Northpoint Posted January 12, 2012 Share Posted January 12, 2012 Since the demise of my garage layout last year, I'm thinking of a new project there - a shelf layout around the walls on two levels. That raises the question of a helix between the two levels. Space is limited and I'm looking at something around a 10 inch separation, approx 22 - 24 in radius which should give a gradient of about 3.5%. Now, the question is to all you helix users or physics graduates - how would that work in practice in terms of the train actually staying on the track and not suffering from "stringing"(?). The train would most likely comprise a loco and up to 7 or 8 cars. No double stacks or tri-level auto racks, just plain old boxcars, hoppers and similar. Any thoughts would be welcome. Link to post Share on other sites More sharing options...
sunshine coast Posted January 12, 2012 Share Posted January 12, 2012 Nick, from what I have seen over the years, the numbers of freight cars you are talking about should give no problems at all.... providing there are no wildly different weights or stiff runners..... ie..... 6 very light cars with a very heavy,poor runner at the end Regards Trevor... Link to post Share on other sites More sharing options...
shortliner Posted January 12, 2012 Share Posted January 12, 2012 Nick - take a look at http://www.trainorde...d.php?3,2607350 and http://www.trainboar...ale-return-loop for some info and advice, Note the comment to "ensure that lighter cars are kept to the rear of the train" Link to post Share on other sites More sharing options...
dave_long Posted January 12, 2012 Share Posted January 12, 2012 One thing to be wary of would be multiple loco working, if you choose to do that as there is usually less slop with couplings due to things like plows and tight coupler boxes, which you wouldn't get with freight cars. Link to post Share on other sites More sharing options...
trevorsmith3489 Posted January 12, 2012 Share Posted January 12, 2012 Hi Nick I am in the process of building a helix http://kaleyyard.wordpress.com/the-helix/ This is my second helix - the first one worked reasonably well, the second one is only in the construction stage and has not been tested with full length and full weight trains. My original helix was twin track with a minimum radius of 28 inches for the downhill segment and 31 inches for the uphill segment. 4 inch seperation between levels, 8 inch elevation per circumnavigation. 20 twin stacks did not string, autoracks did with more than 18 on. No problem with box cars. I try to make NMRA weight standards. No problem with 2/3/4 locos on the front end, did have a problem with locos pushing, more an issue with speed matching than any problem with the helix itself. Hope that helps Trevor Link to post Share on other sites More sharing options...
pH Posted January 12, 2012 Share Posted January 12, 2012 I've read somewhere (I can't remember where, of course!) that building the track in a helix with reverse superelevation, i.e. leaning towards the outside of the curve, can help to reduce the tendency to stringline. Link to post Share on other sites More sharing options...
Northpoint Posted January 12, 2012 Author Share Posted January 12, 2012 Great - thanks for all the advice! It seems that my fears were possibly unfounded, so, watch this space.... (Mind you, I have to clear the junk out of the garage before I can make a start so that might delay things) Link to post Share on other sites More sharing options...
shortliner Posted January 12, 2012 Share Posted January 12, 2012 Nick are you doing the wood spacers (fixed angle), or the Threaded rod and nuts (adjustable gradient) variety Link to post Share on other sites More sharing options...
long island jack Posted January 12, 2012 Share Posted January 12, 2012 Nick when i modeled n gauge,i had a 6 turn helix with 24 radius and woodern spacers, train lengths were 3 gps and 50 freight cars never had any problems, biggest problem was finding the space to build it Ray from deepest west cumbria Link to post Share on other sites More sharing options...
Northpoint Posted January 13, 2012 Author Share Posted January 13, 2012 Nick are you doing the wood spacers (fixed angle), or the Threaded rod and nuts (adjustable gradient) variety When (if?) it happens, I was planning to use the threaded rod idea to help fine adjustment. Link to post Share on other sites More sharing options...
shortliner Posted January 13, 2012 Share Posted January 13, 2012 Sounds sensible - I sometimes wonder if some people plan and build the solid version, and then find the chosen gradient too restrictive. Link to post Share on other sites More sharing options...
dave1905 Posted January 13, 2012 Share Posted January 13, 2012 One friend has 2 helices (helixes, helixs, helii??) on his layout and I helped build both. One was made of identical segments to make an octagonal shape (supposedly to save material) and the other was longer arcs of wood . In my opinion the one made of arcs was easier to fabricate, assemble and adjust than the one made of regular segments. At a smaller radius the arcs actually used less wood than the regular segments. YMMV. PS: Both used the threaded rod support, BUT we used a wood block as a spacer to ensure consistent spacing between the levels while adjusting the bolts and washers. Link to post Share on other sites More sharing options...
RMweb Gold Budgie Posted January 13, 2012 RMweb Gold Share Posted January 13, 2012 I've got a helix on my garden railway. See http://www.janesullivan.webspace.virginmedia.com/railway/helix.html Link to post Share on other sites More sharing options...
dave1905 Posted January 13, 2012 Share Posted January 13, 2012 I also played with cutting arcs from 1/4" plywood and then laminating them together to form a 1/2" thick spiral, with offsetting joints in the layers. Didn't have enough clamps to get a consistent joint between layers, but it did result in a very smooth roadbed. I built it to test the feasibility of making a 2 level layout, I built one turn of the helix and put track on it, then did tests with some of my engines to see if they could reliably make it up the grade. Unfortunately the 4-4-0's and 4-6-0's wouldn't reliably climb the grade with 8 and 12 car trains (respectively) and so I stayed with a one level design. Link to post Share on other sites More sharing options...
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