Hi Baggio,

Just some of my thoughts on the subject

A) Re: My space does not really allow for any wider helix.
While most people conceive a helix to be made solely of curved track and of the same radii, consider the option of an oval with progressive curves or even insert straights in one dimension. Anything to allow reduced gradients.
- A related specification here is the height you need - i.e. do you use catenary?

B1) Allow for servicing, and good construction access
- if the track to track height distance does not allow for your hand to get hold of a derailed loco and do basic maneuvering you will be sorry,
- for getting your head and hand/arm up the middle of the helix, eliminate any bulky infrastructure - e.g. use metal rods instead of 4x2's
- getting track laid properly is well worth a bit of extra time, however designing for ease of access to do the work is just as important.

B2) Expect derailments - e.g. of the type caused by a 2nd train rear ending the fist and causing an accordion effect
- this may mean adding some side barrier for protection to prevent items testing their bounce coefficient as they fall to the ground.
- In lieu of B1 - accessibility - it may be worth making the barriers removable.

C) The Entry and Exit slope transitions should never be overlooked - reference the bridge approach diagrams in the Marklin Catalogs.
- Tip. for C-Track, you may make saw cuts across the roadbed from the underside (say 10 cuts per piece) , this will allow for a better curving rather than leaving the gradient change to a kink at the join of track pieces.
- ideally do not start the track curving until the locomotive has all wheels on the main gradient
- maintain a consistent gradient - hyper-elevation may creep in with construction and may assist with draw-bar effort but it has to be extremely well designed if you want max traction with all tires touching the rails.

D) Unlike a straight incline where you can get away with a stiff board and in-frequent pillars, (I believe) a curve/helix should be supported at least once per piece of track. In doing so you need smaller (thinner) supports and may benefit by using 6mm, 4.5mm or even 3mm base board which will better conform to gradient changes while curving.
- suggest cutting track baseboard out of a single sheet (as much as practical) to allow natural conforming of gradient changes.
- work with the board - not against it.
- suggest the width of the base board (where the track sits) be only marginally wider than the track itself (safety consideration of A2 not withstanding)

if you have space, consider a big oval instead of a circle for a helix
I work on 10cm space between tracks as a minimum
I treat catenary as cosmetic and don't pretend there is any in hidden track areas (helix) (and in visible areas I only put the poles up no actual wires)
fixed curves such as 2221 and 2231 are better for a helix than flex
from the radius of the curve you can calculate the circumference of a circle and thus work out the minimum gradient to change 100mm in height

2221??? Won’t they be a problem as being too tight for some passenger cars.

Hello,
Get some big cardboard, like from a refrigerator box.
Get a hot glue gun.
Get a utility knife (Real sharp).
Go to work and build a mock-up.
Get it running and take pictures for all of us Marklin wash women.
I guarantee that you will find all sorts of answers to your questions.
After making all of your adjustments, and you are happy with it, take it all apart then go ahead and build the real thing using all the
cardboard pieces as templates.
You may find out that a helix is not for you. Ya never know.

Have fun,
Mikey

I doubt it, why not try some out with your cars....

Puttputtmaru,

How is your German? I found this link interesting and intend to give it a try (you may have to use a translation program):

Helix construction

At the bottom of the article is a link to a spreadsheet, it allows you to enter the radius of curve pieces you want to use, you also pick the type of track you want to use and if you want overhead wire clearance or not (adjusts layer height accordingly). Then it automatically calculates the trapezoid sizes for construction and gives the resulting slope in percentage. If you have to have a different height change then use multiples of the circle.

Constructing a sample out of cardboard and testing your rolling stock would definitely be useful.

Hope this helps,

Harold.

I did my helix in R4/R5 K track (2241/2251) and suitable for catenary - the grade is enough that the clearance of 95mm minimum lets e-loks have their pantographs up without touching the next helix.
You can of course reduce this to say 70mm and just run a thick wire underneath the next helix for the pantographs to contact.

My R3 helix has a clearance of 70mm I think but no E-loks on that one (branchline)