if scaled down! I come up with a different number: A typical loaded freight car these days weighs about 263,000 pounds (131.5 tons). I divide that by 87.1 THREE times and get .398 pound (6.37 oz). A typical HO model of a modern freight car is about 8" long. NMRA standards suggest a weight of 5 oz. Ed Divide by three? lol. That's why model hump yards don't work, the cars are WAY WAY too light! |
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Post by edwardsutorik on May 1, 2016 9:58:10 GMT -8
I surely did not say that. I said divide by 87.1 three times. As opposed to once. Ed |
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Post by edwardsutorik on May 1, 2016 10:44:18 GMT -8
I earlier figured out the weight of a loaded HO scale freight car at 6.37 oz.
An empty car weighs about 65,000 pounds. I get an HO car weight of 1.57 oz.
That's quite a difference, and I don't think any of us would care to run loads and empties like these in a train. And yet, the real railroads do. Up to a point. They can do it while we can't because we operate on curves that are not scaled down properly. High speed mainline freight curves are usually no sharper than a mile radius. That would be a 60' radius (that's 60 real feet) in HO. If I had such curves on my layout, I'm pretty sure I could pull off a mix of loads and empties without problems.
Ed
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Post by Paul Cutler III on May 1, 2016 13:48:13 GMT -8
As Ed says, weight is figured out by volume, so when figuring out scale weight, you need to divide the measure by the scale for length, width and height, or IOW, divide it by 87.1 three times for HO scale.
Weight (a force) is figured out by the mass of the object multiplied by the acceleration (in this case, gravity): Force = mass x acceleration. Or Weight = mass x gravity (same thing). Gravity is a constant (32.2 ft./s^2). Mass is defined as the density of an object multiplied by the volume (mass = density x volume). Density is a constant (depends on the material). To get the volume of any object, one needs to multiply the length, width and height.
Therefore, take any prototype weight, like 50 tons (100,000 lb). Convert to ounces (100,000 x 16), then divide it by 87.1^3, or 1,600,000 / 87.1 / 87.1 / 87.1 = 2.42 ounces.
The real issue with working hump yards in HO scale is that while weight scales, friction and momentum doesn't. If you take a real freight car, get it going on flat level track at 10mph and let it go, it'll roll a long way before it stops...many times it's own car length. If you did that in HO scale at 10 scale mph, it's not going to roll too far.
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Post by mrsocal on May 1, 2016 18:29:14 GMT -8
Simply put... friction and energy are constant and can not be scaled down. Makes sense.
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Post by edwardsutorik on May 1, 2016 21:43:29 GMT -8
Momentum and energy DO have to scale down, until you get to quantum dimensions. If basic physics didn't scale, we would be living in a MUCH different universe.
Friction doesn't have to scale down. When a 1 pound block of steel is placed on a steel surface and the surface is tilted, the angle at which it slides will be the same as for a 10,000 pound block.
Except. There's several kinds of friction. And SOME of them might have non-linear elements. Might.
I think that the Delrin bearings that we use almost exclusively today make a hump yard doable. Partly because of lower friction than in "the old days". And partly because Delrin bearing friction doesn't change much over time compared to the "old" bearings that were lubrication dependent.
Easy for me to say, 'cause I'm not actually going to devote the enormous amount of energy to do it, but I think a working hump yard could be nicely done with a computer (big surprise), a large amount of photo sensors (to get velocities), and some decent (perhaps I should capitalize: DECENT) car retarders. I will note that real hump yards use three layers of retarders. That means for a 6 track yard, you need about nine retarders. And those photo sensors? Lots of them, too.
Ed
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Post by Paul Cutler III on May 2, 2016 10:55:48 GMT -8
Ed,
While the coefficient of friction is the same for the 1 lb block of steel vs. a 10,000 lb block of steel, the friction force (resisting movement) is different because this force is based on mass, and the greater the mass, the more friction you have. IOW, a larger mass needs a steeper sloped angle before it will slide vs. a smaller mass made of the same material on the same slope.
The problem, really, for an HO scale hump yard is that cars don't roll the same distance. If you take the care to make all your cars roll well and be very similar to each other, then sure, do a hump yard. I've seen them work in HO scale, and the best one used compressed air to slow the cars (or even blow them back up the hill). But the cars being humped were all cars the hump owner had worked on so that they would roll really well. There are some cars that just don't roll worth a darn.
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Post by edwardsutorik on May 2, 2016 13:39:17 GMT -8
Ed, While the coefficient of friction is the same for the 1 lb block of steel vs. a 10,000 lb block of steel, the friction force (resisting movement) is different because this force is based on mass, and the greater the mass, the more friction you have. IOW, a larger mass needs a steeper sloped angle before it will slide vs. a smaller mass made of the same material on the same slope. "A block on an inclined plane will accelerate down the plane. The amount of acceleration is determined by acceleration due to gravity, the angle of the plane, and the coefficient of friction of the block with the plane." from: www.cs.utah.edu/~zachary/ispmma/applets/SlidingBlock/SlidingBlock.html Note that there is no mention of the mass of the object. First of all, any cars that can't actually roll down the hill should be culled and/or repaired. Then, once you have those decent retarders I mentioned, there's two approaches that should work. One is to program the rolling characteristics of each car into yer computer. Then as the cars are pushed over the hump, you enter the reporting marks and the retarders operate accordingly. While entering the reporting marks might be a PIA, it seems pretty authentic. Not to mention, you then have trainlists for all your yard tracks. The other approach is to install those photo sensors I mentioned. The car velocities can then be measured, and the car retarders operated accordingly. So variability of rolling qualities won't matter. Ed |
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