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
22" helix sounds unrealistic
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:
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
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".
I have both on my HO layout at a steeper grade of 3½% to gain 10½”, the helix has 30” radius the rest of my mainline has 32”. I haven’t had any problems on either the long grade or the helix. I do however have very heavy locomotives with a lot of traction. My lighter Three Truck Shays do well with a dozen Shorty log cars but my 2-8-0 doesn’t do well with more than three 28’ coaches pulling the helix. It does better on the long grade.
My norm is going up the long grade and down the helix, less wheel slipping with lighter locomotives.
My 2-8-0 has Bullfrog Snot on two wheels and when it wears down it’s a goner, I don’t like Bullfrog Snot. Passenger Service to the mountain communities will be a goner when the Snot is gone. They will have to make do with a Drovers Caboose on a Shorty log train powered by a Shay.
Mel
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
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
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.
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?
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".
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