Laying track in a helix

[Bob]

I am replacing my troublesome helix with a new one, and it is going well.  On the first level I applied a thin layer of caulk to hold the track, followed by track nails (am using Atlas spikes - they are pretty long).  My question is can I just skip the caulk and use track spikes? I would think this would be good enough but I'm sure some of you have experience with this.  Any suggestions are weclome!  Bob

[randgust]

What are you using for track?  Flex?  Sectional? Kato? 

There's a noise function in there as well.

But whatever you do, don't skimp on feeders, or depend on rail joiners to feed that much power over that many feet of track, or deal with expansion kinks due to any temp variation.  Spikes will allow a bit of movement that caulk might not.

Biggest helix I'ver ever seen was Jerry Britton's on his PRR layout that never got finished, I think he had a four-track helix that must have been about 30" radius because you could climb inside of it comfortably.   All Atlas C55, well engineered, no roadbed I remember.

On my semi-modular layout I transitioned to sectional anyplace I was crossing expansion joints to try to prevent kinking on any curves.   Has worked very well over time.   I still solder up anything 11" or tighter with sectional track rather than use flex,  at that tight radius any kinking at all at a flextrack joint (unsoldered) is an invitation for derailments.

[BCR 570]

I used Peco Code 55 flex track in my helix which was laid on a 16" radius curve.  I used Woodland Scenics Foam Tack Glue.  I installed little jam blocks against the outer rail joiners to prevent any chance of kinking.  That was in 2008 and I have had trouble-free operation ever since.

Tim

[Bob]

Thanks - I am using Atlas code 55 attached directly to high-grade plywood.  Right now just using track nails.

[randgust]

Oh, and define troublesome.   What made it troublesome?

I'd never use Atlas C55 on a helix.   You get no extra points for c55 appearance in there and you're burning up a lot of nice flextrack.   

Something heavier, damage resistant, perhaps cheaper.     On all my hidden storage track I laid old Atlas and Trix C80 flex before they ever went to the 'flex tie' stuff that had gauge problems with it.  Its been in there since 1984 with no issues, I put feeders to every section.   Ugly as sin and just as tough.   Maybe Peco C80 is the equivalent today.

I've always followed the 'solder first then bend' rule on Flex, and where I wanted an expansion gap, transition to sectional on both sides with short sections.  I discovered that you could take a section of Atlas C80 19" and 'change the radius' to anything you wanted by selectively cutting out ties or expanding it on the outer line with some knife cuts.  Still do that today on module connections that are not Ttrak compliant.

[peteski]

PECO, both C55 and C80 should be trouble free and due to their design they will stay in gauge.

[Bob]

Yeah, you guys are right - I should have used CODE 80 or PECO 55.  Oh well - I am really taking my time soldering track together and laying it really carefully.  Thanks for the responses.  Bob

[ednadolski]

If using Atlas C55 in a helix then be careful cutting gaps.  The sliding rail wants to straighten back out and can end up kinking.  It may help to solder onto a couple of PCB ties at that point, and or slide the rail out of the flextrack, so that you can pre-bend it with say the FastTracks rail bending tool before sliding it back into place.

Ed

[GaryHinshaw]

My helix is configured as an oval and uses Peco c55 flex track (which I highly recommend for this purpose).  It serves as a 3-track serial staging yard for the south end of my layout, and it feeds a 9-track linear staging yard at the bottom.  The end curves are formed from 2 full pieces of flex soldered together in the middle of the curve which connect to short straight sections with regular joiners.  All sections have their own feeders and the track is glued to cork with adhesive caulk. 

Aside from human error, it has been trouble-free for 10 years now.  Here is a snippet from last night's ops session, where 3 trains are simultaneously flushed from the staging helix down to the linear yard (off to the lower right of the picture).  The 3 operators have their trains exactly speed matched. 

[Bob]

THank you all for the replies - I need to cut some gaps.  Fortunately the layout is in the basement which has virtually no temperature variation.  I think I will add some glue as well as the spikes.  Excellent speed matching there Gary in the video you posted!  Bob

[Maletrain]

Temperature variation is not the only issue, and probably not the most important.  Changes in relative humidity can be the big factor for expansion and contraction of wooden benchwork.

So, perhaps consider a dehumidifier in the basement, too, set for something like 50%.

[NtheBasement]

IMO expansion/contraction joints are not needed on helices if you use caulk to fix the track.  Caulk flexes enough to allow the curve radius to expand and contract slightly to make up for changes in rail length relative to subroadbed length.  So I would definitely solder everything for reliability.

Reliability is the single most important factor in enjoying your layout and the close clearance in a helix make it difficult to fix anything not done correctly in the first place.  Peco is a great choice for a helix but it is thicker, requiring a teensy increase in rise per rev (and thus grade) to maintain clearance above the rail.