Helix..Just how much trouble are they?

I'm looking at my RR,and it would be very easy for me to add a second level along the back wall.If I keep it under 30 inches wide,it won't even require extra lighting.I'd like to add a Bethlehem PA section,or Allentown on the CNJ/LV,maybe Bethlehem steel,and the CNJ/LV Bethlehem roundhouse would be possible then.There's also a prime spot where the main loops around at the far end of the layout where I can put a helix without losing anything,I'm stuck with the loop one way or the other.Just how much trouble is a helix? On this particular part of the RR,it will only see typical early '70's stuff,no stacks,racks,ETC..

 

Hi Lou,
I just completed my first helix...a double tracked helix with inner radius 23" and outer 25" that has four turns to change elevation 20" that I built out of 5/8" plywood. I would say it was harder and easier than I expected:
- what made it harder: there are just so many different opinions on what to do and a helix seems so daunting...different than everything else you do to design/build benchwork and lay/wire track and that it eats up so much track. You can get lost in all the varying opinions, so making the decision to move forward with design and construction was the hardest part. What radius? Double track or single? what track to to use? What separation between levels? What material to use? What wiring? How to keep the levels separate? Will it be sturdy enough?
- what made is easier: after reading a bunch and asking some questions, I dove right in and designed my helix and then started construction. Sure I made mistakes on the way as I built the helix and then added track, and then wired it...in that order; I would not do that again. But actually building the helix was pretty straightforward...I made mistakes and was able to recover from those mistakes and I'm pretty happy with how it turned out.
My key lesson learned? I treated it differently, so I approached it differently than my other benchwork. I did not share my design and construction plan like I do my normal benchwork, so others who have done a helix could give me some pointers on my helix directly. If I had done so, I think I could have avoided the mistakes. But even with the mistakes, it still turned out fine.
John

 

Thanks John! As far as construction or operation,construction/design/ETC,is no problem for me.I guess I'm more concerned about after it's done.How reliable are they[if built right] are derailments gonna happen even with perfect trackwork,do they warp,ETC.I'm kinda kicking around maybe routing out the track area to drop it into the plywood so it's easy to install after I build it.I thought it out a little,I may not even nail the track down.If I route out the area where the track goes so it drops into the plywood,I could leave a little leeway for track expansion.Lay it at the outer edge on a hot day,so if it gets cold and shrinks,it will have somewhere to go.This way,I could solder all the joints.My train room temp is pretty consistent,it only varies maybe 15 degrees year round anyway.Probably gonna use PECO C55 on the helix..

 

I used Ashlin designs for their Helix kit. I used Kato superelevated dual track ans hot glued it in place. Never had a derailment (knock on wood). Be in operation for over a year. Works great. Uses 2 percent grade and is 36 inches across?

 

Lou, opinions do vary, for whatever it's worth, I've abandoned mine. It was a 5.5 turn two track, 19" radius, reliable, but I found it booooooooooring....kind of took the joy and authenticity out of running. Helixes just swallow up amazing amounts of track, over 50' for each track in my case. I would avoid anything over two turns at all costs, work trackage around the room to gain elevation. But that's just me....
Best, Otto K.

 

I'm completely with Otto! It took as long for the trains to go through my Helix as it did for them to go around the upper (larger) level of my layout. It was as if trains were transported to a far away galaxy for some time. Also, don't build one out of plywood, as it makes a very unstable base with temperature and humidity changes.

 

Actually, that's an advantage for some of us. It's nice to have the train 'away' for awhile while you tend to switching duties or preparing the next train to go out. Gives your pike a sense of distance when the train isn't passing in front of you every 45 secs.

 

Well,I'm not too worried about transit time.I have 4 mainlines,I could just wait for the train to "get" there while I switch or do something else.I look at that as a good thing..I considered trying to use regular elevations to run it up,but I just don't have the room,and I'd end up losing room on the main RR.And as far as distance,helix or grade,if you run a 2% grade up 2 feet,you still use the same amount of track,it's still 2 inches in 100 inches,if you go up 20 inches total,you still use 1000 inches of track no matter how you get there..Bill,what do you suggest it be built from,if not plywood?

 

Yeah, but it's mostly visible trackage with trains slugging it up the mountain!
Works for my mountainous layout, but maybe not for Kansas..
Otto

 

Bill, would you agree that your counsel to not use plywood is based more on the local environment of the layout? If the layout is in temperature controlled space (heated, cooled with humidity control like a room above grade), why would plywood move so much? I've used plywood on a number of layouts in the midwest in the basement (heated, cooled, humidity controlled), and I've never experienced an issue. If the layout was in the garage, an attic, a basement with a lot of moisture, etc, I would agree you have to watch out more for your construction material. And a high quality plywood like 5/8" birch smooth faced is not going to be as susceptible to moisture as thinner plywood.
John

 

My layout was originally 30" wide by 10' long. I really wanted to get trains to a higher level above the main level so did a double track main. The outer track is a basic loop around the outer edges of the table. The inner track has a helix at each end to gain some elevation for the track near the rear of the layout. As many of stressed (and I ignored) a given grade is MUCH worse when it is curving in a helix at the same time compared to a grade on the straight. This really limits the length of trains. Also I underestimated how much overhang my longest cars (an RDC unit in my case) experience and I found after the helix was buried in a mountain that the RDC hung up on the rising roadbed of the loop as it entered the lower portion of the loop. This took very difficult work from below with dremel tool to grind away some of the roadbed for the rising loop. Finally the space needed by a helix at each end ate up most of the layout space so there was little left for industry etc. in the center foreground. The outer track is also mostly hidden under the scenery along the rear of the layout. Now that I have expanded beyond the initial size this is not quite so much a problem but if I was starting fresh now I would probably not go the helix route. As to the construction itself I used two overlapping layers of 1/8" masonite for the helix roadbed with the track glued to that. This was supported by 1/2" square wooden posts with 1/4" notches to hold the rising roadbed. (The notches at higher and higher locations to provide the needed grade as you progress with the supports around the helix.)

 

I like the laminated Masonite idea.Do most helix not have transition to the grade from level? The RDC problem would not exist if you made the first and last circles "P" shaped,and used the tail to transition to level.This would even cut down on the number of levels,since you could use the transition to eliminate exactly one coil..I assumed that's how everybody built them?

 

The Sep/Oct '05 issue of NSR has an article on incorporating a hidden single turn helix at the end of a peninsula to gain elevation. The same concept could be used not only at the end of a peninsula, but along aisles, where trackage could curve back behind a small hill. That way, instead of a single large helix that takes up a lot of time, you could spread it around the layout. It would help increase the distance between towns and give a longer overall main line as well.

 

greetings all, and thanks for your posts! one thing to keep in mind is the thicker the subroadbed and roadbed the less clearance between levels. I do not know why the use of hardboard (the kind so many use for backdrops and frontals but in the thicker dimension: 1/4" or 3/8"). it is sufficient to not sag, will not be altered or compromised by temperature or humidity, is cost effective and readily cut. just my thoughts FWIW...Peace, Gary L Lake Dillensnyder

 

Yes! Exactly! thanks for posting! Respectfully, Gary L Lake Dillensnyder

 

Gary,the more I think about it,I'm not gonna laminate the Masonite,I'll just use 1/4",and add more supports,probably the wooden riser idea someone posted with slits in it.I'll make a nice accurate fixture for my tablesaw to cut them.The nice thing about a helix on my RR is,I have nothing to lose because there's already a hidden loop under a mountain it will replace,and there's no way to even use the area above the loop,because there's no sensible way to run a track up there.No lose situation..

 

I had Soo Line of this forum build one for me. You can see it in the Layout Engineering Reports on Railwire if you like, under the IHB of Texas thread.

Well built, pretty well designed (could have probably squeezed 2" more radius out of it, lower level entry is near the back and difficult to access, and we added a turnout at the top for bi directional running which occasionally has out of scale cars picking the switch)

It seems like the picked switch at the top give some trouble, as does the bottom of the grade, which does have a small transition grade. Nonetheless, the whole train pushes on the loco at that point, and if there is a small hesitation, it can push a few cars off the track. Anywhere in the helix, the crapumates can uncouple and occaisonally do. Even with a perfect helix (and I think mine is close) your rolling stock flaws of gauge, couplers, etc. will be exposed.

I have also found, that even on a 10 x 24 layout, which is fairly large, that the time in helix (esp if I have to rerail something) to time on layout is quite high.

In short, and I say this at age 58, and as a owner/builder of at least five layouts, that model trains rarely run perfectly. As such, the simpler the better and I question whether that second level will give you as much enjoyment as you think, even with the best built helix and benchwork, etc. Simple, simple, simple. Less maintenance, hassle, etc and more run time.

 

The only problems I've had on my four helices have been caused by human error and a certain car that has accumates on it. I made mine from plywood cut to strips and made 22-1/2 degree cuts in the plywood and threaded rods. I'd seen it in a RMC article a ways back(think in '98) and don't really know why I went this way, as I wasn't on a tight budget and had plenty of access to ply, one of the main factors the author of the article had given for using this method.:uhoh:Not to mention, it required about 4X the labor than the other methods. I run 18-24 car coal trains and don't have any troubles, even on my tightest radius(13-1/2") which happens to be used as a predominately descending grade. One helix acts as a passing track, with just the ends protruding through the backdrops on the top two levels. If I didn't have the helices I wouldn't be able to model what I want to do as I've got about 188 square feet of railroad in a 144 square foot space!