11" Radious Unitrak Helix?

Grey One Feb 23, 2014

  1. Grey One

    Grey One TrainBoard Supporter

    8,070
    381
    102
    Ya, I know it is a HUGE stretch but thought I'd explore it if just for a minute. There is a 2 foot square corner of my future 3 shelf layout that is begging for a helix between the bottom and middle shelf.
    Parameters:
    • 15" Rise - Approximate distance from shelf to shelf with some wiggle room
    • 6% Grade - ya, I know it is steep but I've done it before - and it worked.
    • 11" Radius - It is s 2'x2' space with no wiggle room
    Am I crazy? Probably.
    Alternates:
    • None - The most practical sollution
    • Ramp / 'Nolex' - can't be done because it would block the living room window and by extension violate the land grant from the "Ministry of Acceptable Living Room Usage".
    I truly don't believe this is a viable option but I'm open to suggestion or gales of hysterical laughter.
     
  2. PaulBeinert

    PaulBeinert TrainBoard Supporter

    622
    1
    13
    I would not want to pull a long train up an 11" helix.
    The 6% grade can easily be reduced to 2% so why 6%?
     
  3. Grey One

    Grey One TrainBoard Supporter

    8,070
    381
    102
    6% - because I can. It would not be for long trains. Over the past few years I have experimented with adjusting train configuration to enable it to make it up various grades and curves. The gist of which is to use short cars and place Atlas GPs mid and end train. No, definitely not prototypical and not to be tried where cars can fall to a hard surface.
    2% I think would be difficult because of the spacing between the top of the rails and the track support above it.
    Please don't put too much energy into this as it most likely will not come to fruition.
     
  4. David K. Smith

    David K. Smith TrainBoard Supporter

    1,211
    0
    22
    Bear in mind that curves will increase the effective grade. A 6% grade (following a straight path) can become 8% or more on a curve, and the sharper the curve, the higher the effective grade.
     
  5. TwinDad

    TwinDad TrainBoard Member

    1,844
    548
    34
    Aside from the cost of the track, which you can probably recoup by selling it, what have you got to lose? Build one up and test it with your trains.

    If anything can work on radii that tight and grade that steep it'll be short trains and short wheelbases, but you'll be really pushing the limits of the tractive effort of the locos. DKS is (of course) right that the radius will only compound the grade, so if you can get the grade lower (or the curve wider) then by all means do so. If you could extend that 24" space in either direction -- make it a 24x36 oval, or make it a 32" circle to get 15" curves -- you can make things easier.

    A 6% 11"R helix is going to be tough. But you'll really only know if you can make it work for your specific situation and the compromises YOU are willing to make if you try it.
     
  6. wcfn100

    wcfn100 TrainBoard Member

    1,045
    54
    28
    With the size train you could get up that helix, it would probably be faster to just pick up the cars and move them to the next level. :)


    Jason
     
  7. BoxcabE50

    BoxcabE50 Staff Member TrainBoard Supporter

    62,026
    7,721
    651
    If you had a siding at the bottom, and another at the top, you could pull cuts of cars up to the top, and reassemble your train. Just like the prototype in similar situations.
     
  8. Doug A.

    Doug A. TrainBoard Supporter

    3,469
    104
    53
    Like others, my initial thought is...no. I think it would be a lesson in frustration.

    But, for grins I'll throw a ray of sunshine....use it for "one way" traffic. (hint: trains going down the helix) Then 0-5-0 them back to the top as needed. Another idea: build a "lead sled" locomotive for ferrying cars back up...something like an SD9 mech with a "box shell" that's crammed with weight. You might need two or three to pull a handful of cars, but maybe it would work.
     
  9. Jeepy84

    Jeepy84 TrainBoard Member

    1,054
    128
    25
    I made a 6% grade break-in figure-8 with an over-under just to run something while I'm working on the wood frames and support structure for my sectional lay out. With an Atlas GP-38, I could haul 4 cars and a caboose around the 8, otherwise the wheels slipped. I built in "easements" by starting with 15in. radius 15degree curve, then a 12.4" 15degree, then into the apex with 9.8"Rs, all Unitrack. You might get a few more cars around the 11Rs, but not many more.
    What kind of spacing between the spirals are you looking at with that grade and radius I wonder... I kinda want to see one built just to satisfy the curiosity.
     
  10. Grey One

    Grey One TrainBoard Supporter

    8,070
    381
    102
    Interesting / constructive / helpful comments and suggestions.
    Hmmm:
    • Gravity feed down and O-5-0 Up - Workable
    • "siding at the bottom, and another at the top," - Viable
    • "What have I got to lose?" - Just my time
    • "Easment from 15 down to 11" - Good idea
    • "I kinda want to see one built just to satisfy the curiosity." - Ya, so would I
    The separation needs to be enough for a GP to fit through.
    Thanks ! for the responses!
     
  11. Doug A.

    Doug A. TrainBoard Supporter

    3,469
    104
    53
    Hmmm, no. Well if you're just hauling squatty/short gons or flatcars maybe? The loco is NOT the tallest part of a train, hardly ever. I would shoot for 1-3/4" railhead to fouling point. (goes without saying that you might weed out some autoracks and doublestacks at that point, none of which really love 11" radii anyway.) Best thing to do is test/measure cars and allow some fudge factor.
     
  12. glakedylan

    glakedylan TrainBoard Member

    402
    4
    12
    unitrak does have a connection track to which other brands of track can be connected
    transitioning from unitrak to another brand of code 80 without the roadbed attached
    would create a decreased degree of incline not needing to have the same clearance as
    if unitrak was used in the helix.
    just a thought, fwiw
    respectfully
    Gary
     
  13. David K. Smith

    David K. Smith TrainBoard Supporter

    1,211
    0
    22
    If you're still half-serious about trying this, one way to reduce that awful grade is to eliminate continuous track support, since Unitrack supports itself, more or less. Support the track on a series of small steel L-brackets attached edgewise to vertical 1x2s. This way, clearance-wise you only have to worry about the roadbed thickness plus a small faction of an inch for the L-brackets.

    Since this may be difficult to visualize, I've made a sketch to illustrate the method. Note that, for clarity, only four sets of supports are shown; there would be eight or more as needed. Also note that the Unitrack joints may or may not need to be reinforced for this to work; trial and error should indicate what's needed.

    [​IMG]
     
    Last edited by a moderator: Feb 24, 2014
  14. jimil

    jimil TrainBoard Member

    32
    0
    4
    Alternate solution #3 is use the space for a track elevator to run between the two levels. Granted, it's not a continuous run, probably would need to be curved or double/triple track to have a meaningful car capactity, and requires some engineering. But, if you really, really want trains to be able to bridge the levels, it's an option. If it fits your layout, you could model it as a rail barge so you don't even need to hide it so much.

    It's not really needed. Peco will slide right into a unijoiner (both C80 and c55 due to the unique way they profiled the c55 rail). Atlas needs some joiner crimping from what I understand. From what I've seen on other forums, its intended more to bridge Kato to Tomix.
     
  15. Grey One

    Grey One TrainBoard Supporter

    8,070
    381
    102
    • @Doug A - Good point. For a train of that nature I would likely run beer can tank cars, 2 bay covered hoppers, and 40' box cars. I have no intention of running anything modern up that slope.
    • @Glake Dylan - Thanks! Ya, I could do change to flex track which would give me greater 'flexibility'.
    • @David Smith - Thanks for the illustration. It will be very helpful should I go that rout. There is a nearby sign shop. I plan to ask them if they can cut circles 1/8" thick to the right radius.
    • @Jimil - Thanks! - Certainly a viable option. If I go that rout it will likely be a cassette system where the cars roll onto the 'cassette, I lift it out and place it in a waiting socket on the next shelf, (maybe at the interchange track).
    Thanks again guys! Lots to think about.
     
  16. Dwyane

    Dwyane TrainBoard Member

    170
    1
    24
  17. Grey One

    Grey One TrainBoard Supporter

    8,070
    381
    102
    @Dwyane - WOW - Thanks! That was coooooool.
     
  18. ppuinn

    ppuinn Staff Member

    2,196
    461
    42
    Ditto!!

    Steve, For what it's worth...When I constructed a double-tracked, stacked helix many years ago, I trimmed and soldered each segment of my Atlas C80 Flextrack and slid the track down around the helix, just as Mike Fifer demonstrated in his video with his Unitrack. It worked like a charm to get the soldered track into place on all of the loops. I then used track nails through the holes Atlas had provided on some ties to secure the track to my Homasote subroadbed...and yes, it was very hard to find the specific ties with the predrilled holes on every loop except the very top one, because the overhead clearance prevented seeing between the rails so I was forced to probe with the point of the nail to find the hole and then use my needlenose pliers to drive the nails into the Homasote. A difficult and tedious job, but do-able. For me, problems came months later when a section of rail separated from the ties (the plastic spikes broke) and attempts to superglue the rail failed. The subsequent replacement of a short section of helix track was my worst modeling experience ever and prompted me to develop the bowl-shaped helixes I have on my current layout.

    If you decide to use something like Mike Fifer's Masonite helix design for your stacked helix, you can solder sections of track together and then slide the track around/down the helix (just as Mike showed in his video). But instead of permanently securing the track to the subroadbed, I'd encourage you to keep the track in place by gluing small squares of Masonite to the Masonite subroadbed at the four points of the compass on each loop of your helix (touching but NOT glued to the inside edge of the plastic ballast of your Unitrack). If you do not solder the rail joiners where helix track joins deck track at the top and bottom of the helix, then, in the (unlikely) event of needing to make repairs in the future, you should be able disconnect the helix track from the deck track and slide the track around/up the helix to remove it from the helix structure.

    You may have considered this already, but just in case...
    Each helix loop will have about 6 ft of track, so to rise 15 inches, you will have about 21 ft of track in the helix. Even if you solder all rail joins from top to bottom of the helix to ensure conductivity, you should also solder some electrical feeders at a few places within the helix to ensure there is not a drop off in voltage due to the long distance between feeders at the top and bottom exits of the helix.

    DO NOT install track on the helix and then install the helix on the layout without any feeders!!! (Sadly, that is the booming voice of experience.)
    If the helix is attached to the benchwork, you may be able to reach most of the outside rail by pulling the benchwork away from walls or bending between the decks; but, to solder a feeder to the inside rail, it will be necessary to stand inside the helix (perhaps a maximum diameter of 20 inches) or else reach inside the helix while standing and leaning over it from above the upper deck (and straining back muscles while blocking any light from above--says the voice of experience).

    The easiest way to install feeders on a stacked helix, is very early in the construction process, by soldering a pair of feeders to the rails once every loop AS YOU SOLDER the rails before sliding the track around/down the helix.
    If you prefer to attach feeders later in the construction process when track is already installed on the helix, it will be easier to accomplish if the helix is still free to move around on a workbench, table, or on the floor, instead of already connected to the upper and/or lower decks of the layout benchwork. On a workbench or table you can easily turn the helix to reach most of the outside rail with your soldering iron and solder, and on the floor, you can sit in a chair to lean over the 15 inch tall helix to reach the inside rail of each loop (much easier on the back than leaning over when the top of the helix is at upper deck height).

    If you decide you want two decks connected by a stacked helix, please post a track plan and list some of your givens and druthers. While your givens already include 11 inch radius helix with 15 inch deck separation, your druthers could affect positioning of helix entrances/exits at the front or back of the decks, how much of the heighest and lower helix loop is visible (and sceniced), and how much the track rises from the lower deck elevation or falls from the upper deck elevation before disappearing into (or behind) the helix.

    Are you interested in a double track helix? In your opening post, you indicated the land grant was restricted to a 24x24 space and I assume David Smith's 24x36 inch oval helix may have complied with the window boundary, but intruded too far into the rest of the living room to receive approval by the Ministery of Acceptable Living Room Usage. Is it possible to re-negotiate for a 27.5x27.5 inch space that could accommodate a double track circular helix with 11" and 12.75" radius loops? ...or have you reached the limit on accommodations, variances, and waivers you can get from the M. of A.L.R.U.?
     
  19. cne_craig

    cne_craig New Member

    7
    1
    4
    I use a helix on my small layout that illustrates what David has suggested. Here's a pic:
    helix.jpg

    It uses 3% grade which is established using the Woodland Scenics riser set at the first level. There are 8 L brackets extending from posts(8) and I use a leftover L strip from suspended ceiling tile to provide the point to point support. I used the 12" Unitrack pieces which do need to be supported between each post (they'll twist and flip with the weight of a locomotive.) Each post aligns with the unitrack joint. I used a spacer block to define the location of L brackets on each successive level using the woodland scenics incline as the defined grade.

    I tested this with autoracks and 6 axle diesels for clearance, but I model the 1890's so nothing to worry about as far as clearance goes.

    Cheers,
    Craig
     
  20. Grey One

    Grey One TrainBoard Supporter

    8,070
    381
    102
    @David - Nice to see / hear from you again. I hope all is good in your world. As you may have heard I'll be getting married on May 31st, 2014.
    Thanks for the information. It has been bookmarked and will be studied.
    @Craig - Thanks for the comments.
    I do apologize for getting back so late. Planning for a wedding, working, and taking care of a 4yo is rather time consuming. Still, you can be sure I'm not complaining. :)
     

Share This Page