At some point I hope to start building my first real layout at home and based on my desire for continuous loop operation I know I will need not only a Helix but what I think will be a complex entry / exit to it. To help you visualize what’s solely in my mind is a 3 or 4 level HO layout that each level would have two loops (outer circle loop / inner figure eight) and the two main lines could operate DC (later DCC) trains running in opposite directions or via switches one running over both lines. The Outer Loop would be slightly lower than the Inner Loop and the Inner loop would have the trestle crossing point type design as part of the figure eight. At each level at the far end on the loops both lines would enter a tunnel where the trains can be switched onto the helix to change to the next level or remain at the same level. The bottom level would easily enter the helix and the upper layer can easily enter the helix. My issue is how one would get the middle level(s) to enter/exit the helix; especially the inner loop being the primary trouble point. My ultimate goal is to run a passenger train over the entire layout and thus the curves would need to be wide enough within the helix to support this train without blowing out the space available. Access to the layout would be from both long sides as well as the one end not supporting the helix. Internal Helix access would be a duck under. So, envision 3 to 4 long rectangle layouts stacked on each other with one short end of the rectangle against the wall and this would be the end the Helix would reside in. Then picture this as several levels of track using trestles between two peaks which one peak hides the helix within it and the other just there to support the track travelling around it. Hopefully this gives you a mind’s eye view of my current vision and maybe someone can tell me how one might approach the Helix entry / exit points of the middle layers for the inner loop OR tell me I’m completely mad… - -
Sounds like you've got a good plan. The photo attachments you shared show off some good looking passenger cars and stove. A helix and switch hidden inside a helix can spell maintenance problems. I ought to know. I tried this on an earlier layout and swore I wouldn't do that again. I do like the overall idea and purpose of the helix. It has loads of potential. Plan to use as wide a curve as possible in the helix. This will lessen the drag created by the curve and helps to reduce the overall percentage of the grade. Have fun.
That's a photo of my 4-6-6-4 Challenger with a couple examples of passenger cars that I would like to be able to traverse the layout continuiously with; hence the wide curve requirements. I hear you about the switch issue but this is more outside the Helix within the "Black Box" that contains it. The switch is to anwser the question of does the train go around the Helix or switch onto a track that will us it to travel either up or down. I think this might be simple as 2+ Helix's stacked onto each other with 4 tracks on the Helix itself; (1) Inner Down, (2) Inner Up, (3) Outer Down, (4) Outer Up. I think where I get my head in a spin is how to get to the Helix Inner Up/Down tracks without running into the Outer Up/Down at the middle level(s). I'm sure I'm missing something basic that I will go DUH! in the end... :tb-smile: :tb-smile: :tb-smile: :tb-smile:
You might want to take a look at my layout on RailImages. See invite below. Not that I expect you to copy it. Glean an idea or two...perhaps. I have four tracks in a helix and end up running two of them, on the inside (part of the coal district) out and around the other two that serves as an uphill and downhill main. Go to Final Phase in my albums page 2.
Trust me, I've been looking at your layout images as well as others looking for that tid bit of information that will solve my question. For space reasons, I know I will have to have a tight design such as this one in Maritimer's gallery; but, I believe I need two (one nested inside the other), that spiral in opposite directions so trains from the Middle Level(s) can travel either up/down of stay at the same level from their respective main lines. So, when looking at this design that handles getting 1 train from an Upper Level to a lower staging area and back again, how would another level access this from a Mid-Helix and go either up or down. Once I understand that then toss in the train #2 that would independently also need to do this in the opposite direction. THis is why I thinking I'm going mad trying to do this... :tb-confused: :tb-confused: :tb-confused:
Have a look at this article. It may allow you to do what you want. An oval helix with a crosover in the middle on some levels. Expand the strait legs a but and put double crosses in there and you might be able to do what you want. http://users.rcn.com/weyand/tractronics/helix/hlxartcl.htm
Gosh Darn that is one amazing helix! I should of had you build mine. And, to think I was going to help you. Now that's funny! I knew you had visited my images from the interesting, non-verbal messages. I appreciate your interest. Now that you have my attention, look out. The key to having one track for the up hill and one downhill run, is to have a dog bone that connects them both to each other. From what I can see you may have already done that. You'll figure it out.
Darren: If you want to run 2 trains simultaneously across all levels (one on the outside loops of each level and the other on the Figure 8 inside loops of each level) AND want to let both trains orbit at their own pace instead of constantly monitoring or scheduling both trains, you will need two separate 2-track helixes, not one 4-track helix, because the inside and outside loops for all 3 levels and the respective helix that connects them must be independent of each other and must never cross each other at the same elevation. One way to accomplish this would be to put a 2-track helix for the outer loops at one end of the layout, and a 2-track helix for the Figure 8 inside loops at the other end. Like this: The inside loop helix would be set 3 or 4 inches higher than the outside loop helix so crossing the outside loop track on an overpass bridge would maintain the independence of the inside and outside loops. The inside loop helix would have exactly as many turns as the outside loop helix, but each inside loop helix turn would be 3 or 4 inches higher than the corresponding turn of the outside loop helix. At a 2% grade, the inside track on the helix would need to be at least a 32 inch radius to yield a 4 inch rise between railheads for each turn of the helix. The radius of the outside track on a 2-track helix would be about 35 inches and the outside edge of the turn ramp would have about a 37 or 38 inches radius (outside diameter of a 2-track helix footprint = 6 feet, 4 inches; 2 helixes would take up about 13 feet of the layout). Assuming a 2% grade to the trestle bridge on each level and 4 inches clearance between the lower and upper tracks of the Figure 8 inside loops, then the track plan would need 13 feet of helixes and about 13 feet of layout shelves. As an alternative to putting a 2-track helix at both ends of the layout, it would be possible to have two 2-track helixes that rise 8 inches in a single turn instead of only 4 inches. The 2 helixes would be nested within each other so that one helix would start at 0 inches and climb to 8 inches with its first complete turn, and the other would start at 4 inches and rise to 12 inches by the end of the the first complete turn. Radius of the inside track would be 64 inches, outside track radius = 67 and outside edge of the ramp would be about 70 inches (a little less than 12 feet diameter). To fit such a helix into a room more efficiently, it would be possible to construct an oval shaped helix that had 6 foot, 4 inch outside diameter curved ends and 3 foot long straight sides; an oval helix would take up about 9 feet, 4 inches of the layout).
Thanks All!!!!!!! 216"(18') x 96"(8') Drawn with Atlas Right Track (Freeware) v8.0 OK, using the input all of you have posted I think I've "roughed" out Level#1 of what this monster might look like some day. The outer two Helix's are for Upward travel and the inner two Helix's are for Downward travel at a steep grade. As talked about before, there is very limited space so it's tough to build a HO layout in this space and to mazimize mainline lengths vertical lift using as tight of curves is a must. At the same time the goal is to run long passenger cars so one can't go too tight either. Obviously there are areas that need work but at least there is a drawn picture now to work from. The "exit" of the inner two Helix's onto Level#1 would have to be low enough to duck under the outer making it's first loop upward. The inner figure eight idea is tossed out and replaced with a inner oval; will need the center open for access. So far I have not attempted to connect the Outer Oval to the Inner Oval but obvious the potential is there currently and desired. Both Helix's "extend" onto the layout in such a way a train on either line can enter onto Level#1 via the Helix and exit via the Helix without entering either Oval loop. Trains can switch on/off the Helix lines via the "extended" sections to avoid maintenance issue. Level #2 to be drawn next; but, what do you think of this roughed out drawing of Level#1?
Thanks for posting the plan and providing the dimensions of the workspace. The plan shows the inner 2 tracks rise as they circle clockwise to the 2nd level and the outer 2 tracks rise as they circle counter-clockwise. This will lead to a problem with clearance. Assume each helix loop rises 4 inches in a single loop and that the 2 outer helix loops start at 0 inches elevation at the 6:00 position and the 2 inner helix loops start at 0 inches elevation at the 12:00 position. (Note that the inner helix loops will also be at 0 inches elevation when they pass under the outer loops at about the 10:30 position.) When the outer loops are at the 3:00 position on the first loop, they will have risen 1 inch, and at the 12:00 position they will be at 2 inches elevation. By the time they get to the 10:30 position, the railheads on the outer tracks will be at 2.5 inches. That is sufficient clearance for N-scale but not for HO, especially if there is any thickness to the helix ramp, itself. I'll try to generate an alternative.
Level#1 - Cleaned up the layout plus a few adjustments I've spent some more time on Level#1 today to clean up the rough edges, flipped the design over, and got the entire layout connected. This DC designed layout would therefore run clockwise and the switches with the right insulated points should allow each the the four color coded lines to operate independently. ==Light Purple== (Outer Loop Line) ==Dark Purple== (Outer Helix Line) ==Dark Green== (Inner Helix Line) ==Light Green== (Inner Loop Line) Dave, part of my madness behind this design is the "extension" of both Helix lines onto the layout itself to create what I will call a "gap" within the main section of the Helix to create the needed clearance. I have not yet added in "Elevation" data into the layout software but the idea here is that the Outer and Inner Loop & Helix lines can operate at slightly different base elevations (if needed) and by also "extending" the both Helix lines on to the layout one can have the equivalent rotation(s) occur at a different grade since there is no track above to worry about clearance. Keep in mind looking at this, each of the four (4) Helix loops are not connected, they are nested as two separate parallel Helix spiraling in opposite directions. The Inner two Helix loops bring the trains down from Level#2, the trains would be exiting onto Level#1 and passing under the Outer two Helix Loops with the needed clearance built into the design. Once the trains pass by the lower crossing section these two Helix lines would start a upward grade toward the top section of the design before entering the Outer Helix loops to climb to Level#2. So, let's say for now, the Inner Helix loops enter onto Level#1 at baseline 0" and the bottom of the Outer Helix Loops are at baseline 2" so by the time the Inner and Outer Helix lines cross each other there will be 4+" of clearance and if that is not enough, then the bottom of the Outer Helix Loops will start higher to create the needed clearance. The elevation of the two Loop lines will be initially based on whatever the elevation is of the crossing sections end up being and then Otter Loop line can slightly change elevations around the loop if desired. This will mean the Inner Loop will be slightly higher then the Outer Loop line. Since the layout dimensions are not yet set in stone and potentially would be reduced I've also adjusted some of the track lengths to pull the layout inward away from the edges. Currently this generates about a 4' walkway on the bottom end of the layout with the top of the layout being against the outer wall of the room. The right/Helix side would also be against the outer wall leaving about 6' on the left side which needs exist. The center of the loop line will need to be accessible via duck under but will likely contain some sort of scenery that can be dropped out. The center of the Helix will be accessible via a duck under which is roughly a 3'x3' opening. This leaves the upper/right corner as the "danger" spot for access so I might have to have a cleaver way to reach that area from below as well. Also, most of the Outer Helix will also be tough to access, so I might also need a cleaver way to drop the Inner Helix out. As you can see, the engineering behind this monster will have to be considered carefully unless I find a way to have access from the right and top of the design which currently doesn't look possible. Only time will tell whenever the room gets built; so, this is still just a preliminary idea of how to maximize usage of the proposed space. :tb-rolleyes: :tb-rolleyes: :tb-rolleyes:
Your dimensions are working out to--essentially--about a 4.5 inch rise for each loop of any of the 4 helixes. If I understand correctly, you want all helixes to go to all 3 levels, although the up and down helixes associated with the outer loop of the bottom level will be independent of (i.e., the tracks never connect with or cross at grade with) the tracks of the up and down helixes associated with the inner loop of the bottom level. How do you plan to enter the second level...perhaps on the other side of Helix 26R at 11.25, 15.75, or 20.5 inches above the lower/first level? It would seem like, at some point, you will not have enough clearance. Suppose the base of Helix 26R is at 0 inches elevation. Upper elevation of each loop will be at 4.5 for Loop 1, 9.0 for Loop 2, 13.5 for Loop 3, 18 for Loop 4, etc; and exits to the second/middle level will be at 11.25, 15.75, or 20.5 inches. Adjusting the base of Helix 30R to be somewhere between 0 and 4.5 inches above the Helix 26R will yield clearance for Helix 30 to pass over Helix 26R on the lowest/first level; but, where Helix 26R and Helix 30R enter the second level, there will only be a maximum clearance of 2.25 inches between the railheads of Helix 26R and Helix 30R . Is that enough clearance for HO? Even if Helix 26R and Helix 30R will only connect the top/third level and the bottom/first level, it would seem like you will still have the same clearance issues with Helix 34R and Helix 38R where they enter the middle/second level. How are you configuring your helix tracks for exit/entrance to the middle level?
Once I finish working elevations on Level#1 to make sure I have the needed rough clearances within Level#1 I will put together Level#2 of 3 where the issue of how to get in / out of the Inner Helix at Level#2 magic will be divulged as I believe the solution to that is at hand. I think you will find my slide of hand a interesting and workable solution. :tb-wink: :tb-wink: :tb-wink: :tb-wink:
OK, I've convinced myself that the clearances for Level#1 will work; but, roughing in the room I'm not sure how happy I will be with the plan. Still, will work on Level#2 to at least prove the concept of my Extended Helix idea would work if I went with this type of design... :tb-nerd: :tb-nerd: :tb-nerd:
Drop back and Punt OK, I finished roughing out Level #2 tonight just to prove that the concept would work with enough space. With a few exaggerated grades to force fit the concept into the confines of the space I have come up with the attached drawing in 3D view. As you can see, by "extending" the Outer Helix onto the layout it creates the "gap" needed to allow the Inner Helix to also extend onto the layout as well. Well, obviously with my limited space the concept will end with this drawing as a non-workable design. So, the next plan is to basically make the entire layout a type of Helix with less main line options. Thank you all for your inputs as it at least gives me ideas on what can work and won't work in the limited space I'm going to be confined too. :tb-wink: :tb-wink: :tb-wink: :tb-wink:
