Questions, Answers & Tips -
Unfortunately, that combination produces a 5.3% grade.
To achieve a 4% (1:25) grade, the track radius will need
to be greater, the roadbed and access space thinner, or the
helix will need to be stretched into an oval to put more run-
ning track into each level. Calculations say 96" divided by 25 =
3-3/4" of separation. That’s linear run divided by grade equals
rise-per-lap.
Jeff Shultz noted that with all that track in a helix (1), double
or triple track could make the helix an extension of the staging
yard, and maybe allow stealing room from the staging yard to
make the helix a bit larger.
A solution to extend the run in the helix is "herniating" one or
more of the mid-helix loops into a little shadowbox scene, as a
check if the train is still moving. "Crawling worm" indicator sys-
tems can trace trains as they navigate the helix, and if a "worm"
of LED indicators suddenly splits in two, you know there’s a
breakaway! Cheap security cameras are another way to monitor
action within the helix.
D.K. Austin suggests searching eBay for a commercial helix kit to
get a good idea of what is involved. Even an N scale helix with a
15” inch total rise is going to take up a table area of about 36” x
36”. That is deeper than a modern house closet.
CoolRidge69Vette is planning a new N scale layout with a helix at
the end of his mainline run, to spiral down to a lower level stag-
ing and storage yard. “I was formerly considering a 36" diameter
unit,” he said. “The discussion fits my arrangement as well, so
now I'll be designing it around the idea of a 40" helix. I appreci-
ate the discussion ... I love the information on this site.”
Helixes –
– MRH
MRH-Mar 2013
