One thing to remember above all - make sure you have furnace access, and I don't mean by just crawling under the layout.

If you don't, I can near guarantee your furnace will die and require replacement within 6 months of bulding the benchwork in front of it.

You also need to be able to replace the furnace filters on a regular basis.

rblundon Go back to page 1 of this threed and read the post by Russ Bellinis & the post just after it by joef and jurgen you need to read them also. I wasn't telling anybody to build 4% grades it's just how I avoided the helix but Russ has the best idea. My final suggestion is build a model of your drawing of the RR and the room using cardboard and use 1 inch = 1 foot for a scale and build the whole thing and you'll get a good look at what your about to build and what the helix will do to your work space. also you talk about the duck unders the helix is the most cumbersome duck under you will have as after the frame work you'll end up with a 24 inch circle to have to climb inside of to work on the helix as well as retreve trains. I wish Russ had posted the Idea of around the wall Ne-lix a year ago.

Dan

I'm not sure that I have been here a year, yet.  I usually post ideas that I get from analysing a problem that another modeler has posted about, rather than doing a lot of original ideas just in case it helps someone. 

To reiterate my original idea, since the discussion has seemed to have moved beyond what I originally posted.  The concept I had was to make the room a big helix (nolix) on a constant grade shelf a maximum of 4 inches wide (six for a double track).  The nolix is entirely to be treated as "hidden tracks" and is not a part of the layout and not connected to the layout except at the switches where the train moves from the modelled part of the layout on or off of the nolix.  I think a small view block going up to slightly higher than a normal sight line when operating in a scene just in front of the nolix will be sufficient to hide the nolix except when a train is going up or down.  I can't speak for anyone else, but I prefer not to have my trains hidden from sight for long stretches; since no matter how good the track, Mr Murphy dictates that trains will always derail anyplace that tracks are either hidden or hard to reach.

 I'll start with some honesty.  I like the helix over the nolix.  This doesn't mean I can't be persuaded, I'm just skeptical it will work in my space.

I did the math and one trip around the room on the wall with 30" radius is 500".  

I'll lower the clearance for each deck to 16" instead of 20".

Keep in mind that the area I'm modeling is relatively flat and has a swing gate.  Ok, so let's assume I'm going this route...  How do I disguise the tracks behind the buildings?  It wouldn't look very prototypical...  I also want continuous running, so I've gotten up the layout into staging, how do I get back down?  I either need reversing loops at each end of the layout, or I'll still need a helix to get back down the layout.

Now, here's my math on the helix (I'll use my inside radius (187" long)for the calculations) (inner radius (down) 29.75", outer radius (up) 32") :

2.1% was my planned downward grade.  I realize that being on a constant curve increases the effective grade, let's not get into that debate for the next week, it's been beaten to death enough...

Ok. Maybe I'm not understainding. But what understanding I believe I have says that a "nolix" makes the layout itself a helix. As pointed out  by Mr. Blundon one lap of the room is 500" (roughly 42'). A 2% grade yields about 10" of rise per lap.

BUT (also as pointed out)

You can't build switching areas on a 2% grade. Cars simply won't stay put. If half of each deck is to be dedicated for towns, sidings, or switching, that implies the loss of at least 1/3 of the run on the grade. To achieve that 10" of deck separation you're now talking a 3% grade.

A 3% grade is fine for a mountain railroad but would look odd if one is modeling Nebraska or Kansas.  Having a 10" deck separation also would mean not modeling much of the mountainside.

I'm afraid that a pure no-lix approach in a 12'x12' room isn't terribly attractive, at least not in HO. I would recommend NOT doing a no-lix in such a space. Yes, it can be forced in place but I don't think the result would be terribly satifactory.

An alternative: using twice around designs for each of the two active decks.

This has the issues of:

* not sincere - the train appears to run through each scene multiple times

* reducing the space available on the already a bit narrow benchwork for industries, interchanges, etc.

But the benefits are:

* twice (roughly) the trackage on each deck reducing the visible to hidden-in-helix track ratio by a factor of 2.

* if the two laps are at a 4" elevation difference use a 1 lap helix to connect the two laps on the two decks (which then reduces the time in helix to go to the next deck (does help much with the trip from staging to the lower deck)

Actually, the keys for the design as presented are probably:

1) can you stomach to amount of time needed for trains to run through the helix. Joe Fugate makes a valid point when he says that running in hidden trackage is more than a little like running trains with your eyes closed. Hoever, not completely enclosing the helix so you can keep an eye of the trains in there will help - a bit. I think than anyone contemplating a large helix would be advised to find a layout with a large helix and see how well they tolerate the traversal times.

2) a nested helix - separate inner and outer laps - is a nasty bit of work to construct. Are you up to such construction?

3) the over/under swing bridges across the entrance door are going to be tricky to construct. But possible. I had such an arrangement on my second BC&SJ railroad and it worked ok. But, where/how are you going to anchor the ends of the bridges? It is VERY important that the ends be strong and stable. I noticed that you designed in space for the bridges to swing without hitting the peninsula - good job on that (easily forgotten) detail!

All that said, the only thing you can't get around by utilizing skillful construction (or persuading friends who know what they're doing to help) is the helix issue. If you are ok with the times-in-helix (and the need for extra motive power for long uphill trains) then I'd say "go ahead".

But this layout does put an awful lot into a relatively small space.

Charlie

 Ok, Here's the start of something with the helix completely in the back room.  Note: accessibility is not an issue.  I'd like thoughts on how I could turn this lower deck into a twice around (not prototypical) also, thoughts on how I could incorporate a stub yard into a center peninsula.  A thought is that all (most) of the industries could be serviced from the peninsula yard.

Thanks for your ideas!

You layout is about the size of my layout that was upstairs at my uncles.  You might look at what I did with that, there's a post in my blog section, I do believe [I hope!]

My layout had a staging stub yard under the higher level, about 16" separation.  The area was tied to the upper level by a level on one side that was halfway between the two, and then I used 3% grades.  There were wide flat areas, while a single mainline connected the two.

There's much to be considered in your room!

This is basically what you want to do do now and is the plan I abondened with a helix outside the room. Now my plan is 12ft 6in wide and 14ft 10in long with the helix in a second room and is designed as adouble deck with 16" between decks.

here is a card board mock up of the first level after I removed the helix. I not saying build your Railroad like this. I'm saying build a Cardboard mock up of your Railroad and then see what kind of space and room you will have. In this photo from left to right is 12' 6" and then another 4' 6" into the next room where I was going to put my Helix. Just to give you and idea of how to build a mock up of your Railroad. It helps alot to visualize what your building.

Dan

 Dan,

Thanks for the picture! I'll give your idea a try.

Ryan

If I were to put (through) staging under the lower level, how much clearance would I need?  Mind you that Torts will be running the turnouts.