I'd like to hear the latest from those who have installed helices on their layouts -- particularly, the plusses and minuses. I'm aware that they consume inordinate amounts of real estate and are prone to derailments (especially on the descending track, when the slack collapses and impacts the front of the train). What's the maximum grade and radius you'd consider? Did you homebrew your helix or purchase a commercial one? Would you use a helix again on your next layout?
Mine was 2%, designed an built myself. There was no way in the shaped space available, to gain height to a second deck, other than a helix. I had no troubles with slack, as my rolling stock is all weighted, and equipped with drag springs. My primary dislike was the amount of time a train was out of sight, waiting for it to re-appear. That seemed to break the illusion I wanted to create. If necessary I would build another, but ideally not again.
Helix ?!.... that's a long , never ending, story.... without a other option i'd go for it ! Here in Europe we don't always have enough room for a good, nice and large layout So YES the helix is the right option if you want to climb easily to the second level. I've had a lot of issue with my first helix : - too tight radii - 3% grade - and my main issue was with the flex track joints beeing angled instead of nicely curved. This was mainly due to the tight radii (less than 15 inches) You can imagine a string of 40 ore cars braking up on the last loop and the 30 last cars running downhill... half of them jump of the helix before the end.... A disaster !!! Now I have a better helix : - 2.3 grade - Larger radiis (14 and 15 inches) I know it's tight but it work quite well. Anyway i can't do it any larger. - I made it oval instead of round with a 12 inch staight portion, This allow me a longer ramp, and easier track connection espcially with insulated joiners. It still means a lot of work to make sure the track alignement is perfect. The easy way would be to go with Kato unitrack if you have the $$$$$ Concerning the construction : I bought 7 sheets of plywood that i firmly attached together. Then i had all the sheets cut in one go. So i was sure to have the same shape for every level. After that i drilled holes all around the plywood in order to slip stems. Between each levels I've add some plactic tubes around the stems. Each plastic tube have the same length so once you've ajust the first ramp level , the tube (that you slip between each levels on the stem) will give you the same ramp all the way up. I hope you got the main idea... if you go on my Flickr page you'll find one or two pics of the helix.
I have two Ashlin helices -both are the N scale #2007. It is okay but there are some issues. If I were to do it again, I would go with their larger helix or maybe try the Noch helix. The structure diameter on mine is 30" ----- 36" would have been better. The vertical is 6" at a 2.5% grade (would be 2% with the larger one). The quoted track radii are 12 3/4" & 14"; however, I tried a single 13 3/4" radius but found my Big Boy loco to bump against the support pillars. I had to modify by replacing ~1/4 of the 13 3/4" curves with 12 3/8". The larger helix has 15" & 16.5" - this would enable the use of the Kato superelevated double track curves - although the support posts could be an issue. superelevation- banking the curves - is helpful. The problem, in my case, occurs on the upgrade where the Big Boys pilot wheels derail - banking helps. I also ran into a problem with using a Kato loco (ES44AC) and their Bethgon hoppers. The front truck on the car coupled to the loco will lift off the track on the uphill. Banking helps but simply putting another car inbetween also solves the problem. Overall, the helices do their job - I simply have to pay attention. Dan
Need more options. I would only use a limited helix if it were part of a non mainline run. Like a hostler run into and out of staging, and even then as short as possible.
I have 4 helixes on my current layout. See my blog and albums linked below for entries and pics about why I designed my bowl-shaped helixes as i did, and how I constructed them. Personally, I am comfortable with the short amount of time a train is temporarily out of sight in a helix. When rail fanning 1:1, I may know a train is scheduled soon or I may hear it approaching before I see it, but I rarely see an entire train all at once...just a short section that is close to me and not hidden by trees, hills, or buildings. So, watching a model train disappear into a helix and then waiting briefly for it to reappear, is very much like watching a prototype train temporarily disappear behind something while performing a switching move and reappearing after a short wait...it may not be visible, but I know it will appear soon. I suspect my discomfort, anxiety, or impatience while waiting for a train to reappear is increased or decreased in direct correlation to how confident I am that the train will, indeed, reappear from the helix: since my current helixes are very reliable, my discomfort is very low.
There is nothing wrong with using helixes. Not to toot my own horn here but I will anyway. Here's how I feel about them. I use a number of helixes to gain elevation and hide the trains momentarily so the layout is broken up a bit and not as obvious when viewing my elongated (dog bone) of a loopity loop. Others have called it a spaghetti bowl but my favorite was when someone described it as a, "Folded over pretzled dog bone", originators name escapes me. Other versions have since surfaced. One rule of thumb to remember, "The wider the curves the better it looks". Other advantages as well but you will figure that out all by yourself. Rule #1 is to have fun.
Dave (ppuinn) was the inspiration for my helix on my Montana layout (since dismantled). Mine was a spiral, bowl-type helix, with increasing radius. That simply means the tracks were clear above with no vertical obstructions until the bottom where the helix entered the layout. Dave helped me engineer it well, and it was a great success. I had more derailments on the modeled layout than I did in the helix, FWIW. My helix, IIRC, was a 2% grade, started with a 15.5" rad and increased to a 21" rad before exiting to the top of the second level, about 11 vertical inches or so from staging. See the entire build in my older layout thread, post #186-235. http://www.trainboard.com/grapevine...-D-amp-RGW-Secret-Places-Sub-layout-progress/
Huh? About the same amount as a turn back curve at the end of a peninsula. Again, HUH?? Prone to derailments? Where are you getting your information? Some "real world experience".... I built mine from scratch, used 1/2" mdf and cut out four "quarters" or 90 degree curves for each loop. They are spliced together on the underside with 1/8" hardboard. Vertical pieces of 1/2" mdf with slots cut out of them hold the inside of the loops up. Threaded round stock holds the outside since the layout facia will be attached to the outside of the helix. It sounds like it was a challenge but it wasn't any different than building the rest of the layout's benchwork. The diameter of my helix is 44" (22" radius) and it is located at the end of a peninsula. So it's eating up the same amount of room as the other turnback curve on other peninsula. It rises 3" for every turn (2.17% grade) which is enough room to get my fingers in there IF I ever need to. 30 car trains detail 0% of the time on my helix, going either up or down. There is not really any slack action, the weight of the train is constant against the locomotives going down, and fully stretched out when going up. I even run pushers on the longer trains (40+ cars) and there isn't any problems with slack action or derailments. Trackwork is key, but it's not any different than any other place on the layout. I used a bit more glue since I didn't want the flex track to move at all with expansion/contraction. And no super elevation, that seems like a stringline just waiting to happen. As far as the train being out of view, plexiglass solves that problem, adding a few "windows" so operators can see where their train is. One thing people don't consider is the need for a "ramp" between the flat benchwork and the grade of the helix. You just can't go from flat to a 2 or 3 percent grade. And know your limits. 30 car train on a 12" radius, 3% helix is bound to have problems. The one big thing that I didn't account for when designing a layout with a helix is the amount of drag added to a train while going around the constant curves. 3 locos can pull 40 cars up a straight 2% grade, but put that same grade in a curve, and it will cut down those 40 cars to 30 or less. Even so, if I had to do it all over again, I'd still have a helix. -Mike
Years ago I had considered a helix to gain more main line lenght, but decided against it. All of my track is down and scenery is being put in. Too late to add a helix, but I am satisfied with what I have.
