LION use salvaged OSB board. Helix of him works just fine. [on the east helix, the west helix is described below].
Here is other helix of LION. It is mostly built oc 1/2" Celotex material supported by foam risers. The track directly behind the buildings is built on 2" thick fiberglass roofing insulation (you can buy the stuff in home stores cheap enough, but LION got his for free by dumpster diving on a job site.)
The helix leaves the middle level (with the yellow and green trains parked on it.) and travels down two complete turns to the lower level. From the middle level it also goes up two complete turns to the upper level. You can see the 42nd Street Station just above the green train, that is the middle level of the upper helix. This too, is 2" fibber glass roofing insulation. As you can see, there is not much in the way of risers holding that level in place, as the material is that stiff, light and stable. Note the joint on the 42nd Street level just above the signal at chain mark 1296: that is not a joint in the main track deck, but is only a joint in a 2" wide extension that was added later to accommodate a static local track to complete the illusion of a four track station.
The helix represents a huge change in levels as the three decks along the south and east walls of the layout are about 15" apart., but then the table holding this oval helix is 6’ wide x 18’ long.
I disagree with trainnut250. I used good old BC plywood. Cabinet grade plywood is an unnecessary waste of money (unless it’s on sale and cheaper than BC, of course). You’re not doing finished carpentry; you’re making rough-cut subroadbed. BC is plenty strong, and with sufficient risers it shouldn’t distort (twist, warp or other heinous movement). If your environment is such that it’s likely to do that (say, large humidity swings throughout the year), paint it after you cut it to seal it from those changes.
Then spend the money you save on plywood elsewhere on the layout.
I only skimmed through all the responses here, but I have designed several layouts for myself and others using one or helix transitions from level to level.
For any kind of long trains, I have found nothing less than a minimum radius of 36" to be satisfactory. This provides a grade of aprox 1.8% and has proven to be very reliable. One layout I designed for a friend has two such helix rises - we regularly pull trains of 50-100 cars with no problems - no need for excessive motive power, no stringlining or derailment problems.
There is no subsitute for large enough curves - in a helex or elsewhere.
Having a 36 inch radius and a 1.8 percent grade should handle any HO train one can throw at it. Anything less than that and performance and reliability begins to fall.
LION has 5’ wide table, figure radius of 28, 26, 24 and 22" on the four track helix. Him uses some super elevation, but what saves the operation is that him runs standard trains of 6 50’ cars, with powered units toward the middle of the train.
LION thinks everybody should build subway layouts.
Hi I have read all the comments about the Helix… I am new to the hobby although I have been slowly buying some engines and cars and things, I bought a Helix from Ashlin Designs, with a double track, 26 and 28 inches, 2 percent grade, 2.5 levels, overall dimensions 59.5 wide and 11 inches tall… I have both Locomotives like the Challenger and the Big Boy, also some Diesels… I see everyone has suggested 30 inch radius or more… so the question is, can I run all or some of my stock on this size Helix?? my e-mail is dtbarron@hotmail.com I would really like to hear what you think thanks David
As for the locomotives, you will have to see what works and what does not. It may make an interesting operation to have to pull the big guys off and let a fleet of smaller locomotives double the train up the grade. For pulling a train up a long grade the UP Bigboys had no equal, but wending through the mountains, me thinks knot. NP conquered the mountains with electrics. Maybe your steam brings the train to the mountain, and then the Electrics (Little Joes and or BiPolars) could pull them over the mountain.
meeting a polar bear is not so bad, I do not want to meet a bi-polar bear!
Some of the Ashlin Helix products are not advertised accurately in terms of the grade, and this might be one of them. The standard Ashlin helixes are made from 1/4" MDF with a 4" clearance between roadbed turns, which implies 4.25" railhead-to-railhead elevation gain. This results in a nominal 2.6% grade for the inner turn and 2.4% for the outer turn, not “2 percent” as advertised. I have emailed Ashlin about this a couple of times, but the published specs have not been changed.
When you add the effective grade caused by the sharpness of the curve from the formula mentioned earlier, this results in a grade of 3.8% for the inner turn and 3.5% for the outer turn, fairly steep.
I think it could be a challenge for some of the longer engines coupled to longer cars, no pun intended. Also concerning is the 2" track-to-track clearance for the two tracks. that may prove to be too close together for your longer equipment to avoid side-swiping. 2 1/4" to 2 1/2" between tracks would be safer, but I don’t know if that is possible on the Ashlin helix as built. And if it means a tighter radius for the inner loop, that would increase the grade, of course.
I hear you on the expense thing…After bad experiences with cheaper grades of plywood on my old layout, I just bit the bullet and went with cabinet grade everywhere on my layout for sub-roadbed…No warps no fuss and dead flat level. Could be that the quality of plywood is different where I live - All the BC sheets in the stores in my area were potato chips… Never regretted the extra expense…Roughly $10 - $15 per sheet…
Nope. LIONS are not made out of money. LIONS have not the carpentry skills required for using furniture grade bench work. Which is another way of saying that carpentry skills of LION will produce no better a product than if him used OSB board.
If your skills are different, you can use better, but if your skills are that good, you would not need to use better anyway. Or so thinks the LION
You have so much space it makes me jealous… My whole room is not much bigger than the space you have just for the helix.
Because I have less space, my tolerances are much tighter. I can’t use many of the materials that you have suggested in this thread because they won’t meet specs. - especially in terms of thickness…
For example, looking at your helix pics, your sub roadbed thickness appears to be in the neighborhood of 2" - way too thick for the design specs dictated by my space.
Notice how tight everything is - plywood must not warp and there isn’t space to reinforce it all over the place…This design drives my choice of materials…
I love your approach to building a layout. The miserly side of me really likes your thrifty ideas which I try to apply where I can. Sometimes it works for me, other times not so much. I’m sure you feel the same way about some of my layout building ideas…
IMHO: Seeing different solutions to the same problems is what makes the forum a good place to be…
Now maybe I missed it but before anyone says this or that is bad, one of the first questions that should have been asked is how long of trains and made up of what type cars. You can run a pretty tight helix with a short train using 40’ cars. Where you run into the things discused is that the longer the train, the more the preceding factors fiqure in. Even on a simple curve of say 18" that I think everyone will agree will take a 40’ boxcar. Once you start getting a very long train (say 20 cars), this starts to be a problem on many levels, and this is on the flat, the rise just magnifys the problem.
The “helix” with the 2" thick decks is large, but only the straight sections are thick foam, the curves and the back section are 1/2" Celotex.
Here is OSB helix which of course is now finished. This helix raises the line only about six inches. The tables are a pair of 5x9 ping pong tables. (sturdy ones hand made for use of students in the days when we actually ran a school here. There are ramps at the north end of this table, for all of this track work fallse between the lower and middle levels as seen along the back wall you can see the three levels of the main line.
The other table is a pair of 3x18 foot tables side by side, and no I cannot reach the middle of the table: who cares: there is nothing there.
This is the north end of the west helix, the south end being about 12 feet away.
Here is the back side of that table.
On the bottom, that pink foam represents the location of the Cortland Street station. It is the lowest level of the layout. Behind that is the Nevins Street Station, it joins to the lower level at the far end
