I am in process of figuring out what to put into a 10x20 room I will inherit in a few weeks. It seems to get smaller every time I contemplate 85’ passenger cars, which are a “must” unless I rethink everything.
Double decks for part of the run would also be nice. To that end, I am trying out layout designs which would have one grand helix with three incorporated turnouts. Two of the turnouts would enable the helix to double as a reversing loop, and the third would accommodate a middle yard/terminal level which I need in order to keep grades under 3%.
I do have a way of gaining access to two opposite sides of the helix, so I think maintenance will be reasonable when required.
My question right now is a simple one. Have folks had success with helixes incorporating turnouts in their run, or am I just begging for trouble if I do this.
on my pull out track from the yard I installed a turn out. This turn out is on a half loop down that is about 3% of grade. This loop is 30 inch radius. I installed a #6 Atlas turn out and it seems to work well. I can push and pull 12 car consists through it without any worries. Would I install a turn out on the other 6 loops of the upper helix, no. I believe that it would cause derailments when pulling up or descending with a 30 car freight.
Hope it helps[:)]
Frank
PS: There is this great layout in my area, here is their web site http://www.wrmrc.ca/ . They have turnouts at the top and bottom of a helix but not in the middle, at least from what I can remember. They are the authority on helix’s so maybe ask them.
When we built the helix for my friends layout we copied almost exactly what Cliff Powers had done with his layout ( now 3 levels) we had thought about using a turnout for each level but both agreed that getting smooth operation in a helix is enough of a challenge so why throw turnouts into the mix to complicate things which would have to be curved turnouts as well. So what we finally decided on and it seems to be working very well is that we actually split the helix in two. You run from level one to level two and out onto the main and make the circuit back to the helix and then continue up to level 3. You can not take a train directly from level 1 to level 3. Once on any particular level your train can remain there as each section are continuous loops. The main line on all three levels are pretty much identical with some minor variations. He is doing this in a 35x45’ basement so he has a massive amount of mainline running. The helix does take up a 6’ square section which doesn’t sound like a lot until you see it. The helxi took months of preparation and planning and a weekend to build.
Very similar to my design. I would not bury turnouts in a helix as they will be very hard ro repair or replace if they become a problem. I have turnouts at the entrance and on top level of my helix, but not buried inside it. I also opted to split my helix into two sections as described above…
I hand-lay all my specialwork, so odd radii, curved turnouts or even a double slip as part of a helix would hardly stretch my tracklaying ‘muscles.’
The closest I come to a helix, approximately 540 degrees of 350mm radius on a 3.5% grade, 1:80 scale, 16.5mm gauge, does not need and will not get any turnouts built on it.
Putting a turnout on a helix should be no big thing as long as the turnout is ‘flat,’ i.e., built with no grade transition until well clear of the frog. Putting a turnout on a helix is no different from putting it on a grade on a tangent. At the worst, you might want to install a guard rail to guide flanges away from the outside-of-the-curve point. (I have done this on a curved turnout on the flat - cheap derailment insurance where it would be awkward to have one.)
Chuck (Modeling Central Japan in September, 1964 - with lots of turnouts in strange places)
The above flat-surface turnout insight is sound advice!
Still thinking about adding a “third level” dedicated for staging to the multi-level CR&T with an oval-shaped helix which will reduce the grade and coupler-tension. Occassional rerailers are planned as a derailment safeguard on the helix straight sections.
Helix accessibility & visibility are critical, and turnouts add complexity.
The CR&T helix will have 2-tracks, and perhaps a third track, but; consideration is still there to design additional staging with access from the top level only to the staging level – in effect more than 2 tracks (likely outer tracks) for only part of the helix. So, there may be no need for any helix turnouts.
As mentioned, my MA&G incorporates a double track helix which serves three levels. The lowest level is 30 inches from the floor and has staging for 30 trains. The second level, at 40 inches, represents the rural mainline run south of Hattiesburg, MS to the fictional town of Edna, MS. The upper level is 57 inches and entirely represents New Orleans. “Bridges” made from 2 x 4’s span the doorway and connect the helix to the layout eastbound. The opposite side of the helix exits across or above my desk westbound. These photos will help identify these areas.
These were my design dilemmas…
When MA&G/Southern/GM&O trains leave staging over shared trackage, they take the OUTSIDE track of the helix, traverse 3 laps, then exit on the second level. After making the run over the second level, they re-enter the helix at the same point they left by way of a strategically placed 30 degree crossing (the helix briefly levels out at that point). The trains then negotiate 5 more laps until they enter the third level. You will also notice in the photos that I made provisions for continuous running on all three levels independent of each other. This is because the layout was completed one level at a time beginning with the lower level. I was always able to enjoy just running trains while construction was underway on the next level. These “continuous running” tracks will not be used during Op Sessions, however.
Because I model the New Orleans Union Passenger Terminal, I needed a way for all of the foreign road passenger trains (SP,
At our club we have a lot of hidden track and helixes and we have avoided putting any switches, crossings or other special track in any hidden sections (except directly in the staging yards).
A well-built switch will usually not cause any problems, but murphy’s law says the switch you can’t access will be the one that gives you issues. Plus having a hidden switch or crossing is just asking for trouble operationally due to human error if a switch gets run through backwards causing a difficult to access derailment, or if two hidden lines cross it’s a definate invitation for two trains to hit each other.
Thank you Cliff. It looks like the CR&T “is thinking” in the right design direction, including your concept, of the unmodeled mainline. Your helix pioneering examples, let alone pictures above, are greatly appreciated!
