I am starting a new HO layout and am looking at a couple of options. I can either put in an oval 4x6 helix with 22" radius curves or descend my track over the length of the room with a 2% grade to the next level. After the first level, that would put each level at a 12" separation from the level above.
My question for the community is: Is a 12" separation practical? My layout is going to be built as a shelf style with a 16" width.
Thanks in advance for everyone's input.
Flying Crow,
I am not fond of helixes, but I am even less enthusiastic about 22 inch radii curves. I personally would not consider anything less than 30 inches especially on grades found on what would be your main line. Twenty two inch radius is the absolute minimum for a lot of HO equipment and, would sour you on your layout to find that car or locomotive you admire so much will not operate through your helix. Also, the combination of gradient and curve radius could cause problems with stringlining, if your trains are long enough. If you must go the helix route, go with the largest possible radius, not knowing what acquisitions the future might hold, such as 85 foot passenger cars, 89 foot intermodal and auto racks as well as 70 foot six axle diesels. Just one man's opinion.
The helix is not my first choice but I don't know how practical a 12" separation between levels is either. I have only 19' to work in and I didn't want a helix taking up 6' of that area because I have no option except to have the helix in the layout room.
If you are going to have two decks, the helix may be your only option. So long as you keep turning upwards, it can cl;imb to whatever height you need while taking up the same floor space. Still, the helix tends to hide your train from view for a long time.
Why do I favor the helix anyway? because a 12" deck separation is going to be very difficult. First, you have to subtract whatever benchwork depth that is required for the upper deck. That's going to be at least three inches, taking you down to 9" max scenery ehight on the first deck. That's really tight, especially with a scene depth of 18".
Here's a pic of Crater Lake Junction on my Cascade Branch, which is in a space that is 10" high and 18" deep, but it's HOn3 so the clearance seems a bit better.
Here's how it looks finished out.
I'd say give yourself at least 15" and better yet, 18". Whatever you need to gain, it's easier to add another turn to the helix than to extend a horizontal run in most cases. A 22" R helix is rather tight for HO standard. I have a 24" R HOn3 one that operates successfully
Mike Lehman
Urbana, IL
22" helix sounds unrealistic
Effective Slope caused by curves
greg - Philadelphia & Reading / Reading
gregc 22" helix sounds unrealistic Effective Slope caused by curves
You beat me to it. A radius of 22 inches is tight enough on it's own, but in a helix it is considerably worse. A fellow at another forum summed it up well:
Curve Equivalent. ... Basically the percent grade the train thinks it is experiencing created by the friction of going through a curve. There is a really fancy formula that the real railroad used to calculate this, but there is a real good rule of thumb. Take 32 and divide it by the radius in inches. Just going through a 24 inch radius the train will feel the effects of going up a 32/24 = 1.3333 % grade. So the 2.65 % grade of a 24 inch radius helix become 3.98% to the train.
There is a really fancy formula that the real railroad used to calculate this, but there is a real good rule of thumb. Take 32 and divide it by the radius in inches.
Just going through a 24 inch radius the train will feel the effects of going up a 32/24 = 1.3333 % grade. So the 2.65 % grade of a 24 inch radius helix become 3.98% to the train.
So planners will likely need to use a broader radius than they were initially thinking of. In some cases, they simply aren't feasible.
I thought about using a helix in a 10x18' room but being the tremendous space wasters they are, I opted for a nolix, so trains ramped up a 2.9% grade to an upper level and back down again.
I have a planned layout and there is an area in the basement which lends itself to a helix and is at one end of the layout - so I am planning on building one with a 33 inch radius. Bigger would be better and I might be able to squeeze in a bit broader but will tackle that at build time.
Anyway, a nolix, ramp to an upper or lower level, is clearly your best choice.
As for deck separation, I was very naughty and has about 7.5 inches of clearance over staging in my last yard and it was 24" deep. It was far from ideal and the result of a compromise between space and what I wasnted to fit.
A 12" ceiling would seem luxurious to me after when I had before, and is probably what I will be doing on a future layout but the depth planned will be 18" and it will be staging and not scenic'd.
Rio Grande. The Action Road - Focus 1977-1983
gregc22" helix sounds unrealistic Effective Slope caused by curves
from the link
a target compensated grade of 2% would require a radius of 46, 44 or 42" for board thicknesses of 1, 3/4 and 1/2".
As others have noted, a 22” multi-turn helix in HO is likely not workable, except perhaps for very short trains of short cars. Making it an oval would likley help a bit, but broadening the radius would be the better bet. Any oval helix requires some careful engineering since the effective grade is higher in the curves than in the straights. That variation can lead to stringlining, with cars derailing across the center of the helix.
12” railhead-to-railhead clearance is likely not enough for a conventional multi-deck, particularly if you wish to make all the shelves the same 16” depth. [By the way, there are lots of good reasons not to make the shelves the same depth everywhere. Allowing the depth of the benchwork to vary provides many benefits in construction, scenicking, and maintenance.]
An interesting alternative is to allow the upper scenes to be separated by a low bit of fascia as something like a mezzanine. The low strip of fascia suggests “this is a different place” without requiring all of the climbing necessary for true double decks. Here is an example from Verne Alexander’s Great Northern/Northern Pacific-themed layout. (Verne did his own layout design, which is described in Layout Design Journal #58, published by the Layout Design SIG.)
In this photo, there is probably about 8” railhead-to-railhead elevation difference between the decks. Verne allows structures to tuck under the upper mezzanine deck to increase the feeling of depth. Some builders have preferred not to extend scenery and structures so far under the mezzanine – or not at all. In that case, there’s just a low bit of subtle backdrop behind the lower deck. This is a matter of personal taste and a mock-up would probably help you think about what works best for you.
In the photo below, railhead-to-railhead separation is about the same, but the upper mezzanine fascia is a bit deeper. To my eye, a thinner mezzanine fascia works better, but viewing this scene in Verne’s layout room works fine.
His space is about 13’X13’ and he uses both the mezzanine and true multi-deck approaches. Tracks climb twice around on the main and mezzanine decks and then enounter a steep oval helix to reach the upper deck. Verne runs relatively short trains of short cars.
The mezzanine idea won’t appeal to everyone’s taste, but personally I think it works fine. I have used this technique in a number of layouts for clients who felt it worked well. A key is varying the depth of the mezzanine decks: in some places either the upper or lower can become very narrow to focus attention on the other deck.
The old-school alternative is to use multiple tiers of layout on the same deck. This multi-pass technique works fine operationally, but can be challenging scenically, with unnaturally steep slopes between the decks. The mezzanine approach allows scenery on each deck to be independent of the deck above or below.
Good luck with your layout.
Byron
Layout Design GalleryLayout Design Special Interest Group
To me, the photos that Cuyama posted above don't have enough seperation between the two decks for me. It makes it appear as if it's only one scene. It takes too much imagining to make that work.
I have been planning to use a helix on my layout. The more I read about them, the more I question them.
Ed
Semi newbie HO scale modeler coming from the O scale world
To the orginal poster: You stated that your room is 19' long. How much width can you use?.
A two deck layout of 19'x12' would be huge for one person to build and maintain.
Do you want to work on your layout, or do you want to run trains?
Only a thought.
Dave
I probably wasn't as clear as I should have been. The 12" would be from the top of one level to the bottom of the other, so in effect, there is a 15" separation from the top of one level to the top of the other.
It looks like from all of the comments, a 22" radius helix is out of the question.
davidmurray To the orginal poster: You stated that your room is 19' long. How much width can you use?. A two deck layout of 19'x12' would be huge for one person to build and maintain. Do you want to work on your layout, or do you want to run trains? Only a thought. Dave
I don't know David, my last layout was 18x10' and had two decks essentially and I didn't feel like it was a too huge to build and maintain.
I only have 9' total width in the room. It looks like from all of the comments a drop from the upper level to the lower is the best way to go.
I mispoke as I will have 15" railhead to railhead. The 12" figure is the railhead to the bottom of the level above it. My question is if that is sufficient to work in without feeling cramped?
Flying Crow I probably wasn't as clear as I should have been. The 12" would be from the top of one level to the bottom of the other, so in effect, there is a 15" separation from the top of one level to the top of the other.
To be fair, if three was 15" of separation from the top of one level to the top of the other, you would really have about 14" of clearance over the top of the bottom level. Yes, you would need cross members to support the upper level or shelf brackets, but in between those you would have more clearance which is significant.]
In this photo, you can see I had a sandwich of 1/2" plywood/OSB with 1/2" Homasote on top. Underneath there is 7 1/2 inches clearance in between the 1x2 cross members.
I don't think I like bullfrog snot either. LOL
I misspoke. railhead to railhead is 15". Railhead to the bottom of the next level would be 12".
Flying Crow I misspoke. railhead to railhead is 15". Railhead to the bottom of the next level would be 12".
This sounds like it is correct and more realistic.
Look, the answer to this really depends on what you can tolerate over the long run in the way of bending, reaching, craning your neck, iffy and spotty lighting, and suspending belief or the imposition of that higher deck and its supporting structures. You have asked, so I would not accept that separation for two operating decks. For below-layout staging, sure, excellent in fact. But not for two scenicked decks and to hope to enjoy them. But, that's just me.
Figure out how to get two decks, and to two decks back and forth, with a single track hidden against the wall. Access would be via a tunnel portal near the wall. It's exit up top would be roughly the same idea, but it would look natural. The big idea is to spend a fair bit of time figuring out how to access it. You'd need three or four nesting panels of extruded foam to be lifted away to expose the tracks behind them in case something goes wrong.
I have done a helix. Don't regret it for a second. It was fun, a challenge, and yuge. Really YUUUGE!! I had the room. And now, in a somewhat smaller space, I don't miss it and have done what I suggested you do, a partial no-lix hidden from view.
I have a helix on my railroad, and I wish I didn't. I would go with the 2% grade if you can. Helixes are an "unnatural" land form and a maintenance headache. The curves are tight unless you have a huge amount of space, which leads to more frequent derailments with longer equipment too.
Take care,
Greg
Greg Shindledecker Modeling the =WM= Thomas Sub in the mid-70s
Flying CrowI only have 9' total width in the room
Trying to get an idea of your space, so it's 19' x 9' ?
Mike.
My You Tube
I'm using John Sterling shelving components for the bulk of my layout, so I could do some testing when I first started (just had to move shelves up or down as opposed to re-doing benchwork). I thought about doing a two-level layout and experimented having 12" from the top of the lower level shelf to the bottom of the valance above it (so the upper shelf was about 15" above the lower one). It worked OK, for me I found it easy to work on and operate, but it somehow didn't look or feel right...possibly because my prior layout had very high backdrops. I eventually went with one level, allowing for around 24" of backdrop behind the layout.
IMHO - Your space is a little small for a double deck layout. Yes one will fit, but by the time you build it out to reliable operating standards you will find that you are going to have to make some pretty big compromises to get a double deck in this space. Either you will have to take a big chunk out of the space for the helix (6’ X 6’) or you will have to figure out a clever way to double back through a scene to climb up in a nolix to get a decent deck separation (my definition of that is roughly 20” railhead to railhead).
Building a double deck layout is not a simple task. Way more work than two single deck layouts. It would be a shame to spend lots of time on a layout that was so compromised that in the end that you didn’t like the end product of your labor.
If it were my project, I would explore some other design options.
My two cents,
Guy
see stuff at: the Willoughby Line Site
Correct. 19x9
First question should always be, what are you going to run. I got by fine on 18" radius but then most of my cars were 40'.
You can also go with more than 2% grade.
Flying CrowCorrect. 19x9
OK, well with a room, or space of 9' x 19', a 16" shelf around the room, you should be able to get about 44', or 528" of "run" to climb 15", which would be .028 % grade, right? If that's not "do-able" then I guess you'll need a helix.
What about doing part of the grade with a shorter helix, kind of like going up to the helix, spin around a couple of times in the helix, then back out in the open to continue the climb? You could put it in a corner.
OR what I would do, be happy with the 9' x 19' space for one level lay out.
How bad do you need or want the second level? Just to make it a "bigger" lay out?
The reported 9x19' room is very similar to the room I built my last layout, which was 10x18'. As mentioned, I had a narrow overhead of 7.5 inches over the staging tracks and it took a 2.9% grade to take the track out of staging and up to the yard over the top of staging, the 2.9% back down again.
I could pull about 25 cars up that grade with 2 six axle SD45's by way of example. Of course the clearance was very minimal and the yard over head was 30" wide. However if the layer over the top was much narrower, access to the tracks underneeth would be better. But I wasn't trying to build scenery or a town underneath, just park trains.
mbinsewi4', or 528" of "run" to climb 15", which would be .028 % grade, right?
That would be over a 2.8% grade. and that doesn't allow for transitions from level-to-grade and back nor for level areas for towns along the way, if desired. And it doesn’t take into account the extra effective grade caused by friction in any curves along the way. That would be a do-able grade in some situations, but steep for some combinations of equipment, train length, etc.
If the Original Poster plans for a narrow climbing deck around the room or around part of the room between decks, 2.8% is perhaps OK. But without knowing more about what he wants to accomplish with the layout, it’s hard to give more detailed advice.