My new HO layout is basically dual level. There’s a ramp to the upper level, which is basically a reversing loop (including a bridge) and a yard within the loop. I have not yet attached any risers to precise heights. I find I have an overlooked issue (the yard slope!).
With others’ input, I fugured out a good relationship for ramp slopes from the lower level (1% for 20", then 2.2% to a track crossover (2.8" clearance) within the upper reversing loop, continuing the slope past the bridge abutments, then either doing an upper vertical transition (or keeping the “plane” constant to a high point at the far end of the loop), etc.
What I overlooked is the minor point that the yard cannot be in this 2.2% plane slope, unless I don’t mind all the cars accumulating downhill! So I’ve concluded there may be several factors in the solution to this lack of planning. I have not included the option of putting grit in the wheel bearings to keep the cars from rolling.
Firstly, the yard needs to be close to level. But realistically, how much slope can it have and not have cars move on their own (with good wheelsets)? Second, I can make the far end of the yard level by accomplishing a vertical transition on each yard track beyond the turnouts. But this would limit the useable storage length unles a pretty quick vertical bend. Third, I could do some or all of the vertical transitioning within the (three) sequential yard turnouts downstream of the mainline turnout to the yard. This would create a vertical kink at each turnout-to-turnout joint (rounded upward), obviously not desireable to a large degree. (May be a “whatever you do, don’t do that” item). Fourth, I could increase the grade (significantly) from lower to upper level (to get the track crossover clearance I need earlier), include an earlier upper vertical transition and have the
Where you come off the main, can you level the rest of the yard?
On individual sidings some folks have used a piece of piano wire, stiff bristle or similar item sticking up through the track to just barely catch the axles of the cars. Supposedly does not have enough resistance to bother the loco pulling them out of the yard. They say very thin pieces that short don’t show up much. If the tracks are not heavily used some grass or small bushes could be used to hide them. You could place several, at random spacing along each track, making it so the cars would not all have to be bunched together.
Practically speaking, a mechanical stop would be the most cost-effective way to do it. The challenge would be to make it obscure, as well as strong enough to hold the total amount of cars possible for a given piece of yard track.
A little more hair-brained idea might be to use a small rare earth magnet on the bottom side of a piece of rolling stock that would have enough N/S attraction to another magnet (located under the track) at the far end of a given piece of yard track . Not sure what the working distance would need to be for it to work effectively though.
If you are stuck with a graded yard, I’d lean towards a mechanical stop of some kind.
Hmmm. Actually I am aiming at a sloped yard because it will be a fiddle yard and the yardmaster, probably me, will be standing at the end of the yard, and moving cars around by hand at the ends of the yard tracks, taking them off line, or putting them on different tracks, possibly using a sector plate or cassette or other British style solution to fiddle yard operation, but possibly just using rerailers and the old “0-5-0” for power. I want those cars to come to me – within reason of course.
This may sound odd but if I did not want the cars rolling to the far end of a yard, yet the entrance to the yard is on a grade, I would think about a “bowl” effect for the yard so that the natural tendency even of very free rolling cars would be for them to congregate in the middle, which would be the center of the “dip” so to speak.
As a matter of fact there is a sound prototype basis for bowl type yards and they can involve some rather precise civil engineering.
You could a choke or throttle cable or something similar, to push a pin (the end of the cable) up to catch the axil. It would be stiffer than the piano wire I mentioned earlier and would have to be pulled down before you could pull the cars out of the yard, but the stiff cable could hold more cars.
Some folks have used these cables for turnout controls and to move uncoupling magnets into place.
That seems to happen a lot for folks. After allowing room for vertical transitions, many folks find that their plans don’t work as they imagined.
Paulus’ suggestion is the same as my experience: about .5% with free-rolling equipment.
“Quick vertical bends” are generally not consistent with reliable operation.
That seems to me to be one of the worst ideas of all. Vertical transitions within sets of turnouts typically cause no end of problems.
Seems to me you were already talking about some significant grades. To increase these substantially seems problematic.
Some of the other suggestions, like stiff weeds between the tracks or choke cables, might be practical on one stub-end siding, but they are going to be too difficult to work around in an active yard, in my experience.
Unfortunately, it sounds to me as if a ground-up redesign is in order. And the “many feet of vertical rock wall” issue you identified might also be something you could address at the same time, if desired.
Of course, if you were to post your track plan (and the room it fits
If you have free-rolling cars, any grade at all is too much. (I have some cheap RTR hoppers that will roll on laser-leveled track if somebody sneezes at the far end of the room!) OTOH, the yard at Dunsmuir, CA is built on a grade (1%, IIRC) which allows hump yard operation without the hump.
To make a graded yard workable, just plant nylon brush bristles, sloped slightly upgrade, just outside the rail base on both sides of each track, starting about a carlength beyond the clearance point, then every 2.5 inches or so until the end of track. The bristles should be just tall enough to make solid contact with the axle between wheel and journal box. Make sure the end-of-track bumper is functional, not just decorative. Anything can switch cars into the yard, but you’ll probably need a 2-10-2, a Mallet or a pair of 6-axle diesels to get them out.
Of course, if you can make the ends of the tracks level, the throat can be on a grade. You might still need the nylon retarders, just not as many of them.
I have one siding on a slight slope allowing cars to roll back onto a turnout. My solution was to take advantage of the difference in height between track from different manufacturers. The back portion of this siding was made from track with a slightly lower profile (Shinohara) than the track at the begining of the siding (Atlas)----this difference allows the slightly higher rails on the Atlas portion to keep the cars from backing up any further. Now this isn’t something I would tolerate on a main line but at the speeds going into and out of a siding this difference in rail height is an advantage.
I did a cookie cutter of the yard today so it’s now independent on elevation from the surrounding reversing loop. The yard entry turnout is at 2.2% upward grade, so the next 3 turnouts in the yard should be at that slope. I’ve got temporary riser blocks roughing out the elevations.
I’ll take a look at a combination of a bit af remaining yard slope (0.5% or less), with a vert 1.7% transition past the turnouts, about 3/4 of longest car. If that seems to shorten the useable yard too much, maybe add a tad to the main grade slope to reduce the transition in the yard. I doubt I will want to do that as the grade is already 2.2", a curved ramp, and I have no rolling stock to test out. I think I will be ordering a loco and some DCC sooner as the cork / track laying get started so I can experiment.
When I get to adding risers, I will clamp them first and then only screw them to joists so adjustment as needed is not painful.
I’ll look into how to add a layout diagram. Mine is in XTrackCAD and I don’t know how to add such a file as a picture. Is it ok to do so and do I first need to make it a pdf from a scan, etc? Still learning.
if one of your vertical easements is placed beyond the ladder the length of your grade will be 12 ft. Not counting of course the extra length for easements.
With a rail-head to rail-head distance of 4" the grade will be about 3%. But is the extra length 1,5 times the length of your longest piece of equipment? (3 percent / 2)
And yes the use-able part of your yard is limited.
When the grade would start before the ladder you will have only 6 ft of length to gain height; i would surely choose for a 3" distance between the rail-heads then.
I would go for slightly smaller radii and having the yard facing the other direction along the edge of your table.
BTW with grades in the 4% range you will have to accept rather short trains. Not a real important issue on a smallish layout.
I didn’t realize from the original written description that you planned to shove cars up-grade through a fairly steep grade in the yard ladder, as seems to be the case when viewing the track plan. I don’t think that will work very well, if at all.
It seems like there might be less challenging track arrangements that offer as much or more interest in the same space (the classic out-and-back, for example). Many of these are illustrated in John Armstrong’s Track Planning for Realistic Operation.
You got some serious grades going on there, everywhere. And they’re all on turns also. Shoving cars up that grade to the yard throat is asking for troubles. Wouldn’t be so bad if it was a smaller yard for mining/ lumber and the larger yard could be on the lowered level. It can work though, if more clearance or less grad needed on the incline, try to depress the decending track earlier than you have it figured. This would of course mean moving that curved crossover further around to the back. This would allow you to start decending even while still follwing that outer radius. Tricky and lots of cuts trough base, but could work. Is rather large layout, don;t know if access from all sides, but reach may end up a problem.