Access to lower level


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dstern350

New Member
I am working on a new layout where I want inbound and outbound trains to be able to run through a "portal" and end up below the main level of the table - I have little space outside of my 4x8. I have never worked much with grading. Is there a standard way to build a ramp from one level to the next?

Thanks
 
You need to be mindful of how steep the ramp is. You can't run very long trains on your layout so you should be able to get away with a steeper grade, i.e. 4-5%.
 
There are a few different ways to achieve what you appear to want but we need more information - such as a diagram of the layout you wish to build.

Also, just in case you don't know, the steepness of a grade in percentage is simply the ratio of the "rise to the run", or the change in elevation over the length of the track. For example if you have a 200" of track and it rises 8" over that distance the percentage is ((8 / 200) * 100) which works out to 4%.
 
You also need to allow for a transition at top and bottom so that the changes from each level are not too sharp, so that couplers remain coupled.
 
fcwilt said:
There are a few different ways to achieve what you appear to want but we need more information - such as a diagram of the layout you wish to build.

Also, just in case you don't know, the steepness of a grade in percentage is simply the ratio of the "rise to the run", or the change in elevation over the length of the track. For example if you have a 200" of track and it rises 8" over that distance the percentage is ((8 / 200) * 100) which works out to 4%.
Click to expand...

I actually have a clean slate on this one. It is a a 4x8 table that will sit next to an existing table. The main line will run from the top of the other table across to this new one and then down one of the long sides. I am thinking about having that side laid out as a mountain. My idea is that when the main line gets to the bottom of the new table, it will run through a portal/tunnel and then down under into a suspended figure 8. I guess my first calculation must then be how to use 3.5 feet to drop at 3%? Can I make more gradual with a curve?

Thanks,
 
Distance is distance when it comes to grades.

You also need to consider clearance from the lower level to the upper level. If you allow 4" clearance then at 3% you need a bit more then 11 feet of distance (4" / .03 = 133.33").

I try to keep grades no more then 2%.
 
Ok so using that example, I need to drop 4inches over the course of 11feet and I can do that in any path that gets me there. Thanks.
 
Sorry, I should have said 4" railhead-to-railhead distance. Clearance is from railhead to the underside of the upper level sub-roadbed. On my helix I have a 4" rise per turn. Using 1/4" MDF sub-roadbed and Woodland Scenics foam roadbed I end up with a clearance of 3-3/8" inches.
 
A decision you'll need to make considering the constraints of a 4' width of table is, what sizes of locos/rolling stock you're going to run, also what scale? I think we're all assuming HO, in which the max radius to fit within 48" is 22". This is as tight as you would want to go for 6 axle locos and 85' coaches and some would say too tight. 4 axle locos and 50-60' max stock OK.

If N scale, no problem.

The reason for the proviso with HO is that what you are in essence, proposing, would be a helix between 2 levels which would travel around the outer edges of your available width. Then you want to have a figure 8 coming off that which of necessity will need to be within the helix radii, 18" probably. If in HO then I would say longer locos/stock are not advisable.
 
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Why a figure 8 at the bottom? Why not a small staging yard to hold a train or two? It can be done in HO, by just inserting a siding into the track, allowing for one train to hold there.
 
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If this lower level is going to be used to run trains around (or even if not), then a 4" gap between levels is going to be exceedingly cramped, so several turns around the helix will be required to achieve a workable clearance. It would also mean that in order to see or access the trains, the helix would have to occupy the inner space with the track on that lower level restricted to only running around the outside. A figure 8 would be difficult at the least and then you have the problem of how to get your train back up the helix.
 
Ummmmm, if you are going to use a helix to drop just enough for your trains to have head room on the lower level, you aren't going to have several loops in the helix. It will only be an open top loop. You are trying to put big layout features in a small layout area. If you want to keep the grade to no greater than 4%, with rail head to rail head distance of 4", you will need about 15' of track. On a 4X8' sheet of plywood that is over half way around if you are on the outer perimeter. If you are constrained to stay within the 4x8 footprint things just get worse. You will need easement into the grade at the top and bottom. What this means is a gradual change in the grade of the track from level to incline. This has to be at least several car lengths long so your couplers don't separate and locos with three or more axels don't lift off the track.
 
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I ditto what Ken has said. And if a buddy comes over with a steamer the problem will be compounded. Keep in mind that with the steepness of the incline there is added drag created by just the curve. The pulling power of the loco will be greatly diminished. On a 4X8 the drag will no doubt be tremendous. What size train your loco can nominally pull on level ground, could be cut in half or more, just due to the drag from not just the steepness of the incline, but also the drag created from the tight curves.
 
Only other way I think you can make this workable is to make the lower level the actual layout area for your figure 8 with any sidings you wish to have and have your spiral grade rising up from that to join up with the rest. A 4" gap between 2 full levels is just unworkable, especially if 1 or 2 sides i.e. layout in a corner of the room, completely impossible.
 
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